JP3073811B2 - Light source device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device which limits the wavelength range of light from a light emitting means which emits heat by using wavelength limiting means having a large number of cavities.

[0002]

2. Description of the Related Art An incandescent light bulb is generally used as a light source device for lighting for converting electric energy into light. With an incandescent light bulb,
Since light is emitted by incandescently heating the filament when energized, most of the radiated energy is infrared, and the energy of visible light is about 5 to 10%, which is problematic in efficiency. In addition, a continuous spectrum can be obtained with an incandescent light bulb, but since the overall spectrum shows a spectral distribution biased toward red, the color temperature is low and the color rendering properties are inferior. Is likely to evaporate and the life is shortened.

As a light source device which solves such a problem, a device provided with a light radiating means for radiating electromagnetic waves in a light range and a wavelength limiting means for limiting a wavelength range of light radiated from the light radiating means is provided. It is disclosed in Japanese Unexamined Patent Publication No. 3-102701. This light source device uses wavelength limiting means in which a large number of fine cavities are opened on the surface, and by restricting the radiation field of light in the cavities, the existence probability of photons with a predetermined energy or less is significantly reduced. By using the effect, it is possible to block light in a wavelength region equal to or longer than a predetermined wavelength. If the effect of the cavity is interpreted in the classical physics, it can be considered that the cavity is regarded as a waveguide with low tuning and does not transmit light in a wavelength region equal to or longer than the cutoff wavelength. Thus, by suppressing the emission of infrared rays from the light emitting means, the luminous efficiency is increased and the life is extended.

As an incandescent lamp using this principle, Japanese Patent Laid-Open Publication No. 3-102701 discloses an incandescent lamp having a configuration in which light emitting means and wavelength limiting means are integrated as shown in FIG. That is, a large number of fine cavities 2 are formed on the surface of an incandescent radiator 1 ′ made of tungsten, and each cavity 2 is formed in a square cross section. In order to suppress infrared radiation, the cutoff wavelength of each cavity 2 is 700 nm.
Is selected, and the dimension L of one side, which is the characteristic dimension of the cross section of the opening of the cavity 2, is set to 350 nm as a design condition satisfying the cutoff wavelength. The distance d between adjacent cavities 2 is set to 150 nm, which is about the skin depth for a wavelength of 700 nm. That is, each cavity 2 functions independently as a waveguide, and the connection of the cavities 2 prevents the cutoff wavelength from becoming long. Further, the depth D of the cavity 2 is set to 7000 nm.

In the incandescent lamp using the incandescent radiator 1 'having such a configuration, as shown by a solid line in FIG.
Has a power spectrum higher than that of the related art (indicated by a broken line in FIG. 5).
Significantly smaller, providing the same energy in the visible light range.
Energy supply is greatly reduced,
Get higher. In other words, the luminous efficiency is higher than that of an incandescent lamp using a tungsten filament that has been conventionally provided.
High, it is possible to lower the temperature still radiating surface kept at a high efficiency is the amount of evaporation of the white heat radiator 1 'be reduced lifetime is prolonged.

[0006]

However, as described above, there is a problem that the temperature of the incandescent radiator 1 'cannot be raised too much because the cavity 2 has a fine structure. That is, the recrystallization temperature of a metal is generally 2
When the temperature greatly exceeds this temperature, the fine structure is lost due to the movement of the grain boundaries. The practical operating temperature when tungsten is used as the incandescent body 1 'is about 2100 ° K. That is, the color temperature of light is also 2
It cannot exceed 100K. For general lighting, it is required to increase the color temperature to about 2800K.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to provide a light source device having high luminous efficiency and capable of controlling a spectral distribution to adjust a color temperature of a luminescent color to a desired color temperature. It is intended to provide.

[0008]

According to the present invention, in order to achieve the above object, light emitting means for emitting light by heat radiation and wavelength limiting means for limiting a wavelength range of light emitted from the light emitting means are provided. in the light source device provided, the wavelength restricting means, the surface of the substrate covering over the surface of the light emitting means on the entire surface
The base material is provided with a plurality of types of cavities, each of which has a plurality of fine cavities that are opened to block light in a wavelength region equal to or greater than a predetermined wavelength and that have different characteristic dimensions of the cross section of the opening.

[0009]

According to the above construction, since a plurality of types of cavities having different characteristic dimensions of the opening cross section are provided in the base material, the wavelength range limited by the different types of cavities is different, and the cavities of the respective types of cavities are different. The spectral distribution can be changed by changing the characteristic size and the number ratio. That is, the wavelength restricting means, if so as not to cause infrared than visible light is a long wavelength, and than high luminous efficiency light source is obtained, moreover, by setting the cut-off wavelength in a plurality of stages spectroscopy By changing the distribution, it is possible to obtain a luminescent color at a desired color temperature.

