JP2013171623A - Light source device, and lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remarkably reduce color irregularities and luminance unevenness, in a light source device combining semiconductor light-emitting elements (solid light sources) and wavelength conversion elements (a wavelength conversion member).SOLUTION: A light source device includes: a ring-shaped wavelength conversion member 12 of the same thickness D as a disc-shape transparent member 11, arranged so as to surround an outer periphery of the disc-shape transparent member 11, and with a width H in a radial direction uniform along a circumferential direction of the disc-shape transparent member 11; and a solid light source 15 positioned spatially away from the disc-shape transparent member 11, emitting light of a given wavelength out of a wavelength region from ultraviolet to visible light as excitation light and letting the excitation light incident into a center part of the disc-shape transparent member 11.

Description

  The present invention relates to a light source device and an illumination device.

  In recent years, light source devices in which semiconductor light emitting elements such as LEDs and LDs and wavelength conversion elements such as phosphors are combined have started to become widespread, and their application ranges such as general lighting and automobile headlamps have expanded.

  Conventionally, light source devices as shown in Patent Document 1, Patent Document 2, and Patent Document 3 are known as light source devices that combine such semiconductor light emitting elements and wavelength conversion elements such as phosphors.

  FIG. 1 shows a light source device (illumination device) of Patent Document 1. Referring to FIG. 1, in this light source device (illumination device), a plurality of LED chips 120 are mounted on a mounting substrate 110 so as to be separated from each other, and fluorescent light is emitted around the LED chips 120 and in the gaps between the LED chips 120. A body part 130 is disposed. And the groove part 141 is provided in the site | part which covers the gap | interval between LED chips 120 among this fluorescent substance part 130. FIG. Thereby, the optical path length until the light radiated | emitted from LED chip 120 is radiated | emitted outside the fluorescent substance part 130 becomes substantially equal irrespective of the radiation | emission direction of light. Therefore, the ratio of the light converted into a different color by the phosphor portion 130 and the light not converted is substantially uniform regardless of the place, and thus color unevenness can be suppressed. Moreover, since the periphery of the LED chip 120 is covered with the phosphor part 130 without a gap, the light emitted from the side surface of the LED chip 120 also contributes to light emission by being converted into a different color by the phosphor. Therefore, high luminous efficiency can be obtained. As described above, the light source device (illumination device) of Patent Document 1 intends to provide an illumination device with little color unevenness and high luminous efficiency.

  FIG. 2 shows a light source device (light emitting module) of Patent Document 2. Referring to FIG. 2, in this light source device (light emitting module), the light wavelength conversion ceramic 258 converts the wavelength of light emitted from the semiconductor light emitting element 252. The light wavelength conversion ceramic 258 is provided so as to have a total light transmittance of 40% or more in the converted light wavelength region. The reflective film 260 is provided on the surface of the light wavelength conversion ceramic 258, and narrows the emission area of light that has passed through the light wavelength conversion ceramic 258 to be smaller than the light emission area of the semiconductor light emitting element 252. At this time, the reflective film 260 guides light so that light is emitted substantially parallel to the light emitting surface of the semiconductor light emitting element 252.

  FIG. 3 shows the light source device (illumination device) of Patent Document 3. Referring to FIG. 3, in this light source device (illumination device), an LED chip 310 that emits blue light, a mounting substrate 320 that is a base member on which the LED chip 310 is mounted via a submount member 330, and an LED chip A yellow phosphor, which is a fluorescent material that surrounds 310 and is excited by light emitted from the LED chip 310 and emits light of a color different from the emission color of the LED chip 310, is molded together with a transparent material (for example, a silicone resin). And a dome-shaped color conversion member 340 made of a molded product. The color conversion member 340 is formed so as to have a uniform thickness (thickness), but the mixed color light emitted from the color conversion member 340 according to the intensity distribution of the light emitted from the LED chip 310. The concentration distribution of the fluorescent material is given so as to eliminate the color unevenness.

JP 2011-60967 A WO2010 / 044240A publication JP 2007-35802 A

  As described above, the conventional example described above is intended to reduce color unevenness in a light source device in which a semiconductor light emitting element and a wavelength conversion element such as a phosphor are combined.

  By the way, in a light source device in which a semiconductor light emitting element and a wavelength conversion element are combined, improvement in brightness (light utilization efficiency) and reduction in color unevenness and brightness unevenness are in an inverse relationship. That is, there is a problem that when the light emitting area is widened so as to increase the light use efficiency, it is necessary to make the large area light with less color unevenness and luminance unevenness.

