JP2014186897A - Light source device, and front lamp for vehicle using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change a tone of radiation light without using plural light emission bodies and an additional component, and form a visual environment more adapted to visual sensitivity.SOLUTION: An LED light source 2 comprises: an LED 22 mounted at a front part of a vehicle, used for a front lamp of a vehicle for radiating to the front, and mounted on a substrate; and fluorescent bodies 23 arranged to cover the LED 22. The LED 22 includes a blue LED. Among the fluorescent bodies 23 arranged on the LED 22, a first fluorescent body 23a arranged near a center on a light emission face, i.e., on an optical axis Ax of the LED 22, and a second fluorescent body 23b arranged at a peripheral part of the first fluorescent body 23a on the light emission face are formed of different materials at different thickness.

Description

  The present invention relates to a light source device used for a vehicle headlamp such as a headlamp or a fog lamp mounted on the front of a vehicle such as an automobile or a motorcycle, and a vehicle headlamp using the same.

  Various vehicle headlamps mounted on vehicles include multi-reflector type headlamps using parabolic multi-reflectors, projector-type headlights using ellipsoidal reflectors and projection lenses, and projections. There is a direct projection type headlight using a lens. These vehicle headlamps can change the color (color temperature) of the light emitted from the vehicle headlamps appropriately so that appropriate lighting can be obtained even if the weather around the vehicle changes or the environment changes. There is a request to make.

  Conventionally, as a light source for a vehicle headlamp, a plurality of light sources that emit different spectrums or an additional optical unit that emits different spectra is used to irradiate the vehicle headlamps. A part of the color of the light was changed to form a visual environment more adapted to the visibility.

  Here, the visibility means the degree of brightness perceived by the human eye. Normally, the visibility characteristics of the human eye are darker than the red color of the photoreceptor cell that recognizes the periphery of the field of view. It is said that blue is more sensitive. Therefore, when the surrounding environment is dark, visibility can be ensured by illuminating with irradiation light containing a large amount of blue components. However, the photoreceptor cone that recognizes the center of the field of view, such as the color and shape of the object, is more sensitive to light that contains more red components. Therefore, the irradiation amount of the red component light is increased in a predetermined area where there is a thing (a road sign, a road sign, etc.) that is desired to be recognized in the irradiation area, such as a color or a shape, than in other areas. As a result, the recognizability can be improved. In this way, the visual cells of the human eye have a rod that controls peripheral vision and a cone that controls central vision, and each has different visual characteristics. Development of a vehicular headlamp that improves recognition is desired.

  By the way, in recent years, as a light source for vehicle headlamps, LEDs (Light Emitting Diodes), which have a longer lifespan and better power-saving environmental performance than halogen light bulbs, have been increasingly used. It is becoming. As a vehicle headlamp using such an LED as a light source, for example, a vehicle headlamp having an LED light source formed by arranging a plurality of LED groups each including a red LED, a green LED, and a blue LED has been developed (for example, a patent). Reference 1).

  In such a vehicle headlamp disclosed in Patent Document 1, human visual sensitivity characteristics are taken into consideration, and when the surrounding environment is dark by irradiating the front of the vehicle with light containing more blue component light than red component light. While ensuring visibility and irradiating the predetermined region in the irradiation region with light containing a larger amount of red component light than other regions, the color and shape recognition in the predetermined region can be improved. It is like that.

JP 2008-204727 A

  However, in the vehicle headlamp of Patent Document 1, in order to ensure visibility when the surrounding environment is dark and to improve recognition in a predetermined region in the irradiation region, a plurality of light emitters (red LED, green) It is necessary to arrange a plurality of LED groups having LEDs and blue LEDs), and a cooling mechanism and a circuit are necessary for each of the plurality of light emitters. Therefore, as the number of parts increases, There was concern that it would increase costs.

  Therefore, the present invention has been made in view of the above-described circumstances, and in a light source device and a vehicle headlamp using the light source device, it is possible to change the color of irradiation light without using a plurality of light emitters and additional components. It is possible to form a visual environment adapted to the visibility.