[0010]

EXAMPLES (Example 1) This example, as shown in FIG. 1 (a), the thermal radiation
Incandescent with integrated wavelength limiting means in emitting light emitting means
The radiator 1 is provided in a bulb 3 . As shown in FIG. 1B, the incandescent radiator 1 has a number of fine cavities 2a and 2b, which are wavelength limiting means, formed in a ribbon shape formed on substantially the entire surface using tungsten. The cross sections of the openings 2a and 2b have a square shape.
That is, the cavities 2a and 2b are incandescent radiation
Open to the surface of body 1. As the cavities 2a and 2b, there are two types of cavities 2a and 2b having different side lengths L ₁ and L ₂ which are characteristic dimensions of the opening cross section. One cavity 2a is 260 nm, and the other cavity 2b is 3 nm.
It is set to 25 nm. The distribution ratio between the two cavities 2a and 2b is 1: 4, so that red light can be emitted more than blue light. The depth of the cavities 2a and 2b is, for example, 7
000 nm.

The incandescent radiator 1 thus formed is energized as a filament, and the surface temperature of the incandescent radiator 1 is reduced to 21.
When set to 00 ° K, the spectral distribution has a shape having two peaks as shown in FIG.
Of white light was obtained, the luminous efficiency was 100 lumen / W, and the color rendering index was 96, which was excellent. (Embodiment 2) In this embodiment, two types of cavities 2a and 2b are formed on the surface of the ribbon-shaped incandescent radiator 1 and the length L of one side of the cavity 2a is set to 32, as in the first embodiment.
5 nm, the length L of one side of the other cavity 2b is 255
The distribution ratio is set to 1 to 10 as nm.

In an incandescent lamp using such an incandescent radiator 1 as a filament, the surface temperature of the incandescent radiator 1 is set to 210
When the temperature was set to 0 ° K, white light with a color temperature of 7000K was obtained, and the luminous efficiency was 70 lumen / W. The color rendering index was 98. Other configurations are the same as in the first embodiment. (Embodiment 3) In this embodiment, two kinds of cavities 2a and 2b having the same dimensions as those in Embodiment 1 are formed on the surface of a ribbon-shaped incandescent radiator 1, and the distribution ratio of both cavities 2a and 2b is Is set to 1: 2.

In this configuration, when the incandescent radiator 1 is used as a filament and energized so that the surface temperature becomes 2100 ° K, white light having a color temperature of 3100 K is obtained, the luminous efficiency is 110 lumen / W, and the color rendering index is Was 97.
As described above, the color temperature can be controlled by changing the characteristic size and distribution ratio of the cavity, and it is possible to set an arbitrary spectral distribution. In the above-described embodiment, the shape of the cross section of the opening of the cavity is square, but another shape such as a circular shape may be adopted. For example, when the shape of the cross section of the opening of the cavity is circular, the diameter may be adopted as the characteristic dimension. Furthermore, two types of cavities are used.
More than two types may be provided. Further, tungsten is exemplified as a constituent material of the incandescent radiator 1, but may be formed of another high melting point metal material. Furthermore, the above embodiment
Uses a direct-heating incandescent radiator 1 which also serves as a heater.
However, the heater may be separated into an incandescent incandescent body 1
No. That is, as shown in FIG. 3, key Yabiti 2a, 2
The outer shell 1b which b is open may be used those placed so as to cover the heater 1a. In this case, the outer shell 1b emits light.
It will serve as both the emitting means and the substrate. Specifically, FIG.
As shown in FIG. 3A, a plate-shaped heater 1a is used, and the heater 1a is sandwiched between a pair of plate-shaped outer shells 1b. Alternatively, as shown in FIG. And the heater 1a may be wrapped by the cylindrical outer shell 1b .

[0014]

According to the present invention, as described above, since a plurality of types of cavities having different characteristic dimensions of the opening cross section are provided in the base material , the wavelength range limited by the different types of cavities is different. The effect is that the spectral distribution can be changed by changing the characteristic size and the ratio of the number of types of cavities. That is, cavite
Thus the I, if not to cause infrared than visible light is a long wavelength, and than high luminous efficiency light source is obtained. Moreover, if changing the spectral distribution by setting the cut-off wavelength in a plurality of stages There is an advantage that a luminescent color having a desired color temperature can be obtained.

[Brief description of the drawings]

1A and 1B show an embodiment, in which FIG. 1A is a front view, and FIG. 1B is an enlarged view of a main part.

FIG. 2 is an operation explanatory diagram showing an example of the spectral distribution of the embodiment.

FIGS. 3 (a) and 3 (b) are main part perspective views showing other embodiments.

4A and 4B show a conventional example, in which FIG. 4A is a plan view of a main part, and FIG.

FIG. 5 is an operation explanatory diagram showing an example of a conventional spectral distribution.

[Explanation of symbols]

 1 incandescent radiator 2a cavity 2b cavity 3 valve

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01K 1/14 F21H 1/00

Claims (1)

(57) [Claims] A light emitting means for emitting light by heat radiation ;
In the light source device provided with a wavelength limiting means for limiting the wavelength range of light emitted from the light emitting means, the wavelength restricting means, the surface of the light emitting means to the surface of the substrate covering over the entire surface
Opening to a large number of fine cavities of blocking light of a predetermined wavelength or wavelength range, a plurality of types of cavities, wherein different dimensions of the opening cross-section is characterized by comprising provided on a substrate a light source apparatus.