JP6923792B2 - Lighting device and its driving method - Google Patents

Description

The present invention relates to a lighting device and a method for driving the lighting device.

A first light source for excitation, a second light source for illumination, a wheel provided with a phosphor layer and a light scattering layer, and a wheel provided directly above the phosphor layer are provided so as to fluoresce the light of the first light source. A dichroic mirror that reflects toward the body layer and transmits the light of the second light source and a second light source that is provided at a distance directly above the light scattering layer and passes through the dichroic mirror are directed toward the light scattering layer. A lighting device including a light source that reflects light sources has been proposed. This lighting device adjusts the output of the first light source and the output of the second light source to adjust the white balance of the illumination light (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-186566

In a conventional lighting device, a plurality of optical components (a dichroic mirror for separating light from a first light source and light from a second light source, a mirror that reflects light after passing through the dichroic mirror, etc.) are used. Since it is used, the number of parts may increase and the device configuration may become complicated.

The above problem can be solved by, for example, the following means.

It has a first semiconductor laser element, a second semiconductor laser element, a first surface, and a second surface facing the first surface, and the laser light of the first semiconductor laser element and the second semiconductor laser element is emitted. The first semiconductor laser element includes a wavelength conversion member that is incident on the first surface and wavelength-converts at least a part of the laser light incident on the first surface to be taken out from the first surface. The laser diode is arranged so as to be incident mainly on the first surface of the conversion member with P polarization, and in the second semiconductor laser element, the laser light is mainly S-polarized with respect to the first surface of the wavelength conversion member. The first semiconductor laser element and the second semiconductor laser element are both arranged so as to be incidentally incident on the first surface of the wavelength conversion member. At least one of the incident angle of the laser light from the first semiconductor laser element with respect to the first surface of the wavelength conversion member and the incident angle of the laser light from the second semiconductor laser element with respect to the first surface of the wavelength conversion member are adjusted. A lighting device that is possible.

A wavelength conversion member having a first surface and a second surface facing the first surface, wavelength-converting at least a part of laser light incident on the first surface and extracting the wavelength from the first surface, and the wavelength. The first semiconductor laser element arranged so that the laser light is mainly incident on the first surface of the conversion member with P-polarized light, and the laser light is mainly S-polarized on the first surface of the wavelength conversion member. A step of preparing an illumination device including a second semiconductor laser element arranged so as to be incident, an incident angle of laser light from the first semiconductor laser element with respect to the first surface of the wavelength conversion member, and the second. Driving a lighting device having a step of adjusting at least one of the incident angle of the laser light from the semiconductor laser element with respect to the first surface of the wavelength conversion member and adjusting the chromaticity of the light extracted from the wavelength conversion member. Method.

It has a semiconductor laser element and a first surface and a second surface facing the first surface, and is arranged so that the laser light of the semiconductor laser element is obliquely incident on the first surface and is incident. A wavelength conversion member that performs wavelength conversion of at least a part of the laser light and extracts it from the first surface, and P-polarized light and S-polarized light in the laser light that is incident on the first surface of the wavelength conversion member by rotating the semiconductor laser element. A lighting device equipped with a rotating mechanism that changes the mixing ratio of the light emitting device.

A wavelength conversion member having a first surface and a second surface facing the first surface, wavelength-converting at least a part of laser light incident on the first surface and extracting from the first surface, and a semiconductor laser. A step of preparing an illumination device including an element and a rotation mechanism for rotating the semiconductor laser element, and by rotating the semiconductor laser element using the rotation mechanism, P-polarized light and S-polarized light in the laser light can be obtained. A method for driving an illuminating device, which includes a step of changing the mixing ratio of light and adjusting the chromaticity of light extracted from the wavelength conversion member.

According to the above configuration, it is possible to provide a lighting device capable of adjusting the chromaticity of emitted light and a driving method thereof with a small number of parts and a simple configuration.

It is a schematic block diagram explaining the lighting apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the part of the wavelength conversion member shown in FIG. 1 in an enlarged manner. It is a figure which simulated the relationship between the incident angle and the reflectance at the time when the light of the wavelength of 450 nm travels in the air and is incident on the wavelength conversion member containing YAG. It is a schematic block diagram explaining another example of the lighting apparatus which concerns on Embodiment 1. FIG. It is a schematic block diagram explaining the lighting apparatus which concerns on Embodiment 2. FIG.

