Light source system

Abstract

The present invention enables dimming and color adjustment, and improves color rendering. In a light source system (100), a first light source device (1) includes a first laser light source and emits first light (L1) of a first wavelength. A second light source device (2) includes a second laser light source and emits second light (L2) of a second wavelength that is a longer wavelength than the first wavelength. A distribution unit (3) distributes the first light (L1) emitted from the first light source device (1) to third light (L3) of a third wavelength that is a wavelength identical to the first wavelength, and distributes fourth light (L4) of a fourth wavelength that is a wavelength identical to the first wavelength. A wavelength conversion unit (4) emits fifth light (L5) that is excited by the third light (L3) and that has an emission peak at a fifth wavelength between the third wavelength and the second wavelength. A combined optical system (5) combines the second light (L2), the fourth light (L4), and the fifth light (L5). A control device (8) controls light output of the second light source device (2), and a distribution ratio of the third light (L3) and the fourth light (4) by the distribution unit (3).

Description

Light source system

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to light source systems, and more particularly to light source systems that include laser light sources.

[0002] Patent Document 1 discloses a display device including a red light source, a green light source, a blue light source, and a multiplexing prism. The display device disclosed in Patent Document 1 uses a red semiconductor laser as the red light source, a blue semiconductor laser as the blue light source, and an SHG (Second Harmonic Generation) laser as the green light source.

[0003] The configuration disclosed in Patent Document 1 is a configuration for a display device, and is not intended for use in lighting applications. It is difficult to use it as a lighting light source that is capable of dimming and color adjustment and requires a spectrum with high color rendering properties.

[0004] Japanese Patent Application Laid-Open No. 2007-156438

[0005] An object of the present disclosure is to provide a light source system that is capable of adjusting the brightness and color and improving the color rendering properties.

[0006] A light source system according to one aspect of the present disclosure includes a first light source device, a second light source device, a distributor, a wavelength converter, a combining optical system, and a control device. The first light source device includes a first laser light source and emits first light of a first wavelength. The second light source device includes a second laser light source and emits second light of a second wavelength longer than the first wavelength. The distributor distributes the first light emitted from the first light source device into third light of a third wavelength that is the same as the first wavelength and fourth light of a fourth wavelength that is the same as the first wavelength. The wavelength converter is excited by the third light and emits fifth light having an emission peak at a fifth wavelength between the third wavelength and the second wavelength. The combining optical system combines the second light, the fourth light, and the fifth light. The control device controls the optical output of the second light source device and the distribution ratio of the third light and the fourth light in the distributor.

[0007] FIG. 1 is a conceptual diagram of a light source system according to a first embodiment. FIG. 2A is a spectrum of light emitted from a first laser light source in the light source system. FIG. 2B is a spectrum including the spectrum of light emitted from the first laser light source in the light source system and the fluorescence spectrum of the wavelength conversion element of the wavelength conversion unit. FIG. 2C is a spectrum of light emitted from a second laser light source in the light source system. FIG. 3 is a configuration diagram of the light source system. FIG. 4 is a spectrum showing the spectral characteristics of a first dichroic mirror in the light source system and the first light emitted from a first light source device. FIG. 5 is a configuration diagram of a light source system according to a second embodiment.

[0008] The drawings described in the following embodiments 1, 2, etc. are schematic drawings, and the ratios of the sizes and thicknesses of the components in the drawings do not necessarily reflect the actual dimensional ratios.

[0009] First Embodiment A light source system 100 according to a first embodiment will be described below with reference to FIGS.

[0010] (1.1) Overview As shown in FIG. 1 , the light source system 100 includes a first light source device 1, a second light source device 2, a distributor 3, a wavelength converter 4, a combining optical system 5, and a control device 8. The first light source device 1 includes a first laser light source 10 (see FIG. 3 ) and emits a first light L1 having a first wavelength λ1 (see FIG. 2A ). The first wavelength λ1 of the first light L1 is the same as the wavelength of the light emitted from the first laser light source 10. The second light source device 2 includes a second laser light source 20 (see FIG. 3 ) and emits a second light L2 having a second wavelength λ2 (see FIG. 2C ) that is longer than the first wavelength λ1. The second wavelength λ2 of the second light L2 is the same as the wavelength of the light emitted from the second laser light source 20. The distributor 3 distributes the first light L1 emitted from the first light source device 1 into third light L3 having a third wavelength λ3 (see FIG. 2A ), which is the same wavelength as the first wavelength λ1, and fourth light L4 having a fourth wavelength λ4 (see FIG. 2A ), which is the same wavelength as the first wavelength λ1. The wavelength converter 4 is excited by the third light L3 and emits fifth light L5 having an emission peak at a fifth wavelength λ5 (see FIG. 2B ), which is between the third wavelength λ3 and the second wavelength λ2. The combining optical system 5 combines the second light L2, the fourth light L4, and the fifth light L5. The control device 8 controls the optical output of the second light source device 2 and the distribution ratio between the third light L3 and the fourth light L4 in the distributor 3.