In order to solve the above-described problem, a light source device according to claim 1 includes:
A light-emitting element mounted on a substrate and used for a vehicle headlamp that emits light toward the front, and a phosphor that is disposed so as to cover the light-emitting surface of the light-emitting element A light source device comprising:
The light emitting element is a blue LED, and among the phosphors disposed on the light emitting element, the first phosphor disposed near the center on the light emitting surface on the optical axis of the light emitting element; The second phosphor disposed in the periphery of the first phosphor on the light emitting surface is formed of a different material or thickness.

At this time, the invention according to claim 2 is the light source device according to claim 1,
The first phosphor and the second phosphor are:
Either one is made of a fluorescent material containing a red component or a green component, and the other is made of a fluorescent material containing a yellow component.

Moreover, invention of Claim 3 is a light source device of Claim 1,
The first phosphor and the second phosphor are:
The thickness of either one is 0.05 mm or less at the maximum, and the thickness of the other is 0.06 mm or more at the minimum.

Furthermore, the invention according to claim 4 is the light source device according to any one of claims 1 to 3,
The first phosphor and the second phosphor have different emission spectrum distributions, and the scotopic brightness obtained by the product of the respective spectral characteristics and scotopic visual sensitivities, and the respective spectral distribution characteristics. When the ratio of the photopic brightness determined by the product of the photopic sensitivity and the S / P ratio is
The S / P ratio of one of the first and second phosphors is about 1.5 or less, and the other S / P ratio is 2.0 or more.

Furthermore, the invention according to claim 5 is the light source device according to claim 4,
When one of the first and second phosphors is made of a fluorescent material containing a red component and a green component, and the S / P ratio is 2.0 or more, three or more wavelength peaks are obtained. It is characterized by having.

Furthermore, the invention according to claim 6 is the light source device according to claim 4,
One of the first and second phosphors has a thickness that is thinner than the other, and has two wavelength peaks when the S / P ratio is 2.0 or more. .

The vehicle headlamp according to claim 7 is:
A vehicle headlamp that includes the light source device according to claim 4 and that is mounted on a front portion of the vehicle and irradiates light emitted from the light source device forward.
The light emitted from the light emitting element via the first or second phosphor having an S / P ratio of 2.0 or more is horizontally left and right around a vertical line on a virtual screen in front of the vehicle. Irradiate the surrounding area of about 10 ° or more,
Light emitted from the light-emitting element via the second or first phosphor having an S / P ratio of 1.5 or less is horizontally left and right around a vertical line on a virtual screen in front of the vehicle. It is characterized by irradiating the central region within about 10 °.

According to the light source device of the present invention, in the light source device used for the vehicle headlamp, the light emitting element is a blue LED, and the phosphor disposed on the light emitting element is on the optical axis of the light emitting element. The first phosphor disposed in the vicinity of the center on the light emitting surface and the second phosphor disposed on the periphery of the first phosphor on the light emitting surface are formed by different materials or thicknesses, respectively. .
At this time, it is preferable that one of the first phosphor and the second phosphor is made of a fluorescent material containing a red component and a green component, and the other is made of a fluorescent material containing a yellow component.
Alternatively, it is preferable that the thickness of one of the first phosphor and the second phosphor is 0.05 mm or less at the maximum and the thickness of the other is 0.06 mm or more at the minimum.
In addition, the first phosphor and the second phosphor have different emission spectrum distributions, and one of the S / P ratios is about 1.5 or less, and the other S / P ratio is It is desirable to set it to 2.0 or more.

