JP6626733B2 - Light emitting device, lighting device, and projection device - Google Patents

Description

  The present invention relates to a light-emitting device, a lighting device, and a projection device including a red laser diode that emits red laser light and a blue laser diode that emits blue laser light.

  In recent years, a light emitting device using a semiconductor laser (laser diode, also referred to as “LD”) as a light source has been known. Laser diodes have various advantages such as small size, high efficiency, long life, and small etendue (product of the size of the light source and the divergence angle). Therefore, by using a laser diode instead of a lamp or a light emitting diode, the efficiency and size of the device can be reduced.

  For example, as shown in FIG. 16, a multi-wavelength semiconductor laser device 100 disclosed in Patent Document 1 includes a two-wavelength laser 111 including a red LD 111a and an infrared LD 111b mounted on a submount 110, and a blue-violet laser. And an LD 112. As a result, information of CD (Compact Disk), DVD (Digital Versatile Disc), and BD (Blu-ray Disc: registered trademark) can be handled by one device, and the chip size can be reduced. That is, the oscillation wavelength of the LD for CD is 780 nm band (infrared), the oscillation wavelength of the LD for DVD is 650 nm band (red), and the oscillation wavelength of the LD for BD is 405 nm band (blue violet). Therefore, in order to handle CD, DVD, and BD information with one optical disk device, three light sources of infrared, red, and blue-violet are required.

JP 2013-16585 A (released on January 24, 2013)

  However, since the multi-wavelength semiconductor laser device 100 disclosed in the conventional patent document 1 is used for an optical disk device using three types of disks, each laser diode is driven independently and a monochromatic laser beam is emitted. Is emitted. Therefore, each laser diode cannot be driven simultaneously. In addition, since each laser diode has one light emitting point (emitter), there is a limitation in increasing the output of each laser diode.

  On the other hand, in a light emitting device used for a projector having a high luminous flux such as a projector, three colors of red (R), green (G), and blue (B) are required at the same time, and the light source output is increased. There is a need to.

  Here, at present, the light intensity characteristics of the red and green laser diodes are smaller than the performance of the blue laser diode, and the light intensity characteristics of the green laser diode are particularly small as compared with the performance of the blue laser diode. . Therefore, instead of using a green laser diode, by irradiating a green phosphor that emits green fluorescence using a blue laser diode, the laser light and the fluorescent light are mixed to efficiently combine white light. Projection devices are known.

  However, in order to obtain a sufficient light source output, it is necessary to increase the output of the red laser diode. For example, in order to obtain white light having a color temperature of 4800K, the ratio of RGB needs to be R: G: B = 3.5: 2: 1. Further, in order to achieve a space-saving and low-cost light emitting device, it is required to reduce the number of packages.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional problems, and has as its object to provide a space-saving and low-cost light emitting device and lighting device capable of appropriately combining white light using a plurality of types of laser diodes. , And a projection device.

  In order to solve the above problem, a light-emitting device according to one embodiment of the present invention is a light-emitting device including a first blue laser diode having at least one or more emitters and a red laser diode having at least two or more emitters. The number of emitters of the red laser diode is larger than the number of emitters of the first blue laser diode.

  Further, in order to solve the above problem, the lighting device according to one embodiment of the present invention includes the light emitting device, a second blue laser diode that emits blue laser light, and light emitted from the second blue laser diode. A green light emitting device having a green phosphor that emits green fluorescence upon receiving the blue laser light, and a red laser light emitted from the red laser diode and a blue laser emitted from the first blue laser diode. The light and the green fluorescent light are combined and emitted to the outside.

  Further, in order to solve the above problem, an illumination device according to one embodiment of the present invention includes the light emitting device, and the first blue laser is provided outside the common optical component in the light emitting device. A green phosphor that emits green fluorescence by being irradiated with the blue laser light emitted from the diode is provided, and the red laser light emitted from the red laser diode and the first blue laser diode emit light. The emitted blue laser light and the green fluorescence are combined and emitted to the outside.

  Further, in order to solve the above problem, a projection device according to one embodiment of the present invention includes the illumination device, and a projection member configured to receive light emitted from the illumination device and project an image. Features.

  According to one embodiment of the present invention, a space-saving and low-cost light-emitting device, lighting device, and projection device capable of appropriately combining white light with a plurality of types of laser diodes are provided.

1A is a side view illustrating a schematic configuration of a light emitting device according to Embodiment 1 of the present invention, and FIG. 2B is a perspective view illustrating a schematic configuration inside the light emitting device. 4 is a drive timing chart of each LD when the light emitting device emits pulsed light. It is a perspective view showing the schematic structure of the light emitting device in Embodiment 2 of the present invention. It is a perspective view showing the schematic structure of the modification of the above-mentioned light emitting device. It is a side view which shows the schematic structure of the illuminating device in Embodiment 3 of this invention. FIG. 2A is a side view showing a schematic configuration of the light emitting device, showing the periphery of an LD as viewed from a laser emission surface side, and FIG. 2B is a plan view showing a schematic configuration of the light emitting device. . FIG. 3 is an enlarged view of an emission end face of an LD of the light emitting device. It is a side view which shows the schematic structure of the illumination device in Embodiment 4 of this invention. It is a side view showing the composition of the phosphor wheel in the above-mentioned lighting device. FIG. 2A is a side view illustrating a schematic configuration of a light emitting device in the lighting device, and is a side view of a periphery of an LD viewed from a laser emission surface side, and FIG. 2B is a schematic configuration of the light emitting device. It is a top view. It is a side view which shows the schematic structure of the illumination device in Embodiment 4 of this invention. It is a side view showing the composition of the slit mirror wheel of the above-mentioned lighting device. 5 is a timing chart showing rotation of a slit mirror wheel of the illumination device, drive timing of an LD of a light emitting device, and a color of light emitted from the illumination device by the rotation of the slit mirror wheel. (A) is a side view which shows the schematic structure of the light emitting device in the illuminating device in Embodiment 5 of this invention, and which looked at the periphery of LD from the laser emission surface side, (b) of FIG. It is a top view which shows a schematic structure. It is a perspective view showing a schematic structure of a projection device in Embodiment 6 of the present invention. FIG. 11 is a perspective view illustrating a schematic configuration of a conventional multi-wavelength semiconductor laser device.

[Embodiment 1]
One embodiment of the present invention is described below with reference to FIG. In this embodiment, for example, a light-emitting device provided in a lighting device used for a projection device such as a projector will be described. However, the light-emitting device of the present invention is not necessarily limited to this. For example, by controlling the light distribution of the red laser light and the blue laser light with an optical element such as a lens or a mirror, the light can be used for various purposes such as lighting instead of the light emitting diode (LED).

  The light emitting device 1A of the present embodiment will be described with reference to FIGS. 1 (a) and 1 (b) and FIG. FIG. 1A is a side view illustrating a schematic configuration of a light emitting device 1A according to the first embodiment. FIG. 1B is a perspective view showing a schematic configuration inside the light emitting device 1A. FIG. 2 is a drive timing chart of each laser diode when the light emitting device 1A emits pulsed light.

  As shown in FIGS. 1A and 1B, a light emitting device 1A according to the present embodiment includes a disc-shaped stem 20, a cap 21 that covers components mounted on an upper surface of the stem 20, and a collimating lens. 22. Further, a red LD (Laser Diode) 12 that emits red laser light and a blue LD 13 that emits blue laser light are provided inside the sealed container.

  The sealing container as described above is generally called a CAN type, but the sealing container included in the light emitting device of the present invention is not limited to this. For example, a flat type or a structure in which a COB package is sealed with sheet glass or the like. It may be.

  The stem 20 supports the red LD 12 and the blue LD 13. The diameter of the stem 20 is larger than the diameter of the cap 21. The stem 20 and the cap 21 are made of a metal such as an Fe alloy, for example.

  In addition, a plurality of terminals 23 are provided on the bottom surface of the stem 20 so as to penetrate the stem 20. Electric power for driving the light emitting device 1A is supplied through the terminal 23.

  A base member 10 is mounted near the center of the upper surface of the stem 20. The base member 10 is formed of a metal having high thermal conductivity such as Cu. A submount 11 is fixed to one surface of the base member 10.

  A red LD 12 that emits red laser light and a blue LD 13 that emits blue laser light are mounted on the submount 11. The submount 11 uses AlN, but is made of a material having good thermal conductivity, such as ceramics such as SiC or diamond or Cu, and having no problem due to a difference in thermal expansion coefficient between the chip and the package. The submount 11 is a heat radiating plate for dissipating heat from the red LD 12 and the blue LD 13, and is also a support substrate for supporting the red LD 12 and the blue LD 13.

  Note that the red LD 12 and the blue LD 13 may have a structure in which one of the n-type cladding layer and the p-type cladding layer is shared.

  The red LD 12 and the blue LD 13 are covered by a cap 21, and an opening (not shown) through which a laser beam passes is formed in the center of the upper surface of the cap 21.

  Each of the red LD 12 and the blue LD 13 emits a laser beam from a laser emission end face which is an end face thereof. Therefore, the submount 11 supports the red LD 12 and the blue LD 13 such that the laser emission end face faces the opening. That is, the red LD 12 and the blue LD 13 are arranged such that the laser light emitted therefrom is emitted in the direction of the opening, that is, in the same direction.

