JP2013130835A - Homogenizer, homogenizer device and illuminating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a homogenizer, a homogenizer device and an illuminating device which can irradiate a range having a small area with parallel light, and are inexpensive.SOLUTION: A condensing lens 3 has an incident surface formed of a projecting spherical surface, has an emission surface of which a center part is formed of a circular plane perpendicular to an optical axis, and has a peripheral portion surrounding the center part of the emission surface formed of a projecting spherical surface. The condensing lens 3 condenses laser light having been emitted from a semiconductor laser 1, and irradiates a phosphor 4 with the condensed laser light. The phosphor 4 emits laser light of which a wavelength of the emitted laser light has been converted into a wavelength different from the wavelength, for instance, a wavelength of visible light. A reflector 5 reflects the laser light from the phosphor 4 thereon, and emits the reflected light as irradiation light 6.

Description

  The present invention relates to a homogenizer, a homogenizer device, and an illuminating device that uniformize a non-uniform light intensity distribution of laser light.

  Lighting devices such as spot lighting and in-vehicle headlights that use laser light sources usually collect the light beam emitted from a blue laser in the vicinity of 400 to 450 nm, and irradiate the phosphor once to convert the wavelength of the phosphor. In order to obtain pseudo white color, it is used with increased illuminance and safety. As the phosphor, for example, an yttrium aluminum garnet (Yttrium Aluminum Garnet: abbreviated as “YAG”) phosphor substituted with a light emitting ion other than rare earth is used.

  However, phosphors with high conversion efficiency used in these lighting devices are generally expensive because they are doped with rare earth metals. In addition, in order to obtain a light distribution different from that of a light emitting diode (hereinafter referred to as “LED”), that is, a light collecting property, these phosphors need to reduce the area of the phosphor itself as a light emitting unit. There is. By forming these phosphors with a light emitting area as small as possible, it is possible to realize an illuminating device that can emit light with a substantially parallel light beam.

  When a phosphor with a Gaussian intensity distribution is irradiated onto a phosphor with a small area, the phosphor itself burns out at the condensed hot spot, that is, the strongest part, or all electrons involved in the fluorescence are excited and become fluorescent. Has a bad influence such as becoming saturated or causing thermal quenching. The non-uniformity of the condensed intensity called a hot spot is mainly caused by the Gaussian intensity distribution and multimode oscillation accompanying the increase in laser output.

  FIG. 27 is a diagram illustrating an example of a lighting device 90 according to the related art. The illumination device 90 includes a semiconductor laser 91, a housing 92, a condenser lens 93, a phosphor 94, and a reflector 95.

  The semiconductor laser 91 is a light source that emits laser light. The housing 92 is a housing that fixes the semiconductor laser 91, the condenser lens 93, and the reflector 95. The condensing lens 93 condenses the diffused light of the laser light emitted from the semiconductor laser 91. The phosphor 94 converts the wavelength of the irradiated laser light into the wavelength of visible light. The reflector 95 is a parabolic reflector for irradiating the Lambertian excitation light from the phosphor 94 while being slightly diffused from parallel.

The phosphor 94 is disposed at the focal position of the reflector 95. When the radius of the opening of the parabolic reflector 95 is R and the depth of the reflector 95, that is, the length in the optical axis direction is L, the parabolic constant a is calculated by the formula “a = L / R ² ”. The focal position f of the parabola is calculated by the calculation formula “f = 1 / (4a)”. The phosphor 94 is disposed at the focal position f of the parabola.

In order to obtain the irradiation light 96 with a substantially parallel narrow emission angle, the area of the reflector 95 needs to be relatively larger than the area of the phosphor 94 that is a substantial light source. In order to make the lighting device 90 smaller, the area of the phosphor 94 is limited to be smaller, and an area of approximately 1 to 9 mm ² is often employed. In order to obtain a high-intensity light source with the phosphor 94 having a small area, the semiconductor laser 91 having an excellent luminous efficiency and a light emitting portion on the order of μm is suitable. In order to obtain high luminance, the only way to obtain high brightness is to increase the light emitting area, and the light emitting area is increased to the order of mm. Therefore, the LED is not suitable for obtaining the irradiation light 96 with a substantially parallel narrow emission angle.

  FIG. 28 is a diagram for explaining the light beam 97 collected by the condenser lens 93. The light emitting unit 98 is a part from which the semiconductor laser 91 emits laser light. The laser light emitted from the light emitting unit 98 is collected by the condensing lens 93, passes through the optical path indicated by the light beam 97, and is collected on the condensing unit 99 which is a condensing spot.

  FIG. 29 is a diagram showing an intensity image of a field pattern and an intensity distribution in the light emitting unit 98 and the light collecting unit 99. FIG. 29A shows a near field pattern (hereinafter referred to as “NFP”) 101 in the light emitting unit 98 and an intensity image 102 of a Gaussian intensity distribution in the XY plane. The NFA, that is, the near field pattern is a light intensity distribution pattern at the beam exit end of the light emitting unit 98. FIG. 29B shows the field pattern 103 in the light condensing unit 99 and the intensity image 104 of the intensity distribution on the XY plane.

  The condensing spot diameter at the condensing unit 99 is substantially determined by the aperture (Numerical Aperture: hereinafter referred to as “NA”) between the entrance surface and the exit surface of the condensing lens 93, that is, the magnification of the finite lens. When a laser is used as the light source, the focused spot diameter is usually focused to 100 μm or less, although it depends on the shape of the beam exit end, that is, the ridge width. The spot diameter φ collected at the diffraction limit is usually calculated by the calculation formula “φ = 1.22 × (λ / NA)”. λ is the wavelength of the laser beam.

  FIG. 30 is a diagram schematically showing an intensity image of the intensity distribution in the light emitting unit 98 and the light collecting unit 99. FIG. 31 is a perspective view of a field pattern in the light emitting unit 98 and the light collecting unit 99. FIG. 31A is a perspective view of the NFP 101 in the light emitting unit 98, and FIG. 31B is a perspective view of the field pattern 103 in the light collecting unit 99.

  In consideration of manufacturing costs, the condenser lens 93 is not an aspherical lens but is a spherical lens on both surfaces, and the larger the off-axis rays, that is, the farther away from the optical axis 20, the more spherical aberration occurs. Normally, the intensity distribution of the diffractive ring of the condensing unit 99 increases and the intensity distribution of the Gaussian intensity is reflected from the light emitting unit 98 to the condensing unit 99 as it is.

  The phosphor 94 is a wavelength conversion element that is indispensable for illumination applications. The phosphor 94 is installed at the focal point of the reflector 95 as a Lambertian excitation light source that strongly excites laser light in a wavelength band from blue to blue-violet to a wavelength close to white light. The laser used for the illumination application is a watt class semiconductor laser having a very high output. When the laser light emitted from the laser is condensed on the phosphor 94, the phosphor 94 reaches a temperature exceeding several hundred degrees, causing thermal burning of the phosphor 94 and thermal quenching that reduces the efficiency of the phosphor 94.

  The phosphor 94 is disposed at a defocused position different from the position of the light condensing unit 99 in order to avoid thermal burnout and thermal quenching. However, even if it is arranged at the defocused position, the Gaussian intensity distribution and the non-uniformity of the intensity distribution are directly reflected in the light irradiated to the phosphor 94. That is, the laser beam condensed by the condenser lens 93 is irradiated to the phosphor 94 with an intensity distribution having a hot spot, and the problem that the temperature of the phosphor 94 increases near the hot spot remains. . Therefore, it is difficult for the condensing lens 93 that is a spherical lens to bring out all of the performance of the phosphor 94, and it is the limit to increase the luminance of the illumination device 90 by increasing the emission intensity of the phosphor 94 by the laser light. There is.