[Lighting device 1 according to the first embodiment]
FIG. 1 is a schematic configuration diagram for explaining the lighting device 1 according to the first embodiment. FIG. 2 is an enlarged view showing a part of the wavelength conversion member shown in FIG. As shown in FIGS. 1 and 2, the lighting device 1 includes a first laser device 12 equipped with a first semiconductor laser element, a second laser device 14 equipped with a second semiconductor laser device, and a first surface. It has a 20a and a second surface 20b facing the first surface 20a, and the laser light of the first semiconductor laser element and the second semiconductor laser element (hereinafter, the laser light from the first semiconductor laser element is referred to as "first laser light". The laser light from the second semiconductor laser device is referred to as "second laser light"), which is incident on the first surface 20a, and at least the first laser light and the second laser light incident on the first surface 20a. A wavelength conversion member 20 that performs wavelength conversion and takes out a part from the first surface 20a is provided. At this time, the first semiconductor laser element is arranged so that the first laser light is incident mainly on the first surface 20a of the wavelength conversion member 20 with P-polarized light, and the second semiconductor laser element is the wavelength conversion member 20. The second laser diode light is arranged so as to be incident mainly on the first surface 20a of the above with S-polarized light, and both the first semiconductor laser element and the second semiconductor laser element are the first surface 20a of the wavelength conversion member 20. The first laser beam and the second laser beam are arranged so as to enter obliquely with respect to the light. Further, the lighting device 1 includes an incident angle θ1 with respect to the first surface 20a of the wavelength conversion member 20 of the first laser light from the first semiconductor laser element and the wavelength conversion member 20 of the second laser light from the second semiconductor laser element. At least one of the incident angle θ2 with respect to the first surface 20a can be adjusted.

FIG. 3 is a diagram simulating the relationship between the incident angle when light having a wavelength of 450 nm travels in the air and is incident on a wavelength conversion member containing YAG, and the reflectance of light having a wavelength of 450 nm. The solid line in FIG. 3 shows the relationship between the incident angle of 450 nm light and the reflectance of 450 nm light when the laser light is composed of only P-polarized light (that is, when the laser light does not include S-polarized light). The broken line in FIG. 3 shows the relationship between the incident angle of 450 nm light and the reflectance of 450 nm light when the laser light is composed of only S-polarized light (that is, when the laser light does not contain P-polarized light). show. Except for the condition of P-polarized light or S-polarized light, the same conditions are set for the former laser beam and the latter laser beam. Here, when the incident angle is 0 degrees, it is assumed that the laser light is incident perpendicular to the wavelength conversion member, and when the incident angle is 90 degrees, the laser light is parallel to the wavelength conversion member. It is supposed to be incident.

As can be seen from FIG. 3, the reflectance of the light of 450 nm is the light of 450 nm with respect to the wavelength conversion member in both the case where the laser light is composed of only P-polarized light and the case where the laser light is composed of only S-polarized light. It changes according to the incident angle of. Here, the smaller the reflectance, the less the light of 450 nm reflected by the wavelength conversion member, and the more the light of 450 nm incident in the wavelength conversion member. On the other hand, the larger the reflectance, the more 450 nm light reflected by the wavelength conversion member, and the less 450 nm light incident on the wavelength conversion member. Therefore, the light extracted from the wavelength conversion member contains more wavelength conversion light as the reflectance is smaller, and contains less wavelength conversion light as the reflectance is larger.

In the illuminating device 1, the relationship between the wavelength-converted light and the reflected light due to such a difference in the incident angle, and the fact that this relationship is different between the P-polarized light and the S-polarized light are used to obtain the light extracted from the wavelength conversion member. Change the proportion of wavelength-converted light contained. Specifically, at least one of the incident angle θ1 of the first laser light and the incident angle θ2 of the second laser light is preferably adjusted, and the ratio of P-polarized light and S-polarized light incident on the wavelength conversion member 20 is changed. By doing so, the ratio of the wavelength conversion light extracted from the wavelength conversion member 20 is changed. According to the lighting device 1, by adjusting the incident angle of the laser beam, the reflectance of the light incident on the P-polarized light and the reflectance of the light incident on the S-polarized light are adjusted, and the first surface 20a of the wavelength conversion member 20 is adjusted. You can change the chromaticity of the light extracted from. Therefore, it is possible to provide a lighting device capable of adjusting the chromaticity of the emitted light with a small number of parts and a simple configuration. The "incident angles θ1 and θ2" referred to in the present specification are calculated based on the normal line of the first surface 20a of the wavelength conversion member 20 and the optical axis of the laser beam immediately before the incident on the first surface 20a. The angle to be done. Further, the "optical axis" as used herein refers to the central path of the entire laser beam. Hereinafter, each device and member will be described in detail.