  Considering the light emitted from the semiconductor light emitting element, incident on a part of the wavelength conversion element, and emitted from the other part of the wavelength conversion element, in order to obtain light with less color unevenness and luminance unevenness, the optical path length of each light ray Must be equal. The spatial positional relationship between the entrance surface and the exit surface must be grasped by a solid angle. For this purpose, for example, as shown in Patent Document 3, the constituent elements have a shape with little angle dependency such as a sphere or a circle. Is required.

  When used as radiated light such as general illumination, the optical path length should be "almost" constant because it is scattered in the air unless it is a laser beam, and unevenness requirements (requirements to reduce unevenness in color and brightness) are Alleviated. However, in the case of an application that uses an optical system to irradiate and project a specific light distribution pattern such as a vehicular lamp, the optical path length must be exactly constant, and the unevenness requirement becomes very severe.

  In a form in which the semiconductor light emitting element and the wavelength conversion element are in close contact as shown in Patent Document 1 and Patent Document 2, it is necessary to dice the semiconductor element into a circle in order to satisfy the non-uniformity requirement, resulting in poor yield. End up.

  In addition, as shown in Patent Document 3, forming a wavelength conversion element into a hemispherical dome shape is effective in reducing color unevenness, but using a chip (semiconductor light emitting element) diced in a square shape. As a result, a brightness distribution (that is, a kind of brightness unevenness) is generated such that the top of the chip is brightest and becomes darker toward the periphery. Such a light source device having a luminance distribution is not suitable because it directly relates to the difficulty of light distribution design.

  The present invention provides a light source device and an illumination device capable of remarkably reducing color unevenness and luminance unevenness in a light source device in which a semiconductor light emitting element (solid light source) and a wavelength conversion element (wavelength conversion member) are combined. It is an object.

In order to achieve the above object, the invention described in claim 1 includes a disk-shaped transparent member,
The disk-shaped transparent member has the same thickness and is disposed so as to surround the outer periphery of the disk-shaped transparent member, and has a radial width along the circumferential direction of the disk-shaped transparent member. A ring-shaped wavelength conversion member that is uniform;
Located at a position spatially separated from the disk-shaped transparent member, emits light having a predetermined wavelength in a wavelength region from ultraviolet light to visible light as excitation light, and emits the excitation light to the disk-shaped transparent member. A solid light source incident on the center of the transparent member,
A light diffusion region for diffusing excitation light incident from the solid light source is provided at the center of the disc-shaped transparent member,
The disk-shaped transparent member and the ring-shaped wavelength conversion member are sandwiched between the disk-shaped transparent member and the ring-shaped wavelength conversion member from above and below in the thickness direction, and the disk-shaped transparent member and the A reflection member that reflects light that guides the ring-shaped wavelength conversion member is provided,
The ring-shaped wavelength converting member emits fluorescence having a wavelength longer than the emission wavelength of the solid light source by being excited by excitation light emitted from the solid light source and incident through the disk-shaped transparent member. It is characterized by containing various kinds of phosphors.

The invention according to claim 2 is a disk-shaped transparent member;
The disk-shaped transparent member has the same thickness and is disposed so as to surround the outer periphery of the disk-shaped transparent member, and has a radial width along the circumferential direction of the disk-shaped transparent member. A ring-shaped wavelength conversion member that is uniform;
Located at a position spatially separated from the disk-shaped transparent member, emits light having a predetermined wavelength in a wavelength region from ultraviolet light to visible light as excitation light, and emits the excitation light to the disk-shaped transparent member. A solid light source incident on the center of the transparent member,
A conical notch that reflects excitation light incident from a solid light source at a predetermined angle is provided at the center of the disk-shaped transparent member,
The ring-shaped wavelength converting member emits fluorescence having a wavelength longer than the emission wavelength of the solid light source by being excited by excitation light emitted from the solid light source and incident through the disk-shaped transparent member. It is characterized by containing various kinds of phosphors.

  According to a third aspect of the present invention, in the light source device according to the second aspect, the disk-shaped transparent member and the ring-shaped wavelength conversion member include the disk-shaped transparent member and the ring-shaped wavelength. It is characterized in that a reflecting member is provided that reflects light guided between the disk-shaped transparent member and the ring-shaped wavelength converting member by sandwiching the converting member from above and below in the thickness direction.

  According to a fourth aspect of the present invention, in the light source device according to any one of the first to third aspects, the excitation light from the solid light source is guided to the central portion of the disk-shaped transparent member. A light guide member is further provided.