[0011] (1.2) Configuration of Light Source System As shown in Fig. 3 , the light source system 100 includes a first light source device 1, a second light source device 2, a distributor 3, a wavelength converter 4, a combining optical system 5, and a control device 8. The light source system 100 also includes a first drive circuit 16 and a second drive circuit 26. The light source system 100 further includes a first plano-concave lens 15, a second plano-concave lens 25, and a second diffuser 27. The light source system 100 also includes a condenser lens 6 and a polarization direction converter 7.

[0012] The first light source device 1 includes a plurality (e.g., 24) of first laser light sources 10, a plurality (e.g., 24) of first collimator lenses 11, and a first plano-convex lens 14. The first light source device 1 further includes a first circuit board 12 and a first heat sink 13.

[0013] In the first light source device 1, a plurality of first laser light sources 10 are mounted on a first circuit board 12. The first circuit board 12 is, for example, a printed wiring board. The plurality of first laser light sources 10 are arranged in a matrix (for example, a 6×4 matrix) on the main surface of the first circuit board 12. The first heat sink 13 is connected to the first circuit board 12.

[0014] Each of the multiple first laser light sources 10 is, for example, a semiconductor laser with an emission wavelength of 440 nm or more and 470 nm or less. The multiple first laser light sources 10 are driven by a first drive circuit 16. The first wavelength λ1 of the first light L1 emitted from the first light source device 1 is the same as the wavelength of the light emitted from each first laser light source 10. Therefore, the first light L1 is blue light having a peak wavelength in the wavelength range of 440 nm or more and 470 nm or less. The blue light emitted from each of the multiple first laser light sources 10 is emitted as linearly polarized light.

[0015] The multiple first collimating lenses 11 correspond one-to-one to the multiple first laser light sources 10. Each of the multiple first collimating lenses 11 collimates the first light L1 emitted from the corresponding one of the multiple first laser light sources 10. The light collimated by the multiple first collimating lenses 11 passes through the convex surface (light incident surface) of the first plano-convex lens 14 and the flat surface (light exit surface) of the first plano-convex lens 14 and is emitted.

[0016] The second light source device 2 includes a plurality of (for example, 24) second laser light sources 20, a plurality of second collimator lenses 21, a second plano-convex lens 24, a second circuit board 22, and a second heat sink 23.

[0017] In the second light source device 2, a plurality of second laser light sources 20 are mounted on a second circuit board 22. The second circuit board 22 is, for example, a printed wiring board. The plurality of second laser light sources 20 are arranged in a matrix (for example, a 6×4 matrix) on the main surface of the second circuit board 22. The second heat sink 23 is connected to the second circuit board 22.

[0018] Each of the multiple second laser light sources 20 is, for example, a semiconductor laser with an emission wavelength of 630 nm or more and 650 nm or less. The second wavelength λ2 of the second light L2 emitted from the second light source device 2 is the same as the wavelength of the light emitted from each second laser light source 20. Therefore, the second light L2 is red light having a peak wavelength in the wavelength range of 630 nm or more and 650 nm or less. The red light emitted from each of the multiple second laser light sources 20 is emitted as linearly polarized light.

[0019] The second collimating lenses 21 correspond one-to-one to the second laser light sources 20. Each of the second collimating lenses 21 collimates the second light L2 emitted from the corresponding second laser light source 20 among the second laser light sources 20. The light collimated by the second collimating lenses 21 passes through the convex surface (light incident surface) of the second plano-convex lens 24 and the flat surface (light exit surface) of the second plano-convex lens 24, and is emitted.

[0020] The first plano-concave lens 15 is disposed between the first light source device 1 and the distribution unit 3 in the first direction D1. The first plano-concave lens 15 has a flat surface (light incident surface) and a concave surface (light exit surface), and is disposed such that, in the first direction D1, the flat surface of the first plano-concave lens 15 faces the first light source device 1 and the concave surface of the first plano-concave lens 15 faces the distribution unit 3. The lens diameter of the first plano-concave lens 15 is smaller than the lens diameter of the first plano-convex lens 14.