  In the present embodiment, a single collimating lens 22 is joined to the upper surface of the cap 21 so as to cover the opening, but for example, glass that transmits laser light is joined and provided. Is also good.

  Here, when the red laser light and the blue laser light emitted from the light emitting device 1A are used for a lighting device, the intensity of the red laser light is important.

  For example, in order to use white light having a color temperature of 4800 K using light of wavelengths of 638 nm, 525 nm, and 445 nm as RGB, respectively, R: G: B = 3.5: 2: Must be 1.

  Therefore, in the light emitting device 1A of the present embodiment, at least the red LD 12 of the red LD 12 and the blue LD 13 is a multi-emitter LD having a plurality of red emitters. That is, the red LD 12 has at least two or more emitters. In order to increase the output of the red LD 12, it is conceivable to use a wide-striped emitter. However, the wide-striped emitter has a problem of heat and a problem that a refractive index distribution is formed inside.

  Normally, the temperature characteristics of the red LD 12 are poor, and the output of laser light per emitter of the red LD 12 is smaller than that of the blue LD 13. However, the total output of the laser light from the red LD 12 can be increased by using the multi-emitter as described above.

  In the light emitting device 1A of the present embodiment, the blue LD 13 may be a multi-emitter. In other words, it can be said that the blue LD 13 has at least one or more emitters.

  The light emitting device 1A of the present embodiment is configured such that the number of emitters of the red LD 12 is greater than the number of emitters of the blue LD 13 regardless of the case of the red LD 12 and the blue LD 13.

  Therefore, the intensity of the red laser light emitted from the light emitting device 1A can be increased. In other words, the ratio of the intensity of the red laser light to the intensity of the blue laser light in the laser light emitted from the light emitting device 1A can be increased.

  As described above, in the light emitting device 1A of the present embodiment, the red LD 12 and the blue LD 13 are provided in the same package, and the red laser light with respect to the intensity of the blue laser light in the laser light emitted from the light emitting device 1A. Can be increased. Therefore, a space-saving and low-cost light emitting device that can appropriately combine white light using a plurality of types of laser diodes can be provided.

  Further, the light emitting device 1A of the present embodiment further includes a control unit 24 that controls the operations of the red LD 12 and the blue LD 13. The control unit 24 is provided, for example, outside the package including the stem 20, the cap 21, and the collimating lens 22, and controls the red LD 12 and the blue LD 13 via the terminal 23.

  It is preferable that the control unit 24 controls the red LD 12 and the blue LD 13 to emit light simultaneously. Here, “emit light simultaneously” includes not only the case where the red LD 12 and the blue LD 13 emit light continuously and simultaneously, but also the case where each emits pulse laser light. That is, the control unit 24 may perform control such that the red pulse laser light from the red LD 12 and the blue pulse laser light from the blue LD 13 are generated alternately.

  In this case, the laser light emitted from the light emitting device 1A is either one of the red pulse laser light and the blue pulse laser light for a certain moment, but the other pulse laser light is emitted at the next moment. Is emitted. They are then repeated instantaneously at very short time intervals. Therefore, in this case, the red pulsed laser light and the blue pulsed laser light can be regarded as being generated simultaneously.

  Specifically, as an example, as illustrated in FIG. 2, the control unit 24 controls the red LD 12 and the blue LD 13 to emit laser light alternately at short time intervals. 2, the horizontal axis represents time, the upper side of the vertical axis represents ON and OFF of the blue LD 13, and the lower side of the vertical axis represents ON and OFF of the red LD 12. Here, the time when the control unit 24 controls the blue LD 13 to be ON and the red LD 12 to be OFF is referred to as time T0. In the following, it is assumed that the control unit 24 continues the control up to that point unless otherwise specified.

  The control unit 24 turns off the blue LD 13 at time T1, and turns on the red LD 12 at time T2, which is the next moment. Thus, blue laser light is emitted from time T0 to T1, and red laser light is emitted from time T2.

  Then, the control unit 24 turns off the red LD 12 at time T3 and turns on the blue LD 13 at time T4 which is the next moment. As a result, a red laser beam is emitted from time T2 to T3, and a blue laser beam is emitted from time T4.

  Thereafter, at times T5 and T6, the same control as at times T1 and T2 is performed. In this manner, the same control is repeated with time T1 to T5 or time T2 to T6 as one cycle.

  The control unit 24 controls one cycle of time T1 to T5 or time T2 to T6 to be repeated 180 times (180 Hz) per second, for example. The red pulse laser light and the blue pulse laser light that are instantaneously repeated at such a very short time interval can be regarded as emitting light at the same time. That is, the light emitting device 1A emits a mixed pulse laser beam in which a red pulse laser beam and a blue pulse laser beam that are repeated instantaneously are mixed, and the mixed pulse laser beam is a mixture of continuous laser beams. Visually indistinguishable from mixed laser light. Note that there is a momentary time lag between the times T1 and T2 in which both the blue LD 13 and the red LD 12 are turned off, but such a shorter moment does not matter.

  Therefore, the term “emit light simultaneously” in the present specification includes the case where the red LD 12 and the blue LD 13 emit pulsed laser light alternately as described above.

  Here, the control unit 24 determines that the time during which the red LD 12 is ON (for example, between time T2 and time T3) is longer than the time when the blue LD 13 is ON (for example, between time T4 and time T5). ) May be controlled to be longer. In this case, the ratio of the intensity of the red laser light to the intensity of the blue laser light in the mixed pulse laser light in which the red pulse laser light and the blue pulse laser light are mixed can be further increased.

  Thus, in the light emitting device 1A of the present embodiment, the red LD 12 and the blue LD 13 can emit light at the same time, and the laser light from the red LD 12 and the blue LD 13 can be emitted as mixed laser light. Here, when the mixed laser light emitted from the light emitting device 1A is used for a lighting device, as described above, the intensity of the red laser light in the mixed laser light is important.

  The light emitting device 1A of the present embodiment is configured such that the number of emitters of the red LD 12 is greater than the number of emitters of the blue LD 13 regardless of the case of the red LD 12 and the blue LD 13.

  Therefore, the intensity of the red laser light in the mixed laser light from the light emitting device 1A can be increased. In other words, the ratio of the intensity of the red laser light to the intensity of the blue laser light in the mixed laser light from the light emitting device 1A can be increased.

  As described above, in the light emitting device 1A of the present embodiment, the red LD 12 and the blue LD 13 are provided in the same package, and the red laser light with respect to the intensity of the blue laser light in the mixed laser light from the light emitting device 1A. Can be increased. Therefore, a space-saving and low-cost light emitting device that can appropriately combine white light using a plurality of types of laser diodes can be provided.

  Further, in the light emitting device 1A of the present embodiment, as described above, it is preferable that the single collimating lens 22 is provided on the upper surface of the cap 21 so as to cover the opening. The method of joining the cap 21 and the collimating lens 22 is not particularly limited, or another member may be inserted between the cap 21 and the collimating lens 22.

  In this case, the laser light emitted from each of the red LD 12 and the blue LD 13 is emitted toward the collimator lens 22.

  The collimating lens 22 is optically designed to appropriately collimate or condense the laser light. Therefore, the laser beams from the red LD 12 and the blue LD 13 are substantially collimated or condensed by one collimating lens 22 and emitted.

  Here, the collimating lens 22 is, for example, an aspherical lens. An aspheric lens for blue laser light has a problem in durability with plastic. Therefore, the collimating lens 22 is an expensive member, which is one of the factors that increase the manufacturing cost of the device.

  Therefore, in the light emitting device 1A of the present embodiment, the laser light from the red LD 12 and the blue LD 13 is emitted through the collimating lens 22 as a single lens provided only in one. That is, the collimator lens 22 is a common optical component of the red LD 12 and the blue LD 13. As the common optical component, other optical components (for example, a collimating mirror) that can collimate the laser beam can be used in addition to the collimating lens 22.

  As described above, in the light emitting device 1A of the present embodiment, it is preferable that the red LD 12 and the blue LD 13 are provided in the same package, and the collimating lens 22 is shared with them. Thereby, the manufacturing cost can be reduced. Further, since the number of parts can be reduced, the space of the apparatus can be reduced.

  Therefore, a space-saving and low-cost light-emitting device that can appropriately combine white light using a plurality of types of laser diodes can be provided.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIG. The configuration other than that described in the present embodiment is the same as that of the first embodiment. Further, for convenience of explanation, members having the same functions as those shown in the drawings of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The light emitting device 1A of the first embodiment is a small package in which the red LD 12 and the blue LD 13 are sealed by the stem 20, the cap 21, and the collimating lens 22. In the present embodiment, assuming that the red LD 12, the blue LD 13, and the common optical component are one set, the light emitting device 1B as a large package in which a plurality of sets are arranged in a large base in a matrix and accommodated. explain.

  The configuration of the light emitting device 1B of the present embodiment will be described with reference to FIG. FIG. 3 is a perspective view illustrating a schematic configuration of the light emitting device 1B.

  As shown in FIG. 3, the light emitting device 1B according to the present embodiment includes a laser light emitting unit 14 including a red LD 12 and a blue LD 13 and a collimating mirror 26 serving as a common optical component in a base 25. They are arranged in a matrix and housed.

  The base 25 has a hole 25a as a space for accommodating the plurality of laser light emitting units 14 and the collimating mirror 26. The hole 25 a has four sides and a bottom surface formed by the base 25, and the top surface is covered by the transparent sealing plate 27. The material forming the transparent sealing plate 27 is, for example, glass, but is not particularly limited as long as the material transmits the laser light from the laser emitting unit 14.

