JP2012155907A - Lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting system that can further improve visibility under crepuscular circumstances.SOLUTION: The lighting system includes a light-emitting part 11 with a peak wavelength existing between 470-505 nm, and a half width at half maximum B to its peak value of 20-40 nm.

Description

  The present invention relates to a lighting device.

  Various illumination devices such as fluorescent lamps and light emitting diodes (LED elements) are generally designed to increase photopic brightness in a bright environment (photopic vision). This is to make the cone for perceiving brightness work in photopic vision, and by increasing the photopic brightness, a person can perceive brighter.

  However, in so-called mesopic vision such as nighttime street space and road space, in addition to the cone having a peak value of spectral luminous efficiency of 555 nm, a frame having a peak value of spectral luminous efficiency of 507 nm works. Even if only the photopic brightness is increased, the effect is low.

  Therefore, for example, in the illumination device of Patent Document 1, in consideration of the fact that both the cones and the rods existing in the retina of a person work in the dim vision, a plurality of the cones and the rods have an effect so as to appear. It has a light source. And it is set as the structure which becomes a peak value between 450-550 nm so that at least 1 of the light sources may become a wavelength range containing 507 nm which is the peak wavelength of the spectral luminous efficiency of the said housing.

JP 2008-91232 A

  By the way, in the illumination device as described above, a light source having a configuration in which a peak value is between 450 to 550 nm is provided to improve visibility in thin vision. Development of a lighting device that can be improved is desired.

  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 that can further improve the visibility in the low vision environment.

  In order to solve the above-described problems, the illumination device of the present invention includes a light emitting unit having a peak wavelength between 470 and 505 nm and a half width at half maximum with respect to the peak value of 20 to 40 nm.

In the above configuration, the light emitting unit preferably has a first peak wavelength existing between 470 and 505 nm and a second peak wavelength existing on the longer wavelength side than 530 nm.
In the above structure, the second peak wavelength of the light emitting portion is preferably 555 nm.

  In the above configuration, the light emitting unit is preferably configured such that the light emission output decreases from 560 to 590 nm longer than the second peak wavelength.

  ADVANTAGE OF THE INVENTION According to this invention, the illuminating device which can improve visibility can be provided.

The schematic block diagram of the illuminating device in this embodiment. The graph for demonstrating the influence degree to S / P ratio by the difference in a wavelength. The characteristic view of the spectrum of the light emission part based on the influence degree to S / P ratio. The schematic block diagram of the illuminating device in another example. The schematic block diagram of the illuminating device in another example. The schematic block diagram of the illuminating device in another example. The schematic block diagram of the illuminating device in another example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
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.

  The light emitting unit 11 includes one LED element 11a electrically connected to the lighting circuit 12, and one phosphor 11b that covers the LED element 11a and a predetermined gap so as to emit light substantially yellow. It is configured. And based on the electric power supply from the lighting circuit 12, the light emission part 11 lights up substantially white.

Next, the spectral characteristics of the light emitting unit 11 of the illumination device 10 in a dimming environment will be described.
The inventor firstly calculates the dark visual brightness Ls calculated by adding the spectral characteristics of the lamp to the spectral luminous efficiency V ′ (λ) in the dark place, and the spectral luminous efficiency V ( Attention was paid to the S / P ratio, which is a ratio to the photopic brightness Lp calculated by integrating the spectral characteristics of the lamp with λ). And it investigated by evaluation experiment how energy of each wavelength of the light emission part 11 affected with respect to this S / P ratio. Note that the S / P ratio is a performance evaluation index for visibility under dimmed vision. For example, when the scotopic luminance is Ls and the photopic luminance is Lp, the S / P ratio can be calculated by the following equation. .

S / P ratio = Ls / Lp (Formula 1)
Based on the above formula 1, it is investigated how the S / P ratio changes when the energy of a specific wavelength is doubled every 5 nm, and the result of the investigation is shown in FIG.

  As can be seen from FIG. 2, here, for example, when the energy at a wavelength of about 500 nm is doubled, the S / P ratio is increased by about 3.5%. Thus, it can be seen from FIG. 2 that the wavelength that acts positively on the S / P ratio when the energy is increased is 405 to 530 nm, and in particular, the degree of positive action increases at 470 to 505 nm. On the other hand, it can be seen that when the wavelength is 535 to 680 nm, it acts negatively, and in particular, it has a high degree of negative effect at 560 to 590 nm. Moreover, it turns out that the gradient which turns is steep in 520 nm-545 nm which is 530 nm-535 nm vicinity which changes from a positive effect | action to a negative effect | action.

  Based on the above results, the light emitting unit 11 of the illumination device 10 of the present embodiment has a first peak wavelength of the light emitting unit 11 (illumination device 10) illustrated in FIG. 1 in a wavelength region of 470 to 505 nm as illustrated in FIG. Spectral characteristics such that The light emitting unit 11 is configured so that the first peak value and the relative spectral intensity are substantially equal in the wavelength region A of 470 to 505 nm as shown in FIG. In FIG. 3, the relative spectral intensity at the first peak wavelength is set to 1, and the spectral intensity at each wavelength is shown relative to the first peak wavelength.

