JP2011076911A - Lighting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting apparatus capable of visualizing true colors of an object, and achieving various illumination colors. <P>SOLUTION: The lighting apparatus 1A is provided with an optical fiber 20, a semiconductor laser device 30A optically coupled with one end of the optical fiber 20 and outputting mixed-color laser light L containing at least red-color laser light, blue-color laser light and green-color laser light, and an adjuster (a control circuit 40) for adjusting chromaticity of the mixed-color laser light L output from the semiconductor laser device 30A. The mixed-color laser light L is irradiated outside from the other end and at least one of the side faces of the optical fiber 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lighting device.

  Patent Document 1 discloses an excitation light source that emits excitation light, a wavelength conversion member that absorbs excitation light emitted from the excitation light source, converts the wavelength and emits illumination light in a predetermined wavelength range, and one end as an excitation light source. A light-emitting device is described that includes an optical fiber that is coupled, has the other end coupled to a wavelength conversion member, and guides excitation light emitted from the excitation light source to the wavelength conversion member.

JP 2005-205195 A

  In recent years, lighting devices using white LEDs have been actively developed. For example, in the medical field, with the miniaturization of the surgical site, the surgical field may become a shadow in the conventional illumination device, and illumination using white LEDs as a device that can appropriately illuminate such a surgical field The device looks promising.

  However, in a white LED that is currently widely used, blue light (wavelength of about 450 [nm]) emitted from a blue LED and yellow light (wavelength of about 580 [nm]) emitted from a phosphor excited by the blue light. White light is obtained. Therefore, the red wavelength component (wavelength of about 650 [nm]) that should be included in the white light is extremely small, and even if a white object is irradiated with the white light, the object remains the original red color. Invisible is a problem. In order to solve such problems, phosphors have been improved, but sufficient ones have not been realized yet.

  Moreover, although white LED is used also for decoration, in the illuminating device using the conventional white LED as described above, only blue and yellow wavelength regions are included, and the light source is only blue. Therefore, it is difficult to realize various illumination colors to entertain passers-by.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an illumination device that can visually recognize the original color of an object and can realize various illumination colors.

  In order to solve the above-described problems, an illumination device according to the present invention is optically coupled to an optical fiber and one end of the optical fiber, and outputs at least mixed color laser light including red laser light, blue laser light, and green laser light. And a adjusting means for adjusting the chromaticity of the mixed color laser light output from the semiconductor laser device. The mixed color laser light is emitted to the outside from at least one of the other end and the side surface of the optical fiber. It is characterized by that.

  In this illumination device, since the semiconductor laser device outputs mixed color laser light including at least red laser light, blue laser light, and green laser light, for example, by irradiating a red object with the mixed light, It can be visually recognized as the original red color. In addition, by adjusting the chromaticity of the mixed color laser light by the adjusting means, various illumination colors for entertaining passersby can be realized.

  In addition, the illumination device supplies the current to the first electrode for supplying current to the optical resonator for generating red laser light and to the optical resonator for generating blue laser light. And a third electrode for supplying current to the optical resonator for generating the green laser light, and the adjusting means includes the first, second and third electrodes. The control circuit may adjust the chromaticity of the mixed-color laser beam by individually controlling the amount of current supplied to each of the two. When the semiconductor laser device and the adjusting means have these configurations, the chromaticity of the mixed color laser light can be suitably adjusted.

  In the illumination device, the adjusting means includes temperature control means for controlling the temperature of the semiconductor laser device, and a neutral density filter or an optical attenuator disposed between one end of the optical fiber and the semiconductor laser device. It is good. When the adjusting means has these configurations, the chromaticity of the mixed color laser light can be adjusted suitably.

  In the illumination device, the peak wavelength of the red laser light is included in the range of 600 [nm] to 700 [nm], and the peak wavelength of the blue laser light is in the range of 430 [nm] to 480 [nm]. It is preferable that the peak wavelength of the green laser light be included in the range of 500 [nm] to 550 [nm].