  Also, a plurality of submounts 28 are arranged in parallel in the hole 25a. On each of the submounts 28, a plurality of laser emitting units 14 are provided at intervals. For example, in the light emitting device 1B of the present embodiment, six submounts 28 are provided, and each submount 28 is provided with five laser light emitting units 14. That is, thirty laser emission units 14 are accommodated in a matrix. The number of the laser emitting units 14 is not limited to this.

  Each of the laser emitting units 14 includes one blue LD 13 and two red LDs 12 provided on both sides of the blue LD 13. The number of emitters of the red LD 12 is larger than the number of emitters of the blue LD 13. Therefore, the ratio of the intensity of the red laser light to the intensity of the blue laser light in the mixed laser light emitted from the light emitting device 1B can be increased.

  In addition, the number and arrangement of the red LD 12 and the blue LD 13 included in the laser light emitting unit 14 are not limited to these, and can be changed as appropriate.

  In the plurality of red LDs 12 included in the light emitting device 1B, the red laser light emitted from each of the red LDs 12 may have different center wavelengths selected from a range of 615 nm or more and 640 nm or less. In the plurality of blue LDs 13 included in the light emitting device 1B, the blue laser light emitted from each of the blue LDs 13 may have different center wavelengths selected from a range of 445 nm or more and 470 nm or less.

  Note that the “different center wavelengths” here mainly mean a center wavelength difference of 1 nm or more caused by intentional design, not a slight difference in center wavelength physically inevitable in each LD. are doing.

  By using laser beams having different center wavelengths as described above, speckle noise peculiar to light having high time coherence such as laser light can be reduced. In other words, when irradiating rough surfaces such as paper and walls with coherent light such as laser light and observing the reflected light or transmitted light, you can see bright and dark spot patterns that shine on the rough surfaces such as paper and walls. Can be. Such a speckled pattern is called speckle noise. This phenomenon is a random interference phenomenon that occurs when laser light is randomly scattered by the object and scattered waves overlap at each point on the observation surface. In order to prevent this interference phenomenon, it is preferable that the wavelengths of the laser beams emitted from the red LD 12 and the blue LD 13 are not uniform. Thereby, speckle noise can be reduced.

  The center wavelength of the red laser light is preferably 638 nm. At a center wavelength of 638 nm, a high-output red LD 12 is easily obtained.

  On the other hand, the center wavelength of the blue laser light is preferably 465 nm. At a center wavelength of 465 nm, a high-output blue LD 13 is easily obtained.

  Here, the laser light from the laser light emitting unit 14 provided on the submount 28 is emitted not in the upper surface of the hole 25a but in the lateral direction. Each is provided with a collimating mirror 26. Therefore, the laser light is reflected by the collimating mirror 26 and emitted through the transparent sealing plate 27 on the upper surface of the hole 25a.

  The collimating mirror 26 is optically designed to appropriately collimate or collect and reflect the laser light. Therefore, the laser light from each laser light emitting unit 14 is substantially collimated or condensed by one collimating mirror 26, reflected, and emitted from the light emitting device 1B.

  The collimating mirror 26 is an aspherical collimating mirror and is an expensive member. In the light emitting device 1B of the present embodiment, the red LD 12 and the blue LD 13 share the collimating mirror 26 in each laser light emitting unit 14. For this reason, manufacturing costs can be reduced.

  In addition, the light emitting device 1B of the present embodiment can emit high-power laser light by including the plurality of laser light emitting units 14. Further, with such a large package, a light-emitting device that emits high-power laser light in a small space can be obtained.

  Therefore, a space-saving and low-cost light-emitting device that can appropriately combine white light using a plurality of types of laser diodes can be provided.

(Modification)
A modification of the light emitting device 1B of the present embodiment will be described below with reference to FIG. For convenience of explanation, members having the same functions as those shown in the drawings of the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted. FIG. 4 is a perspective view illustrating a schematic configuration of a modified example of the light emitting device 1B.

  In the light emitting device 1B according to the second embodiment, the laser light from each of the laser light emitting units 14 is substantially collimated or condensed by the collimating mirror 26 and reflected and emitted. In the present modification, the laser light from each laser light emitting section 14 is substantially collimated or condensed by the collimating lens 22 and emitted.

  As shown in FIG. 4, the light emitting device 1B of this modification includes a plurality of laser light emitting units 14 arranged in a matrix in a hole 25a of a base 25. Are provided with a collimator lens 22 as a common optical component.

  For example, in the light emitting device 1B of the present modification, 20 (4 × 5) laser light emitting units 14 and corresponding 20 collimating lenses 22 are arranged in a matrix.

  In the light emitting device 1B of the present modification, the laser light emitting section 14 emits laser light in the direction of the upper surface of the hole 25a, and this laser light is substantially collimated or condensed by the collimating lens 22. Is emitted.

  In each laser light emitting section 14, since the red LD 12 and the blue LD 13 share the collimating lens 22, the manufacturing cost can be reduced. In addition, by providing a plurality of laser light emitting units 14, high-power laser light can be emitted. Further, with such a large package, a light-emitting device that emits high-power laser light in a small space can be obtained.

  Therefore, a space-saving and low-cost light-emitting device that can appropriately combine white light using a plurality of types of laser diodes can be provided.

[Embodiment 3]
Another embodiment of the present invention will be described below with reference to FIGS. The configuration other than what is described in the present embodiment is the same as that in the first and second embodiments. For convenience of explanation, members having the same functions as those shown in the drawings of the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted.

  The light emitting devices 1A and 1B of the first and second embodiments can emit a mixed laser beam of a blue laser beam and a red laser beam while increasing the intensity ratio of the red laser beam. there were. In the present embodiment, a light emitting device capable of emitting such a red laser beam with a high intensity ratio is provided, wherein the light emitting device defines a positional relationship between a red LD 12 and a blue LD 13 and a common optical component. 1C, and a lighting device 2 including a green phosphor 30 emitting green fluorescence and a green light emitting device 34 having a blue LD 31b for exciting the phosphor in a separate system will be described.

  Hereinafter, the configuration of the lighting device 2 of the present embodiment will be described first, and then the configuration of the light emitting device 1C included in the lighting device 2 will be described.

(Configuration of lighting device)
The configuration of the illumination device 2 of the present embodiment will be described with reference to FIG. FIG. 5 is a side view showing a schematic configuration of the lighting device 2.

  As shown in FIG. 5, the illumination device 2 of the present embodiment includes a light emitting device 1C, a green phosphor 30 that emits green fluorescence, and an excitation blue laser device that emits blue laser light that excites the green phosphor 30. 31 and two dichroic mirrors 32a and 32b for guiding each light of RGB. Here, the green phosphor 30 and the excitation blue laser device 31 are a green light emitting device 34 that emits green light. That is, in the lighting device 2 of the present embodiment, the light emitting device 1C including the red LD 12 and the blue LD 13 and the green light emitting device 34 including the second blue laser diode that emits green fluorescence by the green phosphor 30 Are configured as separate systems.

  Then, the illumination device 2 combines the red laser light and the blue laser light from the light emitting device 1C and the green fluorescent light from the green light emitting device 34 simultaneously and in the same direction, and emits them as white illumination light 33 to the outside. It is supposed to.

  The light emitting device 1C of the present embodiment has the same configuration as the light emitting device 1A and the light emitting device 1B described in the first and second embodiments, and has a red LD12, a blue LD13, and a collimating lens therein as described later. 22 is defined.

  A plurality of light emitting devices 1C are provided on the radiation fin 40 such that the stem 20 and the radiation fin 40 are in contact with each other. Therefore, a plurality of laser beams are emitted from the plurality of light emitting devices 1C. As a result, a high-flux laser beam can be emitted from the illumination device 2. Note that the light emitting device 1C may be provided with only one light emitting device.

  Here, it is preferable that the red laser beams emitted from each of the plurality of light emitting devices 1C have different center wavelengths selected from the range of 615 nm or more and 640 nm or less. That is, it is preferable that the center wavelengths of the red laser beams emitted from the respective light emitting devices 1C are slightly different from each other, and are different.

  Further, it is preferable that the blue laser beams emitted from each of the plurality of light emitting devices 1C have different center wavelengths selected from the range of 445 nm or more and 470 nm or less. That is, it is preferable that the center wavelengths of the blue laser beams emitted from the respective light emitting devices 1C are slightly different from each other, and are different.

  By using laser beams having different center wavelengths as described above, speckle noise can be reduced.

  The center wavelength of the red laser light is preferably 638 nm. At a center wavelength of 638 nm, a high-output red LD 12 is easily obtained.

  On the other hand, the center wavelength of the blue laser light from the blue LD 13 is preferably 445 nm or more and 470 nm or less, and more preferably 465 nm. At a center wavelength of 465 nm, a high-output blue LD 13 is easily obtained.

  In the case where the light emitting device 1C includes a plurality of red LDs 12, the red laser light emitted from each of the red LDs 12 has a different center wavelength selected from a range of 615 nm or more and 640 nm or less. May be. In the case where the light emitting device 1C includes a plurality of blue LDs 13, the blue laser light emitted from each of the blue LDs 13 has a different center wavelength selected from a range of 445 nm or more and 470 nm or less. May be. Thereby, speckle noise can be reduced.