[0021] The second plano-concave lens 25 is disposed between the second light source device 2 and the combining optical system 5 in the first direction D1. The second plano-concave lens 25 has a flat surface (light incident surface) and a concave surface (light exit surface), and is disposed such that, in the first direction D1, the flat surface of the second plano-concave lens 25 is located on the second light source device 2 side and the concave surface of the second plano-concave lens 25 is located on the combining optical system 5 side. The lens diameter of the second plano-concave lens 25 is smaller than the lens diameter of the second plano-convex lens 24.

[0022] The distributor 3 includes a half-wave plate 32 (wave plate), a first diffuser 33, and a first dichroic mirror 31 (polarizing beam splitter). In the distributor 3, the half-wave plate 32, the first diffuser 33, and the first dichroic mirror 31 are arranged in this order from the first light source device 1 side in the first direction D1.

[0023] The half-wave plate 32 is a retardation plate that has a phase difference of approximately half a wavelength at the dominant wavelength of the first laser light source 10, and converts the polarization direction of the linearly polarized light that is incident on it. The half-wave plate 32 is disposed, for example, so that the S-polarized component and the P-polarized component of the light that is incident on the first dichroic mirror 31 are 80% and 20%, respectively, but the ratio of the S-polarized component to the P-polarized component is not limited to 80%:20% and may be, for example, 90%:10% or 70%:30%.

[0024] The first diffusion plate 33 diffuses the light incident from the half-wave plate 32 side by using the fine uneven shape of the light exit surface on the first dichroic mirror 31 side, and then emits the diffused light.

[0025] In the light source system 100, in a first direction D1, the first light source device 1, the first plano-concave lens 15, the half-wave plate 32, the first diffuser 33, the first dichroic mirror 31, and the polarization direction conversion unit 7 are arranged in this order: first light source device 1, first plano-concave lens 15, the half-wave plate 32, the first diffuser 33, the first dichroic mirror 31, and the polarization direction conversion unit 7. In the light source system 100, in a second direction D2 orthogonal to the first direction D1, the combining optical system 5, the first dichroic mirror 31, the condenser lens 6, and the wavelength conversion unit 4 are arranged in this order: combining optical system 5, first dichroic mirror 31, the condenser lens 6, and the wavelength conversion unit 4. The first dichroic mirror 31 reflects a portion of the first light L1 from the first light source device 1 and transmits the remaining portion. In the light source system 100, the light of the first light L1 emitted from the first light source device 1 that is reflected by the first dichroic mirror 31 toward the wavelength conversion unit 4 is the third light L3. Also, in the light source system 100, the light of the first light L1 emitted from the first light source device 1 that is transmitted through the first dichroic mirror 31 is the fourth light L4.

[0026] FIG. 4 shows the spectral characteristics of the first dichroic mirror 31 and the emission spectrum B1 of the light emitted from the first laser light source 10. The emission spectrum B1 of the light emitted from the first laser light source 10 is the same as the spectrum of the first light L1 emitted from the first light source device 1. The spectral characteristics of the first dichroic mirror 31 are shown in terms of transmittance versus wavelength. A1 in FIG. 4 shows the spectral characteristics for the P-polarized component, and A2 in FIG. 4 shows the spectral characteristics for the S-polarized component. The emission spectrum B1 is shown in terms of relative intensity versus wavelength. The dichroic mirror 31 reflects the S-polarized component of the first light L1 around a wavelength of 445 nm and transmits the P-polarized component. In the light source system 100, the third light L3 described above includes the S-polarized component of the first light L1 reflected by the first dichroic mirror 31, and the fourth light L4 described above includes the P-polarized component of the first light L1 transmitted through the first dichroic mirror 31.

[0027] The third light L3 (the S-polarized component of the first light L1 reflected by the first dichroic mirror 31) is collected by the condenser lens 6 and enters the wavelength conversion unit 4.

[0028] The wavelength converter 4 includes a first wavelength conversion element that is excited by the third light L3 and emits light having a wavelength of the fifth light L5. The third light L3 is, for example, blue light. The fifth light L5 is, for example, yellow light.