  In the illumination device, the semiconductor laser device includes a first semiconductor laser element that generates red laser light, a second semiconductor laser element that generates blue laser light, and a third semiconductor laser element that generates green laser light. The second and third semiconductor laser elements may include an InAlGaN-based semiconductor layer grown on a GaN substrate. When the second and third semiconductor laser elements have such a configuration, blue laser light and green laser light can be suitably output, respectively. The InAlGaN-based semiconductor layer is a concept that includes, for example, GaN, InGaN, AlGaN, and InAlGaN.

  In the illumination device, the semiconductor laser device includes a first semiconductor laser element that generates red laser light, a second semiconductor laser element that generates blue laser light, and a third semiconductor laser element that generates green laser light. The first semiconductor laser element may include an AlGaInAsP-based semiconductor layer grown on a GaAs substrate. When the first semiconductor laser element has such a configuration, red laser light can be suitably output. The AlGaInAsP-based semiconductor layer is a concept including, for example, GaAs, GaAsP, InGaAsP, InGaP, AlGaInP, and AlInP.

  The lighting device may be characterized in that the optical fiber uses quartz as a base material. Alternatively, the lighting device may be characterized in that the optical fiber is made of plastic. When the optical fiber is made of quartz as a base material, transmission loss of the mixed color laser light transmitted through the optical fiber can be reduced. Further, when the optical fiber is made of plastic, the lighting device can be configured at a low cost, and the setting is easy because the optical fiber is not easily broken.

  According to the illumination device according to the present invention, the original color of an object can be visually recognized, and various illumination colors can be realized.

FIG. 1 is a diagram illustrating an overall configuration of a lighting device 1A according to the first embodiment. FIG. 2 is a diagram illustrating an internal configuration of the light source unit 10A of the illumination device 1A according to the first embodiment. FIG. 3 is a diagram showing a cross-sectional structure of the semiconductor laser element 33 provided in the light source unit 10A. FIG. 4 is a side sectional view taken along line IV-IV of the semiconductor laser element 33 shown in FIG. FIG. 5 is a diagram illustrating an internal configuration of the light source unit 10B of the lighting apparatus according to the second embodiment. FIG. 6 is a diagram illustrating an overall configuration of a lighting apparatus 1C according to the third embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a lighting device according to the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
FIG. 1 is a diagram showing an overall configuration of a lighting device 1A according to the first embodiment of the present invention. Referring to FIG. 1, the lighting device 1 </ b> A includes a light source unit 10 </ b> A and an optical fiber 20. The light source unit 10A receives power supply from the outside of the illumination device 1A, and outputs a mixed color laser light L including at least red laser light, blue laser light, and green laser light. The light emitting end of the light source unit 10A is optically coupled to one end of the optical fiber 20, and the mixed color laser light L is emitted from the other end of the optical fiber 20 to the outside of the illumination device 1A.

  The optical fiber 20 is configured by an optical fiber having, for example, quartz as a base material. Alternatively, the optical fiber 20 is composed of a plastic optical fiber (POF) made of plastic. When the optical fiber 20 uses quartz as a base material, the transmission loss of the mixed-color laser beam L transmitted through the optical fiber 20 can be reduced. When the optical fiber 20 is made of plastic, the lighting device 1A can be configured at low cost, and the optical fiber 20 is not easily broken, so that setting is easy.

  FIG. 2 is a diagram illustrating an internal configuration of the light source unit 10A of the lighting apparatus 1A. Referring to FIG. 2, the light source unit 10A includes a semiconductor laser device 30A and a control circuit 40 that supplies power to the semiconductor laser device 30A.