  Note that the “different center wavelengths” here mainly mean a center wavelength difference of 1 nm or more caused by intentional design, not a slight difference in center wavelength physically inevitable in each LD. are doing.

  The radiation fins 40 can efficiently radiate the heat generated from the light emitting device 1C. Note that the radiation fins 40 are not an essential component.

  Hereinafter, red, blue, and green colors are respectively expressed as R, G, and B. For example, red laser light may be referred to as R laser light, and green fluorescence may be referred to as G fluorescence. Further, for example, a mixed laser light of a red laser light and a blue laser light is referred to as an RB mixed laser light. The same applies to other combinations. Note that the RB mixed laser light as an example also includes a case where the red laser light and the blue laser light are respectively emitted almost simultaneously as pulse laser lights and mixed as described above.

  A dichroic mirror 32a that transmits RB light and reflects G light is provided above the light emitting device 1C and on the optical path of the RB mixed laser light. The RB mixed laser light emitted from the light emitting device 1C passes through the dichroic mirror 32a, is mixed with the G fluorescence from the green light emitting device 34, and is emitted from the lighting device 2 as white illumination light 33.

  The green light emitting device 34 includes a green phosphor 30 and an excitation blue laser device 31 that emits blue laser light for exciting the green phosphor 30.

  The type, shape, composition, and the like of the fluorescent substance are not particularly limited as long as the green phosphor 30 contains a fluorescent substance that emits green fluorescence, but the fluorescent substance preferably has a high quantum yield. Examples of such a fluorescent substance include cerium-activated lutetium aluminum garnet (Ce: LuAG). Ce: LuAG emits green fluorescence at around 520 nm.

  The green phosphor 30 is provided on the radiation fin 41. Thereby, the heat generated by irradiating the green phosphor 30 with the laser beam for excitation can be efficiently dissipated. Note that the radiation fins 41 are not an essential component.

  The light emitting device 1 </ b> C according to the present embodiment includes an excitation blue laser device 31 for exciting the green phosphor 30. A plurality of excitation blue laser devices 31 may be provided, or only one may be provided.

  The blue laser device for excitation 31 has a configuration similar to that of the light emitting device 1C and includes a package including a stem 20, a cap 21, and a collimating lens 31a. An excitation blue LD 31b for emitting B laser light is provided in the package. The stem 20 and the cap 21 may be made of the same material as the light emitting device 1C, or may be different.

  The excitation blue laser device 31 is installed on the radiation fin 42. Thereby, the heat generated by emitting the excitation B laser light can be efficiently dissipated. Note that the radiation fins 42 are not an essential component.

  In the excitation blue laser device 31 as well, it is preferable that only one collimating lens 31a for substantially collimating or condensing the laser light is provided. Thereby, the manufacturing cost can be reduced.

  The center wavelength of the B laser light emitted from the excitation blue LD 31b is, for example, 445 nm, but is not limited thereto. The B laser light from the excitation blue LD 31b is substantially collimated or condensed by the collimating lens 31a of the excitation blue laser device 31, and is emitted from the excitation blue laser device 31.

  Another dichroic mirror 32b that transmits B light and reflects G light is provided on the optical path of B laser light (hereinafter, referred to as excitation B laser light) emitted from the excitation blue laser device 31. ing.

  Since the dichroic mirror 32b transmits B light, the excitation B laser light passes through the dichroic mirror 32b and travels straight without changing its direction. The green phosphor 30 is provided on the optical path of the excitation B laser light behind the dichroic mirror 32b, so that the excitation B laser light irradiates the green phosphor 30.

  The green phosphor 30 emits G fluorescence by the irradiation of the excitation B laser beam. The G fluorescence is applied to the dichroic mirror 32b. Here, it is preferable that a condenser lens 30a is provided above the green phosphor 30. The condenser lens 30a condenses the G fluorescence emitted radially from the green phosphor 30 and can efficiently emit the G fluorescence toward the dichroic mirror 32b.

  Note that a plurality of condenser lenses 30a may be provided. In this case, the G fluorescence can be accurately and efficiently condensed by transmitting through the plurality of condenser lenses 30a. it can.

  The G fluorescent light is reflected by the dichroic mirror 32b, and thereafter, the reflected G fluorescent light enters another dichroic mirror 32a and is reflected again. The G fluorescence reflected again is mixed with the RB mixed laser light from the light emitting device 1B, and is emitted from the lighting device 2 as white illumination light 33.

  The configuration of the optical path for synthesizing the RGB light and emitting it from the illumination device 2 as the white illumination light 33 is not limited to the above configuration. The position of each member and the number of dichroic mirrors can be changed as appropriate.

  Further, in the lighting device 2 of the present embodiment, a plurality of light emitting devices 1C may be provided as described above, or the light emitting device 1C may be large, like the light emitting device 1B of the second embodiment. May be provided as a package. Further, a configuration including a plurality of large packages may be employed.

  Note that the excitation blue laser device 31 may also be a package arranged in a matrix like the light emitting device 1C.

  As described above, the lighting device 2 of the present embodiment includes the light emitting device 1C and the green light emitting device 34. Hereinafter, a description will be given of a preferable configuration of the red LD 12 and the blue LD 13 included in the light emitting device 1C in the case of such a configuration, that is, a relationship between the collimator lens 22 as a shared optical component and the red LD 12 and the blue LD 13.

(Configuration of light emitting device)
The configuration of the light emitting device 1C according to the present embodiment will be described with reference to FIGS. FIG. 6A is a side view showing the schematic configuration of the light emitting device 1C, showing the periphery of the LD as viewed from the laser emission surface side. FIG. 6B is a plan view illustrating a schematic configuration of the light emitting device 1C. FIG. 7 is an enlarged view of the emission end face of the LD of the light emitting device 1C.

  As shown in FIGS. 6A and 6B, the light emitting device 1C of the present embodiment is provided with a base member 10, a submount 11 provided on the base member 10, and a submount 11. A red LD 12 and two blue LDs 13 are provided.

  Each of the red LD 12 and the blue LD 13 has an emitter as a laser light emitting point. This emitter has an elliptical shape as shown in FIG.

  The red LD 12 is a multi-emitter, and includes, for example, three emitters each having a diameter of 60 μm on the major axis side of the ellipse and 1 μm on the minor axis side. The output in this case is, for example, about 2 watts (W). The length from one end to the other end of the three arranged emitters is 260 μm.

  The blue LD 13 is a single emitter, and includes, for example, one emitter having a diameter of 35 μm on the major axis side of the ellipse and 1 μm on the minor axis side. The output in this case is, for example, about 3.5W.

  Normally, in focusing by a lens, the B laser light has a shorter focal length due to the difference in refractive index between the R laser light and the B laser light. This is known as chromatic aberration of the lens. From this viewpoint, it can be assumed that the blue LD 13 is installed on the side near the center axis A1 of the collimator lens 22 on the submount 11.

  However, in the light emitting device 1C of the present embodiment, the red LD 12 is disposed on the sub-mount 11 closer to the center axis A1 of the collimating lens 22 than the blue LD 13 is. That is, the optical axis of the red LD 12 and the central axis A1 of the collimator lens 22 are close to each other. The blue LD 13 is installed on both sides of the red LD 12.

  The above configuration of the light emitting device 1C of the present embodiment is based on the following reason.

  First, in order to emit the white illumination light 33 from the lighting device 2, the intensity of the R laser light in the RB mixed laser light needs to be increased as the light emitting device 1 </ b> C used in the lighting device 2.

  Further, since the red LD 12 is a multi-emitter, the apparent light emitting point of the red LD 12 is large. Therefore, the R laser beam from the red LD 12 has a horizontally long near-field pattern, which is the light intensity distribution at the beam emitting end of the semiconductor chip, and has a far-intensity light distribution, for example, at a location 1 m away from the semiconductor laser chip. The field pattern is a vertically long laser beam, that is, an elliptical laser beam. Here, “horizontal” indicates a major axis direction of the elliptical shape of the emitter in which the respective emitters are arranged on the emission end face of the red LD 12. In order to effectively couple the R laser light from the red LD 12 having such a large apparent light emission point to the collimator lens 22, it is preferable that the R laser light pass through the center of the collimator lens 22.

  For this reason, in the light emitting device 1C of the present embodiment, the red LD 12 is disposed on the side closer to the center axis A1 of the collimating lens 22. As a result, the R laser beam can be effectively collimated or focused by the collimating lens 22 effectively.

  In the light emitting device 1C, the number of emitters that emit B laser light is smaller than the number of emitters that emit R laser light.

  This makes it possible to increase the ratio of the intensity of the R laser light to the intensity of the B laser light in the RB mixed laser light.

  Further, on the submount 11, the emission end face of the blue LD 13 may be arranged farther from the collimating lens 22 than the emission end face of the red LD 12. As a result, the difference between the actual positional relationship between the blue LD 13 and the collimating lens 22 and the ideal focal position increases, and the intensity of the B laser light in the RB mixed laser light can be reduced. As a result, the ratio of the intensity of the R laser beam to the B laser beam in the RB mixed laser beam can be further increased.

  Therefore, the illumination device 2 using the light emitting device 1C easily emits white illumination light 33 of 6500K.

  As described above, according to the illumination device 2 including the light emitting device 1C of the present embodiment, in a configuration in which the blue LD that excites the green phosphor is provided in a separate system, white light can be appropriately applied using a plurality of laser diodes. A lighting device including a space-saving and low-cost light-emitting device that can be combined with a light-emitting device can be provided.