[0029] The wavelength conversion element included in the wavelength conversion unit 4 is excited by the third light L3 incident on the wavelength conversion unit 4, and the wavelength conversion unit 4 emits fifth light L5 including yellow light. The fifth light L5 is fluorescent light having light components over the entire wavelength range of 500 nm to 600 nm.

[0030] The wavelength conversion unit 4 includes, for example, a light-transmitting material portion and phosphor particles. In this case, the wavelength conversion unit 4 is formed from a mixture of the light-transmitting material portion and phosphor particles. In the wavelength conversion unit 4, a large number of phosphor particles are present in the light-transmitting material portion. The material of the light-transmitting material portion (light-transmitting material) is preferably a material with high transmittance to visible light. The light-transmitting material is, for example, a silicone-based resin. Examples of "silicone-based resin" include silicone resin and modified silicone resin. For example, yellow phosphor particles that emit yellow light can be used as the phosphor particles. The light (fluorescence) emitted from the yellow phosphor particles preferably has an emission spectrum with a peak wavelength in the wavelength range of 530 nm or more and 580 nm or less. The phosphor particles are, for example, Y ３ Al ５ O １２ : Ce ３＋ However, the present invention is not limited to this. ３ Al ５ O １２ : Ce ３＋ 1 shows an example of the spectrum of light emitted from the wavelength conversion unit 4 when excited.

[0031] As shown in Fig. 3, the light source system 100 further includes a glass substrate 41, a reflective film 42, and a motor 43. The glass substrate 41 is arranged so that its thickness direction is parallel to the second direction D2. The glass substrate 41 is connected to the rotation shaft of the motor 43. The motor 43 rotates the glass substrate 41. The reflective film 42 is interposed between the wavelength conversion unit 4 and the glass substrate 41 and is a dielectric multilayer film that reflects visible light. The wavelength conversion unit 4 is ring-shaped when viewed from the second direction D2. The outer edge of the glass substrate 41 is circular when viewed from the second direction D2.

[0032] The fifth light L5 emitted from the wavelength conversion unit 4 toward the condenser lens 6 is collimated by the condenser lens 6 and is emitted through the first dichroic mirror 31 and the combining optical system 5.

[0033] The polarization direction conversion unit 7 converts the P-polarized component (fourth light L4) of the first light L1 that has passed through the first dichroic mirror 31 into S-polarized light. The fourth light L4 converted into S-polarized light by the polarization direction conversion unit 7 is reflected by the first dichroic mirror 31 toward the second dichroic mirror 51.

[0034] The polarization direction conversion unit 7 includes a quarter-wave plate 18 and a reflector 19. In the light source system 100, the P-polarized fourth light L4 is incident on the quarter-wave plate 18. The quarter-wave plate 18 is a retardation plate that has a phase difference of approximately a quarter wavelength near the peak wavelength (also referred to as the dominant wavelength) of the light emitted from the first laser light source 10. In the light source system 100, the P-polarized fourth light L4 incident on the quarter-wave plate 18 is converted into circularly polarized light by the quarter-wave plate 18, has its phase inverted by the reflector 19, and is then polarized again by the quarter-wave plate 18 to become S-polarized light. The reflector 19 includes, for example, a glass substrate and a reflective film made of an aluminum film or a dielectric multilayer film formed on the glass substrate. The fourth light L4 converted into S-polarized light by the polarization direction conversion unit 7 is reflected by the first dichroic mirror 31 toward the second dichroic mirror 51.

[0035] In addition, in the light source system 100, in the first direction D1, the second light source device 2, the second plano-concave lens 25, the second diffuser plate 27 and the synthetic optical system 5 are arranged in the order of the second light source device 2, the second plano-concave lens 25, the second diffuser plate 27 and the synthetic optical system 5.

[0036] The second diffuser plate 27 diffuses the second light L2 incident from the second plano-concave lens 25 side by using the fine uneven shape of the light exit surface on the combining optical system 5 side, and then emits the second light L2.

[0037] The combining optical system 5 includes a second dichroic mirror 51. The second dichroic mirror 51 is disposed so as to be non-parallel to the first dichroic mirror 31. The second dichroic mirror 51 reflects the second light L2 from the second light source device 2 in the second direction D2 toward the opposite side from the first dichroic mirror 31, and transmits the fourth light L4 and the fifth light L5 incident from the first dichroic mirror 31 side in the second direction D2. Therefore, the combining optical system 5 emits white light Lw obtained by combining the second light L2, the fourth light L4, and the fifth light L5.