  As a result, among the light emitted from the light source device, the hue of the light emitted through the first phosphor and the light emitted through the second phosphor can be changed, and the lights having different colors. (E.g., light with a lot of red component and light with a lot of blue component) into a central area centered on a vertical line and a horizontal left and right peripheral area centered on the vertical line on the virtual screen in front of the vehicle Irradiate with appropriate light distribution. In this case, light with a large amount of red component is applied to the central area centered on the vertical line on the virtual screen in front of the vehicle, and light with a large amount of blue component is emitted in the horizontal direction centered on the vertical line on the virtual screen in front of the vehicle. The light is distributed so as to irradiate the left and right peripheral areas. As a result, the visibility when the surrounding environment is dark can be ensured, and the recognizability in a predetermined area in the irradiation area can be improved, and a visual environment more suitable for the visibility can be formed. At this time, since no additional parts as in the prior art are required, the apparatus is not increased in size and cost.

  Further, according to the vehicle headlamp of the present invention, the light emitting element is a blue LED, and among the phosphors arranged on the light emitting element, near the center on the light emitting surface on the optical axis of the light emitting element. The first phosphor arranged and the second phosphor arranged in the peripheral portion of the first phosphor on the light emitting surface each include a light source device formed of a different material or thickness, and the light emission The light emitted from the element through the first or second phosphor having an S / P ratio of 2.0 or more is about 10 ° or more in the horizontal direction around the vertical line on the virtual screen in front of the vehicle. The light emitted from the light emitting element via the second or first phosphor having an S / P ratio of 1.5 or less is centered on the vertical line on the virtual screen in front of the vehicle. About 10 ° or more on the left and right in the horizontal direction The center area was irradiated.

  As a result, of the light emitted from the light source device, the light emitted through the first or second phosphor having an S / P ratio of 2.0 or more (for example, light with a large blue component), and S / P The hue of light (for example, light with a large red component) emitted through the second or first phosphor having a ratio of 1.5 or less can be changed. Then, light of different colors is appropriately distributed and irradiated to a central region centered on a vertical line on the virtual screen in front of the vehicle and a horizontal left and right peripheral region centered on the vertical line. In this case, light with a large amount of red component is applied to the central area centered on the vertical line on the virtual screen in front of the vehicle, and light with a large amount of blue component is emitted in the horizontal direction centered on the vertical line on the virtual screen in front of the vehicle. The light is distributed so as to irradiate the left and right peripheral areas. As a result, the visibility when the surrounding environment is dark can be ensured, and the recognizability in a predetermined area in the irradiation area can be improved, and a visual environment more suitable for the visibility can be formed. At this time, since no additional parts as in the prior art are required, the apparatus is not increased in size and cost.

  Thus, according to the light source device of the present invention and the vehicle headlamp using the light source device, it is possible to change the color of the irradiation light without using a plurality of light emitters and additional parts, and to achieve a more suitable visual sensitivity. An environment can be formed.