  The invention according to claim 5 is an illumination device characterized by using the light source device according to any one of claims 1 to 4.

According to invention of Claim 1, Claim 4, Claim 5, a disk-shaped transparent member,
The disk-shaped transparent member has the same thickness and is disposed so as to surround the outer periphery of the disk-shaped transparent member, and has a radial width along the circumferential direction of the disk-shaped transparent member. A ring-shaped wavelength conversion member that is uniform;
Located at a position spatially separated from the disk-shaped transparent member, emits light having a predetermined wavelength in a wavelength region from ultraviolet light to visible light as excitation light, and emits the excitation light to the disk-shaped transparent member. A solid light source incident on the center of the transparent member,
A light diffusion region for diffusing excitation light incident from the solid light source is provided at the center of the disc-shaped transparent member,
The disk-shaped transparent member and the ring-shaped wavelength conversion member are sandwiched between the disk-shaped transparent member and the ring-shaped wavelength conversion member from above and below in the thickness direction, and the disk-shaped transparent member and the A reflection member that reflects light that guides the ring-shaped wavelength conversion member is provided,
The ring-shaped wavelength converting member emits fluorescence having a wavelength longer than the emission wavelength of the solid light source by being excited by excitation light emitted from the solid light source and incident through the disk-shaped transparent member. Including various types of phosphors,
In the disk-shaped transparent member, the excitation light from the solid light source incident on the center is guided by isotropically guiding in the radial direction regardless of the angle in the circumferential direction while repeating diffusion and reflection. The ring-shaped wavelength conversion member is incident on the ring-shaped wavelength conversion member (at this time, the distribution of light in the circumferential direction is uniform). From the member, the color-mixed light of the wavelength-converted light (fluorescence) and the excitation light is emitted only from the outer peripheral portion. At this time, the optical path length of the light (fluorescence, excitation light) in the ring-shaped wavelength conversion member is The ring-shaped wavelength converting member has a uniform width and thickness in the radial direction along the circumferential direction of the disk-shaped transparent member, and therefore, the color variation and luminance are constant. Unevenness can be significantly reduced.

Moreover, according to invention of Claim 2, Claim 3, Claim 4, Claim 5, a disk-shaped transparent member,
The disk-shaped transparent member has the same thickness and is disposed so as to surround the outer periphery of the disk-shaped transparent member, and has a radial width along the circumferential direction of the disk-shaped transparent member. A ring-shaped wavelength conversion member that is uniform;
Located at a position spatially separated from the disk-shaped transparent member, emits light having a predetermined wavelength in a wavelength region from ultraviolet light to visible light as excitation light, and emits the excitation light to the disk-shaped transparent member. A solid light source incident on the center of the transparent member,
A conical notch that reflects excitation light incident from a solid light source at a predetermined angle is provided at the center of the disk-shaped transparent member,
The ring-shaped wavelength converting member emits fluorescence having a wavelength longer than the emission wavelength of the solid light source by being excited by excitation light emitted from the solid light source and incident through the disk-shaped transparent member. Including various types of phosphors,
In the disk-shaped transparent member, the excitation light from the solid light source incident on the center is guided isotropically in the radial direction regardless of the angle in the circumferential direction while repeating reflection (total reflection). The ring-shaped wavelength conversion member (at this time, the distribution of light in the circumferential direction is uniform), and in the ring-shaped wavelength conversion member, part of the excitation light is wavelength-converted, and the ring-shaped wavelength conversion member From the wavelength conversion member, the color-mixed light of the wavelength-converted light (fluorescence) and the excitation light is emitted only from the outer peripheral portion. At this time, the optical path of the light (fluorescence, excitation light) in the ring-shaped wavelength conversion member The length is constant because the ring-shaped wavelength conversion member has a uniform width and thickness in the radial direction along the circumferential direction of the disk-shaped transparent member. -Brightness unevenness can be significantly reduced.

It is a figure which shows the conventional light source device. It is a figure which shows the conventional light source device. It is a figure which shows the conventional light source device. It is a figure which shows the 1st structural example of the light source device of this invention. It is a figure which shows the 2nd structural example of the light source device of this invention. It is a figure which shows the example of a preparation process of a disk-shaped transparent member and a wavelength conversion member. It is a figure which shows the example of a preparation process of a disk-shaped transparent member and a wavelength conversion member. It is a figure which shows an example of the illuminating device using the light source device of this invention. It is a figure which shows the modification of the light source device of this invention. It is a figure which shows the modification of the light source device of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  4A and 4B are diagrams showing a first configuration example of the light source device of the present invention. 4A is an overall cross-sectional view, and FIG. 4B is a disk-shaped transparent member and a ring-shaped wavelength conversion member disposed so as to surround the outer periphery of the disk-shaped transparent member. FIG.