[0038] The light source system 100 further includes a drive unit 34 that rotates the half-wave plate 32 about the optical axis thereof. In the light source system 100, by rotating the half-wave plate 32, the intensity of the first light L1 emitted from the half-wave plate 32 can be controlled.

[0039] In the light source system 100, the control device 8 controls the first drive circuit 16, the second drive circuit 26, and the drive unit 34, respectively.

[0040] The control device 8 controls the first drive circuit 16, the second drive circuit 26, and the drive unit 34, for example, in accordance with a signal provided from an external device (e.g., an input signal instructing at least one of dimming and color adjustment). In the light source system 100, the control device 8 controls the first drive circuit 16 and the drive unit 34 to control the intensity of the first light L1 (blue light), the intensity of the third light L3 (blue light) incident on the wavelength conversion unit 4, the intensity of the fourth light L4 incident on the combining optical system 5, and the intensity of the fifth light L5 (yellow light) emitted from the wavelength conversion unit 4 and incident on the combining optical system 5. In the light source system 100, the control device 8 controls the second drive circuit 26 to control the intensity of the second light (red light) L2 incident on the combining optical system 5. In the light source system 100, the control device 8 controls the first drive circuit 16, the second drive circuit 26, and the drive unit 34, respectively, to adjust the dimming and color of the white light Lw emitted from the combining optical system 5. It is possible to change the color temperature of the white light Lw within a range of 3000 K to 6500 K, which is required as the color temperature of an illumination light source. Here, in the light source system 100, it is possible to change the chromaticity of the white light Lw along the blackbody locus.

[0041] The control device 8 includes a computer system. The computer system is primarily composed of a processor and memory as hardware. The functions of the control device 8 of the present disclosure are realized by the processor executing a program stored in the memory of the computer system. The program may be pre-recorded in the memory of the computer system, provided via a telecommunications line, or provided on a non-transitory recording medium readable by the computer system, such as a memory card, optical disk, or hard disk drive. The processor of the computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The integrated circuits, such as ICs and LSIs, are referred to by different names depending on the degree of integration, and include integrated circuits called system LSIs, very large-scale integrations (VLSIs), or ultra-large-scale integrations (ULSIs). Furthermore, field-programmable gate arrays (FPGAs), which are programmed after the LSI is manufactured, or logic devices that allow the reconfiguration of internal connections or internal circuit partitions of the LSI, can also be used as processors. The electronic circuits may be integrated into one chip or distributed across multiple chips. The chips may be integrated into one device or distributed across multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller is also composed of one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

[0042] In the light source system 100, the first drive circuit 16 is supplied with a power supply voltage from, for example, a first power supply circuit of the power supply unit. The second drive circuit 26 is supplied with a power supply voltage from, for example, a second power supply circuit of the power supply unit. The control device 8 is supplied with a power supply voltage from, for example, a third power supply circuit of the power supply unit. The first power supply circuit, the second power supply circuit, and the third power supply circuit are not included in the components of the light source system 100, but may be included therein.

[0043] (1.3) Summary The light source system 100 according to the first embodiment includes a first light source device 1, a second light source device 2, a distributor 3, a wavelength converter 4, a synthesizing optical system 5, and a control device 8. The first light source device 1 includes a first laser light source 10 and emits a first light L1 having a first wavelength λ1. The second light source device 2 includes a second laser light source 20 and emits a second light L2 having a second wavelength λ2 that is longer than the first wavelength λ1. The distributor 3 distributes the first light L1 emitted from the first light source device 1 into a third light L3 having a third wavelength λ3 that is the same as the first wavelength λ1, and a fourth light L4 having a fourth wavelength λ4 that is the same as the first wavelength λ1. The wavelength converter 4 is excited by the third light L3 and emits a fifth light L5 having an emission peak between the third wavelength λ3 and the second wavelength λ2. The combining optical system 5 combines the second light L2, the fourth light L4, and the fifth light L5. The control device 8 controls the optical output of the second light source device 2 and the distribution ratio between the third light L3 and the fourth light L4 in the distribution unit 3.

[0044] The light source system 100 according to the first embodiment is capable of adjusting the light intensity and color, and can also improve the color rendering properties.