  In recent years, fluorescent materials with less thermal quenching have been developed together with doped ions, including production methods, using α-sialon phosphors and β-sialon phosphors that are also resistant to ultraviolet rays, electron beams, and heat resistance, or rubidium vanadate. Developed and used in LED applications. However, problems still remain in the durability of the phosphor at the hot spot due to the Gaussian intensity distribution of the laser light.

  In other fields as well, a beam having a uniform power in a certain spatial range may be required in an application in which a light beam from a laser is condensed and used. Unlike a Gaussian beam, that is, a Gaussian intensity-distributed laser beam, there is a need for a beam whose intensity is not strong only in the center, but is uniform in a certain range and zero in the outside of that range. ing. Such a beam is called a top hat type because it has an intensity distribution resembling the shape of a bowler hat. An optical system for shaping a Gaussian beam into a wide-range top-hat beam is called a homogenizer.

  Conventionally, several proposals have been made to obtain a top-hat type intensity distribution. For example, a combination of a diffractive optical element having a function of splitting a laser beam into a plurality of beams within a certain range and a condensing lens provided subsequent to the diffractive optical element can be combined with a defocusing lens. There is a proposal that the image plane coincides with the focus plane, and the beams branched by the diffractive optical element are combined at the defocus plane to form a desired intensity distribution. In addition, an optical system that uses a microlens array instead of a diffractive optical element to form a top hat intensity distribution has been proposed. However, in these proposals, there is a limit to miniaturization and cost reduction.

  As a first conventional technique, there is a lamp described in Patent Document 1. This lamp is an illumination device including a plurality of light source units. Each light source unit includes a light source unit that generates ultraviolet light, a phosphor that generates white light in response to the ultraviolet light from the light source unit, and a reflector that reflects diffused light generated by the phosphor into parallel light. And irradiating the front of the vehicle with white light of a predetermined color arrangement pattern. The light source unit includes a laser diode and a lens that condenses the light generated by the laser diode on a phosphor.

  As a second prior art, there is a tilt error reducing aspherical homogenizer described in Patent Document 2. This tilt error reducing aspherical homogenizer refracts and reduces a parallel incident beam whose energy distribution is a Gaussian distribution, and forms a beam having a uniform energy distribution on an irradiation surface having a diameter smaller than the diameter of the incident beam. An aspherical homogenizer consisting of a single lens. This tilt error-reducing aspheric homogenizer can prevent the uniformity of the energy distribution of the beam on the irradiation surface from being slightly tilted.

JP 2005-150041 A JP 2005-134681 A

  The homogenizer device combining the diffractive optical element and the microlens array according to the above-mentioned proposal needs to combine several optical components in addition to the diffractive optical element and the microlens array, which increases the cost. In addition, this homogenizer device has increased equipment cost and assembly tact required for assembly and adjustment, and a cheaper homogenizer is required. In lighting devices that use laser light sources, which are expected to expand in the future, inexpensive homogenizer devices are very important in order to maintain the durability and efficiency of phosphors and reduce the negative effects on phosphors. It is increasing.

  The first prior art relates to the arrangement of lamp members, and does not convert the Gaussian intensity distribution into a top hat type. The second prior art is related to a homogenizer, and is intended to prevent the uniformity of the energy distribution of the beam on the irradiation surface from being impaired with respect to a slight inclination of the lens. It is impossible to irradiate parallel light on a small area.

  An object of the present invention is to provide an inexpensive homogenizer, a homogenizer device, and an illumination device that can irradiate parallel light in a small area range.

The present invention relates to fluorescence that emits laser light obtained by converting laser light emitted from a light emitting element that emits laser light having a Gaussian distribution of light into a wavelength different from the wavelength of the irradiated laser light. A condensing lens that collects light so that the intensity distribution on the body is substantially uniform at the central portion and substantially zero at the peripheral edge surrounding the central portion;
The incident surface is formed of a convex spherical surface, the central portion of the output surface is formed of a circular plane perpendicular to the optical axis, the peripheral edge connected to the central portion is formed of a convex spherical surface, and the diameter of the central portion is previously set. A homogenizer including a condenser lens having a length within a predetermined range.

Further, the present invention emits a laser beam obtained by converting a laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser beam. A condensing lens that collects light so that the intensity distribution on the phosphor is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
The central portion of the incident surface is formed by a circular plane perpendicular to the optical axis, the peripheral edge connected to the central portion is formed by a convex spherical surface, the output surface is formed by a convex spherical surface, and the diameter of the central portion is previously set. A homogenizer including a condenser lens having a length within a predetermined range.

Further, the present invention emits a laser beam obtained by converting a laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser beam. A condensing lens that collects light so that the intensity distribution on the phosphor is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
The central part of the incident surface is formed by a circular plane perpendicular to the optical axis, the peripheral part connected to the central part of the incident surface is formed by a convex spherical surface, and the central part of the outgoing surface is a circular plane perpendicular to the optical axis. A homogenizer including a condensing lens having a peripheral spherical portion formed in a convex spherical surface and having a diameter within a predetermined range. .

Further, the present invention emits a laser beam obtained by converting a laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser beam. A condensing lens that collects light so that the intensity distribution on the phosphor is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
The central portion of the incident surface is formed by a circular plane perpendicular to the optical axis, the peripheral edge connected to the central portion of the incident surface is formed by a convex spherical surface, and the central portion of the outgoing surface has a side surface perpendicular to the optical axis. It is formed in a cylindrical shape, the peripheral edge connected to the center of the exit surface is formed as a convex spherical surface, the diameter of the center of the entrance surface is a length within a predetermined range, the length of the side surface of the cylindrical shape and The homogenizer includes a condensing lens whose lateral width is a length within a predetermined range.

Further, the present invention emits a laser beam obtained by converting a laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser beam. A condensing lens that collects light so that the intensity distribution on the phosphor is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
The central part of the incident surface is formed in a cylindrical shape having a side surface perpendicular to the optical axis, the peripheral edge connected to the central part of the incident surface is formed as a convex spherical surface, and the central part of the outgoing surface is a circle perpendicular to the optical axis. The peripheral edge connected to the central portion of the exit surface is formed of a convex spherical surface, the length and lateral width of the cylindrical side are within a predetermined range, and the length of the center portion of the exit surface is The homogenizer includes a condenser lens having a diameter within a predetermined range.

Further, the present invention emits a laser beam obtained by converting a laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser beam. A condensing prism that collects light so that the intensity distribution on the phosphor is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
The homogenizer includes a condensing prism having an incident surface formed in a convex polygonal pyramid shape having four or more corners and an output surface formed in a plane perpendicular to the optical axis.

Further, the present invention emits a laser beam obtained by converting a laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser beam. A condensing prism that collects light so that the intensity distribution on the phosphor is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
The homogenizer includes a condensing prism in which an incident surface is formed by a plane perpendicular to the optical axis, and an output surface is formed in a convex polygonal pyramid shape having four or more corners.

Further, the present invention emits a laser beam obtained by converting a laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser beam. A condensing prism that collects light so that the intensity distribution on the phosphor is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
The homogenizer includes a condensing prism in which an incident surface is formed in a convex polygonal pyramid shape with four or more corners and an output surface is formed in a convex polygonal pyramid shape with four or more corners.

The present invention also includes the homogenizer,
A cylindrical shape having a circular or polygonal cross section is disposed between the homogenizer and the phosphor so that the central axis of the cylinder coincides with the optical axis, and the inner surface is formed by a reflection surface of total reflection. A homogenizer device including an optical member.

  In the invention, it is preferable that the light guide member has an exit area smaller than an entrance area.