(Lighting device 1)
The lighting device 1 can be used for vehicle headlights and the like. The visibility of vehicle headlights varies between rainy and sunny weather. Therefore, it is necessary to adjust the chromaticity of the vehicle headlights according to the weather. However, if an attempt is made to adjust the chromaticity by changing the light emission intensity or the number of the semiconductor laser elements, the light emission intensity of the lighting device also changes according to the adjustment of the chromaticity. On the other hand, according to the present embodiment, the chromaticity of the lighting device 1 can be changed without changing the light emitting intensity of the lighting device 1. Therefore, when the lighting device 1 is used as a vehicle headlight, it is possible to provide a vehicle headlight that suppresses a decrease in visibility due to a change in the weather.

(1st semiconductor laser element, 2nd semiconductor laser element)
The first semiconductor laser element is mounted on the first laser device 12, and the second semiconductor laser element is mounted on the second laser device 14. In the lighting device 1, one laser device 12 includes a first semiconductor laser device and the other laser device 14 includes a second semiconductor laser device, but one laser device includes a first semiconductor laser device and a second semiconductor. Both laser elements may be included. That is, the first laser beam and the second laser beam may be emitted from one laser device. Further, the light from the first laser device 12 and the second laser device 14 may be arranged so as to be irradiated to the wavelength conversion member 20 via the optical fiber. Further, in the present embodiment, one first semiconductor laser element and one second semiconductor laser element are used, but the first semiconductor laser element and the second semiconductor laser element are each a plurality of each. May be good.

As the first semiconductor laser element and the second semiconductor laser element, for example, a semiconductor laser element using a nitride semiconductor can be used. The first semiconductor laser element and the second semiconductor laser element are preferably semiconductor laser elements that emit light of the same color. In this way, the lifespan of the first semiconductor laser element and the second semiconductor laser element can be shortened as compared with the case of using a semiconductor laser element that emits light of different colors. When the semiconductor laser element emits "light of the same color", the wavelength of the first laser light and the wavelength of the second laser light are exactly the same, and between the two wavelengths at the time of manufacture. It also includes cases where there is a difference that can be regarded as a variation of. The case where there is a difference to the extent that it can be regarded as a variation during manufacturing is, for example, a case where the difference in emission peak wavelength is within 20 nm.

In the present embodiment, as the first semiconductor laser element and the second semiconductor laser element, a blue light emitting semiconductor laser element having an emission peak wavelength of 450 nm is used. In this way, when the wavelength conversion member 20 contains the YAG phosphor, the wavelength conversion member 20 can be irradiated with the light having the maximum excitation wavelength of the YAG phosphor, so that the light from the wavelength conversion member 20 can be efficiently emitted. Can be taken out.

The first semiconductor laser element is arranged so that the first laser beam emitted from the first semiconductor laser element is incident on the first surface 20a of the wavelength conversion member 20 mainly with P-polarized light. Further, the second semiconductor laser element is arranged so that the second laser beam emitted from the second semiconductor laser element is incident on the first surface 20a of the wavelength conversion member 20 mainly with S-polarized light. When the first surface 20a of the wavelength conversion member 20 has an inclined surface as shown in FIG. 2, it is arranged so as to be incident on the inclined surface with P-polarized light or S-polarized light. In this case, the normal of the inclined surface irradiated with each laser beam and the optical axis of each laser beam are defined as the incident angles θ1 and θ2 of each laser beam. Further, the direction of each laser beam is defined as the direction of the optical axis of each laser beam.

The P-polarized light (P component) of the laser beam incident on the first surface 20a means a component that vibrates in parallel with the plane including the optical axis of the laser beam and the normal of the first surface 20a. The S-polarized light (S component) of the laser beam incident on the first surface 20a means a component that vibrates perpendicularly to a plane including the optical axis of the laser beam and the normal line of the first surface 20a. For example, on a surface parallel to the paper surface of FIG. 1, when the laser beam travels from the upper left to the lower right and is incident on the first surface 20a, a component that vibrates parallel to the paper surface of FIG. Is the P-polarized light (P component) of the laser light, and it is the S-polarized light (S component) of the laser light that vibrates vertically.

Incident mainly with P-polarized light means that the ratio of P-polarized light (P component) in the laser beam is larger than the ratio of S-polarized light (S component), specifically 51% or more and 100% or less. Further, mainly incident with S-polarized light means that the ratio of S-polarized light (S component) in the laser beam is larger than the ratio of P-polarized light (P component), specifically, 51% or more and 100% or less. To say. The first laser beam is preferably composed of only P-polarized light, and the second laser beam is composed of only S-polarized light so that the difference in reflectance with respect to the incident angle of the first laser beam and the second laser beam can be efficiently utilized. Is preferable. However, even if a small amount of S-polarized light is included due to a mounting deviation of the semiconductor laser element, it is assumed to be included in "consisting of only P-polarized light", and a small amount of P-polarized light is included due to a mounting deviation of the semiconductor laser element. Even if it is, it is included in "consisting of only S polarized light" here.