[0045] Incidentally, when white light is realized by combining blue light emitted from a blue laser light source and yellow light emitted from a yellow phosphor (e.g., YAG phosphor), white light with a relatively high correlated color temperature (e.g., 6500 K) can be realized, but the range of 3000 K to 6000 K required for an illumination light source cannot be covered. Furthermore, even if the balance between the blue light emitted from the blue laser light source and the yellow light emitted from the yellow phosphor (e.g., YAG phosphor) is adjusted, the correlated color temperature of the resulting white light does not move along the blackbody locus. Furthermore, in order to realize white light with a relatively low color temperature, Eu-activated (Sr, Ca)AlSiN ３ (called "SCASN") or Eu-activated CaAlSiN ３ When a CASN (CasN) is used, the light emission efficiency is significantly reduced when high density excitation is performed with laser light.

[0046] Furthermore, the combined light of blue light emitted from a blue laser light source, green light emitted from a green laser light source, and red light emitted from a red laser light source has the problems of large speckle noise and low color rendering properties.

[0047] In the light source system 100 according to the first embodiment, the intensities of the first light L1 including blue light emitted from the first light source device 1 including the first laser light source 10, the fifth light L5 including yellow light emitted from the wavelength conversion unit 4, and the second light L2 including red light emitted from the second light source device 2 can be adjusted, and the correlated color temperature of the combined light emitted from the combining optical system 5 can be adjusted within a range of at least 3000 K to 5000 K. Correlated color temperature is used to represent the light color of a light source (here, the light source system 100) and is defined as the absolute temperature of blackbody radiation having chromaticity coordinates closest to the UV chromaticity coordinates of the light source. Correlated color temperature is defined in JIS Z8113:1998, IEC 60050-845, and the like. Correlated color temperature is a value determined, for example, according to the method for measuring correlated color temperature specified in JIS Z8725:1999. The chromaticity coordinates of the blackbody radiation closest to the chromaticity coordinates of the light source are found as the intersection point of a perpendicular line drawn from the chromaticity coordinate point of the light source to the blackbody radiation locus in the CIE 1960 UCS (uniform-chromaticity-scale) chromaticity coordinates.

[0048] In the light source system 100, the distributor 3 includes a half-wave plate 32, a polarizing beam splitter (first dichroic mirror 31), and a driver 34 that rotates the half-wave plate 32 about the optical axis of the half-wave plate 32. As a result, the light source system 100 according to the first embodiment can change the correlated color temperature of the combined light by adjusting the D ＵＶ It is possible to make the absolute value of D smaller. ＵＶ is defined in, for example, JIS Z8725-1999. ＵＶ is the deviation of the CIE 1960 UCS chromaticity coordinates from the blackbody radiation locus, d ＵＶ The value obtained by multiplying this by 1000 (D ＵＶ = 1000d ＵＶ ) d ＵＶ and D ＵＶtakes a positive value when the chromaticity coordinates of the white light Lw emitted from the light source (here, light source system 100) are above the blackbody radiation locus, and takes a negative value when they are below the blackbody radiation locus. In light source system 100, it is also possible to change the chromaticity coordinates of the combined light on the blackbody locus. "It is possible to change the chromaticity coordinates on the blackbody locus when changing the correlated color temperature of the combined light" means that D ＵＶ This means that

[0049] Furthermore, the light source system 100 can improve color rendering properties. "Improving color rendering properties" means, for example, improving the general color rendering index Ra.

[0050] Second Embodiment A light source system 100 according to a second embodiment will be described below with reference to FIG.

[0051] The light source system 100 according to the second embodiment differs from the light source system 100 according to the first embodiment in that the distribution unit 3 further includes a dimming device 35 (hereinafter also referred to as a first dimming device 35) and a dimming device 36 (hereinafter also referred to as a second dimming device 36). In the light source system 100 according to the second embodiment, components similar to those in the light source system 100 according to the first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0052] The first dimming device 35 is located between the first dichroic mirror 31 and the condenser lens 6 in the second direction D2.

[0053] The second dimming device 36 is located between the first dichroic mirror 31 and the polarization direction conversion unit 7 in the first direction D1.

[0054] The light source system 100 according to the second embodiment further includes a third drive circuit 351 that drives the first dimming device 35 and a fourth drive circuit 361 that drives the second dimming device 36 .