  As shown in FIG. 3, the light emitting unit 11 sharply reduces the spectral intensity outside the wavelength range of 405 to 530 nm and outside the range of 470 to 505 nm, so that the half-width B with respect to the first peak wavelength is 20 to 40 nm. It is comprised so that.

  Further, as shown in FIG. 3, the light emitting unit 11 reduces the spectrum intensity from the first peak wavelength to the wavelength C (about 530 nm), and is the second peak wavelength with the wavelength C as a turning point. It is configured to increase the spectral intensity up to the wavelength D (about 555 nm). At this time, the light emitting unit 11 is configured such that the spectral intensity of the first peak wavelength> the spectral intensity of the second peak wavelength. And the light emission part 11 is comprised so that light emission output (spectral intensity) may be reduced from wavelength D which is the 2nd peak wavelength to at least 590 nm, as shown in FIG.

Next, characteristic effects of the present embodiment will be described.
(1) The light emitting unit 11 having a peak wavelength between 470 and 505 nm and having a half width B at a peak value of 20 to 40 nm is provided. By adopting such a configuration, as shown in FIG. 2, the degree of influence on the S / P ratio, which is the ratio of the scotopic brightness and the photopic brightness, can be increased efficiently. For this reason, it is possible to provide the lighting device 10 that can improve visibility and brightness in a low vision environment, and as a result, improve safety and security.

  (2) The light emitting unit 11 has a first peak wavelength that exists between 470 and 505 nm and a second peak wavelength that exists on the longer wavelength side than 530 nm. In this way, by configuring the light emitting unit 11 to have the second peak wavelength on the longer wavelength side than 530 nm, the cones in the human retina can work to increase the photopic brightness. In particular, since the second peak wavelength of the light emitting unit 11 is 555 nm, the photopic brightness can be more reliably increased.

  (3) The light emitting unit 11 is configured such that the light emission output decreases from 560 to 590 nm on the longer wavelength side than the second peak wavelength. By adopting such a configuration, since the light output is low in the wavelength region of 560 to 590 nm where the influence on the S / P ratio acts particularly on the negative side, the influence on the negative side on the S / P ratio is suppressed. S / P can be increased.

In addition, you may change embodiment of this invention as follows.
In the above embodiment, the predetermined gap is provided between the LED element 11a and the phosphor 11b. However, a configuration in which the phosphor is applied to the LED element 11a may be employed.

  In the embodiment described above, the light emitting unit 11 is configured by one LED element 11a and one phosphor 11b. However, the present invention is not limited to this, and the light emitting unit 11 may be appropriately changed according to specifications and the like. As a modification of the light emitting unit 11 that lights up substantially white, the following configuration is conceivable. However, the present invention is not limited to this as long as the present invention is applicable.

  For example, as shown in FIG. 4, in addition to one LED element 11a and one phosphor 11b covering this element 11a, a configuration including an LED element 20 having a peak wavelength different from that of the LED element 11a may be adopted. .

  Further, as shown in FIG. 5, in addition to one LED element 11a and one phosphor 11b covering the element 11a, the LED element 21a and the phosphor 11b having the same peak wavelength as the LED element 11a You may employ | adopt the structure provided with different fluorescent substance 21b.

  Further, as shown in FIG. 6, a blue LED element 22a and a phosphor 22b that covers the element 22a and emits red light, and a blue LED element 23a and a phosphor 23b that covers the element 23a and emits green light. The light emitting unit 11 may be configured with the blue LED element 24.

Further, as shown in FIG. 7, the light emitting unit 11 may be configured by a blue LED element 25, a green LED element 26, and a red LED element 27.
Further, the light emitting unit 11 may be configured using a transmission / diffusion filter, and for example, a configuration satisfying spectral characteristics as shown in FIG. 3 may be employed.

  In the above embodiment, the light source 10 satisfying each condition has the spectral characteristics shown in FIG. 3, but may be appropriately changed as long as the conditions satisfy each condition.

  DESCRIPTION OF SYMBOLS 10 ... Illuminating device, 11 ... Light emission part, B ... Half value half width.

Claims (4)

  An illuminating device comprising: a light emitting portion having a peak wavelength of 470 to 505 nm and a half width at half maximum with respect to the peak value of 20 to 40 nm. The lighting device according to claim 1.
The light emitting unit has a first peak wavelength existing between 470 nm and 505 nm and a second peak wavelength existing on a longer wavelength side than 530 nm. The lighting device according to claim 2,
The second peak wavelength of the light emitting unit is 555 nm. The lighting device according to claim 2 or 3,
The illumination device is configured such that the light emission output decreases from 560 to 590 nm on the longer wavelength side than the second peak wavelength.

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