Both the first semiconductor laser element and the second semiconductor laser element are arranged so that the laser beam is obliquely incident on the first surface 20a of the wavelength conversion member 20. Thereby, the difference between the reflectance of P-polarized light and the reflectance of S-polarized light with respect to the incident angle can be utilized. As shown in FIG. 3, the difference in reflectance between the P-polarized light and the S-polarized light with respect to the incident angle occurs in the range where the incident angles θ1 and θ2 of the laser light are larger than 10 degrees and less than 90 degrees. Further, if the first semiconductor laser element and the second semiconductor laser element are arranged so that the laser light is incident at an angle, the laser light can be first emitted without arranging an optical component such as a dichroic mirror directly above the wavelength conversion member 20. Light that has been wavelength-converted by irradiating the surface can be extracted from the first surface. As a result, it is possible to prevent the light from the wavelength conversion member 20 from being absorbed by an optical component such as a dichroic mirror. Therefore, it is possible to suppress a decrease in light extraction efficiency as compared with a lighting device in which an optical member such as a dichroic mirror is arranged directly above the wavelength conversion member.

The first semiconductor laser element and the second semiconductor laser element are preferably arranged so that the laser beam is incident on the first surface 20a of the wavelength conversion member 20 from the same direction. By doing so, it is possible to improve the light extraction efficiency as a lighting device as compared with the case where the first semiconductor laser element and the second semiconductor laser element are arranged so as to face each other with the wavelength conversion member 20 interposed therebetween. can. This point will be described in detail below. When the wavelength conversion member is arranged so as to face each other, the light from the first semiconductor laser element and the light from the second semiconductor laser element are reflected in the same direction by the first inclination on the first surface of the wavelength conversion member. It is necessary to provide two types of inclined surfaces having different inclination directions, that is, a surface and a second inclined surface. However, in this way, the portion of the first laser beam irradiated to the first inclined surface is reflected upward, but the portion irradiated to the second inclined surface is not reflected upward. Does not enter the collimator lens. Similarly, the portion of the second laser beam irradiated to the second inclined surface is reflected upward, but the portion irradiated to the first inclined surface is not reflected upward and is incident on the collimator lens. do not. On the other hand, if the first laser beam and the second laser beam are incident from the same direction, the light can be reflected by one kind of inclined surface, and the light reflected by the wavelength conversion member 20 can be efficiently reflected. Can be incident on the collimator lens 40.

When the first laser beam and the second laser beam are incident from the same direction, it is preferable that the first semiconductor laser element and the second semiconductor laser element are arranged close to each other. In this way, the lighting device 1 can be miniaturized, so that the lighting device 1 that can be easily adopted for the headlight can be provided.

The incident angle θ1 of the wavelength conversion member 20 of the first laser light from the first semiconductor laser element with respect to the first surface 20a and the incident angle of the second laser light from the second semiconductor laser element with respect to the first surface 20a of the wavelength conversion member 20. At least one of θ2 is adjustable, preferably both are adjustable. Such adjustment can be performed, for example, by adjusting the arrangement of each semiconductor laser element and the orientation of the mirrors 52 and 54, which will be described later.

The incident angles θ1 and θ2 of the first laser beam and the second laser beam, respectively, are preferably adjusted within an angle including the Brewster angle, particularly within a range of the Brewster angle ± 20 degrees. As a result, the first laser beam can be easily incident on the wavelength conversion member 20 to some extent, so that the wavelength-converted light can be easily taken out. Further, since the light having the wavelength of the second laser light can be reflected while the second laser light is incident on the wavelength conversion member 20 to some extent, white light can be easily obtained. The Brewster angle is an incident angle at which the reflectance of P-polarized light becomes zero.

When phosphor ceramics containing a YAG phosphor are used as the wavelength conversion member 20, the incident angles θ1 and θ2 of the first laser beam and the second laser beam, respectively, are adjusted within a range of 20 degrees or more and 80 degrees or less. Is preferable. As shown in FIG. 3, since the difference in reflectance between P-polarized light and S-polarized light becomes remarkable in the above range, the laser light from each semiconductor laser element should be adjusted so that the incident angles θ1 and θ2 are in these ranges. For example, the difference in reflectance between P-polarized light and S-polarized light can be effectively used.

Further, the incident angles θ1 and θ2 of the first laser beam and the second laser beam, respectively, are preferably adjusted within a range in which the difference between the reflectance of P-polarized light and the reflectance of S-polarized light is 10% or more. In this way, the difference in reflectance between P-polarized light and S-polarized light can be further effectively utilized. However, if the reflectance of blue light is too high, it is difficult to obtain white light, and if the reflectance difference between P-polarized light and S-polarized light is too small, it is difficult to obtain the effect of the present embodiment. Therefore, when adjusting within the above range, it is more preferable that the incident angles θ1 and θ2 are 40 degrees or more and 70 degrees or less, respectively.