Referring to FIGS. 4A and 4B, the light source device 10 includes a disk-shaped transparent member 11,
The disk-shaped transparent member 11 has the same thickness D and is disposed so as to surround the outer periphery of the disk-shaped transparent member 11, and has a radius along the circumferential direction of the disk-shaped transparent member 11. A ring-shaped wavelength conversion member 12 having a uniform width H in the direction;
The disc-like transparent member 11 is spatially separated, emits light having a predetermined wavelength in a wavelength region from ultraviolet light to visible light as excitation light, and emits the excitation light to the disc-like shape. And a solid light source (semiconductor light emitting element) 15 that is incident on the center of the transparent member 11.

  Here, in the first configuration example, a light diffusion region 13 for diffusing the excitation light incident from the solid light source 15 is provided at the center of the disk-shaped transparent member 11.

  Moreover, in this 1st structural example, the said disk-shaped transparent member 11 and the said ring-shaped wavelength conversion member 12 are made into thickness at the said disk-shaped transparent member 11 and the said ring-shaped wavelength conversion member 12. A reflecting member 14 is provided that reflects light guided between the disk-shaped transparent member 11 and the ring-shaped wavelength conversion member 12 sandwiched from above and below in the direction.

  The ring-shaped wavelength conversion member 12 is emitted from the solid light source 15 and is excited by the excitation light incident through the disk-shaped transparent member 11 and has a longer wavelength than the emission wavelength of the solid light source 15. It contains at least one phosphor that emits fluorescence.

  In the first configuration example, a light guide member 16 that guides the excitation light from the solid light source 15 to the center of the disk-shaped transparent member 11 is further provided.

  In the light source device 10 having such a configuration, the excitation light from the solid light source 15 is guided to the center of the disk-shaped transparent member 11 by the light guide member 16. In the disk-shaped transparent member 11, the excitation light from the solid light source 15 incident on the central portion is diffused by the light diffusion region 13, and the diffusion direction and the reflection in the disk-shaped transparent member 11 are repeated in the circumferential direction. Regardless of the angle, the light isotropically guided in the radial direction and enters the ring-shaped wavelength conversion member 12 (at this time, the distribution of light in the circumferential direction is uniform). In the ring-shaped wavelength conversion member 12, a part of the excitation light is wavelength-converted, and from the ring-shaped wavelength conversion member 12, the wavelength-converted light (fluorescence (for example, yellow light)) and excitation are excited only from the outer periphery. Mixed color light (white light) with light (for example, blue light) is emitted. At this time, the optical path length of light (fluorescence, excitation light) in the ring-shaped wavelength conversion member 12 is such that the ring-shaped wavelength conversion member 12 has a radial width H along the circumferential direction of the disk-shaped transparent member 11. In addition, since the thickness D is uniform, it is constant, thereby making it possible to significantly reduce color unevenness and luminance unevenness (at all positions on the outer periphery of the ring-shaped wavelength conversion member 12). (Same chromaticity and same brightness)

  FIGS. 5A and 5B are diagrams showing a second configuration example of the light source device of the present invention. 5A is an overall cross-sectional view, and FIG. 5B is a disk-shaped transparent member and a ring-shaped wavelength conversion member disposed so as to surround the outer periphery of the disk-shaped transparent member. In FIGS. 5 (a) and 5 (b), the same parts as those in FIGS. 4 (a) and 4 (b) are denoted by the same reference numerals.

Referring to FIGS. 5A and 5B, the light source device 20 includes a disk-shaped transparent member 21,
The disk-shaped transparent member 21 has the same thickness D and is disposed so as to surround the outer periphery of the disk-shaped transparent member 21, and has a radius along the circumferential direction of the disk-shaped transparent member 21. A ring-shaped wavelength conversion member 12 having a uniform width H in the direction;
The disc-shaped transparent member 21 is spatially separated, emits light having a predetermined wavelength in a wavelength region from ultraviolet light to visible light as excitation light, and the excitation light is emitted into the disc-like shape. And a solid light source 15 that is incident on the center of the transparent member 21.