It is sectional drawing which shows roughly the vehicle headlamp which concerns on one Embodiment of this invention. It is sectional drawing and a top view which show roughly the light source device used for the vehicle headlamp of FIG. It is a schematic diagram which shows the light distribution by the vehicle headlamp of FIG. 1, and the light distribution pattern by it. It is a graph which shows the emission spectrum distribution of the light radiate | emitted through the 2nd fluorescent substance in the light source device of FIG. It is a graph which shows the emission spectrum distribution of the light radiate | emitted through the 1st fluorescent substance in the light source device of FIG. It is a bird's-eye view which shows the light distribution range in the vehicle headlamp of FIG. It is a schematic diagram which shows the image of the light distribution range in the vehicle headlamp of FIG. It is sectional drawing which shows roughly the modification of the light source device of this invention. It is sectional drawing which shows roughly the modification of the light source device of this invention. It is sectional drawing which shows roughly the modification of the light source device of this invention. It is a graph which shows the emission spectrum distribution of the light radiate | emitted through the 1st fluorescent substance in the light source device of FIG. 9 and FIG.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.
FIG. 1 is a cross-sectional view schematically showing a vehicle headlamp 1 in the present embodiment, and FIG. 2A schematically shows an LED light source 2 used in the vehicle headlamp 1 of FIG. 2 (b) is a top view schematically showing an LED light source 2 used in the vehicle headlamp 1 of FIG. 1, and FIG. 3 is a vehicle headlamp of FIG. 2 is a schematic diagram showing a light distribution in 1 and a light distribution pattern thereby. FIG. FIG. 4 is a graph showing the emission spectrum distribution of the light emitted through the first phosphor 23a in the LED light source 2 of FIG. 2, and FIG. 5 shows the second phosphor 23b in the LED light source 2 of FIG. It is a graph which shows the emission spectrum distribution of the light radiate | emitted via.
In the following description, the terms “front”, “rear”, “upper”, “lower”, “left”, and “right” refer to the direction viewed from the vehicle headlamp 1, that is, the vehicle, unless otherwise specified. It shall refer to the direction seen from the vehicle on which the headlight 1 is mounted, and shall be used in correspondence with the description in the drawings. Further, in the following description, a case where the vehicle headlamp 1 is applied to a headlamp attached to the front left and right of a left-passing vehicle having the right side of the vehicle as a driver seat will be described, but the present invention is not limited to this. It can be widely applied to lamps mounted on the front part of the vehicle such as fog lamps, and it is suitable for right-hand traffic using the left side of the vehicle as the driver's seat by changing the following lamp configuration and arrangement as appropriate. Needless to say, the present invention can also be applied as a headlamp of a vehicle or the like.

As shown in FIG. 1, a vehicle headlamp 1 according to the present embodiment is a so-called reflector type lamp unit that is mounted on a front portion of a vehicle (not shown) and used for a headlamp that irradiates light in front of the vehicle. Here, since a parabolic multi-reflector (reflector 3 to be described later) is used, it is generally called a multi-reflector type lamp unit.
The vehicular headlamp 1 irradiates light emitted from the LED 22 by being disposed so as to cover the LED light source 2 and an LED light source 2 as a light source device in which an LED 22 as a light emitting element is mounted on a substrate 21. A reflector 3 having a reflection surface 3a reflecting forward in the direction, a housing 4 surrounding the LED light source 2 and the reflector 3, and an outer lens 5 made of a transparent material closing the open front end of the housing 4. And a heat sink 6 disposed in thermal contact with the substrate 21. In addition, the board | substrate 21 is arrange | positioned substantially parallel to the installation part of the heat sink 6, and LED22 is mounted in the lower surface.

  The reflector 3 is formed from a resin material and includes a parabolic reflecting surface having a focal point in the vicinity of the LED 22 on the substrate 21. The reflector 3 is connected to the lower surface of the substrate 21 via a heat insulating member 7 made of a material having low thermal conductivity, for example, a resin material such as polyimide, grease or adhesive. At this time, the heat insulating member 7 is preferably made of a resin material having a low embrittlement temperature and a high load deflection temperature. The reflecting surface 3a of the reflector 3 is formed by a reflecting film provided by a technique such as aluminum vapor deposition or silver coating.

  The housing 4 has an open front surface and an opening 4a on the upper surface. The substrate 2 is attached via a heat sink 6 so as to seal the opening 4a. The heat sink 6 is made of a material having good thermal conductivity, and is thermally connected to the upper surface of the substrate 2 via a sheet-like heat conductive member 6a.

  In the case of this embodiment, as shown in FIG. 2, the LED light source 2 is configured such that the LED 22 mounted on the substrate 21 (see FIG. 1) is configured by, for example, a blue LED and covers the light emitting surface of the LED 22. A phosphor 23 is provided. Of the phosphors 23 disposed on the light emitting surface of the LED 22, the first phosphor 23a disposed near the center of the light emitting surface on the optical axis Ax of the LED 22, and the first phosphor 23a on the light emitting surface. The second phosphors 23b disposed in the periphery of each are formed of different materials.