  The semiconductor laser device 30A outputs a mixed color laser beam L including at least a red laser beam, a blue laser beam, and a green laser beam. The semiconductor laser device 30 </ b> A has an appearance such as a CAN package, for example, and includes at least three semiconductor laser elements 31 to 33. The semiconductor laser element 31 is the first semiconductor laser element in this embodiment, and has an optical resonator for generating red laser light. The semiconductor laser element 32 is the second semiconductor laser element in the present embodiment, and has an optical resonator for generating blue laser light. The semiconductor laser element 33 is the third semiconductor laser element in this embodiment, and has an optical resonator for generating green laser light. The oscillation wavelength of the semiconductor laser element 31 (that is, the peak wavelength of red laser light) is included in the range of 600 [nm] to 700 [nm], and the oscillation wavelength of the semiconductor laser element 32 (that is, the peak wavelength of blue laser light). Is included in the range of 430 [nm] to 480 [nm], and the oscillation wavelength of the semiconductor laser element 31 (that is, the peak wavelength of the green laser light) is included in the range of 500 [nm] to 550 [nm]. It is.

  Further, the semiconductor laser device 30 </ b> A has a condenser lens 34. The condenser lens 34 is optically coupled to the semiconductor laser elements 31 to 33, and the condenser lens 34 is optically coupled to one end of the optical fiber 20. The mixed color laser light L output from the semiconductor laser device 30 </ b> A is incident on one end of the optical fiber 20 via the condenser lens 34.

  The semiconductor laser device 30A includes an electrode 35a (first electrode) for supplying current to the anode of the semiconductor laser element 31, and an electrode 35b (second electrode) for supplying current to the anode of the semiconductor laser element 32. ), An electrode 35c (third electrode) for supplying a current to the anode of the semiconductor laser element 33, and an electrode 35d connected to the cathodes of the semiconductor laser elements 31 to 33. These electrodes 35a to 35d are electrically connected to the control circuit 40 via metal wirings 36a to 36d.

  The control circuit 40 is an adjusting unit in this embodiment. The control circuit 40 adjusts the chromaticity of the mixed color laser light L output from the semiconductor laser device 30A. Specifically, each amount of red laser light, blue laser light, and green laser light output from the semiconductor laser elements 31 to 33 is controlled by individually controlling the amount of current supplied to the anodes of the semiconductor laser elements 31 to 33. Adjust the intensity individually. The control circuit 40 preferably has input means for adjusting chromaticity by an operation input from the operator. The control circuit 40 receives an electrical signal from a photodiode (not shown) that monitors the back light of the semiconductor laser elements 31 to 33, and based on the electrical signal, controls the current amount to the semiconductor laser elements 31 to 33. It is preferable to control.

  Here, the structure of the semiconductor laser element 33 that outputs green laser light among the semiconductor laser elements 31 to 33 will be described in detail. FIG. 3 is a view showing an example of a cross-sectional configuration of the semiconductor laser elements 31 to 33, and FIG. 4 is a view showing a IV-IV cross section shown in FIG. As shown in FIGS. 3 and 4, the semiconductor laser element 33 includes a semiconductor substrate 50. The semiconductor substrate 50 is a GaN substrate, for example.

  The main surface 50a of the semiconductor substrate 50 is inclined with respect to the c-plane of the GaN crystal. As shown in FIG. 4, the inclination angle of the principal surface 50a is defined by an angle α formed by a normal vector NV indicating the normal axis Nx and a c-axis vector VC indicating the c-axis direction. This angle α can be in a range of 45 ° or more and 135 ° or less with respect to a reference plane Rx (that is, {0001} plane or {000-1} plane) orthogonal to the c-axis of the GaN crystal. This angular range can provide the nonpolar (semipolar or nonpolar) nature of GaN.