The present invention also includes the homogenizer,
A light emitting element that emits laser light having a Gaussian light intensity distribution;
A phosphor that emits a laser beam in which the wavelength of the irradiated laser beam is converted to a wavelength different from the wavelength;
And a parabolic reflector that reflects the laser light emitted from the phosphor.

  According to the present invention, the homogenizer converts a laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser beam. It consists of a condensing lens that collects light so that the intensity distribution on the phosphor that emits light is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center. In the condenser lens, the incident surface is formed as a convex spherical surface, the central portion of the output surface is formed as a circular plane perpendicular to the optical axis, and the peripheral edge connected to the central portion is formed as a convex spherical surface. The condensing lens has a length within a predetermined range in the diameter of the central portion. Therefore, the homogenizer can irradiate parallel light onto a small area of the phosphor and can be formed at low cost.

  According to the invention, the homogenizer converts the laser light emitted from the light emitting element that emits the laser light having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser light. It consists of a condensing lens that collects light so that the intensity distribution on the phosphor emitting the laser light is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center. The condensing lens is formed with a circular plane perpendicular to the optical axis at the center of the entrance surface, a convex spherical surface at the periphery of the central portion, and a convex spherical surface at the exit surface. The condensing lens has a length within a predetermined range in the diameter of the central portion. Therefore, the homogenizer can irradiate parallel light onto a small area of the phosphor and can be formed at low cost.

  According to the invention, the homogenizer converts the laser light emitted from the light emitting element that emits the laser light having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser light. It consists of a condensing lens that collects light so that the intensity distribution on the phosphor emitting the laser light is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center. In the condenser lens, the central portion of the incident surface is formed of a circular plane perpendicular to the optical axis, the peripheral portion connected to the central portion of the incident surface is formed of a convex spherical surface, and the central portion of the output surface is A condensing lens formed of a circular plane perpendicular to the optical axis, a peripheral edge connected to the central portion of the exit surface is formed as a convex spherical surface, and the diameter of both central portions is a length within a predetermined range. The Therefore, the homogenizer can irradiate parallel light onto a small area of the phosphor and can be formed at low cost.

  According to the invention, the homogenizer converts the laser light emitted from the light emitting element that emits the laser light having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser light. It consists of a condensing lens that collects light so that the intensity distribution on the phosphor emitting the laser light is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center. In the condenser lens, the central portion of the incident surface is formed of a circular plane perpendicular to the optical axis, the peripheral portion connected to the central portion of the incident surface is formed of a convex spherical surface, and the central portion of the output surface is It is formed in a cylindrical shape having a side surface perpendicular to the optical axis, the peripheral edge connected to the center of the exit surface is formed as a convex spherical surface, and the diameter of the center of the entrance surface is a length within a predetermined range, The cylindrical lens has a condensing lens whose side length and width are within a predetermined range. Therefore, the homogenizer can irradiate a light emitting element having a wide ridge width with parallel light in a small area of the phosphor, and can be formed at low cost.

  According to the invention, the homogenizer converts the laser light emitted from the light emitting element that emits the laser light having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser light. It consists of a condensing lens that collects light so that the intensity distribution on the phosphor emitting the laser light is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center. The condenser lens is formed in a cylindrical shape in which the central portion of the incident surface has a side surface perpendicular to the optical axis, the peripheral edge connected to the central portion of the incident surface is formed as a convex spherical surface, and the center of the output surface The part is formed by a circular plane perpendicular to the optical axis, the peripheral part connected to the central part of the emission surface is formed by a convex spherical surface, and the length and lateral width of the cylindrical side are within a predetermined range. There is a condensing lens in which the diameter of the central portion of the exit surface is a length within a predetermined range. Therefore, the homogenizer can irradiate a light emitting element having a wide ridge width with parallel light in a small area of the phosphor, and can be formed at low cost.

  According to the invention, the homogenizer converts the laser light emitted from the light emitting element that emits the laser light having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser light. It consists of a condensing prism that collects light so that the intensity distribution on the phosphor emitting laser light is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center. The condensing prism is a condensing prism that is formed in a polygonal pyramid shape with four or more incident surfaces on the convex surface and an output surface formed on a plane perpendicular to the optical axis. Therefore, it is possible to irradiate parallel light onto a small area of the phosphor, and to form the phosphor more inexpensively.

  According to the invention, the homogenizer converts the laser light emitted from the light emitting element that emits the laser light having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser light. It consists of a condensing prism that collects light so that the intensity distribution on the phosphor emitting laser light is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center. The condensing prism is a condensing prism in which the incident surface is formed by a plane perpendicular to the optical axis and the exit surface is formed in a convex polygonal pyramid shape having four or more corners. Therefore, it is possible to irradiate parallel light onto a small area of the phosphor, and to form the phosphor more inexpensively.

  According to the invention, the homogenizer converts the laser light emitted from the light emitting element that emits the laser light having a Gaussian light intensity distribution into a wavelength different from the wavelength of the irradiated laser light. It consists of a condensing prism that collects light so that the intensity distribution on the phosphor emitting laser light is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center. The condensing prism is a condensing prism that is formed in a polygonal pyramid shape having a convex quadrangular pyramid and whose exit surface is formed in a polygonal pyramid shape having a convex quadrangular pyramid. Therefore, it is possible to irradiate parallel light onto a small area of the phosphor, and to form the phosphor more inexpensively.

  Further, according to the present invention, the homogenizer device includes any one of the homogenizers, a cylindrical section having a circular or polygonal cross section, and a cylindrical central axis between the homogenizer and the phosphor. Are arranged so as to coincide with the optical axis, and the inner surface is formed by a reflection surface of total reflection. Therefore, the homogenizer device can irradiate parallel light onto a smaller area of the phosphor and can be formed at a relatively low cost.

  According to the invention, the light guide member has an exit area smaller than an entrance area. Therefore, the homogenizer device can irradiate parallel light onto a smaller area of the phosphor and can be formed at a relatively low cost.

  According to the invention, the illumination device includes any one of the homogenizers, a light emitting element that emits laser light having a Gaussian light intensity distribution, and a wavelength of the irradiated laser light. A phosphor that emits laser light converted to a wavelength different from the wavelength and a parabolic reflector that reflects the laser light emitted from the phosphor are included. Therefore, the illuminating device can irradiate with a substantially parallel light beam to a distant place.

It is a figure which shows the structure of the illuminating device 10 which is the 1st Embodiment of this invention. It is a figure which shows the structure of the illuminating device 11 which is the 2nd Embodiment of this invention. It is a figure which shows the condensing lens 3 which is a 1st Example. It is a figure which shows the intensity | strength image of the field pattern and intensity distribution in the light emission part 8 and fluorescent substance 4 in a 1st Example. It is a figure which shows typically the intensity image of the intensity distribution in the light emission part 8, the plane 3c, and the fluorescent substance 4 in a 1st Example. It is a perspective view of the field pattern in the light emission part 8 and the fluorescent substance 4 in a 1st Example. It is a figure for demonstrating the light beam condensed by the condensing lens. It is a figure which shows the condensing lens 31 which is a 2nd Example. It is a perspective view of the field pattern in the light emission part 8 and the fluorescent substance 4 in a 2nd Example. It is a figure which shows the condensing lens 32 which is a 3rd Example. It is a figure which shows the intensity | strength image of the field pattern and intensity distribution in the light emission part 8 and fluorescent substance 4 in a 3rd Example. It is a figure for demonstrating the light beam condensed by the condensing lens 32 by XY plane. It is a figure which shows the field pattern in the XY plane of the light emission part 8 and the fluorescent substance 4 in a 3rd Example. It is a figure for demonstrating the light beam condensed by the condensing lens 32 on a XZ plane. It is a figure which shows the field pattern in the XZ plane of the light emission part 8 and the fluorescent substance 4 in a 3rd Example. It is a figure which shows the condensing prism 33 which is a 4th Example. It is a figure which shows the condensing prism 33 and its light beam. It is a figure which shows the intensity | strength image of the field pattern and intensity distribution in the light emission part 8 and the fluorescent substance 4 in a 4th Example. It is a figure which shows the spherical aberration curve 31 by a spherical lens. It is a figure which shows the spherical aberration curve 32a of the condensing point vicinity by a polyhedral prism.