(Wavelength conversion member 20)
The wavelength conversion member 20 is arranged on the upper surface of the support 30 with the second surface 20b facing the support 30 side, for example. The first laser light and the second laser light emitted by the first semiconductor laser element of the first laser device 12 and the second semiconductor laser element of the second laser device 14 are incident on the first surface 20a of the wavelength conversion member 20. A part of the laser light incident on the first surface 20a of the wavelength conversion member 20 is wavelength-converted on the surface or inside of the wavelength conversion member 20, and the light including the wavelength-converted light is emitted from the first surface 20a of the wavelength conversion member 20. Taken out.

As the wavelength conversion member 20, a member containing a phosphor, for example, a fluorescent ceramic or a fluorescent single crystal can be used. As the phosphor, a YAG phosphor, a LAG phosphor, a TAG phosphor and the like can be used. The fluorescent ceramics preferably contain a fluorescent substance as a main component, and may contain an inorganic binder. By including the inorganic binder, the concentration of the phosphor can be adjusted according to the desired chromaticity. It is preferable to use aluminum oxide or the like as the inorganic binder so as to increase the binding force.

The wavelength conversion member 20 has, for example, a rectangular parallelepiped shape or a square pyramid shape. The wavelength conversion member 20 has a first surface 20a, a second surface 20b facing the first surface 20a, and a third surface 20c connecting the first surface 20a and the second surface 20b.

As shown in FIG. 2, the first surface 20a may be composed of a plurality of convex portions. As a result, the propagation of light incident on the wavelength conversion member 20 and traveling in the lateral direction can be stopped within one convex portion, so that a decrease in the brightness of the light extracted from the wavelength conversion member 20 can be suppressed. The height of the convex portion (depth of the groove X) is preferably half or less of the height of the wavelength conversion member 20. Although it depends on the length between the adjacent convex portions (width of the groove X) and the height of the wavelength conversion member 20, the height of the convex portions can be, for example, within the range of 50 μm or more and 150 μm or less. By setting it to the above-mentioned lower limit value or more, it is possible to easily reduce the propagation of light, and by setting it to the above-mentioned upper limit value or less, it is possible to reduce the occurrence of unintended cracks in the wavelength conversion member 20 when forming the groove X. can do. The groove X can be formed by, for example, laser processing. On the first surface 20a of the wavelength conversion member 20, it is preferable that the region irradiated with the laser beam includes a plurality of convex portions. That is, in the top view, the area of at least two convex portions is smaller than the area of the first laser beam irradiated on the first surface 20a and the area of the second laser beam irradiated on the first surface 20a. Is preferable. As a result, the propagation of light in the wavelength conversion member 20 can be suppressed, so that the decrease in brightness can be reduced.

The first surface 20a of the wavelength conversion member 20 does not have to face parallel to the second surface 20b. For example, as shown in FIG. 2, it may have an inclined surface that intersects a surface parallel to the second surface 20b and is directly exposed to the laser beam. When the first surface 20a is composed of convex portions, it is preferable that a plurality of inclined surfaces are provided on one convex portion. By having the inclined surface, a part of the blue light emitted to the first surface 20a of the wavelength conversion member 20 can be reflected directly above and in the vicinity thereof, so that it becomes easy to reduce the color unevenness as the lighting device 1. .. When the first surface 20a of the wavelength conversion member 20 has an inclined surface, "arranged so that the laser light is obliquely incident on the first surface 20a" means the laser light of the first semiconductor laser element and the first 2 It means that the first semiconductor laser element and the second semiconductor laser element are arranged so that the laser beam of the semiconductor laser element is obliquely incident on the inclined surface. That is, each semiconductor laser element is arranged so that each laser beam is inclined and incident from the normal line with respect to the inclined surface. Even when the first surface 20a has an inclined surface as shown in FIG. 2 when viewed microscopically, the wavelength conversion member 20 is included in the rectangular parallelepiped shape and the square pyramid shape in the present specification. Shall be.

(Support 30)
The support 30 is for mounting the wavelength conversion member 20. As the support 30, a metal containing copper or a light-reflecting ceramic containing aluminum nitride can be used. Since these materials have a relatively high thermal conductivity, the heat generated by the wavelength conversion member 20 can be easily dissipated. The wavelength conversion member 20 can be fixed to the support 30 by using a metal member. As the metal member, for example, Au-Sn can be used.