  Here, in the second configuration example, a conical cutout 23 that reflects the excitation light incident from the solid light source 15 at a predetermined angle is provided at the center of the disk-shaped transparent member 21. 5 (in the example of FIGS. 5A and 5B, it is provided on the opposite side of the incident side of the excitation light from the solid light source 15 in the central portion of the disc-shaped transparent member 21), The predetermined angle is an angle at which the excitation light incident from the solid light source 15 is reflected so as to be totally reflected within the disc-shaped transparent member 21 and the ring-shaped wavelength conversion member 12 (so as to satisfy the condition of total reflection). It has become.

  The ring-shaped wavelength conversion member 12 is emitted from the solid light source 15 and is excited by the excitation light incident through the disk-shaped transparent member 11 and has a longer wavelength than the emission wavelength of the solid light source 15. It contains at least one phosphor that emits fluorescence.

  In the second configuration example, the light guide member 16 that guides the excitation light from the solid light source 15 to the center of the disk-shaped transparent member 21 is further provided.

  In the light source device 20 having such a configuration, the excitation light from the solid light source 15 is guided to the center of the disk-shaped transparent member 21 by the light guide member 16. In the disk-shaped transparent member 21, the excitation light from the solid light source 15 incident on the central portion is totally reflected by the conical cutout 23 and is reflected (totally reflected) inside the disk-shaped transparent member 21. While being repeated, the light isotropically guided in the radial direction regardless of the angle in the circumferential direction and is incident on the ring-shaped wavelength conversion member 12 (at this time, the distribution of light in the circumferential direction is uniform). . In the ring-shaped wavelength conversion member 12, a part of the excitation light is wavelength-converted, and from the ring-shaped wavelength conversion member 12, the wavelength-converted light (fluorescence (for example, yellow light)) and excitation are excited only from the outer periphery. Mixed color light (white light) with light (for example, blue light) is emitted. At this time, the optical path length of light (fluorescence, excitation light) in the ring-shaped wavelength conversion member 12 is such that the ring-shaped wavelength conversion member 12 has a radial width H along the circumferential direction of the disk-shaped transparent member 11. In addition, since the thickness D is uniform, it is constant, thereby making it possible to significantly reduce color unevenness and luminance unevenness (at all positions on the outer periphery of the ring-shaped wavelength conversion member 12). (Same chromaticity and same brightness)

  Although not provided in the examples of FIGS. 5A and 5B, the disk-shaped transparent member 21 and the ring-shaped wavelength conversion member 12 also have the above-described structure in the second configuration example. The disk-shaped transparent member 21 and the ring-shaped wavelength conversion member 12 are sandwiched from above and below in the thickness direction, and the light that reflects the light guided through the disk-shaped transparent member 21 and the ring-shaped wavelength conversion member 12 is reflected. A member (a reflecting member corresponding to the reflecting member 14 of the first configuration example) may be provided.

  Next, the light source device 10 shown in FIGS. 4A and 4B and the light source device 20 shown in FIGS. 5A and 5B will be described in more detail.

  In the light source device 10 of FIGS. 4A and 4B and the light source device 20 of FIGS. 5A and 5B, the solid-state light source (semiconductor light emitting element) 15 has a light emission wavelength from the ultraviolet light to the visible light region. A light emitting diode, a semiconductor laser, or the like can be used.

More specifically, the solid-state light source 15 may be, for example, a light emitting diode or semiconductor laser that emits near-ultraviolet light having an emission wavelength of about 380 nm using an InGaN-based material. In this case, the phosphor of the wavelength conversion member 12 is excited by ultraviolet light having a wavelength of about 380 nm to about 400 nm. For example, the red phosphor has CaAlSiN ₃ : Eu ²⁺ , Ca ₂ Si ₅ N _8. : Eu ²⁺ , La ₂ O ₂ S: Eu ³⁺ , KSiF ₆ : Mn ⁴⁺ , KTiF ₆ : Mn ^4+, etc. can be used, and for the green phosphor, Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ , (Si, Al) ₆ (O, N) ₈ : Eu ²⁺ , BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ , (Ba, Sr) ₂ SiO ₄ : Eu ^2+, etc. can be used, and (Sr _{, Ca, Ba, Mg) 10} (PO 4) 6 C l2: Eu 2+, BaMgAl 10 O 17: Eu 2+, LaAl (Si, Al) 6 (N, O) 10 : Ce ³⁺ or the like can be used.