  In this case, the main surface 50a is preferably inclined in the m-axis or a-axis direction with respect to the c-plane of the GaN crystal. When tilted in the direction of the m-axis, the tilt angle α is preferably in the range of 63 ° to 80 °, or 100 ° to 117 °. In this case, the main surface 50a may be a {H, 0, -H, L} plane (where H and L are natural numbers) or a {-H, 0, H, -L} plane of a gallium nitride based semiconductor crystal. it can. More preferably, when the main surface 11a is a {2,0, -2,1} plane or {-2,0,2, -1} plane of a gallium nitride based semiconductor crystal, the inclination of the main surface 11a with respect to the c-plane The angle α is 75 ° or 105 °. Moreover, when it inclines in the direction of a-axis, it is preferable that inclination-angle (alpha) exists in the range of 59 to 80 degrees or 100 to 121 degrees. In this case, the main surface 50a is a {H, H, -2H, L} plane (where H and L are natural numbers) or a {-H, -H, 2H, -L} plane of a gallium nitride based semiconductor crystal. Can do. More preferably, when the main surface 50a is a {1, 1, -2, 1} plane or {-1, -1, 2, -1} plane of a gallium nitride based semiconductor crystal, The inclination angle α is 73 ° or 107 °. According to these angular ranges in which the main surface 50a is a semipolar surface, an InGaN layer having an indium composition suitable for an active layer for generating light having a long wavelength of 500 [nm] or more and 550 [nm] or less can be provided. .

  The semiconductor laser element 33 has an optical resonator 60 having a pair of resonance end faces 60a and 60b. The semiconductor laser element 33 includes an n-type semiconductor layer 53 provided on the main surface 50 a of the semiconductor substrate 50, an n-type cladding layer 55 provided on the n-type semiconductor layer 53, and an n-type cladding layer 55. An active layer 57 provided on the active layer 57, and a p-type cladding layer 59 provided on the active layer 57.

  The n-type semiconductor layer 53 is made of an n-type (first conductivity type) GaN-based semiconductor, and can be made of, for example, GaN. The thickness of the n-type semiconductor layer 53 is, for example, 1000 [nm]. The n-type cladding layer 55 constitutes a part of the optical resonator 60. The n-type cladding layer 55 is made of an n-type GaN-based semiconductor, and can be made of, for example, GaN, AlGaN, InAlGaN, or the like. The thickness of the n-type cladding layer 55 is, for example, 1200 [nm]. The p-type cladding layer 59 constitutes a part of the optical resonator 60. The p-type cladding layer 59 is made of a p-type (second conductivity type) GaN-based semiconductor, and can be made of, for example, GaN, AlGaN, InAlGaN, or the like. The thickness of the p-type cladding layer 59 is, for example, 400 [nm].

  The active layer 57 constitutes a part of the optical resonator 60. The active layer 57 may be formed of a single layer or may have a quantum well structure. If required, the quantum well structure can include alternating well layers and barrier layers. The well layer can be made of a III-V group compound semiconductor containing indium, such as InGaN, and the barrier layer can be made of InGaN, GaN, or the like having a larger band gap energy than the well layer. In one embodiment, the thickness of the well layer (InGaN) is, for example, 3 [nm], the thickness of the barrier layer (GaN) is, for example, 15 [nm], and the number of well layers is, for example, two. Can do. The emission wavelength of the active layer 57 is controlled by the band gap of the well layer, the indium composition, the thickness thereof, and the like. The active layer 57 may have an indium composition that generates green light having a peak wavelength in the range of 500 [nm] to 550 [nm].

  The semiconductor laser device 33 further includes a first light guide layer 61 between the n-type cladding layer 55 and the active layer 57. The semiconductor laser device 33 further includes a second light guide layer 63 between the active layer 57 and the p-type cladding layer 59. The first light guide layer 61 and the second light guide layer 63 are provided to confine light in the vicinity of the active layer 57 without letting the light escape to the semiconductor substrate 50 and reduce the threshold current.

  The first light guide layer 61 can include a first layer 71 made of GaN or InGaN and a second layer 73 made of InGaN. The first layer 71 is provided on the n-type cladding layer 55, and the second layer 73 is provided between the first layer 71 and the active layer 57. Note that the indium composition of the second layer 73 is larger than that of the first layer 71 and smaller than that of the InGaN well layer in the active layer 57. In one embodiment, the first layer 71 can be made of n-type GaN and the second layer 73 can be made of undoped InGaN. The thickness of the first layer 71 is, for example, 200 [nm], and the thickness of the second layer 73 is, for example, 65 [nm].