(Light Reflecting Member 60)
A light reflecting member 60 can be provided between the second surface 20b of the wavelength conversion member 20 and the support 30. As a result, among the light incident on the wavelength conversion member 20, the light directed to the second surface 20b can be reflected on the first surface 20a to be easily taken out. The light reflecting member 60 includes, for example, a metal film such as aluminum, titanium, platinum, or gold, or a dielectric multilayer film. Further, a metal film and a dielectric multilayer film may be combined. When the light reflecting member 60 is provided, a metal member is provided between the lower surface of the light reflecting member 60 and the support 30 and fixed to the support 30.

(1st mirror 52 and 2nd mirror 54)
The lighting device 1 includes a movable first mirror 52 that reflects the first laser beam emitted from the first laser device 12, and a movable second mirror that reflects the second laser beam emitted from the second laser device 14. 54 may be provided. As the first mirror 52 and the second mirror 54, movable MEMS (Micro Electro Mechanical System) mirrors can be used, respectively. The MEMS mirror has a reflective film that does not change the polarization of each laser beam in the region irradiated with each laser beam. The reflective film includes, for example, metal. By using the movable first mirror 52 and the movable second mirror 54, the angles of the first mirror 52 and the second mirror 54 can be adjusted, and the first laser beam with respect to the first surface 20a of the wavelength conversion member 20 can be adjusted. The incident angle θ1 of the second laser beam and the incident angle θ2 of the second laser beam with respect to the first surface 20a of the wavelength conversion member 20 can be adjusted. This makes it easier to adjust the chromaticity. Further, since the chromaticity can be adjusted with each laser device fixed, the heat generated by each laser device can be easily dissipated.

The first mirror 52 and the second mirror 54 may be moved in the vertical direction. If such vertical movement is possible, the first laser beam and the second laser beam and the second laser beam and the second laser beam are provided in the same region on the first surface 20a of the wavelength conversion member 20 while adjusting the incident angles θ1 and θ2 of the first laser beam and the second laser beam. Since the laser beam can be irradiated, the decrease in brightness can be reduced.

Although the movable first mirror 52 and the movable second mirror 54 are used in FIG. 1, one of the first mirror 52 and the second mirror 54 is made movable, and the first mirror 52 and the second mirror 52 are used. The other side of the mirror 54 may be fixed. Further, the laser light from each laser device may be directly applied to the first surface 20a of the wavelength conversion member 20 without passing through the first mirror 52 and the second mirror 54. When not using a mirror, the angle of incidence can be changed by adjusting the position and orientation of each laser device. Also in this case, the chromaticity of the illuminating device can be adjusted while reducing the decrease in the brightness of the illuminating device.

(Collimator lens 40)
The collimator lens 40 plays a role of parallelizing the light from the wavelength conversion member 20 and reducing the spread of the light. Glass can be used as the material of the collimator lens 40. Here, the light extracted from the wavelength conversion member 20 is directly incident on the collimator lens 40 without passing through an optical member such as a dichroic mirror.

(Polarizer 50)
FIG. 4 is a schematic configuration diagram illustrating another example of the lighting device according to the first embodiment. As shown in FIG. 4, if the polarizer 50 is arranged between the first laser beam and the second laser beam and the mirror 70, the optical axis of the first laser beam and the optical axis of the second laser beam are overlapped with each other. By irradiating the wavelength conversion member 20, the incident angles θ1 and θ2 of the first laser beam and the second laser beam can be adjusted to be equal to each other. As a result, the first laser beam and the second laser beam can be applied to the same region of the first surface 20a of the wavelength conversion member 20, so that a decrease in brightness as a lighting device can be suppressed. Further, the angles of the first laser beam and the second laser beam can be adjusted with one mirror 70.

As the polarizer 50, a total reflection type can be used. Specifically, one that transmits one of P-polarized light or S-polarized light and reflects the other of P-polarized light or S-polarized light can be used. In FIG. 4, a polarizer 50 that transmits the first laser beam that is P-polarized light and reflects the second laser beam that is S-polarized light is used. By using the polarizer 50, the first semiconductor laser element and the second semiconductor laser element can be arranged at a certain distance from each other. Therefore, when the number of the first semiconductor laser element and the second semiconductor laser element is large, heat is dissipated. It is advantageous.

(Drive method)
The lighting device 1 described above can be driven, for example, as follows.

(Preparation process)
First, the above-mentioned lighting device 1 is prepared.