[Embodiment 4]
The following will describe still another embodiment of the present invention with reference to FIGS. The configuration other than what is described in the present embodiment is the same as in the first to third embodiments. Further, for convenience of explanation, members having the same functions as those shown in the drawings of the first to third embodiments are given the same reference numerals, and descriptions thereof will be omitted.

  The illumination device 2 according to the third embodiment includes a green light emitting device 34 having a green phosphor 30 and an excitation blue laser device 31 that emits an excitation B laser beam that excites the green phosphor 30. On the other hand, the illuminating device 3 of the present embodiment does not include the green light emitting device 34, and emits B laser light from the light emitting device 1D that defines the positional relationship between the red LD 12, the blue LD 13, and the collimating lens 22. , And is used for both the excitation of the green phosphor of the phosphor wheel 60 and the synthesis of white light.

(Configuration of lighting device)
The configuration of the illumination device 3 according to the present embodiment will be described with reference to FIGS. FIG. 8 is a side view showing a schematic configuration of the lighting device 3. FIG. 9 is a side view showing the configuration of the phosphor wheel 60 in the lighting device 3.

  As shown in FIG. 8, a lighting device 3 according to the present embodiment includes a light emitting device 1D, a phosphor wheel 60 on which a green phosphor that emits green fluorescence is mounted, and two dichroics that guide each light of RGB. Mirrors 61a and 61b and two mirrors 62a and 62b are provided. The illuminating device 3 emits white illumination light 33 in which the RB mixed laser light from the light emitting device 1D and the G fluorescent light from the phosphor wheel 60 are mixed simultaneously and in the same direction to the outside.

  In the light emitting device 1D of the present embodiment, in the same configuration as the light emitting device 1C described in the third embodiment, the positional relationship among the internal red LD 12, blue LD 13, and collimating lens 22 is defined as described later. It is a thing.

  A plurality of light emitting devices 1D are provided on the radiation fins 40 such that the stem 20 and the radiation fins 40 are in contact with each other. The light emitting device 1D may be provided as a large package like the light emitting device 1B of the second embodiment. Further, a configuration including a plurality of large packages may be employed. Thereby, a high-flux laser beam can be emitted.

  A dichroic mirror 61a that transmits RB light and reflects G light is provided on an optical path above the light emitting device 1D, and a fluorescent light extends along a straight line connecting the light emitting device 1D and the dichroic mirror 61a. A body wheel 60 is provided. Therefore, the RB mixed laser light emitted from the light emitting device 1D passes through the dichroic mirror 61a and proceeds to the phosphor wheel 60.

  As shown in FIG. 9, the phosphor wheel 60 includes a circular wheel 60a rotatable by a motor (not shown), a green phosphor portion 60b in which a green phosphor is arranged in an arc shape in a part of the wheel 60a, A transmission portion 60c is provided on a part of the wheel 60a on an arc and transmits light. The green fluorescent portion 60b and the transmissive portion 60c are respectively two arc-shaped regions obtained by dividing a circle having the same center as the wheel 60a.

  The green fluorescent section 60b includes a green phosphor that emits green fluorescence. The type of the green phosphor and the method and concentration of the green phosphor can be appropriately selected. For example, Ce: LuAG can be used as the green phosphor. The green phosphor may be applied to a substrate, for example, or may be mixed with glass.

  Preferably, the transmission section 60c is a transmission type holographic diffuser. According to this, it is possible to reduce the speckle noise of the RB mixed laser light passing through the transmission section 60c. In addition, the transmission part 60c may be provided with a diffusion plate, or may be a space in which nothing is provided and light is simply transmitted.

  The RB mixed laser light from the light emitting device 1D applied to the phosphor wheel 60 is applied to the green fluorescent portion 60b at a certain moment and transmitted through the transmitting portion 60c at another moment because the wheel 60a is rotating. I do. The green fluorescent portion 60b absorbs the B laser light of the RB mixed laser light and emits G fluorescence.

  That is, the B laser light of the RB mixed laser light from the light emitting device 1D passes through the phosphor wheel 60 at a certain portion, irradiates the green phosphor portion 60b of the phosphor wheel 60 with the remaining portion, and is absorbed by the green phosphor. It is supposed to be. The ratio of the B laser light in the RB mixed laser light to the B laser light is not particularly limited.

  On the other hand, the R laser light in the RB mixed laser light from the light emitting device 1D is substantially transmitted when the RB mixed laser light irradiates the green fluorescent portion 60b of the phosphor wheel 60. This is because the absorbance of the R laser light in the green fluorescent section 60b is small. Therefore, the R laser light in the RB mixed laser light is transmitted through the phosphor wheel 60.

  The G fluorescent light from the green fluorescent portion 60b of the phosphor wheel 60 is emitted in the direction of the dichroic mirror 61a and is reflected by the dichroic mirror 61a. Another dichroic mirror 61b is provided in the traveling direction of the reflected G fluorescence.

  The dichroic mirror 61b transmits G fluorescence and reflects RB light. Therefore, the G fluorescence reflected by the dichroic mirror 61a passes through the dichroic mirror 61b.

  On the other hand, the RB mixed laser light that has passed through the transmitting portion 60c of the phosphor wheel 60 is reflected by the mirrors 62a and 62b and travels to the dichroic mirror 61b. The RB mixed laser light is reflected by the dichroic mirror 61b.

  Thereby, the white illumination light 33 in which the G fluorescence and the RB mixed laser light are mixed is emitted from the dichroic mirror 61b.

  Note that a condenser lens 63 may be provided before and after the phosphor wheel 60. The RB mixed laser beam that enters and passes through the phosphor wheel 60 and the G fluorescence from the green fluorescence unit 60b are collected by the condenser lens 63. As a result, the efficiency of the lighting device 3 can be increased.

  Further, in the lighting device 3 of the present embodiment, the green phosphor is mounted on the phosphor wheel 60, but the lighting device of the present invention is not limited to this. That is, it is only necessary that the RB mixed laser light from the light emitting device 1D is irradiated to the green fluorescent member on which the green phosphor is mounted, and a part of the RB mixed laser light is absorbed by the green phosphor.

  As described above, the lighting device 3 of the present embodiment includes the light emitting device 1D and the phosphor wheel 60 on which the green phosphor that emits green fluorescence is mounted, and the green phosphor is emitted from the light emitting device 1D. B laser light. Hereinafter, a preferred configuration of the red LD 12 and the blue LD 13 included in the light emitting device 1D in such a configuration, that is, a relationship between the collimating lens 22 and the red LD 12 and the blue LD 13 will be described.

(Configuration of light emitting device)
The configuration of the light emitting device 1D according to the present embodiment will be described with reference to FIGS. FIG. 10A is a side view showing a schematic configuration of the light emitting device 1D in the illumination device 3 and showing the periphery of the LD as viewed from the laser emission surface side. FIG. 10B is a plan view illustrating a schematic configuration of the light emitting device 1D.

  As shown in FIGS. 10A and 10B, the light emitting device 1D of the present embodiment is provided with a base member 10, a submount 11 provided on the base member 10, and a submount 11. A red LD 12 and a blue LD 13 are provided.

  In the light emitting device 1C of the third embodiment, the red LD 12 is disposed on the sub-mount 11 closer to the center axis A1 of the collimating lens 22 than the blue LD 13 is. On the other hand, in the light emitting device 1D of the present embodiment, on the submount 11, the blue LD 13 is disposed closer to the center axis A1 of the collimating lens 22 than the red LD 12. That is, the optical axis of the blue LD 13 and the central axis A1 of the collimator lens 22 are close to each other. The red LD 12 is installed on both sides of the blue LD 13.

  In the light emitting device 1D of the present embodiment, in the lighting device 3, the B laser light emitted from the blue LD 13 is used for both synthesis of white light and excitation of the green phosphor of the phosphor wheel 60. Therefore, it is necessary to increase the output of the B laser light.

  Therefore, from the viewpoint of the chromatic aberration of the collimator lens 22, the blue LD 13 is installed at a position near the center axis A1 of the collimator lens 22. Thereby, the B laser light can be efficiently collimated or condensed efficiently. As a result, the intensity of the B laser light in the RB mixed laser light can be increased.

  Further, it is preferable that the laser light emitting end faces of the red LD 12 and the blue LD 13 supported on the submount 11 are on the same plane. As a result, the distance from the emission end faces of the red LD 12 and the blue LD 13 to the collimating lens 22 is slightly longer in the red LD 12, and the laser light is appropriately approximated by the collimating lens 22 using the chromatic aberration of the collimating lens 22. It can be collimated or focused.

  As described above, according to the illumination device 3 including the light emitting device 1D of the present embodiment, in a configuration in which the blue LD for exciting the green phosphor is not provided in a separate system, the white light is emitted by using a plurality of laser diodes. Can be appropriately combined with a space-saving and low-cost light-emitting device.

[Embodiment 5]
Another embodiment of the present invention will be described below with reference to FIGS. The configuration other than that described in the present embodiment is the same as that of the first to fourth embodiments. For convenience of explanation, members having the same functions as those shown in the drawings of the above-described first to fourth embodiments are given the same reference numerals, and descriptions thereof will be omitted.