FIG. 6 is an enlarged view of the vicinity of a circle 24 of minimum confusion of light beams by a condensing prism 33. It is a figure which shows the structure of the illuminating device 12 which is the 3rd Embodiment of this invention. It is a figure which shows the structure of the illuminating device 13 which is the 4th Embodiment of this invention. It is a perspective view of the light emitting point and the field pattern in the fluorescent substance 4 in 4th Embodiment. It is a figure which shows the structure of the illuminating device 14 which is the 5th Embodiment of this invention. It is an enlarged view of the light guide member and the fluorescent substance. It is a figure which shows an example of the illuminating device 90 by a prior art. It is a figure for demonstrating the light beam 97 condensed by the condensing lens 93. FIG. It is a figure which shows the intensity | strength image of the field pattern and intensity distribution in the light emission part 98 and the condensing part 99. FIG. It is a figure which shows typically the intensity image of the intensity distribution in the light emission part 98 and the condensing part 99. FIG. It is a perspective view of the field pattern in the light emission part 98 and the condensing part 99. FIG.

  FIG. 1 is a diagram showing a configuration of a lighting device 10 according to the first embodiment of the present invention. The illumination device 10 includes a semiconductor laser 1, a housing 2, a condenser lens 3, a phosphor 4 and a reflector 5. Hereinafter, in an embodiment different from the first embodiment, corresponding portions are denoted by the same reference numerals, and description thereof is omitted to avoid duplication.

  The semiconductor laser 1 that is a light emitting element is a light source that emits laser light having a Gaussian distribution of light intensity. The semiconductor laser 1 is not required to be coherent or monochromatic. The laser light emitted from the semiconductor laser 1 reaches the condenser lens 3. The housing 2 is a housing that fixes the semiconductor laser 1, the condenser lens 3, and the reflector 5.

  The condensing lens 3 condenses the diffused light of the laser light emitted from the semiconductor laser 1 as a light beam 7 and irradiates the phosphor 4. The condenser lens 3 is the first embodiment and is a homogenizer. Hereinafter, in an embodiment different from the first embodiment, corresponding portions are denoted by the same reference numerals, and description thereof is omitted to avoid duplication.

  The phosphor 4 emits, as Lambertian excitation light, laser light obtained by converting the wavelength of the irradiated laser light to a wavelength different from the wavelength, for example, visible light. The phosphor 4 is disposed at the focal position of the reflector 5. The reflector 5 serving as a reflection portion is a parabolic reflector for irradiating reflected light obtained by diffusing the Lambertian excitation light from the phosphor 4 slightly from parallel to the irradiation light 6.

  FIG. 2 is a diagram showing a configuration of the illumination device 11 according to the second embodiment of the present invention. The illumination device 11 includes a semiconductor laser 1, a housing 2a, a condenser lens 3, a phosphor 4a, and a reflector 5a. The illuminating device 11 is configured to use the upper half of the upper side of the reflector 5 of the illuminating device 10 shown in FIG.

  The housing 2a is a housing that fixes the semiconductor laser 1, the condenser lens 3, and the reflector 5a. The reflector 5 a has a configuration excluding the lower half of the lower side of the reflector 5. The phosphor 4a emits laser light having a wavelength of visible light after conversion only in the direction of reflection by the reflector 5a. Since the illuminating device 11 uses the reflector 5a excluding the lower half of the lower side of the reflector 5 shown in FIG. 1, the illuminating device 11 can be made smaller than the illuminating device 10.

  FIG. 3 is a diagram illustrating the condenser lens 3 according to the first embodiment. The condenser lens 3 is formed of a spherical surface 3a having a convex entrance surface, a central portion of the exit surface is formed of a circular plane 3c perpendicular to the optical axis 20, and a peripheral portion surrounding the central portion of the exit surface is convex. It is ground so as to be formed by the spherical surface 3b. The optical axis 20 is the central axis of the light beam 7.

  Since the condensing lens 3 is a lens in which the vicinity of the optical axis 20 of the exit surface forms a flat surface 3c, only the central portion of the laser light having the Gaussian intensity distribution is not subjected to the refraction action of the condensing lens 3, and thus condensing. The light is not condensed on the portion 9. Referring to FIG. 3, it can be seen that the light beam 7 transmitted through the plane 3 c is irradiated near the outer periphery of the phosphor 4 as it is away from the optical axis 20 except for the central light beam region 21 at the very center.

  FIG. 4 is a diagram showing an intensity image of the field pattern and intensity distribution in the light emitting section 8 and the phosphor 4 in the first embodiment. FIG. 4A shows the NFP 11 and the intensity image 12 a of the intensity distribution in the light emitting unit 8. FIG. 4B shows the field pattern 13 and the intensity image 14 of the intensity distribution in the phosphor 4.

  In the intensity image 12a shown in FIG. 4 (a), the central portion, which is a Gaussian intensity distribution, is dispersed with high intensity around the spot in the intensity image 14 shown in FIG. 4 (b). Shows a flat intensity distribution with no peak. That is, the intensity distribution on the phosphor 4 is a top-hat type condensing state without a hot spot. Therefore, the condensing lens 3 can reduce the thermal load on the phosphor 4 and can exhibit 100% of the performance of the phosphor 4.

  FIG. 5 is a diagram schematically showing intensity images of intensity distributions in the light emitting unit 8, the plane 3c, and the phosphor 4 in the first embodiment. FIG. 5 is a diagram contrasted with the intensity image according to the prior art shown in FIG. The intensity image 12 b is an intensity image of the intensity distribution in the light emitting unit 8, the intensity image 16 is an intensity image of the intensity distribution on the plane 3 c, and the intensity image 14 is an intensity image of the intensity distribution in the phosphor 4. It is. In the intensity image 16, the light condensing effect by the condensing lens 3 is reduced by the plane 3 c formed in the central portion of the exit surface of the light beam in the central portion of the Gaussian intensity distribution, and the outer periphery of the phosphor 4. The state which radiate | emits toward the side is shown.

  FIG. 6 is a perspective view of a field pattern in the light emitting section 8 and the phosphor 4 in the first embodiment. The NFP 11a shown in FIG. 6A is a perspective view of the NFP 11 shown in FIG. 4A, and the field pattern 13a shown in FIG. 6B is the field pattern 13 shown in FIG. 4B. FIG. Like the field pattern 13 and the intensity image 14 shown in FIG. 4B, the intensity image 14 shown in FIG. 5, and the field pattern 13a shown in FIG. 6B, the intensity distribution on the phosphor 4 is as follows. This is a top-hat type condensing state without a hot spot, and the condensing lens 3 can reduce the thermal load of the phosphor 4.

  FIG. 7 is a diagram for explaining a light beam condensed by the condenser lens 3. The light emitted from the semiconductor laser 1 will be referred to as light L1, light L2, light L3, light L4, light L5, and light L6 in this order from the side closer to the optical axis 20, and hereinafter the condenser lens 3 has a top hat type intensity distribution. Will be explained.

  The light L1 is light near the optical axis 20. In accordance with Snell's law, the light L1 is refracted slightly toward the optical axis 20 on the spherical surface 3a that is the incident surface of the condenser lens 3, and passes through the inside of the condenser lens 3. The lights L1 to L3 are emitted from the condenser lens 3 in a substantially straight direction without being refracted toward the collecting point because the central portion of the emission surface is processed as the plane 3c. Strictly speaking, refraction according to Snell's law occurs on the exit surface, but it may be handled as almost straight because it is very small.