The solid-state light source 15 may be, for example, a light emitting diode or semiconductor laser that emits blue light having a light emission wavelength of about 460 nm using a GaN-based material. In this case, the phosphor of the wavelength conversion member 12 is excited by blue light having a wavelength of about 440 nm to about 470 nm. For example, the red phosphor includes CaAlSiN ₃ : Eu ²⁺ , Ca ₂ Si ₅ N _8. : Eu ²⁺ , KSiF ₆ : Mn ⁴⁺ , KTiF ₆ : Mn ^{4+ and the} like can be used, and for the green phosphor, Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ , Y ₃ (Ga, Al) ₅ O ₁₂ : Ce ³⁺ , Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce ³⁺ , CaSc ₂ O ₄ : Eu ²⁺ , (Ba, Sr) ₂ SiO ₄ : Eu ²⁺ , Ba ₃ Si ₆ O ₁₂ N ₂ : Eu ²⁺ , (Si, Al ) ₆ (O, N) ₈ : Eu ²⁺ or the like can be used. Moreover, as what is excited by blue light with a wavelength of about 440 nm to about 470 nm, for example, Y ₃ Al ₅ O ₁₂ : Ce ³⁺ (YAG), (Sr, Ba) ₂ SiO ₄ : Eu ²⁺ , Ca _x (Si , Al) ₁₂ (O, N) ₁₆ : Eu ²⁺ or the like can be used.

  Examples of the wavelength conversion member 12 include those obtained by dispersing these phosphor powders in glass or resin, glass phosphors obtained by adding luminescent center ions to a glass matrix, phosphor ceramics that do not include a binding member such as a resin, and the like. Among them, it is desirable to use phosphor ceramics.

Here, a method of manufacturing a phosphor ceramic having translucency will be described by taking as an example a Y ₃ Al ₅ O ₁₂ : Ce ³⁺ phosphor which is a blue-excited yellow light-emitting phosphor. The phosphor ceramic is manufactured through a starting material mixing step, a forming step, a firing step, and a processing step. As starting materials, yttrium oxide, cerium oxide, alumina, and the like, oxides of constituent elements of Y ₃ Al ₅ O ₁₂ : Ce ³⁺ phosphor, carbonates, nitrates, sulfates and the like that become oxides after firing are used. The particle size of the starting material is preferably a submicron size. These raw materials are weighed so as to have a stoichiometric ratio. At this time, for the purpose of improving the transmittance of the ceramic after firing, it is also possible to add a compound such as calcium or silicon. The weighed raw materials are sufficiently dispersed and mixed by a wet ball mill using water or an organic solvent. Next, the mixture is formed into a predetermined shape. As the molding method, a uniaxial pressing method, a cold isostatic pressing method, a slip casting method, an injection molding method, or the like can be used. The obtained molded body is fired at 1600 to 1800 ° C. Thus, translucent ^{_{Y 3 Al 5 O 12: Ce}} 3+ phosphor ceramic can be obtained.

Further, in the light source device 10 of FIGS. 4A and 4B and the light source device 20 of FIGS. 5A and 5B, the disk-like transparent members 11 and 21 are made of, for example, colorless and transparent ceramics. Used. In this case, alumina (Al ₂ O ₃ ) is suitable as a material. For example, alumina powder is put into a mold and pressed (about 100 MPa) and then fired (at 2000 ° C. for about 1 hour) to be colorless and transparent. Ceramics can be obtained.

  The reason why ceramics are used for the wavelength conversion member 12 and the transparent members 11 and 21 is heat resistance. That is, when the light output of the solid light source 15 increases, the Stokes loss (heat generation) in the wavelength conversion member 12 increases, and an organic material such as a resin has a low heat resistant temperature and melts immediately. Therefore, it is preferable that the wavelength conversion member 12 and the transparent members 11 and 21 are composed only of an inorganic material having a heat resistant temperature of 1000 ° C. or higher, that is, ceramics.

  Further, in the light source device 10 of FIGS. 4A and 4B, the light diffusion region 13 provided at the center of the disk-shaped transparent member (for example, colorless and transparent ceramics) 11 is formed on the transparent member 11. For example, it can be formed by mixing 5 to 10% of zinc oxide (ZnO) as a diffusing material or polycrystallizing it by lowering the firing temperature (about 1200 to 1500 ° C.).

  Further, in the light source device 10 of FIGS. 4A and 4B and the light source device 20 of FIGS. 5A and 5B, the radius R of the disk-shaped transparent members 11 and 21 is, for example, about 1.0 mm. Yes, the width H of the wavelength conversion member 12 is about 0.3 to 0.5 mm, and the thickness D of the disk-shaped transparent members 11 and 21 and the wavelength conversion member 12 is about 0.3 to 0.5 mm. .