  Specifically, one of the first phosphor 23a and the second phosphor 23b is made of a fluorescent material containing a red component or a green component (for example, a BOS material such as barium or orthosilicate), and the other. Is made of a fluorescent material containing a yellow component (for example, YAG-based material such as yttrium, aluminum, garnet). In this case, the first phosphor 23a is formed of a fluorescent material containing a yellow component, and the second phosphor 23b is formed of a fluorescent material containing a red component and a green component.

  According to the vehicular lamp 10 having such a configuration, as shown in FIG. 3, the LED 22 on the substrate 21 of the LED light source 2 is driven to emit light, and the light emitted from the light emitting surface of the LED 22 is reflected by the reflector 3. And is irradiated forward in the light irradiation direction through the outer lens 5 (see FIG. 1).

  At this time, out of the light emitted from the LED light source 2, the light L1 emitted in the range of 20 ° around the optical axis Ax via the first phosphor 23a and the first via the second phosphor 23b. It becomes possible to change the hue of the light L2 and L3 emitted from the periphery of the phosphor 23a. That is, among the light emitted from the light emitting surface of the LED 22, the light emitted through the first phosphor 23a is colored by the first phosphor 23a, so that there are three or more as shown in FIG. The light L1 having a blue component having a wavelength having an emission spectrum distribution with a peak and having a large blue component and emitted through the second phosphor 23b is colored by the second phosphor 23b. It becomes light L2 and L3 with many red components which consist of the wavelength which has the emission spectrum distribution shown.

  More specifically, the first phosphor 23a and the second phosphor 23b have different emission spectrum distributions, and the scotopic luminance determined by the product of the respective spectral characteristics and scotopic sensitivity. And the ratio of the photopic brightness determined by the product of the respective spectral distribution characteristics and photopic sensitivity is the S / P ratio, the S / P ratio of the first phosphor 23a is 2.0 or more. Thus, the S / P ratio of the second phosphor 23b is about 1.5 or less.

  Here, the S / P ratio will be described based on known cases. The spectral distribution of light emitted from the LED 22 is f (λ), the photosensitivity characteristic of photopic vision is g (λ), and the photosensitivity characteristic h (λ) of scotopic vision is that of all wavelengths in the visible light region. It is assumed that ∫f (λ) · g (λ) dλ and ∫f (λ) · h (λ) dλ are obtained in the range. At this time, the former value is called photopic brightness Lp, and the latter value is called scotopic brightness Ls. Further, the ratio (= Ls / Lp) of the dark place visual brightness Ls to the light place visual brightness Lp is referred to as an S / P ratio.

  In general, it is said that the higher the photopic brightness Lp at the center of the human visual field, the higher the visibility, and the higher the scotopic visual brightness Ls at the peripheral part of the visual field, the higher the visibility. Therefore, it is known that the smaller the S / P ratio, the higher the visibility in the region corresponding to the central portion of the visual field, and the higher the visibility in the region corresponding to the peripheral portion of the visual field. .

  In the present embodiment, based on the above-described phenomenon, light of different colors (light L1 with a lot of blue components, light L2 and L3 with a lot of red components) is centered on a vertical line VV on a virtual screen in front of the vehicle. Within about 10 ° each on the left and right in the horizontal direction centered on the vertical line VV on the virtual screen in front of the vehicle and the surrounding irradiation region Q1 (peripheral region) of about 10 ° or more in the horizontal direction (HH) The irradiation region Q2 (the central region in the irradiation region Q1) was appropriately distributed and irradiated.

  Specifically, among the light of different colors (light L1 having a large blue component, light L2 and L3 having a large red component), the light L1 having a large blue component is centered on the vertical line VV on the virtual screen in front of the vehicle. In the horizontal direction (H-H), the left and right peripheral irradiation areas Q1 are distributed and irradiated (see FIG. 3). At this time, the first phosphor 23a is made of a fluorescent material containing a red component and a green component, and the S / P ratio is 2.0 or more, so that the first phosphor 23a is emitted through the first phosphor 23a. The light becomes light L1 with a large blue component having a wavelength having an emission spectrum distribution (see FIG. 4) having three or more wavelength peaks. Further, light L2 and L3 having a large amount of red component is distributed and applied to an irradiation area Q2 (a predetermined area in the irradiation area Q1) centered on the vertical line VV on the virtual screen in front of the vehicle (see FIG. 3). .