  As the lights L1 to L3 pass through the plane 3c away from the optical axis 20, the irradiation position on the phosphor 4 is further away from the optical axis 20. Referring to FIG. 7, it can be seen that the positions of the lights L2 and L3 on the phosphor 4 are further outward from the center of the phosphor 4 than the light L1. That is, light very close to the optical axis 20 is irradiated near the center of the phosphor 4, but is diffused to the outside of the phosphor 4 as the distance from the optical axis 20 increases.

  Further, according to Snell's law, the light L4 is refracted by the spherical surface 3a that is the entrance surface of the condenser lens 3, passes through the inside of the condenser lens 3, and is further refracted by the spherical surface 3b at the peripheral portion of the exit surface, thereby It is condensed on the body 4. Here, as a characteristic of the spherical lens, as the distance from the optical axis 20 increases, spherical aberration occurs, and the light from the outside is condensed closer to the focal point. The focal point here means a paraxial ray focused by a spherical lens, that is, paraxial imaging. As shown in FIG. 7, by arranging the phosphor 4 substantially at the focal position, it becomes possible to irradiate the phosphor 4 with a light beam having a flat intensity distribution.

  The plane 3c of the condenser lens 3 is circular. The diameter of the plane 3c is set to 1/4 to 1/5 of the effective lens diameter so that the spot on the phosphor 4, that is, the minimum circle of confusion is less than 1 to 2 mm in diameter. The minimum circle of confusion is a cross-sectional shape of a light beam cut by a virtual plane orthogonal to the optical axis 20 at a position called a beam waist where the light beam is most focused. Since the minimum circle of confusion is set to be a little less than 1 to 2 mm in diameter, the phosphor 4 can achieve a surface light emission efficiency that cannot be achieved by an LED, and is an optimal light source for spot condensing by a parabolic reflector 5. is there.

  Therefore, the condensing lens 3 can use the phosphor 4 as a point light source with high efficiency and a small area as compared with the LED surface light source. Furthermore, the illuminating device 10 can make the reflected light emitted from the phosphor 4 and reflected by the reflector 5 into the substantially parallel irradiation light 6, and is collected as a separate part for making the reflected light into parallel light. Even without using an optical lens, it is possible to irradiate far away.

  In the first embodiment, the flat surface 3c is provided at the center of the exit surface of the condenser lens 3. However, the shape of the entrance surface and the shape of the exit surface are interchanged to provide a flat surface at the center of the entrance surface. Also good.

  FIG. 8 is a diagram illustrating a condenser lens 31 according to the second embodiment. FIG. 9 is a perspective view of a field pattern in the light emitting section 8 and the phosphor 4 in the second embodiment. FIG. 9A shows the NFP 11b in the light emitting unit 8, and FIG. 9B shows the field pattern 13b in the phosphor 4.

  The condenser lens 31 is a second embodiment and is a homogenizer. The condensing lens 31 is formed by a circular plane 31d having a central portion of the incident surface perpendicular to the optical axis 20, a peripheral portion surrounding the central portion of the incident surface is formed by a convex spherical surface 31a, and the central portion of the emitting surface. Is formed by a circular plane 3c perpendicular to the optical axis 20, and a peripheral portion surrounding the center of the exit surface is formed by a convex spherical surface 3b.

  As described above, the condensing lens 31 has flat surfaces on both the incident surface and the exit surface. That is, since the condensing lens 31 is provided with planes orthogonal to the optical axis 20 on both sides of the spherical lens, a method of polishing the lens from cylindrical glass is applicable, and these planes are used. The unit assembly with the semiconductor laser 1 can be improved. In the condensing lens 31, the maximum intensity distribution in the two parallel planes in the central portion is evenly distributed around the focal point, so that the uniform region of the intensity distribution in the minimum circle of confusion can be expanded. The range of the position where the phosphor 4 is provided can be expanded while maintaining the intensity distribution on the phosphor 4.

  FIG. 10 is a diagram showing a condenser lens 32 according to the third embodiment. The condenser lens 32 is not a homogenizer for correcting a normal ridge width, that is, a Gaussian intensity distribution of a laser whose light emitting section 8 has the same vertical and horizontal sizes, but is used for a high-power horizontal multimode laser having a wide ridge width. It is a homogenizer.

  Normally, the θ‖ direction of a watt-class high-power laser, that is, the Y direction in FIG. 10 oscillates in multimode, although the emission angle is narrow, and is not a normal Gaussian intensity distribution. Conversely, the θ⊥ direction, that is, the Z direction has a wide radiation angle and the oscillation intensity has a Gaussian distribution. The standard of the laser emission point is about 1 μm × 10 μm in length and width, and has a horizontal magnification of about 10 times the normal. The condensing spot by the homogenizer comprising the condensing lens 32 is condensed into a rectangular shape 10 times the light emitting point, that is, 10 μm × 100 μm in length and width. Even when the phosphor 4 is irradiated at the defocus position, the surface of the phosphor 4 cannot be used effectively, and it is difficult to use the phosphor 4 as an ideal light source.

  FIG. 11 is a diagram showing intensity images of field patterns and intensity distributions in the light emitting section 8 and the phosphor 4 in the third embodiment. FIG. 11A shows the NFP 11c and the intensity image 12c of the intensity distribution in the light emitting unit 8. FIG. FIG. 11B shows a field pattern 13 c and an intensity image 14 c of the intensity distribution in the phosphor 4.

  The condensing lens 32 is formed by a circular plane 31d whose central portion of the incident surface is perpendicular to the optical axis 20, and a peripheral portion surrounding the central portion of the incident surface is formed by a convex spherical surface 31a. Is formed in a cylindrical shape 32c having a side surface perpendicular to the optical axis 20, and a peripheral edge connected to the central portion of the emission surface is formed as a convex spherical surface 32b. The cylindrical shape is a kamaboko shape.

  The direction in which the side surface of the cylindrical shape 32c shown in FIG. 11 is a straight line is the θ‖ direction of the laser, that is, the Y direction. As shown in FIG. 11B, the condenser lens 32 can form a substantially square and symmetrical field pattern 13c on the phosphor 4 with respect to the multi-mode laser spot having a wide ridge width.

  FIG. 12 is a diagram for explaining the light beam collected by the condenser lens 32 on the XY plane. FIG. 13 is a diagram showing field patterns on the XY plane of the light emitting section 8 and the phosphor 4 in the third embodiment. FIG. 13A shows the NFP 11 c in the light emitting unit 8. FIG. 13B shows the field pattern 13 c and the intensity image 14 c of the intensity distribution in the phosphor 4.

  The condenser lens 32 has no effect due to the cylindrical shape in the XY plane. Due to the homogenizer effect in the central portion flat in the Y direction, a top hat type field pattern 14c is formed on the phosphor 4 at the flat surface 32d and the cylindrical central flat portion. Spots can be avoided.

  FIG. 14 is a diagram for explaining the light beam collected by the condenser lens 32 on the XZ plane. FIG. 15 is a diagram showing field patterns in the XZ plane of the light emitting section 8 and the phosphor 4 in the third embodiment. FIG. 15A shows the NFP 11 c in the light emitting unit 8. FIG. 15B shows the field pattern 13 c and the intensity image 14 c of the intensity distribution in the phosphor 4.

  In the XZ plane, the condensing lens 32 condenses the light emission spot in the long ridge direction of the wide ridge into a substantially square shape at the condensing spot due to the spherical lens effect of the cylindrical shape 32c. The condensing lens 32 can be formed so that the shape of the condensing spot on the phosphor 4 is changed from a rectangle to a quadrangle by forming the central portion of the emission surface in a spherical shape in the Z direction.