(Drive process)
Next, by adjusting at least one of the incident angle θ1 with respect to the first surface 20a of the wavelength conversion member 20 of the first laser light and the incident angle θ2 with respect to the first surface 20a of the wavelength conversion member 20 of the second laser light. The chromaticity of the light extracted from the lighting device 1 is adjusted. Preferably, the chromaticity of the light extracted from the illuminating device 1 is adjusted by adjusting both the incident angle of the first laser beam and the incident angle of the second laser beam. Specifically, the first laser beam and the second laser beam are adjusted so that the incident angles θ1 and θ2 of the first laser beam and the second laser beam are 30 degrees or more and 70 degrees or less, respectively. For example, it is preferable to adjust the color temperature between 5000K and 6500K.

According to the lighting device 1 and its driving method described above, the light is taken out from the first surface 20a of the wavelength conversion member 20 by adjusting the incident angle of the laser light by utilizing the difference in reflectance between P-polarized light and S-polarized light. Since the chromaticity of the emitted light can be changed, it is possible to provide an illuminating device capable of adjusting the chromaticity of the emitted light and a driving method thereof with a small number of parts and a simple configuration.

Further, when adjusting the output of the laser beam to adjust the chromaticity, it is necessary to change the emission intensity of each semiconductor laser element according to the chromaticity, so that the emission intensity of the lighting device may change. However, according to the illumination device 1 and the driving method thereof described above, it is possible to adjust the chromaticity without significantly changing the emission intensity of each semiconductor laser element.

[Lighting device 2 according to the second embodiment]
FIG. 5 is a schematic configuration diagram illustrating the lighting device 2 according to the second embodiment. As shown in FIG. 5, the lighting device 2 according to the second embodiment is the first of the wavelength conversion members 20 described above by rotating one laser device 16 having a semiconductor laser element and the one laser device 16. It differs from the lighting device 1 according to the first embodiment in that it includes a rotating mechanism that changes the mixing ratio of P-polarized light and S-polarized light in the laser beam incident on the surface 20a. Other points have the same configuration as the lighting device 1 according to the first embodiment. A polarized state that is neither P-polarized light nor S-polarized light can be considered as a combination of P-polarized light and S-polarized light with different distribution ratios. By rotating the semiconductor laser element, the distribution ratio of P-polarized light and S-polarized light changes, so that the mixing ratio of P-polarized light and S-polarized light can be changed.

In the present embodiment, one laser device 16 includes one semiconductor laser device, but one laser device 16 may include a plurality of semiconductor laser devices. Further, the semiconductor laser element is preferably arranged so that the incident angle of the laser light with respect to the first surface 20a of the wavelength conversion member 20 is 20 degrees or more and 80 degrees or less, and is 30 degrees or more and 70 degrees or less. It is more preferable to be arranged in. Although it is not essential to adjust the incident angle in the lighting device 2, the incident angle of the laser beam may be adjusted.

The rotation mechanism rotates, for example, the laser device 16 about the optical axis of the laser beam as a rotation axis, whereby the semiconductor laser element mounted on the laser device 16 is rotated in a direction perpendicular to the optical axis. As the rotation mechanism, for example, a holder incorporating a stepping motor is used. The semiconductor laser element can be rotated by arranging and rotating the laser device 16 in a holder incorporating a stepping motor.

(Drive method)
The lighting device 2 described above can be driven, for example, as follows.

(Preparation process)
First, the above-mentioned lighting device 2 is prepared.

(Drive process)
Next, by rotating the semiconductor laser element with the optical axis of the semiconductor laser element as the rotation axis using a rotation mechanism, the mixing ratio of P-polarized light and S-polarized light in the laser light is changed and taken out from the wavelength conversion member 20. Adjust the chromaticity of the emitted light.

Also in the second embodiment described above, similarly to the first embodiment, the chromaticity of the light extracted from the first surface 20a of the wavelength conversion member 20 is changed by utilizing the difference in the reflectance of the P-polarized light and the S-polarized light. Therefore, it is possible to provide a lighting device capable of adjusting the chromaticity of the emitted light and a driving method thereof with a small number of parts and a simple configuration. Further, according to the illumination device 2 and the driving method thereof, it is possible to adjust the chromaticity without significantly changing the emission intensity of the semiconductor laser element.

Although the embodiments have been described above, the configurations described in the claims are not limited by these explanations.