[0055] Each of the first dimming device 35 and the second dimming device 36 is, for example, a liquid crystal element (liquid crystal panel). The first dimming device 35 and the second dimming device 36 are controlled by a control device 8. The control device 8 controls the first dimming device 35 by controlling a third drive circuit 351. More specifically, the control device 8 controls the transmittance of the liquid crystal element constituting the first dimming device 35 to dim the third light L3 and the fifth light L5. The control device 8 controls the fourth drive circuit 361 to control the second dimming device 36. More specifically, the control device 8 controls the transmittance of the liquid crystal element constituting the second dimming device 36 to dim the fourth light L4. The control device 8 can also control the first dimming device 35 and the second dimming device 36 in accordance with the input signal described in the first embodiment.

[0056] The light source system 100 of embodiment 2 is equipped with a first dimming device 35 and a second dimming device 36, and thus is capable of dimming control with a smaller range of change in light output within the dimming range and color tuning control with a smaller range of change in chromaticity within the color tuning range compared to the light source system 100 of embodiment 1.

[0057] (Modifications) The above-described first and second embodiments are merely examples of various embodiments of the present disclosure. The above-described first and second embodiments can be modified in various ways depending on the design and the like as long as the object of the present disclosure can be achieved.

[0058] For example, the number of first laser light sources 10 included in the first light source device 1 is not limited to a plurality of numbers and may be 1. Furthermore, the number of second laser light sources 20 included in the second light source device 2 is not limited to a plurality of numbers and may be 1.

[0059] Furthermore, although the light source system 100 according to the second embodiment includes two dimming devices 35 and 36, it is sufficient that at least one of the two dimming devices 35 and 36 is included.

[0060] In the light source system 100 of the second embodiment, each of the first light modulating device 35 and the second light modulating device 36 is not limited to a liquid crystal element, and may be, for example, an electrophoretic element.

[0061] (Aspects) Based on the above-described first and second embodiments, the present specification discloses the following aspects.

[0062] A light source system (100) according to a first aspect includes a first light source device (1), a second light source device (2), a distributor (3), a wavelength converter (4), a combining optical system (5), and a control device (8). The first light source device (1) includes a first laser light source (10) and emits a first light (L1) having a first wavelength (λ1). The second light source device (2) includes a second laser light source (20) and emits a second light (L2) having a second wavelength (λ2) that is longer than the first wavelength (λ1). The distributor (3) distributes the first light (L1) emitted from the first light source device (1) into a third light (L3) having a third wavelength (λ3) that is the same as the first wavelength (λ1), and a fourth light (L4) having a fourth wavelength (λ4) that is the same as the first wavelength (λ1). The wavelength conversion unit (4) is excited by the third light (L3) and emits fifth light (L5) having an emission peak at a fifth wavelength (λ5) between the third wavelength (λ3) and the second wavelength (λ2). The combining optical system (5) combines the second light (L2), the fourth light (L4), and the fifth light (L5). The control device (8) controls the optical output of the second light source device (2) and the distribution ratio of the third light (L3) and the fourth light (L4) in the distribution unit (3).

[0063] The light source system (100) according to the first aspect is capable of adjusting the light intensity and color, and can improve color rendering properties.

[0064] In the light source system (100) according to the second aspect, in the first aspect, the first light (L1), the third light (L3), and the fourth light (L4) are each blue light, the second light (L2) is red light, and the fifth light (L5) is yellow light.

[0065] According to the light source system (100) of the second aspect, the fifth light (L5) is yellow light, so that it is possible to improve the color rendering properties of the white light (Lw).

[0066] In the light source system (100) according to the third aspect, in the first aspect, the first laser light source (10) includes a semiconductor laser having an emission wavelength of 440 nm or more and 470 nm or less, the second laser light source (20) includes a semiconductor laser having an emission wavelength of 630 nm or more and 650 nm or less, and the wavelength conversion unit (4) is excited by the third light (L3) to emit fluorescence having light components over the entire wavelength range of 500 nm or more and 600 nm or less.

[0067] According to the light source system (100) of the third aspect, the fifth light (L5) emitted by the wavelength conversion unit (4) has light components over the entire wavelength range of 500 nm or more and 600 nm or less, thereby making it possible to improve the color rendering properties of the white light (Lw).

[0068] In a light source system (100) according to a fourth aspect, in any one of the first to third aspects, the distributor (3) includes a half-wave plate (32), a polarizing beam splitter (first dichroic mirror 31), and a driver (34). The driver (34) rotates the half-wave plate (32) around the optical axis of the half-wave plate (32).

[0069] According to the light source system (100) of the fourth aspect, it is possible to adjust the intensity of the first light (L1).

[0070] In the light source system (100) according to the fifth aspect, in any one of the first to third aspects, the distributor (3) includes a dimming device (35) that dims the third light (L3).