  Thereby, for example, as shown in FIG. 6 (bird's-eye view showing the light distribution range in the vehicle headlamp 1) and FIG. 7 (schematic diagram showing an image of the light distribution range in the vehicle headlamp 1), Even when the surrounding environment K1 irradiated by the irradiation area Q1 (see FIG. 3) is dark, it becomes possible to ensure the visibility of pedestrians, road signs, etc., and the irradiation area Q2 (see FIG. 3) in front of the vehicle. The recognizability for oncoming vehicles, road markings, and the like in the central environment K2 to be irradiated can also be improved.

  The heat generated from the LED 22 is transmitted from the substrate 21 to the heat sink 6 via the heat conducting member 6a, and is released from the heat sink 6 to the outside of the housing 4, whereby the temperature rise of the LED 22 is suppressed. ing.

  In this case, since the reflector 3 is connected to the substrate 21 via the heat insulating member 7, the heat generated from the LED 22 is difficult to transfer from the substrate 21 to the reflector 3 by the heat insulating member 7. Therefore, the reflector 3 is partially melted and deformed at the contact surface with the substrate 21 so that the melting point is not exceeded by the heat from the LED 22 by suppressing the temperature rise due to the heat from the LED 22. There is nothing to do. Therefore, the use of the LED light source 2 can prevent the reflection characteristics and light distribution characteristics of the reflector 3 from being impaired.

As described above, in the vehicle headlamp 1 according to the present embodiment, the LED light source 2 used in the vehicle headlamp 1 includes the LED 22 made of a blue LED, and the fluorescent light disposed on the LED 22 element. Of the body 23, a first phosphor 23a disposed in the vicinity of the center on the light emitting surface on the optical axis Ax of the LED 22, and a second fluorescence disposed on the periphery of the first phosphor 23a on the light emitting surface. The body 23b is made of different materials.
Specifically, the first phosphor 23a is made of a fluorescent material containing a yellow component, and the second phosphor 23b is made of a fluorescent material containing a red component and a green component.
At this time, the S / P ratio of the first phosphor 23a is 2.0 or more, and the S / P ratio of the second phosphor 23b is about 1.5 or less.

  As a result of adopting the LED light source 2, among the light emitted from the LEDs 22 of the LED light source 2, the light emitted through the first phosphor 23 a becomes the light L <b> 1 having a large blue component, and passes through the second phosphor 23 b. The emitted light becomes light L2 and L3 with a large red component. That is, the hue can be changed between the light L1 having a large blue component and the lights L2 and L3 having a large red component. Of these light of different colors (light L1 with a lot of blue components, light L2 and L3 with a lot of red components), the light L1 with a lot of blue components is horizontal with a vertical line VV on the virtual screen in front of the vehicle as the center. Light is distributed and irradiated to the irradiation region Q1 around the left and right in the direction (HH). Further, light L2 and L3 having a large amount of red component is distributed and irradiated to the irradiation region Q2 on the center side centered on the vertical line VV on the virtual screen in front of the vehicle. That is, the light L1 rich in blue component and the light L2 and L3 rich in red component are appropriately distributed and irradiated.

Thereby, even when the surrounding environment K1 irradiated by the irradiation area Q1 in front of the vehicle is dark, it becomes possible to ensure the visibility of pedestrians, road signs, etc., and the center irradiated by the irradiation area Q2 in front of the vehicle Since it is possible to improve the recognition of oncoming vehicles and road markings in the environment K2, it is possible to form a visual environment that is more adapted to the visibility.
At this time, in such a vehicle headlamp 1, the LED light source 2 does not require any additional parts as in the prior art. Therefore, the device (the LED light source 2 and eventually the vehicle headlamp 1 using it as a light source device) is used. There will be no increase in size or cost.

