WO2018147067A1 - Laser light source device - Google Patents

Abstract

Provided is a laser light source device having a wide color reproduction range and a small size. The laser light source device (100) mixes light-blue laser light (al) and red laser light (rl), and emits laser light of a mixed color.

Description

Laser light source device

The present invention relates to a laser light source device.

Conventionally, halogen lamps, metal halide lamps, or LEDs (Light Emitting Diodes) have been used as light sources for vehicles, projectors, or general lighting. Conventionally, LEDs have often been used as light sources for illumination for outdoor use.

On the other hand, in recent years, laser light sources have attracted attention as light sources that can replace the above-mentioned light sources. The laser light source has a long life and low power consumption, and can emit light with high luminance and color purity as compared with each of the above light sources.

Incidentally, conventionally, when a laser light source is applied to a white light source, one of the following methods (A) to (C) has been adopted.

(A) A pseudo white light is obtained by irradiating a yellow phosphor with a blue laser beam (see Patent Document 1).

(B) White light is obtained by combining the laser and the LED.

(C) White light is obtained by mixing (also called combining) red laser light, green laser light, and blue laser light (refer to Patent Document 2).

Japanese Patent Publication “Japanese Patent Laid-Open No. 2004-241142 (published August 26, 2004)” Japanese Patent Publication “Japanese Patent Laid-Open No. 2016-15415 (published Jan. 28, 2016)”

In the above methods (A) to (C), the following problems occur.

In the method (A), the wavelength range of the light emitted from the yellow phosphor is wide, so that there is a problem that the color reproduction range is narrowed.

Also in the method (B), as in the method (A), the wavelength range of light emitted from the LED is wide, so that the color reproduction range is narrowed.

In the method (C), a laser emitting red laser light (hereinafter referred to as red laser), a laser emitting green laser light (hereinafter referred to as green laser), and a laser emitting blue laser light (hereinafter referred to as green laser light). Hereinafter, it is necessary to accurately arrange the blue laser). And in order to implement | achieve the said arrangement | positioning, the problem that the enlargement of a laser light source device cannot be avoided generate | occur | produces.

That is, since the output of the red laser is large when driven at a high temperature, it is necessary to dispose the red laser away from the green laser and the blue laser that generate heat at high temperatures, or to provide a heat radiation mechanism in the laser light source device. As a result, in the method (C), an increase in the size of the laser light source device is inevitable.

An object of one embodiment of the present invention is to realize a laser light source device that has a wide color reproduction range and is small.

In order to solve the above-described problems, a laser light source device according to an aspect of the present invention is characterized in that light blue laser light and red laser light are mixed and emitted.

According to one embodiment of the present invention, the color reproduction range is wide and small.

It is a top view which shows schematic structure of the laser light source apparatus which concerns on embodiment of this invention. FIG. 2 is a chromaticity diagram showing a color reproduction range of light obtained from the laser light source device shown in FIG. 1.

Embodiments for carrying out the present invention will be described with reference to FIG. 1 and FIG.

FIG. 1 is a top view showing a schematic configuration of a laser light source apparatus 100 according to an embodiment of the present invention. The laser light source device 100 includes a light blue laser package 1, a red laser package 2, apertures 3 and 4, beam correction units 5 and 6, collimating lenses 7 and 8, a mirror 9, a dichroic mirror 10, and an emission window unit 11. .

The light blue laser package 1 is a highly airtight package containing a light blue laser that emits light blue laser light al. The light blue laser is, for example, a GaN (gallium nitride) semiconductor laser, and emits laser light having a wavelength of 490 nm (nanometers) as light blue laser light al. The wavelength of the light blue laser light al emitted from the light blue laser is not limited to 490 nm, and any wavelength from 482 nm to 499 nm can be selected.

The red laser package 2 is a highly airtight package containing a red laser. The red laser is, for example, an AlGaInP semiconductor laser, and emits laser light having a wavelength of 638 nm as red laser light rl. Note that the wavelength of the red laser light rl emitted from the red laser is not limited to 638 nm, and an arbitrary wavelength from 610 nm to 780 nm can be selected.

In the laser light source device 100, the light blue laser package 1 and the red laser package 2 are arranged side by side. Specifically, in FIG. 1, the light blue laser package 1 and the red laser package 2 are arranged such that the optical axis ala of the light blue laser light al and the optical axis rla of the red laser light rl are parallel to each other. ing. However, the arrangement of the light blue laser package 1 and the red laser package 2 in the laser light source device 100 is not limited to this. For example, the light blue laser is removed such that the mirror 9 is removed and the optical axis ala and the optical axis rla are perpendicular to each other. Package 1 and red laser package 2 may be arranged.