  In the second embodiment, the condensing lens 32 is formed by a circular plane 31d whose central portion of the incident surface is perpendicular to the optical axis 20, and a peripheral portion surrounding the central portion of the incident surface is formed by a convex spherical surface 31a. The central portion of the exit surface is formed into a cylindrical shape 32c having a side surface perpendicular to the optical axis 20, and the peripheral edge connected to the central portion of the exit surface is formed as a convex spherical surface 32b. And the shape of the exit surface are interchanged so that the central portion of the incident surface is formed into a cylindrical shape 32c having a side surface perpendicular to the optical axis 20, and the peripheral portion connected to the central portion of the incident surface is formed as a convex spherical surface 32b. The central portion of the emission surface may be formed by a circular plane 31d perpendicular to the optical axis 20, and the peripheral portion surrounding the central portion of the emission surface may be formed by a convex spherical surface 31a.

  FIG. 16 is a diagram showing a condensing prism 33 according to the fourth embodiment. The condensing prism 33 is a fourth embodiment and is a homogenizer. The condensing prism 33 refracts and condenses the incident beam whose intensity distribution of the laser light emitted from the semiconductor laser 1 has a Gaussian distribution, and forms a beam with a substantially uniform energy intensity distribution on the phosphor 4. It is an intensity conversion prism. The condensing prism 33 is a polygonal pyramid prism homogenizer which is formed of a polygonal pyramid prism having four or more corners with a convex entrance surface and a flat exit surface.

  In the fourth embodiment, the condensing prism 33 is a polygonal pyramid prism that is formed by a polygonal pyramid prism having a convex entrance surface of four or more corners and a light exit surface formed by a plane. It is not limited. For example, the condensing prism 33 may be formed of a polyhedral prism having a polygonal pyramid shape with four or more corners in which the incident surface is a flat surface and the output surface is convex. The condensing prism 33 may be formed of a polygonal prism having a polygonal pyramid shape with four or more angles on both the incident surface and the exit surface. Polyhedral prisms such as the condensing prism 33 can be processed by plane polishing, and can be manufactured at a lower cost than spherical lenses.

  FIG. 17 is a diagram illustrating the condensing prism 33 and its light flux. FIG. 18 is a diagram showing intensity images of field patterns and intensity distributions in the light emitting section 8 and the phosphor 4 in the fourth embodiment. FIG. 18A shows the NFP 11d and the intensity image 12d of the intensity distribution in the light emitting unit 8. FIG. FIG. 18B shows the field pattern 13 c and the intensity image 14 d of the intensity distribution in the phosphor 4.

  FIG. 19 is a diagram showing a spherical aberration curve 31 by the spherical lens. FIG. 20 is a diagram showing a spherical aberration curve 32a in the vicinity of a condensing point by the polyhedral prism. The vertical axis represents the luminous flux radius, and the horizontal axis represents the amount of spherical aberration in the direction of the optical axis 20. The spherical aberration due to the spherical lens is small near the optical axis 20 and increases as the distance from the optical axis 20 increases. The spherical aberration due to the prism is maximum near the optical axis 20 and decreases as the distance from the optical axis 20 increases. The spherical aberration amount at a position away from the optical axis 20 in the spherical aberration curve 31 shown in FIG. 19 is W1, and the spherical aberration in the vicinity of the optical axis 20 in the spherical aberration curve 32a shown in FIG. The amount is W2. The large amount of spherical aberration near the optical axis 20 means that the amount of spherical aberration near the center where the Gaussian intensity distribution of the laser light is strong is large, and the Gaussian intensity distribution is easily dispersed.

  FIG. 21 is an enlarged view of the vicinity of the minimum circle of confusion 24 of the light flux by the condensing prism 33. The enlarged view shown in FIG. 21 shows that the condensing prism 33 sufficiently disperses the Gaussian intensity distribution of the laser light even in the vicinity of the minimum circle of confusion 24. In FIG. 21, the amount of spherical aberration in the vicinity of the optical axis 20 is increased by converging the luminous flux of the laser light emitted with the Gaussian intensity distribution by the condenser prism 33, that is, the focal point of the paraxial ray. This indicates that the position becomes closer and the focal position of the light beam away from the optical axis 20 becomes farther.

  Since the spherical aberration caused by the prism in which the spherical aberration occurs at a position opposite to the spherical aberration of the spherical lens is generated more in the vicinity of the optical axis 20, the condensing prism 33 represents the Gaussian intensity distribution of the laser light, It becomes possible to disperse efficiently to the periphery. By disposing the phosphor 4 far from the Gaussian image plane 23, the Gaussian intensity distribution is converted into a hat top type. The Gaussian image plane 23 is a paraxial point where the aberration can be ignored in an optical system with aberration, that is, an imaging point near the optical axis 20.

  FIG. 22 is a diagram showing a configuration of the illumination device 12 according to the third embodiment of the present invention. The illuminating device 12 is a configuration example that irradiates the phosphor 4 with a top-hat type light beam by refraction of the condensing prism 33 without using a lens. The illumination device 12 includes a semiconductor laser 1, a housing 2, a condensing prism 33, a phosphor 4 and a reflector 5.

  FIG. 23 is a diagram showing a configuration of the illumination device 13 according to the fourth embodiment of the present invention. FIG. 24 is a perspective view of a light emitting point and a field pattern in the phosphor 4 in the fourth embodiment. 24A shows the NFP 11e at the light emitting point, and FIG. 24B shows the field pattern 13e in the phosphor 4.

  The illumination device 13 includes a semiconductor laser 1, a housing 2, a condenser lens 3, a light guide member 41, a phosphor 4, and a reflector 5. The condenser lens 3 and the light guide member 41 constitute a homogenizer device. The illuminating device 13 irradiates the phosphor 4 with a light beam collected by a homogenizer composed of a lens such as the condenser lens 3 via the light guide member 41.

  The light guide member 41 has, for example, a polygonal or circular cylindrical cross section, a metal or plastic inner surface total reflection type hollow pipe, or a polygonal or circular rod shaped cross section, and has a total shape at the boundary surface. It is composed of a glass internal total reflection rod that uses reflection. The inner surface total reflection type hollow pipe is provided with reflection plating for reflecting light having a wavelength of 400 nm to 450 nm on the inner surface. The light guide member 41 has the same diameter at the entrance and exit.

  FIG. 25 is a diagram showing the configuration of the illumination device 14 according to the fifth embodiment of the present invention. The illumination device 14 includes the semiconductor laser 1, the housing 2, the condensing prism 33, the light guide member 42, the phosphor 4, and the reflector 5. The condensing prism 33 and the light guide member 42 constitute a homogenizer device. The illuminating device 14 irradiates the phosphor 4 through the light guide member 42 with a light beam collected by a prism homogenizer including a prism having a polygonal pyramid shape such as the condensing prism 33.

  The light guide member 42 is, for example, a cylindrical shape having a polygonal or circular cross section, and is a metal or plastic inner surface total reflection hollow pipe, or a bar shape having a polygonal or circular cross section, and is entirely at the boundary surface. It is composed of a glass internal total reflection rod that uses reflection. The inner surface total reflection type hollow pipe is provided with reflection plating for reflecting light having a wavelength of 400 nm to 450 nm on the inner surface. In the light guide member 42, the diameter of the entrance is larger than the diameter of the exit. The illuminating device 14 can increase the allowable amount of manufacturing error and irradiate the phosphor 4 with a smaller area by making the area of the exit port smaller than the area of the entrance port.