  In the illumination device 3 according to the fourth embodiment, the green phosphor is provided in the green phosphor 60 b of the phosphor wheel 60. Further, the laser light from the light emitting device 1D may be either continuous light or pulsed light. On the other hand, the illuminating device 4 of the present embodiment is provided with a slit mirror wheel that alternately switches the state of transmitting and reflecting the laser light from the light emitting device 1D depending on time, The B laser beam transmitted through the slit mirror wheel excites the green phosphor 30 so that the green phosphor 30 emits G fluorescence. Further, the light emitting device 1D is different in that the R pulse laser light or the B pulse laser light is emitted at a controlled timing.

  The configuration of the illumination device 4 according to the present embodiment will be described with reference to FIGS. FIG. 11 is a side view showing a schematic configuration of the lighting device 4. FIG. 12 is a side view showing the configuration of the slit mirror wheel of the lighting device 4. FIG. 13 is a timing chart showing the rotation of the slit mirror wheel of the illumination device 4, the drive timing of the LD of the light emitting device 1D, and the color of the light emitted from the illumination device 3 by the rotation of the slit mirror wheel.

  Hereinafter, first, the configuration of the illumination device 4 of the present embodiment will be described, and in the description, the slit mirror wheel included in the illumination device 4 will also be described. Then, the control of the timing of the pulse laser beam from the light emitting device 1D and the rotation of the slit mirror wheel will be described in detail. Note that the configuration of the light emitting device 1D is the same as that of the fourth embodiment, and a description thereof will be omitted.

  Illumination device 4 of the present embodiment, as shown in FIG. 11, a light emitting device 1D, a slit mirror wheel 70 that transmits or reflects laser light emitted from light emitting device 1D at a timing, and a light transmitted through slit mirror wheel 70. And the dichroic mirrors 71a and 71b and the mirror 72 for guiding each of the RGB lights. The illumination device 4 combines the R pulse laser light and the B pulse laser light emitted from the light emitting device 1D as pulse laser light and the G fluorescence as the pulse light emitted from the green phosphor 30 as white illumination light 33. The light is emitted.

  Here, the R pulse laser light, the B pulse laser light, and the G fluorescence as the pulse light are emitted without overlapping in time. That is, at any given moment, only one of RGB light is emitted from the lighting device 4. However, the term “emit light simultaneously” in this specification refers to the case where each light of RGB is repeatedly and periodically emitted at a very short time interval as described in the first embodiment. Including.

  In the illumination device 4 of the present embodiment, a polarizing plate 73, a λ / 4 plate 74, a slit mirror wheel 70, and a dichroic mirror 71a are provided in this order on the optical path above the light emitting device 1D.

  The light emitting device 1D emits an R pulse laser beam or a B pulse laser beam at a timing described later.

  By providing the polarizing plate 73 and the λ / 4 plate 74 on the optical path of the laser light from the light emitting device 1D, the reflected light (return light) from the slit mirror wheel 70 does not return to the light emitting device 1D. Therefore, the possibility that laser oscillation becomes unstable can be reduced. This will be described.

  The polarizing plate 73 is, for example, a polarizing beam splitter (PBS). When PBS is used, the PBS transmits the P-polarized light of the incident laser light and reflects the S-polarized light. Therefore, a part of the laser light emitted from the light emitting device 1D is reflected by the PBS, changes its direction by 90 °, and travels, while another part is transmitted as the P-polarized laser light.

  The P-polarized laser light transmitted through the polarizing plate 73 is converted by the λ / 4 plate 74 into circularly polarized laser light. Then, the circularly polarized laser light enters the slit mirror wheel 70 and is transmitted or reflected. When the circularly polarized laser light is reflected by the slit mirror wheel 70, the circularly polarized laser light passes through the λ / 4 plate 74 again and goes to the polarizing plate 73. At this time, since the direction of rotation does not change even if the circularly polarized light is reflected by the mirror, two round trips of the phase difference of the λ / 4 plate 74 are added to obtain a total phase difference of 180 °. become. Due to this phase difference, the polarization direction of the laser beam reflected by the slit mirror wheel 70 and passing through the λ / 4 plate 74 is rotated by 90 ° with respect to the incident polarization direction. This makes it possible to prevent the reflected light from passing through the polarizing plate 73 and returning to the light emitting device 1D.

  Therefore, by installing the polarizing plate 73 and the λ / 4 plate 74, it is possible to reduce the possibility that the reflected light (return light) from the slit mirror wheel 70 returns to the light emitting device 1D and the laser oscillation becomes unstable. Can be.

  Here, as shown in FIG. 12, the slit mirror wheel 70 has a circular wheel mirror 70a rotatable by a motor (not shown) and an arc-shaped light transmitted through a part of the wheel mirror 70a. And a slit 70b as a space to be formed. Note that the slit 70b may have a configuration in which a substance that transmits light is provided.

  The slit 70b intermittently passes through the optical path of the laser beam from the light emitting device 1D when the wheel mirror 70a rotates. In other words, the position where the laser light from the light emitting device 1D is irradiated is such that the laser light is reflected in the case of the wheel mirror 70a and the laser light passes in the case of the slit 70b.

  Here, in the illumination device 4 of the present embodiment, as described later, when the position irradiated with the laser light from the light emitting device 1D is the slit 70b, the light emitting device 1D emits the B pulse laser light. Timing is controlled. Although the timing control will be described later, in short, the slit mirror wheel 70 reflects the R pulse laser beam or the B pulse laser beam and passes the B pulse laser beam depending on time.

  The R-pulse laser light or the B-pulse laser light reflected by the wheel mirror 70a is reflected by the polarizing plate 73 and travels to the dichroic mirror 72b. The dichroic mirror 72b transmits RB light and reflects G light. Therefore, the R-pulse laser light or the B-pulse laser light reflected by the polarizing plate 73 passes through the dichroic mirror 72b.

  On the other hand, the B-pulse laser light that has passed through the slit 70b travels to the dichroic mirror 71a. The dichroic mirror 71a transmits the B light and reflects the G light. For this reason, the B pulse laser light passes through the dichroic mirror 71a. The B pulse laser light transmitted through the dichroic mirror 71a enters the green phosphor 30 and excites the green phosphor 30. The G fluorescence emitted from the green phosphor 30 is reflected by the dichroic mirror 71a and travels to the mirror 72. The G fluorescence is reflected by the mirror 72, travels to the dichroic mirror 71b, and is reflected by the dichroic mirror 71b.

  As described above, the B-pulse laser light and the R-pulse laser light transmitted through the dichroic mirror 71b are combined with the G fluorescence reflected by the dichroic mirror 71b, and the white illumination light 33 is emitted from the illumination device 4. You.

  Next, control of the pulse laser light emitted from the light emitting device 1D and the rotation of the slit mirror wheel 70 in the illumination device 4 of the present embodiment will be described.

  The lighting device 4 further includes a control unit 75 for controlling the light emitting device 1D and a motor (not shown) for rotating the slit mirror wheel 70.

  The control unit 75 controls the rotation of the slit mirror wheel 70 and the emission timing of the pulse laser light from the red LD 12 and the blue LD 13 as shown in FIG. The horizontal axis in FIG. 13 represents time. The vertical axis of FIG. 13 indicates, in order from the top, (i) whether the position where the laser beam is irradiated is located on the slit 70b or the wheel mirror 70a of the slit mirror wheel 70, and (ii) when the blue LD 13 is ON and OFF. And (iii) which state of the red LD 12 is ON or OFF, and (iv) the color of light emitted from the lighting device 4 at a certain time.

  Here, the time point at which the irradiation position of the laser beam is the slit 70b and the blue LD 13 is controlled to be ON and the red LD 12 is controlled to be OFF is defined as time T10. At this time, the G fluorescence emitted from the green phosphor 30 is emitted from the illumination device 4. In the following, the control unit 75 continues the control up to that point unless otherwise specified.

  The control unit 75 controls the laser beam irradiation position to be the wheel mirror 70a at time T11. At this time, the blue LD 13 remains ON and the red LD 12 remains OFF. Thereby, the B laser light is emitted from the illumination device 4.

  The control unit 75 turns off the blue LD 13 at time T12, and turns on the red LD 12 at time T13 which is the next moment. Thereby, the R laser light is emitted from the lighting device 4.

  The control unit 75 turns off the red LD 12 at time T14, turns on the blue LD 13 at time T15 which is the next moment, and controls the laser beam irradiation position to be the slit 70b. Thereby, the G fluorescent light is emitted from the illumination device 3 of the present modification.

  Then, the control unit 75 performs the same control as the times T11, T12, and T13 at times T16, T17, and T18, respectively. That is, the control unit 75 repeats the same control with the times T11 to T16 as one cycle.

  The control unit 75 controls one cycle of the times T11 to T16 to be repeated, for example, 180 times (180 Hz) per second.

  The R laser light, the B laser light, and the G fluorescence that are instantaneously repeated at such very short time intervals can be regarded as emitting light at the same time.

  In addition, the control unit 75 appropriately controls the rotation of the slit mirror wheel 70 and the emission timing of the pulse laser light of the red LD 12 and the blue LD 13 to emit each of the RGB light emitted from the illumination device 4. The length of time can be adjusted. That is, the intensity ratio of each light of RGB in the illumination light 33 emitted from the illumination device 4 can be adjusted.

  Therefore, for example, by increasing the interval between the time T13 and the time T14 as in the control unit 75 in the present embodiment, the R light with respect to the B light and the G light in the illumination light 33 emitted from the illumination device 4 Can be increased.