  The second light guide layer 63 can include a first layer 75 made of GaN or InGaN and a second layer 77 made of InGaN. The first layer 75 is provided on the active layer 57, and the second layer 77 is provided between the active layer 57 and the first layer 75. The indium composition of the second layer 77 is larger than the indium composition of the first layer 75 and smaller than the indium composition of the InGaN well layer in the active layer 57. In one embodiment, the first layer 75 is made of p-type GaN and the second layer 77 is made of undoped InGaN. The thickness of the first layer 75 is, for example, 200 [nm], and the thickness of the second layer 77 is, for example, 65 [nm].

  The semiconductor laser element 33 further includes an electronic block layer 67. The electron blocking layer 67 is provided so as to divide the second light guide layer 63 into two in the layer thickness direction. In the present embodiment, the electron blocking layer 67 is provided between the first layer 75 and the second layer 77. Yes. The electron block layer 67 can be made of, for example, p-type AlGaN. The thickness of the electron block layer 67 is, for example, 20 [nm].

  The semiconductor laser element 33 further includes a p-type contact layer 81 provided on the p-type cladding layer 59. The p-type contact layer 81 can be made of, for example, GaN, AlGaN, or the like. A part of the p-type cladding layer 59 and the p-type contact layer 81 have a ridge shape extending in a predetermined optical waveguide direction, and the side surfaces of the ridge shape and the surface of the p-type cladding layer 59 are covered with an insulating film 87. ing. The extending direction of the ridge, that is, the optical waveguide direction of the optical resonator 60 extends along the direction in which the c-axis of the GaN crystal is projected onto the main surface 50a.

  The semiconductor laser element 33 further includes an anode electrode 85. The anode electrode 85 is provided on the ridge of the optical resonator 60 and is in contact with the p-type contact layer 81 through the opening of the insulating film 87. The semiconductor laser element 33 further includes a cathode electrode 99. The cathode electrode 99 is provided on the back surface 50 b of the semiconductor substrate 50.

  The configuration of the semiconductor laser element 33 that outputs green laser light has been described with reference to FIGS. 3 and 4. However, the semiconductor laser element 31 that outputs red laser light and the semiconductor laser element 32 that outputs blue laser light are described. The cross-sectional structure is also substantially the same as that of the semiconductor laser element 33. However, the semiconductor substrate of the semiconductor laser element 31 is preferably a GaAs substrate, and each semiconductor layer grown thereon is preferably an AlGaInAsP-based semiconductor layer. For example, the active layer may be made of InGaP. The semiconductor substrate of the semiconductor laser element 32 is preferably a GaN substrate, and each semiconductor layer grown thereon is preferably an InAlGaN-based semiconductor layer. However, this InAlGaN-based semiconductor layer may be grown on the c-plane of the GaN substrate.

  In the illuminating device 1A of the present embodiment described above, the semiconductor laser device 30A outputs the mixed color laser beam L including at least the red laser beam, the blue laser beam, and the green laser beam. By irradiating the light L, the object can be visually recognized as the original red color. Further, by adjusting the chromaticity of the mixed-color laser beam L by the control circuit 40, various illumination colors for entertaining passersby can be realized.

  In addition, according to the lighting device 1A of the present embodiment, a brighter color than the conventional white LED can be provided by the so-called Helmholtz-Kohlrausch phenomenon. The Helmholtz-Colllaus effect is the color light (high chroma and high half-width of the spectrum) even if the intensity of the light that physically hits the retina (retinal illuminance / brightness) is the same. The brightness that is visually recognized changes depending on the degree of purity. That is, when the purity of the colored light is high (when the saturation is high), it feels bright, and when the purity of the colored light is low (when the saturation is low), it feels dark. In addition, when comparing high-saturation light and achromatic light with the same luminance rate, the high-saturation light appears to be a brighter color. Note that yellow is less effective than red or blue-violet.