6 (a), (b), (c), and FIGS. 7 (a), (b), (c) show examples of manufacturing steps of the disk-shaped transparent member 11 (21) and the wavelength conversion member 12. FIG. FIG. 6 (a), (b), (c) and FIGS. 7 (a), (b), (c), first, a colorless and transparent ceramic round bar 11 (21) is used as a core (FIG. 6 (a)). In this example, a round bar 11 (21) having a diameter of 2 mm and a length of 20 mm was used as the core material. Alumina (Al ₂ O ₃ ) is suitable as the core material. There are various methods for forming colorless and transparent ceramic round bars. For example, alumina powder is put into a mold and pressed (about 100 MPa), then fired (at about 2000 ° C. for about 1 hour), and desired using a diamond grindstone or the like. There is a method of cutting to the size of. 4A and 4B, since the light diffusion region 13 is provided at the center of the disc-shaped transparent member 11, a diffusing material is mixed in this portion or the firing temperature is lowered. (By about 1200 to 1500 ° C.).

Next, wavelength conversion ceramics (fluorescent ceramics) such as Y ₃ Al ₅ O ₁₂ : Ce ³⁺ phosphor (YAG phosphor) are attached to the periphery of the round bar 11 (21), and further fired. As in the previous step, the wavelength conversion ceramic powder is put together with the round bar 11 (21) into a mold, pressed (about 200 MPa), and sintered (at 1700 ° C. for about 1 hour) to be integrated. . At this time, the round bar 11 (21) is left approximately 1 to 2 mm at both ends so as to be approximately at the center of the wavelength conversion ceramic. As for the state of the wavelength conversion ceramics (fluorescent ceramics) 12 after sintering, the surface is uneven (FIG. 6B).

  Subsequently, the round bar 11 (21) is rotated at a high speed. The both end portions left in the previous process are chucked, and the portion of the wavelength conversion ceramics (fluorescent ceramics) 12 is turned into a uniform thickness (0.3 by using a cutting tool 30 coated with diamond powder or the like in the manner of a lathe. To 0.5 mm and outer diameter: 2.6 to 3.0 mm) (FIG. 6C). By this step, the requirement that the radius is constant over the entire circumference is cleared (FIG. 7A).

  Finally, it slices using a diamond ring cutter etc. at equal intervals (interval of about 0.3-0.5 mm) in the cross-section (circle) direction of a cylinder (FIG.7 (b)). Thereby, disk-shaped composite ceramics (disk-shaped transparent member 11 (21) and wavelength conversion member 12) are completed (FIG.7 (c)). If necessary, the cross section may be further polished to reduce the thickness.

  FIG. 8 is a view showing an example of an illumination device using the above-described light source device 10 (20) of the present invention. In the illuminating device of FIG. 8, the disc-shaped transparent member 11 (21) and the ring-shaped wavelength converting member 12 are installed at the focal position of the reflecting mirror 41 on the paraboloid of revolution. Excitation light (for example, blue light) from the solid light source 15 guides the disk-shaped transparent member 11 (21) and the ring-shaped wavelength conversion member 12, and a part of the ring-shaped wavelength conversion member 12 is fluorescent ( For example, it is converted into yellow light), and uniform light (for example, white light as mixed light of excitation light (blue light) and fluorescence (yellow light)) from the ring-shaped wavelength conversion member 12 is used as a rotating paraboloid. The light is emitted to the reflecting mirror 41, becomes a parallel light beam by the rotating paraboloid reflecting mirror 41, and is emitted from the opening of the reflecting mirror 41. Thereby, uniform white illumination light can be obtained.

  In the example of FIG. 8, the rotating paraboloid reflecting mirror 41 is used. However, not only the reflecting mirror but also a lens system can be freely combined depending on the intended light distribution design.

  In the light source device 10 shown in FIGS. 4A and 4B and the light source device 20 shown in FIGS. 5A and 5B, the excitation light from the solid light source 15 is applied to the central portion of the disc-shaped transparent member 21. Although the light guide member 16 for guiding light is provided, when the solid light source 15 is a highly coherent one such as a semiconductor laser (laser diode), as in the configuration example of FIG. FIG. 9 corresponds to FIG. 5), and the light guide member 16 is not necessarily provided. That is, when the solid light source 15 is a highly coherent one such as a semiconductor laser (laser diode), the light emitted from the solid light source 15 is excellent even if the light guide member 16 is not provided. This is because the central part of the disk-shaped transparent member 21 is reached by straightness.