  As described above, in the illuminating device 4 of the present embodiment, the control unit 75 appropriately controls the rotation of the slit mirror wheel 70 and the emission timing of the pulse laser light from the red LD 12 and the blue LD 13 so that the light emitting device The RB mixed pulse laser beam from 1D and the G fluorescence from the green phosphor 30 can be combined and emitted as illumination light 33.

  Further, by using the light emitting device 1D, the ratio of the intensity of the red laser light to the intensity of the blue laser light in the RB mixed pulse laser light from the light emitting device 1D can be increased.

  Then, the control unit 75 appropriately controls the rotation of the slit mirror wheel 70 and the emission timing of the pulse laser light of the red LD 12 and the blue LD 13 to adjust the emission time of each light in the RBG mixed pulse laser light. Accordingly, the ratio of the intensity of the R light to the B light and the G light in the illumination light 33 from the illumination device 4 can be further increased.

  Therefore, it is possible to provide a space-saving and low-cost lighting device capable of appropriately combining white light using a plurality of types of laser diodes.

[Embodiment 6]
Another embodiment of the present invention will be described below with reference to FIG. Configurations other than those described in the present embodiment are the same as those in the first to fifth embodiments. For convenience of explanation, members having the same functions as those shown in the drawings of the first to fifth embodiments are denoted by the same reference numerals, and description thereof is omitted.

  In the light emitting device 1D of the illumination device 3 according to the fourth embodiment, only one blue LD 13 is provided so that the central axis A1 of the collimator lens 22 and the optical axis are close to each other. On the other hand, the light emitting device 1E of the present embodiment is different in that three blue LDs 13 are provided.

  The lighting device of the present embodiment is the same as that of the fourth embodiment, and the description is omitted.

  The configuration of the light emitting device 1D according to the present embodiment will be described with reference to FIGS. FIG. 14A is a side view showing a schematic configuration of the light emitting device 1E in the illumination device according to the present embodiment, and the periphery of the LD viewed from the laser emission surface side. FIG. 14B is a plan view illustrating a schematic configuration of the light emitting device 1E.

  The light emitting device 1E of the present embodiment includes two red LDs 12 and three blue LDs 13a, 13b, and 13c on a submount 11, as shown in FIGS.

  The blue LD 13b is disposed on the submount 11 at a position near the center axis A1 of the collimator lens 22, and the blue LD 13a and the blue LD 13c are disposed on both sides of the blue LD 13b, respectively.

  A red LD 12 is provided on the side of the blue LDs 13a and 13c opposite to the blue LD 13b.

  Thereby, the light emitting device 1E can emit the B laser light from the blue LDs 13a, 13b, and 13c. As a result, the intensity of the B laser light in the RB mixed laser light from the light emitting device 1E can be further increased.

  The B laser light emitted from each of the blue LDs 13a, 13b, and 13c preferably has a different center wavelength selected from a range of 445 nm or more and 470 nm or less.

  Thus, the light emitting device 1E can prevent speckle noise from being generated by the B laser light from the blue LDs 13a, 13b, and 13c.

[Embodiment 7]
Another embodiment of the present invention will be described below with reference to FIG. The configuration other than that described in the present embodiment is the same as that of the first to sixth embodiments. Further, for convenience of explanation, members having the same functions as those shown in the drawings of Embodiments 1 to 6 are given the same reference numerals, and descriptions thereof are omitted.

  In the first to sixth embodiments, the light emitting devices 1A to 1E and the lighting devices 2 to 4 as one embodiment of the present invention have been described. In contrast, in the present embodiment, a projection device including a light emitting device and a lighting device will be described. In the present embodiment, a single-panel DLP (Digital Light Processing) (registered trademark) projector will be described as an example, but the projection apparatus of the present invention is not necessarily limited to this. For example, it can be used for a three-panel DLP projector, LCD projector, or LCOS projector.

  The configuration of the projection device 5 of the present embodiment will be described with reference to FIG. FIG. 15 is a perspective view illustrating a schematic configuration of the projection device 5.

  As shown in FIG. 15, the projection device 5 according to the present embodiment includes a lighting device 5a having a light emitting device therein, a DLP chip 80 on which light from the lighting device 5a is incident, and light from the DLP chip 80. And a projection optical system 81. The light enlarged by the projection optical system 81 is projected on the projection screen 72. Here, the lighting devices 5a may be the lighting devices 2 to 4 or may be those obtained by appropriately changing the lighting devices 2 to 4.

  The DLP chip 80 includes a digital micromirror device (DMD) 80a, and light from the lighting device 5a enters the DMD 80a and is reflected. The DMD 80a is a digital device in which many small mirrors for the number of pixels are formed on a semiconductor.

  Light from the DMD 80a is enlarged by the projection optical system 81 and projects an image on the projection screen 82.

  In this case, it is preferable that the light emitted from the illumination device 5a is RGB pulse light. Each of the RGB pulse lights enters the DMD 80a, and the mirror of the DMD 80a is controlled corresponding to each of the RGB pulse lights to produce an image.

  Although the projection device 5 of the present embodiment is a single-panel type, when pulse light is emitted from the illumination device 5a, it is not necessary to perform color separation of white light using a color filter or the like. Therefore, the projection device 5 can project an image on the projection screen 82 with high efficiency.

  In addition, since a color filter or the like for performing color separation is not required, the size of the projection device 5 can be reduced.

  Therefore, it is possible to provide a projection device including a lighting device having a space-saving and low-cost light emitting device that can appropriately combine white light using a plurality of laser diodes.

  In addition, continuous light may be emitted from the illumination device 5a, and the projection device 5 may be configured to include a color filter, or the projection device 5 may be a projector of another type described above.

[Summary]
The light emitting device 1A according to the first aspect of the present invention is a light emitting device including a first blue laser diode (blue LD13) having at least one or more emitters and a red laser diode (red LD12) having at least two or more emitters. The number of emitters of the red laser diode (red LD12) is larger than the number of emitters of the first blue laser diode (blue LD13).

  According to the above invention, the light emitting device has the red laser diode and the first blue laser diode provided in the same package, and the red laser with respect to the intensity of the blue laser light in the laser light emitted from the light emitting device. The ratio of light intensity can be increased.

  That is, conventionally, a red laser diode that emits red laser light and a first blue laser diode that emits blue laser light are provided in the same package, and the number of emitters of the red laser diode is equal to that of the first blue laser diode. No light emitting device had more than the number of emitters.

  Therefore, according to the present invention, it is possible to provide a space-saving and low-cost light-emitting device that can appropriately combine white light using a plurality of types of laser diodes.

  The light emitting device 1A according to aspect 2 of the present invention is the light emitting device according to aspect 1, wherein the red laser light emitted from the red laser diode (red LD12) and the blue laser emitted from the first blue laser diode (blue LD13). It is preferable to include a common optical component (collimating lens 22 and collimating mirror 26) that emits light together with the light.

  According to the invention, in the light emitting device, the red laser diode that emits red laser light and the first blue laser diode that emits blue laser light share one optical component. Then, the red laser diode and the first blue laser diode are simultaneously turned on. Thereby, the mixed laser light obtained by combining the red laser light and the blue laser light is substantially collimated or condensed by the common optical component and emitted.

  That is, conventionally, there is no light emitting device that shares one optical component with a red laser diode that emits red laser light and a first blue laser diode that emits blue laser light, and simultaneously turns on both.

  In the present invention, at least the red laser diode of the red laser diode and the first blue laser diode has a plurality of emitters. As a result, the ratio of the intensity of the red laser light to the intensity of the blue laser light in the mixed laser light can be increased.

  In addition, the number can be reduced by sharing expensive optical components.

  Therefore, it is possible to provide a space-saving and low-cost light emitting device that can appropriately combine white light using a plurality of types of laser diodes.

  The light-emitting devices 1A and 1C according to aspect 3 of the present invention are the light-emitting devices according to aspect 2, wherein the red laser diode (red LD12) is compared with the first blue laser diode (blue LD13). It may be arranged on the center axis A1 side of the collimating lens 22 / collimating mirror 26).

  According to the above invention, the red laser light from the red laser diode of the multi-emitter in which the light intensity distribution of light emission has an elliptical shape can be effectively utilized by utilizing the chromatic aberration of the common optical component. By substantially collimating or condensing, the ratio of the intensity of the red laser light to the intensity of the blue laser light in the mixed laser light can be further increased.

  The light-emitting devices 1A and 1C according to aspect 4 of the present invention are the light-emitting devices according to aspect 2 or 3, wherein the emission end face of the first blue laser diode (blue LD13) is higher than the emission end face of the red laser diode (red LD12). May be arranged away from the common optical components (the collimator lens 22 and the collimator mirror 26).

  Since the first blue laser diode has a shorter wavelength of emitted light than the red laser diode, from the viewpoint of the focal position of the common optical component, the blue laser diode originally exists closer to the red laser diode than the red laser diode. Is preferred.

  In the present invention, this is intentionally reversed. As a result, the difference between the actual positional relationship between the first blue laser diode and the shared optical component and the ideal focal position of the optical component increases, and the intensity of the blue laser light in the mixed laser light is reduced. Can be.

  Therefore, the ratio of the intensity of the red laser light to the intensity of the blue laser light in the mixed laser light can be further increased.