  Thus, according to the LED light source 2 of the present embodiment and the vehicle headlamp 1 using the LED light source 2, it is possible to change the color of the irradiated light without using a plurality of conventional light emitters and additional parts. Therefore, it is possible to form a visual environment more adapted to the visibility.

  The present invention is not limited to the above-described embodiments, and various improvements and design changes can be made as appropriate without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the vehicle headlamp 1 is applied to a headlamp including a lamp unit of a reflector type (in particular, a multi-reflector type using a parabolic multi-reflector (reflector 3)). However, the present invention is not limited to this, and other types of vehicle headlamps include, for example, a so-called projector type using an ellipsoidal reflector and a projection lens. The present invention can be widely applied to a lamp unit, a so-called direct projection type lamp unit using a projection lens, and the like.

  In the case of the above-described embodiment, the LED light source 2 includes the first phosphor 23a disposed near the center of the light emitting surface on the optical axis Ax of the LED 22 and is formed of a fluorescent material containing a yellow component. Although the case where the second phosphor 23b disposed on the periphery of the first phosphor 23a on the surface is formed of a fluorescent material containing a red component or a green component is described as an example, the present invention is not limited thereto. As shown in FIG. 8 where the same reference numerals are given to corresponding parts to FIG. 2, the first phosphor 23a is formed of a fluorescent material containing a red component and a green component, and the second phosphor 23b contains a yellow component. Alternatively, it may be formed of a fluorescent material.

  In this case, the light emitted through the first phosphor 23a becomes light L2 and L3 with a lot of red components, and the light emitted through the second phosphor 23b becomes light L1 with a lot of blue components. Therefore, light L2 and L3 with a large amount of red component emitted through the first phosphor 23a is distributed and emitted to the irradiation region Q2 on the vehicle front center side, and is emitted through the second phosphor 23b. By distributing and irradiating light L1 having a large blue component to the irradiation areas Q1 in the horizontal direction (HH) in the horizontal direction (HH) on the virtual screen in front of the vehicle, the same excellent effects as those of the above-described embodiment can be obtained. Can do.

  Further, in the above-described embodiment, among the phosphors 23 arranged on the light emitting surface of the LED 22, the first phosphor 23a arranged near the center of the light emitting surface on the optical axis Ax of the LED 22, and the light emission. The case where the second phosphors 23b arranged on the periphery of the first phosphors 23a on the surface are formed of different materials has been described, but the present invention is not limited to this, and the first phosphors 23a are not limited thereto. And the second phosphor 23b may be formed with different thicknesses.

  Specifically, for example, as shown in FIG. 9 and FIG. 10 in which the same reference numerals are given to corresponding parts to FIG. 2, the thickness of either the first phosphor 23a or the second phosphor 23b is maximized. The thickness is 0.05 mm or less (the first phosphor 23a in FIG. 9 and the second phosphor 23b in FIG. 10), and the other thickness is at least 0.06 mm (the second phosphor 23b in FIG. 9 and the first fluorescence in FIG. 10). The body 23a) is preferred.

  At this time, either the first phosphor 23a or the second phosphor 23b is thinner than the other, like the first phosphor 23a in FIG. 9 and the second phosphor 23b in FIG. In addition, when the S / P ratio is 2.0 or more, the light emitted through the first phosphor 23a in FIG. 9 and the second phosphor 23b in FIG. It can be set as light L1 with many blue components which has the emission spectrum distribution provided with the wavelength peak. Therefore, the light L1 having a large blue component is distributed and irradiated to the irradiation area Q1 in the horizontal direction (HH) around the vertical line VV on the virtual screen in front of the vehicle described above. Thus, even when the surrounding environment K1 irradiated by the irradiation region Q1 in front of the vehicle is dark, it is possible to ensure the visibility of pedestrians, road signs, and the like.