  In both of the illumination device 13 shown in FIG. 23 and the illumination device 14 shown in FIG. 25, the internal reflection at the light guide members 41 and 42 is set to a length L3 at which the light beam having the maximum incident angle repeats reflection several times. The hot spots are further diffused, and it becomes possible to irradiate the phosphor 4 with a hat-top type light beam having a uniform intensity distribution.

  FIG. 26 is an enlarged view of the light guide member 41 and the phosphor 4. In the light guide member 41 shown in FIG. 26, only the upper half of the light beam from the optical axis 20 is shown in order to avoid complication. As shown in FIG. 26, the phosphor 4 is not formed into a plate shape, but is formed into a cone or polygonal pyramid shape, thereby increasing the apparent light emitting area viewed from the direction of the optical axis 20 without increasing the phosphor. 4 can be a small area. In the shape of a cone or a polygonal pyramid, it is possible to irradiate the reflector 5 which is a parabolic reflector more efficiently with the Lambertian scattered light as compared with the plate-like phosphor 4, and the luminous efficiency of the illumination devices 13 and 14 as a whole. Can be increased.

  Further, by adopting the conical shape, the area of the reflector 5 that blocks the reflected light at the most efficient central portion is reduced, and the reflected light reflected by the reflector 5 can be effectively used as the irradiation light 6. . As the ratio between the diameter S and the height H of the bottom surface of the cone-shaped phosphor 4, that is, “H / S” increases, the amount of light shielding decreases. However, in consideration of the efficiency and the cost of the phosphor 4, In the embodiment, the ratio of “1” to “3” is adopted as “H / S”.

  The above-described embodiment can be applied to an illumination device using a laser light source, for example, an illumination device such as a spot illumination or an in-vehicle headlight. The laser output power profile usually has a Gaussian intensity distribution in both the horizontal and vertical directions of the light emitting point. When the Gaussian intensity distribution is collected by an optical component according to the prior art, the intensity distribution is reflected as it is on the focusing point, which may impair the durability of the phosphor 4.

  In other fields as well, in applications where the laser beam is condensed and used, a beam having a uniform power in a certain spatial range may be required. Unlike a Gaussian beam, that is, a Gaussian intensity distribution laser beam, the intensity is not strong only in the vicinity of the center, but the beam intensity is required so that the power is uniform within a certain range and the power is zero outside. .

  The homogenizer and the homogenizer apparatus in the above-described embodiments are optical components for obtaining a top hat type intensity distribution. Such a homogenizer and a homogenizer device can irradiate the fluorescent light 4 of several square millimeters with uniform intensity at the center portion with the light beam from the semiconductor laser 1. Therefore, such a homogenizer and a homogenizer device can maintain the durability of the phosphor 4 and condense the luminous flux of the laser light onto the phosphor 4 at a low cost. Furthermore, such a homogenizer and a homogenizer device can generate a light beam with a high luminance and high efficiency with a small light emitting area on the phosphor 4, and the reflector 5, which is a parabola-shaped mirror, can be used to reach far away. An illuminating device capable of irradiating with a parallel light beam can be realized.

  As described above, the homogenizer is a laser beam obtained by converting the laser beam emitted from the semiconductor laser 1 that emits the laser beam having a Gaussian distribution of light into a wavelength different from the wavelength of the irradiated laser beam. It is composed of a condensing lens that collects light so that the intensity distribution on the phosphor 4 that emits light is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center. In the condenser lens 33, the incident surface is formed as a convex spherical surface, the central portion of the output surface is formed as a circular plane perpendicular to the optical axis, and the peripheral edge connected to the central portion is a convex spherical surface. Formed and having a length within a predetermined range of the diameter of the central portion. Therefore, the homogenizer can irradiate parallel light on a small area of the phosphor 4 and can be formed at low cost.

  Further, the homogenizer emits laser light obtained by converting the laser light emitted from the semiconductor laser 1 that emits laser light whose light intensity distribution is Gaussian distribution into a wavelength different from the wavelength of the irradiated laser light. The condensing lens 3 collects light so that the intensity distribution on the fluorescent substance 4 is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center. The condensing lens 3 is formed with a circular plane perpendicular to the optical axis at the center of the entrance surface, a convex spherical surface at the peripheral edge connected to the central portion, and a convex spherical surface at the exit surface. Formed and having a length within a predetermined range of the diameter of the central portion. Therefore, the homogenizer can irradiate parallel light on a small area of the phosphor 4 and can be formed at low cost.

  Further, the homogenizer emits laser light obtained by converting the laser light emitted from the semiconductor laser 1 that emits laser light whose light intensity distribution is Gaussian distribution into a wavelength different from the wavelength of the irradiated laser light. The condensing lens 31 collects light so that the intensity distribution on the phosphor 4 is substantially uniform at the central portion and is substantially zero at the peripheral portion surrounding the central portion. The condensing lens 31 has a central portion of the incident surface formed of a circular plane perpendicular to the optical axis, a peripheral portion connected to the central portion of the incident surface formed of a convex spherical surface, and a central portion of the output surface. Is formed by a circular plane perpendicular to the optical axis, the peripheral edge connected to the central portion of the emission surface is formed by a convex spherical surface, and the diameter of both central portions has a length within a predetermined range. Therefore, the homogenizer can irradiate parallel light on a small area of the phosphor 4 and can be formed at low cost.

  Further, the homogenizer emits laser light obtained by converting the laser light emitted from the semiconductor laser 1 that emits laser light whose light intensity distribution is Gaussian distribution into a wavelength different from the wavelength of the irradiated laser light. The condensing lens 32 collects light so that the intensity distribution on the fluorescent substance 4 is substantially uniform at the central portion and becomes substantially zero at the peripheral portion surrounding the central portion. In the condensing lens 32, the central portion of the incident surface is formed by a circular plane perpendicular to the optical axis, the peripheral edge connected to the central portion of the incident surface is formed by a convex spherical surface, and the central portion of the output surface. Is formed in a cylindrical shape having a side surface perpendicular to the optical axis, the peripheral edge connected to the center of the exit surface is formed as a convex spherical surface, and the diameter of the center of the entrance surface is within a predetermined range. The length of the side surface and the lateral width of the cylindrical shape have a length within a predetermined range. Therefore, the homogenizer can irradiate parallel light on a small area of the phosphor 4 even to the semiconductor laser 1 having a wide ridge width, and can be formed at low cost.

  Further, the homogenizer emits laser light obtained by converting the laser light emitted from the semiconductor laser 1 that emits laser light whose light intensity distribution is Gaussian distribution into a wavelength different from the wavelength of the irradiated laser light. The condensing lens 32 collects light so that the intensity distribution on the fluorescent substance 4 is substantially uniform at the central portion and becomes substantially zero at the peripheral portion surrounding the central portion. The condensing lens 32 is formed in a cylindrical shape in which the central portion of the incident surface has a side surface perpendicular to the optical axis, and the peripheral portion connected to the central portion of the incident surface is formed as a convex spherical surface. The central part is formed by a circular plane perpendicular to the optical axis, the peripheral part connected to the central part of the exit surface is formed by a convex spherical surface, and the length and width of the cylindrical side faces are within a predetermined range. The diameter of the central part of the exit surface has a length within a predetermined range. Therefore, the homogenizer can irradiate parallel light on a small area of the phosphor 4 even to the semiconductor laser 1 having a wide ridge width, and can be formed at low cost.

  Further, the homogenizer emits laser light obtained by converting the laser light emitted from the semiconductor laser 1 that emits laser light whose light intensity distribution is Gaussian distribution into a wavelength different from the wavelength of the irradiated laser light. The condensing prism 33 condenses light so that the intensity distribution on the phosphor 4 is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center. The condensing prism 33 is formed in a polygonal pyramid shape with four or more incident surfaces, and the exit surface is formed in a plane perpendicular to the optical axis. Therefore, it is possible to irradiate parallel light to a small area range of the phosphor 4 and to form the phosphor 4 at a lower cost.