Further, in the laser light source device 100, the emission angle (FFP: far field pattern) of the light blue laser beam al is larger than the emission angle (FFP) of the red laser beam rl. In order to match the beam spot diameter and beam shape of the light blue laser light al with the beam spot diameter and beam shape of the red laser light rl, in the laser light source device 100, the red laser package 2 is a light blue laser. It is arranged behind the package 1. However, it is not essential that the red laser package 2 is disposed behind the light blue laser package 1. The front-rear relationship between the arrangement of the light blue laser package 1 and the arrangement of the red laser package 2 depends on the magnitude relationship between the emission angle (FFP) of the light blue laser light al and the emission angle (FFP) of the red laser light rl. Can be set appropriately.

The aperture 3 is an opening through which the light blue laser light al emitted from the light blue laser of the light blue laser package 1 passes, and removes unnecessary components (such as leakage light) from the light blue laser light al.

The aperture 4 is an opening through which the red laser light rl emitted from the red laser of the red laser package 2 passes, and removes unnecessary components (such as leakage light) from the red laser light rl.

The beam correction unit 5 includes a biconcave lens 5a and a planoconcave lens 5b. The biconcave lens 5a is a lens having concave shapes on both sides, and mainly adjusts the FFP of the light blue laser light al that has passed through the aperture 3. The plano-concave lens 5b is a lens in which the surface on the light blue laser package 1 side is flat and the surface opposite to the light blue laser package 1 side is concave, and the beam spot diameter of the light blue laser light al transmitted mainly through the biconcave lens 5a. Adjust. However, the beam correction unit 5 can be appropriately changed in design according to the beam spot diameter and beam shape of the light blue laser light al that has passed through the aperture 3.

The beam correction unit 6 includes a biconcave lens 6a and a planoconcave lens 6b. The biconcave lens 6a is a lens having concave shapes on both sides, and mainly adjusts the FFP of the red laser light rl that has passed through the aperture 4. The plano-concave lens 6b is a lens in which the surface on the red laser package 2 side is flat and the surface on the opposite side to the red laser package 2 side is concave, and the beam spot diameter of the red laser light rl mainly transmitted through the biconcave lens 6a. Adjust. However, the beam correction unit 6 can be appropriately changed in design according to the beam spot diameter and beam shape of the red laser light rl that has passed through the aperture 4.

The collimating lens 7 converts the light blue laser light al that has passed through the beam correction unit 5 into substantially parallel light.

The collimating lens 8 converts the red laser light rl that has passed through the beam correction unit 6 into substantially parallel light.

The mirror 9 bends the optical axis ala of the light blue laser light al by reflecting the light blue laser light al that has passed through the collimating lens 7 (in this case, it is bent by 90 °). The dichroic mirror 10 bends the optical axis rla of the red laser beam rl by reflecting the red laser beam rl that has passed through the collimating lens 8 (in this case, it is bent by 90 °). The dichroic mirror 10 transmits the light blue laser light al reflected by the mirror 9.

Here, the mirror 9 and the dichroic mirror 10 are arranged so that the optical axis ala of the light blue laser light al transmitted through the dichroic mirror 10 and the optical axis rla of the red laser light rl reflected by the dichroic mirror 10 substantially coincide. Is arranged. Then, since the optical axis ala of the light blue laser light al and the optical axis rla of the red laser light rl substantially coincide with each other, the light blue laser light al and the red laser light rl are mixed in color (both combined). This produces white light.

The design of the apertures 3 and 4, the beam correction units 5 and 6, the collimating lenses 7 and 8, the mirror 9, and the dichroic mirror 10 can be changed as appropriate without changing the gist of the present invention achieved by the laser light source device 100. Is possible. In addition, the apertures 3 and 4, the beam correction units 5 and 6, the collimating lenses 7 and 8, the mirror 9, and the dichroic mirror 10 can be omitted if they are not necessary in the laser light source device 100.

The exit window portion 11 includes an aperture 11a and a translucent window member 11b that covers the aperture 11a. White light obtained by mixing the light blue laser light al and the red laser light rl passes through the aperture 11a, passes through the window member 11b, and is emitted to the outside of the laser light source device 100.

Unlike the method of obtaining white light by mixing red laser light, green laser light, and blue laser light, the laser light source device 100 uses light blue laser light al and red laser light. By mixing rl, white light can be obtained. Therefore, the laser light source device 100 can be reduced in size as compared with a laser light source device that obtains white light by mixing red laser light, green laser light, and blue laser light.

That is, in order to make the laser light source device as small as possible, it is conceivable to arrange a plurality of lasers so as to make the interval between two adjacent lasers as small as possible. However, each laser generates heat during driving, and may affect the adjacent laser due to the generated heat. In particular, the red laser has a large output drop when driven at a high temperature as compared with the green laser and the blue laser. In the laser light source device 100, the light blue laser of the light blue laser package 1 is used instead of the green laser and the blue laser. As a result, the number of heat sources that can increase the driving temperature of the red laser of the red laser package 2 is reduced, so that the degree of freedom of arrangement of the red laser package 2 is improved and the laser light source device 100 does not need to be provided with a heat dissipation mechanism. Therefore, a small laser light source device 100 can be realized.