The Helmholtz-Cole Rauch effect is also called the L / Y effect or the B / L effect (in the case of colored light), and the effect increases as this value increases.
-L / Y effect: ratio of lightness (brightness) to Y value (luminance rate) of tristimulus values-B / L effect: ratio of brightness (brightness) to luminance (luminance) Lightness is a white surface or The brightness of the sample surface, which is relatively judged compared to the brightness of colorless and transparent. Brightness refers to color perception related to the surface density of light that diverges in the direction of the observer.

  Further, as in this embodiment, the semiconductor laser device 30A is configured to supply current to the electrode 35a for supplying current to the optical resonator for generating red laser light and to the optical resonator for generating blue laser light. The electrode 35b for supplying and the electrode 35c for supplying an electric current to the optical resonator for generating the green laser light are provided, and the control circuit 40 supplies the current supplied to each of the electrodes 35a to 35c. It is preferable to adjust the chromaticity of the mixed-color laser beam L by individually controlling the amount. When the semiconductor laser device 30A and the control circuit 40 have these configurations, the chromaticity of the mixed-color laser beam L can be suitably adjusted.

(Second Embodiment)
FIG. 5 is a diagram illustrating an internal configuration of the light source unit 10B included in the illumination device according to the second embodiment of the present invention. The light source unit 10B receives power supply from the outside of the illumination device, and outputs a mixed color laser light L including at least red laser light, blue laser light, and green laser light. The light emitting end of the light source unit 10B is optically coupled to one end of the optical fiber 20, and the mixed color laser light L is emitted from the other end of the optical fiber 20 to the outside of the illumination device.

  Referring to FIG. 5, the light source unit 10B includes a semiconductor laser device 30B, a control circuit 41 that supplies power to the semiconductor laser device 30B, and a neutral density filter group 42.

  The semiconductor laser device 30B outputs a mixed color laser beam L including at least a red laser beam, a blue laser beam, and a green laser beam. The semiconductor laser device 30B has an external appearance such as a CAN package, for example, and includes at least three semiconductor laser elements 31 to 33 and Peltier elements 37 to 39 on which the semiconductor laser elements 31 to 33 are respectively mounted. Yes. Also, the semiconductor laser device 30B has a condenser lens 34. The form of the semiconductor laser elements 31 to 33, the oscillation wavelength, and the configuration around the condenser lens 34 are the same as those in the first embodiment described above. The Peltier elements 37 to 39 constitute a part of adjusting means for adjusting the chromaticity of the mixed color laser light L output from the semiconductor laser device 30B, and are temperature control means in this embodiment. The Peltier elements 37 to 39 control these temperatures while cooling the semiconductor laser elements 31 to 33, respectively.

  The semiconductor laser device 30B includes electrodes 35a to 35c for supplying current to the anodes of the semiconductor laser elements 31 to 33, an electrode 35d connected to the cathodes of the semiconductor laser elements 31 to 33, and Peltier elements 37 to 39. It has electrodes 35e-35g for supplying a drive current. These electrodes 35a to 35g are electrically connected to the control circuit 41 through metal wirings 36a to 36g.

  The control circuit 41 constitutes a part of the adjusting means in this embodiment, and adjusts the chromaticity of the mixed color laser light L output from the semiconductor laser device 30B. Specifically, by individually controlling the amount of current supplied to the Peltier elements 37 to 39 corresponding to each of the semiconductor laser elements 31 to 33, the respective temperatures of the semiconductor laser elements 31 to 33 are individually changed. The peak wavelengths of the red laser light, blue laser light, and green laser light output from are individually adjusted. The control circuit 41 preferably has an input means for adjusting the chromaticity by an operation input from the operator. In the present embodiment, the amount of current supplied from the control circuit 41 to the semiconductor laser elements 31 to 33 is constant.

  The neutral density filter group 42 is disposed between one end of the optical fiber 20 and the semiconductor laser device 30B. The neutral density filter group 42 includes at least three neutral density filters 42a to 42c corresponding to the red laser light, the blue laser light, and the green laser light output from the semiconductor laser device 30B. The red laser light, blue laser light, and green laser light are individually attenuated by the neutral density filter group 42, whereby the chromaticity of the mixed color laser light L can be changed.