  Further, the homogenizer emits laser light obtained by converting the laser light emitted from the semiconductor laser 1 that emits laser light whose light intensity distribution is Gaussian distribution into a wavelength different from the wavelength of the irradiated laser light. The condensing prism 33 condenses light so that the intensity distribution on the phosphor 4 is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center. The condensing prism 33 has an incident surface formed in a plane perpendicular to the optical axis, and an output surface formed in a convex polygonal pyramid shape having four or more corners. Therefore, it is possible to irradiate parallel light to a small area range of the phosphor 4 and to form the phosphor 4 at a lower cost.

  Further, the homogenizer emits laser light obtained by converting the laser light emitted from the semiconductor laser 1 that emits laser light whose light intensity distribution is Gaussian distribution into a wavelength different from the wavelength of the irradiated laser light. The condensing prism 33 condenses light so that the intensity distribution on the phosphor 4 is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center. The condensing prism 33 is formed in a polygonal pyramid shape with a convex quadrangular pyramid or more on the incident surface, and is formed in a polygonal pyramid shape with convex quadrilateral or more on the exit surface. Therefore, it is possible to irradiate parallel light to a small area range of the phosphor 4 and to form the phosphor 4 at a lower cost.

  Further, the homogenizer device has any one of the homogenizers and a cylindrical tube having a circular or polygonal cross section, and the cylindrical central axis coincides with the optical axis between the homogenizer and the phosphor. The light guide member 41 or the light guide member 42 is arranged so that the inner surface is formed by a reflection surface of total reflection. Therefore, the homogenizer device can irradiate parallel light onto a smaller area of the phosphor 4, and can be formed at a relatively low cost.

  Furthermore, the light guide member 42 has an exit area smaller than an entrance area. Therefore, the homogenizer device can irradiate parallel light onto a smaller area of the phosphor 4 and can be formed at a relatively low cost.

  Furthermore, the illumination devices 10 to 12 include any one of the homogenizers, the semiconductor laser 1 that emits laser light whose light intensity distribution is Gaussian distribution, and the wavelength of the irradiated laser light. A phosphor 4 that emits laser light converted to a different wavelength, and a parabolic reflector 5 that reflects the laser light emitted from the phosphor. Therefore, the illuminating devices 10 to 12 can irradiate with a substantially parallel light beam far away.

DESCRIPTION OF SYMBOLS 1 Semiconductor laser 2 Housing 3, 31, 32 Condensing lens 4 Phosphor 5 Reflector 6 Irradiation light 7 Light flux 10-14 Illumination device 11, 13 NFP
12, 14 Intensity image 20 Optical axis 23 Gaussian image plane 24 Minimum circle of confusion 33 Condensing prism

Claims (11)

A laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution is converted onto a phosphor that emits a laser beam in which the wavelength of the irradiated laser beam is converted to a wavelength different from the wavelength. A condensing lens that collects light so that the intensity distribution is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
The incident surface is formed of a convex spherical surface, the central portion of the output surface is formed of a circular plane perpendicular to the optical axis, the peripheral edge connected to the central portion is formed of a convex spherical surface, and the diameter of the central portion is previously set. A homogenizer comprising a condenser lens having a length within a predetermined range. A laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution is converted onto a phosphor that emits a laser beam in which the wavelength of the irradiated laser beam is converted to a wavelength different from the wavelength. A condensing lens that collects light so that the intensity distribution is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
The central portion of the incident surface is formed by a circular plane perpendicular to the optical axis, the peripheral edge connected to the central portion is formed by a convex spherical surface, the output surface is formed by a convex spherical surface, and the diameter of the central portion is previously set. A homogenizer comprising a condenser lens having a length within a predetermined range. A laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution is converted onto a phosphor that emits a laser beam in which the wavelength of the irradiated laser beam is converted to a wavelength different from the wavelength. A condensing lens that collects light so that the intensity distribution is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
The central part of the incident surface is formed by a circular plane perpendicular to the optical axis, the peripheral part connected to the central part of the incident surface is formed by a convex spherical surface, and the central part of the outgoing surface is a circular plane perpendicular to the optical axis. A homogenizer comprising: a condensing lens having a peripheral edge portion that is continuous with the central portion of the exit surface and is formed of a convex spherical surface, the diameter of both central portions being within a predetermined range. A laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution is converted onto a phosphor that emits a laser beam in which the wavelength of the irradiated laser beam is converted to a wavelength different from the wavelength. A condensing lens that collects light so that the intensity distribution is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
The central portion of the incident surface is formed by a circular plane perpendicular to the optical axis, the peripheral edge connected to the central portion of the incident surface is formed by a convex spherical surface, and the central portion of the outgoing surface has a side surface perpendicular to the optical axis. It is formed in a cylindrical shape, the peripheral edge connected to the center of the exit surface is formed as a convex spherical surface, the diameter of the center of the entrance surface is a length within a predetermined range, the length of the side surface of the cylindrical shape and A homogenizer comprising a condensing lens having a width within a predetermined range. A laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution is converted onto a phosphor that emits a laser beam in which the wavelength of the irradiated laser beam is converted to a wavelength different from the wavelength. A condensing lens that collects light so that the intensity distribution is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
The central part of the incident surface is formed in a cylindrical shape having a side surface perpendicular to the optical axis, the peripheral edge connected to the central part of the incident surface is formed as a convex spherical surface, and the central part of the outgoing surface is a circle perpendicular to the optical axis. The peripheral edge connected to the central portion of the exit surface is formed of a convex spherical surface, the length and lateral width of the cylindrical side are within a predetermined range, and the length of the center portion of the exit surface is A homogenizer comprising a condenser lens having a diameter within a predetermined range. A laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution is converted onto a phosphor that emits a laser beam in which the wavelength of the irradiated laser beam is converted to a wavelength different from the wavelength. A light collecting prism that collects light so that the intensity distribution is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
A homogenizer comprising a condensing prism having an entrance surface formed in a convex polygonal pyramid shape having four or more corners and an exit surface formed in a plane perpendicular to the optical axis. A laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution is converted onto a phosphor that emits a laser beam in which the wavelength of the irradiated laser beam is converted to a wavelength different from the wavelength. A light collecting prism that collects light so that the intensity distribution is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
A homogenizer comprising a condensing prism in which an incident surface is formed in a plane perpendicular to the optical axis and an output surface is formed in a convex polygonal pyramid shape with four or more corners. A laser beam emitted from a light emitting element that emits a laser beam having a Gaussian light intensity distribution is converted onto a phosphor that emits a laser beam in which the wavelength of the irradiated laser beam is converted to a wavelength different from the wavelength. A light collecting prism that collects light so that the intensity distribution is substantially uniform at the center and substantially zero at the peripheral edge surrounding the center;
A homogenizer comprising a condensing prism having an incident surface formed in a convex polygonal pyramid shape with four or more corners and an output surface formed in a convex polygonal pyramid shape with four or more corners. Any one of the homogenizers according to claims 1 to 8, and
A cylindrical shape having a circular or polygonal cross section is disposed between the homogenizer and the phosphor so that the central axis of the cylinder coincides with the optical axis, and the inner surface is formed by a reflection surface of total reflection. A homogenizer device comprising an optical member.   The homogenizer device according to claim 9, wherein the light guide member has an exit area smaller than an entrance area. Any one of the homogenizers according to claims 1 to 8, and
A light emitting element that emits laser light having a Gaussian light intensity distribution;
A phosphor that emits a laser beam in which the wavelength of the irradiated laser beam is converted to a wavelength different from the wavelength;
And a parabolic reflector that reflects the laser light emitted from the phosphor.