1, 2 ... Illumination device 12 ... 1st laser device 14 ... 2nd laser device 16 ... Laser device 20 ... Wavelength conversion member 20a ... 1st surface 20b ... 2nd surface 20c ... 3rd surface 30 ... Support 40 ... Collimator lens 50 ... Polarizer 52 ... First mirror 54 ... Second mirror 60 ... Light reflecting member 70 ... Mirror

Claims (10)

The first semiconductor laser device and
Second semiconductor laser element and
It has a first surface and a second surface facing the first surface, and the laser light of the first semiconductor laser element and the second semiconductor laser element is incident on the first surface and is incident on the first surface. A wavelength conversion member for wavelength-converting at least a part of the laser light to be taken out from the first surface is provided.
The first semiconductor laser element is arranged so that the laser light is incident on the first surface of the wavelength conversion member mainly with P-polarized light.
The second semiconductor laser element is arranged so that the laser light is incident on the first surface of the wavelength conversion member mainly with S-polarized light.
Both the first semiconductor laser element and the second semiconductor laser element are arranged so that the laser beam is obliquely incident on the first surface of the wavelength conversion member.
One of the incident angle of the laser light from the first semiconductor laser element with respect to the first surface of the wavelength conversion member and the incident angle of the laser light from the second semiconductor laser element with respect to the first surface of the wavelength conversion member can be adjusted. The other is a fixed lighting device. The first semiconductor laser device and
Second semiconductor laser element and
It has a first surface and a second surface facing the first surface, and the laser light of the first semiconductor laser element and the second semiconductor laser element is incident on the first surface and is incident on the first surface. A wavelength conversion member for wavelength-converting at least a part of the laser light to be taken out from the first surface is provided.
The first semiconductor laser element is arranged so that the laser light is incident on the first surface of the wavelength conversion member mainly with P-polarized light.
The second semiconductor laser element is arranged so that the laser light is incident on the first surface of the wavelength conversion member mainly with S-polarized light.
Both the first semiconductor laser element and the second semiconductor laser element are arranged so that the laser beam is obliquely incident on the first surface of the wavelength conversion member.
The incident angle adjustable respectively relative to a first surface of the wavelength converting member of the laser beam with the incident angle from the second semiconductor laser element with respect to the first surface of the wavelength conversion member of a laser beam from the first semiconductor laser element A lighting device. The lighting device according to claim 1 or 2 , wherein the first semiconductor laser element and the second semiconductor laser element emit light of the same color. Wherein the first semiconductor laser element and the second semiconductor laser element are both claim 1, the incident angle of the laser beam with respect to the first surface of the wavelength conversion member is arranged to be equal to or less than 80 degrees 20 degrees The lighting device according to any one of 3. The invention according to any one of claims 1 to 4, wherein the first semiconductor laser element and the second semiconductor laser element are arranged so that laser light is incident on the first surface of the wavelength conversion member from the same direction. Lighting device. A light reflecting member to which the laser light from the first semiconductor laser element or the laser light from the second semiconductor laser element is incident is further provided.
The lighting device according to any one of claims 1 to 5, wherein the light reflecting member is a movable light reflecting member capable of adjusting the incident angle of the reflected laser light with respect to the first surface of the wavelength conversion member. .. A wavelength conversion member having a first surface and a second surface facing the first surface, wavelength-converting at least a part of laser light incident on the first surface and extracting from the first surface, and the wavelength. The first semiconductor laser element arranged so that the laser beam is mainly incident on the first surface of the conversion member with P-polarized light, and the laser light is mainly S-polarized on the first surface of the wavelength conversion member. A method of driving an illumination device including a second semiconductor laser element arranged so as to be incidental.
The other of the incident angle of the laser light from the first semiconductor laser element with respect to the first surface of the wavelength conversion member and the incident angle of the laser light from the second semiconductor laser element with respect to the first surface of the wavelength conversion member are fixed. A method for driving a lighting device, which comprises a step of adjusting one side and adjusting the chromaticity of light extracted from the wavelength conversion member. A wavelength conversion member having a first surface and a second surface facing the first surface, wavelength-converting at least a part of laser light incident on the first surface and extracting from the first surface, and the wavelength. The first semiconductor laser element arranged so that the laser beam is mainly incident on the first surface of the conversion member with P-polarized light, and the laser light is mainly S-polarized on the first surface of the wavelength conversion member. A method of driving an illumination device including a second semiconductor laser element arranged so as to be incidental.
The incident angle of the laser light from the first semiconductor laser element with respect to the first surface of the wavelength conversion member and the incident angle of the laser light from the second semiconductor laser element with respect to the first surface of the wavelength conversion member are adjusted. A method for driving a lighting device, which comprises a step of adjusting the chromaticity of light extracted from the wavelength conversion member. The method for driving a lighting device according to claim 7 or 8 , wherein the lighting device uses a semiconductor laser element that emits light of the same color as the first semiconductor laser element and the second semiconductor laser element. In the step of adjusting the chromaticity, the laser beam from the first semiconductor laser element and the laser beam so that the incident angle of the laser beam with respect to the first surface of the wavelength conversion member is 20 degrees or more and 80 degrees or less. The method for driving an illumination device according to any one of claims 7 to 9, wherein the laser beam from the second semiconductor laser element is adjusted.

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