  The light source unit 10B may include an optical attenuator instead of the neutral density filter group 42. By arranging the optical attenuator between one end of the optical fiber 20 and the semiconductor laser device 30B, the chromaticity of the mixed-color laser beam L can be changed in the same manner as described above.

  In addition to the method of providing the Peltier elements 37 to 39, as the temperature control means, for example, three heat sinks that are in contact with the semiconductor laser elements 31 to 33 are provided, and an air cooling fan is disposed opposite to the heat sink, and the air cooling is performed. You may change each temperature of the semiconductor laser elements 31-33 separately with the air volume of a fan. Even in such a system, the peak wavelengths of the red laser light, blue laser light, and green laser light output from the semiconductor laser elements 31 to 33 can be individually adjusted.

  In the illumination device 1B of the present embodiment described above, the semiconductor laser device 30B outputs the mixed laser beam L including at least the red laser beam, the blue laser beam, and the green laser beam. By irradiating the light L, the object can be visually recognized as the original red color. In addition, by adjusting the chromaticity of the mixed color laser light L by the Peltier elements 37 to 39, the control circuit 41, and the neutral density filter group 42, various illumination colors for entertaining passersby can be realized. . Moreover, according to the illuminating device 1B of this embodiment, a brighter color than the conventional white LED can be provided by the Helmholtz-Cole Rauch effect mentioned above.

  Further, as in the present embodiment, as the adjusting means, temperature control means (Peltier elements 37 to 39 and control circuit 41) for controlling the temperature of each of the semiconductor laser elements 31 to 33 of the semiconductor laser device 30B, and a neutral density filter group 42 (or optical attenuator) is more preferably provided. Since the adjusting means has these configurations, the chromaticity of the mixed-color laser beam L can be suitably adjusted. In particular, in applications where strict color reproducibility is required, in the method of the first embodiment (the chromaticity is adjusted by controlling the amount of current to the semiconductor laser elements 31 to 33), the semiconductor laser elements 31 to 33 themselves It is conceivable that the oscillation wavelength becomes longer by several nanometers due to the heat generation of, so that a method of adjusting the chromaticity by the neutral density filter group 42 (or the optical attenuator) as in the present embodiment is suitable.

(Third embodiment)
FIG. 6 is a diagram showing an overall configuration of a lighting apparatus 1C according to the third embodiment of the present invention. Referring to FIG. 6, lighting device 1 </ b> C includes light source unit 10 </ b> A (or 10 </ b> B) and optical fiber 21. The light source unit 10A (or 10B) receives power supply from the outside of the illumination device 1C, and outputs a mixed color laser light L including at least red laser light, blue laser light, and green laser light. The internal configuration of the light source unit 10A (or 10B) is the same as that of the first embodiment (or second embodiment) described above.

  The light emitting end of the light source unit 10 </ b> A (or 10 </ b> B) is optically coupled to one end of the optical fiber 20. In the present embodiment, the mixed color laser light L is emitted from the side surface of the optical fiber 20 to the outside of the illumination device 1C. As described above, the mixed color laser light L is emitted from the side surface of the optical fiber 20 so that a linear light source used for electrical decoration or the like can be suitably realized. The mixed color laser light L may be emitted from the side surface of the optical fiber 20 as in the present embodiment, or may be emitted from both the other end and the side surface of the optical fiber 20.

  Conventionally, there have been cases where LEDs are connected in series in order to realize a linear light source. However, in such a system, if one LED fails, the entire apparatus may not be usable. As in the present embodiment, when a semiconductor laser device is used as a light source and light is incident from one end of the optical fiber 21 and light is extracted little by little from the side, only the light source needs to be replaced even if the light source fails. , Less effort. Further, as described above, according to the illumination device 1C of the present embodiment, the chromaticity can be freely controlled. Furthermore, although only an array of point light sources can be realized with LEDs, a linear light source can be suitably realized with the lighting apparatus 1C.