[0071] According to the light source system (100) of the fifth aspect, it is possible to perform dimming control with a smaller range of change in light output within the dimming range, and color tuning control with a smaller range of change in chromaticity within the color tuning range.

[0072] In the light source system (100) according to the sixth aspect, in any one of the first to third aspects, the distribution section (3) includes a dimming device (36) that dims the fourth light (L4).

[0073] According to the light source system (100) of the sixth aspect, it is possible to perform dimming control with a smaller range of change in light output within the dimming range, and color tuning control with a smaller range of change in chromaticity within the color tuning range.

[0074] In the light source system (100) according to the seventh aspect, in any one of the first to third aspects, the distribution unit (3) includes a first dimming device (35) that is a dimming device (35) that dims the third light (L3), and a second dimming device (36) that is a dimming device (36) that dims the fourth light (L4).

[0075] According to the light source system (100) of the seventh aspect, it is possible to perform dimming control with a smaller range of change in light output within the dimming range, and color tuning control with a smaller range of change in chromaticity within the color tuning range.

[0076] In the light source system (100) according to an eighth aspect, in any one of the fifth to seventh aspects, the dimming device (35; 36) is a liquid crystal element or an electrophoretic element.

[0077] In a light source system (100) according to a ninth aspect, in any one of the first to eighth aspects, the control device (8) controls each of the first light source device (1), the distribution unit (3), and the second light source device (2) according to an input signal instructing at least one of dimming and color adjustment.

[0078] According to the light source system (100) of the ninth aspect, the control device (8) appropriately controls each of the first light source device (1), the distribution unit (3), and the second light source device (2), thereby making it possible to achieve at least one of dimming and color adjustment according to an input signal.

[0079] REFERENCE SIGNS LIST 1 First light source device 10 First laser light source 2 Second light source device 20 Second laser light source 3 Distribution unit 31 First dichroic mirror (polarized beam splitter) 32 Half-wave plate 34 Driver 35 Light modulating device (first light modulating device) 36 Light modulating device (second light modulating device) 4 Wavelength conversion unit 5 Synthesis optical system 8 Control device 100 Light source system L1 First light L2 Second light L3 Third light L4 Fourth light L5 Fifth light Lw White light λ1 First wavelength λ2 Second wavelength λ3 Third wavelength λ4 Fourth wavelength λ5 Fifth wavelength

Claims

1. a first light source device including a first laser light source and configured to emit a first light having a first wavelength; a second light source device including a second laser light source and configured to emit second light having a second wavelength longer than the first wavelength; a distributor that distributes the first light emitted from the first light source device into a third light having a third wavelength that is the same as the first wavelength, and a fourth light having a fourth wavelength that is the same as the first wavelength; a wavelength converting unit that is excited by the third light and emits fifth light having an emission peak at a fifth wavelength between the third wavelength and the second wavelength; a combining optical system that combines the second light, the fourth light, and the fifth light; a control device that controls the light output of the second light source device and the distribution ratio of the third light and the fourth light in the distribution unit, Light source system.

2. each of the first light, the third light, and the fourth light is blue light; the second light is red light, the fifth light is a yellow light; The light source system of claim 1 .

3. the first laser light source includes a semiconductor laser having an emission wavelength of 440 nm or more and 470 nm or less; The second laser light source includes a semiconductor laser having an emission wavelength of 630 nm or more and 650 nm or less. The wavelength conversion unit is excited by the third light and emits fluorescence having light components over the entire wavelength range of 500 nm to 600 nm. The light source system of claim 1 .

4. The distribution unit includes: A half-wave plate; A polarizing beam splitter; A drive unit that rotates the half-wave plate around an optical axis of the half-wave plate. A light source system according to any one of claims 1 to 3.

5. The distribution unit includes: a dimming device for dimming the third light; A light source system according to any one of claims 1 to 3.

6. The distribution unit includes: a dimming device for dimming the fourth light; A light source system according to any one of claims 1 to 3.

7. The distribution unit includes: A first dimming device that dims the third light; A second dimming device that dims the fourth light. A light source system according to any one of claims 1 to 3.

8. The light control device is a liquid crystal element or an electrophoretic element.

6. The light source system of claim 5.

9. The control device controls the first light source device, the distribution unit, and the second light source device according to an input signal instructing at least one of dimming and color adjustment. A light source system according to any one of claims 1 to 3.