  In the light source device 10 shown in FIGS. 4A and 4B described above, the disk-shaped transparent member 11 and the ring-shaped wavelength conversion member 12 include the disk-shaped transparent member 11 and the ring-shaped transparent member 11. The wavelength conversion member 12 is sandwiched from above and below in the thickness direction, and the disk-shaped transparent member 11 and the reflection member 14 for reflecting the light that guides the ring-shaped wavelength conversion member 12 are provided. As shown, the reflecting member 14 may be made larger in the radial direction so as to protrude from the ring-shaped wavelength conversion member 12. Similarly, when a similar reflecting member is provided in the light source device 20 of FIGS. 5A and 5B, the reflecting member is made larger in the radial direction so as to protrude from the ring-shaped wavelength conversion member 12. It may be provided.

  As described above, the present invention can make the optical path length of the light (fluorescence, excitation light) in the ring-shaped wavelength conversion member 12 constant, thereby significantly reducing color unevenness and luminance unevenness. (The same chromaticity and the same brightness are obtained at all positions on the outer periphery of the ring-shaped wavelength conversion member 12), and in particular, a specific light distribution pattern is irradiated using an optical system like a vehicular lamp. This is useful for applications such as projection. That is, in the case of an application such as a vehicular lamp where an optical system is used to irradiate and project a specific light distribution pattern, the optical path length must be exactly constant, and the present invention is applicable to this kind of application. Useful.

  The present invention can be used for lighting in general.

DESCRIPTION OF SYMBOLS 10, 20 Light source device 11, 21 Disc-shaped transparent member 12 Ring-shaped wavelength conversion member 13 Light diffusion region 14 Reflective member 15 Solid light source 16 Light guide member 23 Conical notch 41 Reflective mirror of rotating paraboloid

Claims (5)

A disc-shaped transparent member;
The disk-shaped transparent member has the same thickness and is disposed so as to surround the outer periphery of the disk-shaped transparent member, and has a radial width along the circumferential direction of the disk-shaped transparent member. A ring-shaped wavelength conversion member that is uniform;
Located at a position spatially separated from the disk-shaped transparent member, emits light having a predetermined wavelength in a wavelength region from ultraviolet light to visible light as excitation light, and emits the excitation light to the disk-shaped transparent member. A solid light source incident on the center of the transparent member,
A light diffusion region for diffusing excitation light incident from the solid light source is provided at the center of the disc-shaped transparent member,
The disk-shaped transparent member and the ring-shaped wavelength conversion member are sandwiched between the disk-shaped transparent member and the ring-shaped wavelength conversion member from above and below in the thickness direction, and the disk-shaped transparent member and the A reflection member that reflects light that guides the ring-shaped wavelength conversion member is provided,
The ring-shaped wavelength converting member emits fluorescence having a wavelength longer than the emission wavelength of the solid light source by being excited by excitation light emitted from the solid light source and incident through the disk-shaped transparent member. A light source device comprising a kind of phosphor. A disc-shaped transparent member;
The disk-shaped transparent member has the same thickness and is disposed so as to surround the outer periphery of the disk-shaped transparent member, and has a radial width along the circumferential direction of the disk-shaped transparent member. A ring-shaped wavelength conversion member that is uniform;
Located at a position spatially separated from the disk-shaped transparent member, emits light having a predetermined wavelength in a wavelength region from ultraviolet light to visible light as excitation light, and emits the excitation light to the disk-shaped transparent member. A solid light source incident on the center of the transparent member,
A conical notch that reflects excitation light incident from a solid light source at a predetermined angle is provided at the center of the disk-shaped transparent member,
The ring-shaped wavelength converting member emits fluorescence having a wavelength longer than the emission wavelength of the solid light source by being excited by excitation light emitted from the solid light source and incident through the disk-shaped transparent member. A light source device comprising a kind of phosphor. The light source device according to claim 2, wherein the disk-shaped transparent member and the ring-shaped wavelength conversion member are sandwiched between the disk-shaped transparent member and the ring-shaped wavelength conversion member from above and below in the thickness direction, A light source device comprising a reflective member that reflects light guided through the disk-shaped transparent member and the ring-shaped wavelength conversion member. The light source device according to any one of claims 1 to 3, further comprising a light guide member that guides excitation light from a solid light source to a central portion of the disc-shaped transparent member. A light source device characterized by the above. An illumination device, wherein the light source device according to any one of claims 1 to 4 is used.

Images