  The lighting device according to the present invention is not limited to the above-described embodiment, and various other modifications are possible. For example, in each of the above embodiments, the semiconductor laser device has three semiconductor laser elements that respectively output red laser light, blue laser light, and green laser light. However, in the present invention, red laser light, blue laser light, and green laser light are provided. The semiconductor laser device may have one semiconductor laser element capable of outputting laser light, or an element capable of outputting two colors of laser light and another one of laser light can be output. You may combine with an element. The adjusting means in the present invention is not limited to the configuration of each of the above embodiments, and various configurations for adjusting the chromaticity of the mixed color laser light output from the semiconductor laser device can be applied.

  DESCRIPTION OF SYMBOLS 1A-1C ... Illuminating device, 10A, 10B ... Light source part, 20, 21 ... Optical fiber, 30A, 30B ... Semiconductor laser device, 31-33 ... Semiconductor laser element, 34 ... Condensing lens, 35a-35g ... Electrode, 36a ˜36 g, metal wiring, 37 ˜ 39, Peltier element, 40, 41, control circuit, 42, neutral density filter group, 42 a ˜ 42 c, neutral density filter, 50, semiconductor substrate, 50 a, main surface, 50 b, back surface, 53 ... n-type semiconductor layer, 55 ... n-type cladding layer, 57 ... active layer, 59 ... p-type cladding layer, 60 ... optical resonator, 60a, 60b ... resonance end face, 61 ... first light guide layer, 63 ... second Light guide layer, 67 ... electron blocking layer, 81 ... p-type contact layer, 85 ... anode electrode, 87 ... insulating film, 99 ... cathode electrode.

Claims (8)

Optical fiber,
A semiconductor laser device that is optically coupled to one end of the optical fiber and outputs mixed laser light including at least red laser light, blue laser light, and green laser light;
Adjusting means for adjusting the chromaticity of the mixed-color laser beam output from the semiconductor laser device,
The illumination device characterized in that the mixed color laser light is emitted to the outside from at least one of the other end and the side surface of the optical fiber. A first electrode for supplying current to the optical resonator for generating the red laser light, and a semiconductor laser device for supplying current to the optical resonator for generating the blue laser light. 2 and a third electrode for supplying a current to the optical resonator for generating the green laser light,
The adjusting means is a control circuit that adjusts the chromaticity of the mixed-color laser beam by individually controlling the amount of current supplied to each of the first, second, and third electrodes. The lighting device according to claim 1. The adjusting means is
Temperature control means for controlling the temperature of the semiconductor laser device;
The illumination device according to claim 1, further comprising a neutral density filter or an optical attenuator disposed between one end of the optical fiber and the semiconductor laser device.   The peak wavelength of the red laser light is included in a range of 600 [nm] to 700 [nm], and the peak wavelength of the blue laser light is included in a range of 430 [nm] to 480 [nm], 4. The illumination device according to claim 1, wherein a peak wavelength of the green laser light is included in a range of 500 [nm] or more and 550 [nm] or less. The semiconductor laser device includes a first semiconductor laser element that generates the red laser light, a second semiconductor laser element that generates the blue laser light, and a third semiconductor laser element that generates the green laser light. And
5. The illumination device according to claim 1, wherein each of the second and third semiconductor laser elements has an InAlGaN-based semiconductor layer grown on a GaN substrate. The semiconductor laser device includes a first semiconductor laser element that generates the red laser light, a second semiconductor laser element that generates the blue laser light, and a third semiconductor laser element that generates the green laser light. And
6. The illumination device according to claim 1, wherein the first semiconductor laser element has an AlGaInAsP-based semiconductor layer grown on a GaAs substrate.   The illumination device according to any one of claims 1 to 6, wherein the optical fiber uses quartz as a base material.   The lighting device according to claim 1, wherein the optical fiber is made of plastic.

Images