  Further, in the above-described embodiment, the case where the reflector 3 is provided with the parabolic reflecting surface 3a having a focal point in the vicinity of the LED 22 on the substrate 21 is described as an example, but the present invention is not limited to this. Absent. In other words, the reflector 3 can be appropriately changed depending on the type of the vehicle headlamp 1. For example, the reflector 3 has a substantially bowl shape, opens forward, and the reflection surface is formed in an elliptical shape. good. Here, the elliptical surface means a rotational elliptical surface or a flat elliptical surface having a central axis extending in the front-rear direction as a rotational axis, or a free curved surface based on these. A flat ellipsoid is a spheroid whose top and bottom or left and right are crushed. The vertical cross section along the front-rear direction has an elliptical shape, and the horizontal cross section has a parabolic or elliptical shape (vertical cross section). The focal length of the elliptical shape is different from the focal length of the elliptical shape of the horizontal section). The reflecting surface may be a compound ellipsoid obtained by combining these spheroids, flat ellipsoids, or free-form surfaces.

DESCRIPTION OF SYMBOLS 1 ... Vehicle headlamp 2 ... LED light source (light source device)
21 ... Substrate 22 ... LED (light emitting element)
DESCRIPTION OF SYMBOLS 23 ... Phosphor 23a ... 1st fluorescent substance 23b ... 2nd fluorescent substance 3 ... Reflector 3a ... Reflecting surface L1 ... Light with many blue components L2, L3 ... Light with many red components Q1 ... Irradiation area Q2 ... Irradiation area K1 ... Periphery Environment K2 ... Central environment Ax ... Optical axis

Claims (7)

A light-emitting element mounted on a substrate and used for a vehicle headlamp that emits light toward the front, and a phosphor that is disposed so as to cover the light-emitting surface of the light-emitting element A light source device comprising:
The light emitting element is a blue LED, and among the phosphors disposed on the light emitting element, the first phosphor disposed near the center on the light emitting surface on the optical axis of the light emitting element; A light source device, wherein the second phosphor disposed in the periphery of the first phosphor on the light emitting surface is formed of a different material or thickness. The first phosphor and the second phosphor are:
2. The light source device according to claim 1, wherein either one is made of a fluorescent material containing a red component or a green component, and the other is made of a fluorescent material containing a yellow component. The first phosphor and the second phosphor are:
2. The light source device according to claim 1, wherein the thickness of one of the maximum is 0.05 mm or less and the thickness of the other is 0.06 mm or less. The first phosphor and the second phosphor have different emission spectrum distributions, and the scotopic brightness obtained by the product of the respective spectral characteristics and scotopic visual sensitivities, and the respective spectral distribution characteristics. When the ratio of the photopic brightness determined by the product of the photopic sensitivity and the S / P ratio is
The S / P ratio of one of the first and second phosphors is about 1.5 or less, and the other S / P ratio is 2.0 or more. The light source device according to claim 1.   When one of the first and second phosphors is made of a fluorescent material containing a red component and a green component, and the S / P ratio is 2.0 or more, three or more wavelength peaks are obtained. The light source device according to claim 4, further comprising:   One of the first and second phosphors has a thickness that is thinner than the other, and has two wavelength peaks when the S / P ratio is 2.0 or more. The light source device according to claim 4. A vehicle headlamp that includes the light source device according to claim 4 and that is mounted on a front portion of the vehicle and irradiates light emitted from the light source device forward.
The light emitted from the light emitting element via the first or second phosphor having an S / P ratio of 2.0 or more is horizontally left and right around a vertical line on a virtual screen in front of the vehicle. Irradiate the surrounding area of about 10 ° or more,
Light emitted from the light-emitting element via the second or first phosphor having an S / P ratio of 1.5 or less is horizontally left and right around a vertical line on a virtual screen in front of the vehicle. A vehicle headlamp characterized by irradiating a central region within about 10 °.