The light emitting devices 1A and 1C according to aspect 5 of the present invention are the light emitting device according to any one of aspects 1 to 4, wherein a plurality of the red laser diodes (red LD12) are provided.
The red laser light emitted from each of the red laser diodes (red LD 12) preferably has a different center wavelength selected from the range of 615 nm or more and 640 nm or less.

  That is, each red laser beam emitted from the plurality of emitters of the red laser diode has coherence, and so-called speckle noise occurs in which a bright and dark spot pattern appears brilliantly on the rough irradiation surface due to an interference phenomenon. In order to prevent this speckle noise, it is preferable that the light distribution of each red laser beam emitted from the plurality of red laser diodes is not uniform.

  Therefore, in the present invention, a plurality of red laser diodes are provided, and each red laser beam emitted from each red laser diode has a different center wavelength selected from a range of 615 nm or more and 640 nm or less. . As a result, it is possible to prevent speckle noise from being generated by each red laser beam emitted from each of the plurality of red laser diodes.

  The light emitting devices 1A and 1D according to aspect 6 of the present invention are the light emitting device according to aspect 2, wherein the first blue laser diode (blue LD13) is compared with the red laser diode (red LD12) by the common optical component (collimator). It may be arranged on the center axis A1 side of the lens 22 / collimating mirror 26).

  When the light-emitting device is used for a lighting device, characteristics required for the mixed laser light emitted from the light-emitting device may vary depending on the configuration of the lighting device. For example, in the case where the green phosphor is excited by using the blue laser light in the mixed laser light emitted from the light emitting device, it is necessary to increase the intensity of the blue laser light in the mixed laser light. .

  Therefore, in the present invention, the first blue laser diode is disposed on the central axis side of the common optical component. Thereby, the ratio of the intensity of the blue laser light to the intensity of the red laser light in the mixed laser light can be increased.

  In the light emitting devices 1A and 1D according to the seventh aspect of the present invention, the emission end face of the red laser diode (red LD12) and the emission end face of the first blue laser diode (blue LD13) may be on the same plane.

  According to the above invention, when the red laser light emitted from the red laser diode and the blue laser light emitted from the first blue laser diode are substantially collimated or condensed by the common optical component, chromatic aberration of chromatic aberration is reduced. The influence can be suppressed.

  The lighting device 2 according to aspect 8 of the present invention includes the light-emitting device according to any one of aspects 1 to 5, a second blue laser diode (a blue LD 31b for excitation) that emits blue laser light, and the second blue laser. And a green phosphor 30 that receives the blue laser light emitted from the diode (the excitation blue LD 31b) and emits green fluorescence. The red light emitted from the red laser diode (the red LD 12) is provided. The laser light, the blue laser light emitted from the first blue laser diode (blue LD 13), and the green fluorescent light are combined and emitted outside.

  In the lighting device of the present invention, a light emitting device including a red laser diode that emits red laser light and a first blue laser diode that emits blue laser light, a second blue laser diode that emits blue laser light, A green light emitting device having a green phosphor that emits green fluorescence upon receiving the blue laser light emitted from the second blue laser diode is configured as a separate system.

  In such a lighting device, the red laser diode and the first blue laser diode are provided in the same package, and the red laser with respect to the intensity of the blue laser light in the laser light emitted from the light emitting device. The light intensity ratio can be increased.

  Therefore, it is possible to provide a lighting device including a space-saving and low-cost light emitting device capable of appropriately combining white light using a plurality of types of laser diodes.

  The illuminating device 3 according to the ninth aspect of the present invention includes the light emitting device according to the second, sixth, or seventh aspect, and the light emitting device further includes the above-described common optical components (the collimating lens 22 and the collimating mirror 26) outside the light emitting device. A green phosphor (green fluorescent portion 60b) that emits green fluorescence by being irradiated with the blue laser light emitted from the first blue laser diode (blue LD13) is provided. The red laser light emitted from the red LD 12), the blue laser light emitted from the first blue laser diode (blue LD 13), and the green fluorescence are combined and emitted to the outside.

  In such a lighting device, in the light emitting device, the red laser diode and the first blue laser diode are provided in the same package. Further, since the blue laser light from the first blue laser diode is also used for exciting the green phosphor, a relatively high intensity is required. Even in such a case, by appropriately adjusting the intensity ratio between the blue laser light and the red laser light in the mixed laser light emitted from the light emitting device, it is possible to emit appropriate white light from the lighting device. it can.

  Therefore, it is possible to provide a lighting device including a space-saving and low-cost light emitting device that can appropriately combine white light using a plurality of types of laser diodes.

  The lighting device 3 according to aspect 10 of the present invention is the lighting device according to aspect 9, wherein a plurality of first blue laser diodes (blue LDs 13) of the light emitting device are provided, and the first blue laser diode (blue The blue laser light emitted from each of the LDs 13) preferably has different center wavelengths selected from the range of 445 nm or more and 470 nm or less.

  That is, each of the blue laser beams emitted from the plurality of first blue laser diodes has coherence, and a so-called speckle noise occurs in which a bright and dark spot pattern appears brilliantly on the rough irradiation surface due to an interference phenomenon. I do. In order to prevent the speckle noise, it is preferable that the light distributions of the blue laser beams emitted from the plurality of first blue laser diodes are not uniform.

  Therefore, in the present invention, the blue laser light emitted from each of the plurality of first blue laser diodes has a different center wavelength selected from the range of 445 nm or more and 470 nm or less. As a result, it is possible to prevent speckle noise from being generated by the blue laser light emitted from each of the plurality of first blue laser diodes.

  The lighting device according to an eleventh aspect of the present invention is the lighting device according to any one of the eighth to tenth aspects, wherein a plurality of the light emitting devices are provided, and the light emitting device is a package in which the light emitting devices are arranged in a matrix. Good.

  Accordingly, the lighting device is a package in which a plurality of the light emitting devices are arranged in a matrix, so that the lighting device is compact.

  Therefore, it is possible to provide a lighting device including a space-saving and low-cost light emitting device that can appropriately combine white light using a plurality of types of laser diodes.

  A projection device 5 according to an aspect 12 of the present invention includes the illumination device according to any one of the aspects 8 to 11, and a projection member (DLP chip 80) that receives light emitted from the illumination device and projects an image. It is characterized by having.

  According to the above invention, it is possible to provide a projection device that projects an image on a projection screen by using a projection member with light emitted from the illumination device.

  Therefore, it is possible to provide a projection device including a lighting device having a space-saving and low-cost light emitting device that can appropriately combine white light using a plurality of types of laser diodes.

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

1A to 1E Light-emitting device 2, 3, 4.5, 5a Illumination device 5 Projection device 12 Red LD (red laser diode)
13. Blue LD (first blue laser diode)
22 Collimating lens (common optical component)
26 Collimating mirror (common optical component)
24.75 control unit 30 green phosphor 31b blue LD for excitation (second blue laser diode)
34 green light emitting device 60 phosphor wheel 60b green phosphor (green phosphor)
80 DLP chip (projection member)
81 Projection optical system (projection member)

Claims (10)

A first blue laser diode having at least one or more emitters;
A red laser diode having at least two or more emitters,
The number of emitters of the red laser diode, rather multi than the number of the emitter of the first of the blue laser diode,
Further provided is a common optical component that emits together the red laser light emitted from the red laser diode and the blue laser light emitted from the first blue laser diode,
The light emitting device according to claim 1, wherein an emission end face of said first blue laser diode is arranged farther from said common optical component than an emission end face of said red laser diode . A first blue laser diode having at least one or more emitters;
A red laser diode having at least two or more emitters,
The number of emitters of the red laser diode is greater than the number of emitters of the first blue laser diode,
The red laser diode is provided in plurality,
A light emitting device, wherein the red laser light emitted from each of the red laser diodes has a different center wavelength selected from a range of 615 nm or more and 640 nm or less . The light emitting device according to claim 1 , wherein the red laser diode is disposed closer to a center axis of the common optical component than the first blue laser diode. 2. The light emitting device according to claim 1 , wherein the first blue laser diode is disposed closer to a central axis of the common optical component than the red laser diode. 3. The light emitting device according to claim 4 , wherein an emission end face of the red laser diode and an emission end face of the first blue laser diode are on the same plane. A light emitting device according to any one of claims 1 to 3 ,
A second blue laser diode that emits blue laser light, and a green light emitting device that has a green phosphor that emits green fluorescence by receiving the blue laser light emitted from the second blue laser diode,
A lighting device, wherein a red laser beam emitted from the red laser diode, a blue laser beam emitted from the first blue laser diode, and the green fluorescence are combined and emitted to the outside. A light-emitting device according to claim 1 , 4 or 5 ,
Outside the common optical component in the light emitting device, a green phosphor that emits green fluorescence by being irradiated with blue laser light emitted by the first blue laser diode is provided. A lighting device, wherein a red laser beam emitted from the red laser diode, a blue laser beam emitted from the first blue laser diode, and the green fluorescence are combined and emitted to the outside. A plurality of first blue laser diodes of the light emitting device are provided,
The illumination according to claim 7 , wherein the blue laser light emitted from each of the first blue laser diodes has a different center wavelength selected from a range of 445 nm or more and 470 nm or less. apparatus. A plurality of the light emitting devices are provided,
The lighting device according to any one of claims 6 to 8 , wherein the light emitting device is a package arranged in a matrix. The lighting device according to any one of claims 6 to 9 ,
A projection member that receives the light emitted from the illumination device and projects an image.

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