In the laser light source device 100, the light blue laser is housed in the light blue laser package 1 and the red laser is housed in the red laser package 2, respectively. However, each of the light blue laser and the red laser may be provided in the laser light source device 100 in a so-called open air state that is not housed in a package. Since the blue laser emits a laser beam having a short wavelength, a contaminant is attached to the emission end face, and the life is likely to be shortened. For this reason, it is difficult to mount the blue laser on the laser light source device in an open air state. On the other hand, since the light blue laser emits a laser beam having a longer wavelength than that of the blue laser, contaminants are unlikely to adhere to the emission end face (the lifetime is unlikely to be shortened). Therefore, the light blue laser is more suitable in that it is mounted on the laser light source device 100 in an open air state.

FIG. 2 is a chromaticity diagram showing the color reproduction range of the light obtained from the laser light source device 100. The chromaticity diagram shown in FIG. 2 is obtained by writing a dotted line L and an ellipse E on a general CIE chromaticity diagram.

The dotted line L is a line connecting the wavelength regulation point of the light blue laser beam al (wavelength 490 nm) and the wavelength regulation point of the red laser beam rl (wavelength 661 nm). An ellipse E is a chromaticity range in which the light according to the present embodiment can be regarded as white.

In the laser light source device 100, white having a chromaticity within the range of the ellipse E in FIG. 2 and on the dotted line L by appropriately adjusting the output of the light blue laser light al and the output of the red laser light rl. Can get the light.

Since the light blue laser beam al and the red laser beam rl have narrow wavelengths (that is, the half-value width of the emitted light is narrow), on the straight line L connecting the wavelength defining points on the color gamut boundaries where the chromaticity coordinates are opposed to each other. All colors can be reproduced, and the color reproduction range is wide. Further, since the light blue laser and the red laser have high directivity, they are suitable for spot irradiation with light far away.

On the other hand, the light emitted from the LED or the phosphor has a wide half width, so that it is difficult to reproduce all the colors on the straight line L, and the color reproduction range is narrow. In addition, since LEDs or phosphors have low directivity, they are not suitable for spot irradiation with light far away.

Further, as described above, the wavelength of the light blue laser light al is preferably 482 nm or more and 499 nm or less, and the wavelength of the red laser light rl is preferably 610 nm or more and 780 nm or less. By appropriately selecting the wavelength of the light blue laser beam al and the wavelength of the red laser beam rl, the degree of freedom in color reproduction can be increased.

[Summary]
The laser light source device according to the first aspect of the present invention emits light of a blue laser beam and a red laser beam in a mixed color.

According to the above configuration, the light blue laser beam and the red laser beam have a narrow wavelength (that is, the half-value width of the emitted light is narrow), so that the wavelength defining point on the color gamut boundary where the chromaticity coordinates are opposed to each other. All colors on the straight line connecting the two can be reproduced, and the color reproduction range is wide.

Further, according to the above configuration, since the number of heat sources that can increase the driving temperature of the red laser is reduced, the degree of freedom of arrangement of the red laser is improved, and it is not necessary to provide a heat dissipation mechanism in the laser light source device. Therefore, a small laser light source device can be realized.

In the laser light source device according to aspect 2 of the present invention, in the aspect 1, the wavelength of the light blue laser light is not less than 482 nm and not more than 499 nm.

Further, in the laser light source device according to aspect 3 of the present invention, in the above aspect 1 or 2, the wavelength of the red laser light is 610 nm or more and 780 nm or less.

According to each configuration described above, the degree of freedom in color reproduction can be increased by appropriately selecting the wavelength of the light blue laser light and the wavelength of the red laser light.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

DESCRIPTION OF SYMBOLS 1 Light blue laser package 2 Red laser package 3, 4 Aperture 5, 6 Beam correction part 5a, 6a Biconcave lens 5b, 6b Plano- concave lens 7, 8 Collimate lens 9 Mirror 10 Dichroic mirror 11 Output window part 11a Aperture 11b Window member 100 Laser light source Device al Light blue laser light rl Red laser light ala Optical axis rla of light blue laser light Optical axis E of red laser light Ellipse L Dotted line

Claims (3)

1. A laser light source device that emits a mixture of light blue laser light and red laser light.
2. 2. The laser light source device according to claim 1, wherein the wavelength of the light blue laser light is not less than 482 nm and not more than 499 nm.
3. 3. The laser light source device according to claim 1, wherein the wavelength of the red laser light is 610 nm or more and 780 nm or less.

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