FORM 2
THE PATENT ACT 1970
(39 of 1970)
AND
THE PATENT RULES, 2005
COMPLETE SPECIFICATION (SEE SECTION 10 AND RULE 13)
TITLE OF THE INVENTION
LIGHT SOURCE APPARATUS AND METHOD FOR MANUFACTURING THEREOF
APPLICANTS
TATA MOTORS LIMITED
an Indian company having its registered office
at Bombay house, 24 Homi Mody Street,
Hutatma Chowk, Mumbai 400 001,
Maharashtra, India.
And
TATA MOTORS EUROPEAN TECHNICAL CENTRE plc,
18 Grosvenor Place, London, SW1X 7HS, United Kingdom
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
[0001] The present disclosure relates to a light source apparatus, and more specifically related to the light source apparatus including a phosphor member arranged adjacent to a heat sink source.
BACKGROUND OF THE INVENTION
[0002] Vehicle front-end package is very congested and all manufactures of the vehicle front-end package are struggling for space. Some laser assisted headlamps exists in the vehicle. However, the laser assisted headlamps are only high beam booster systems and still rely on traditional illumination and optics. Hence, these laser assisted headlamps do not deliver package space improvements. FIG. 1a-FIG. 1e illustrates various arrangements of standard headlight systems.
[0003] Thus, it is desired to address the above mentioned disadvantages or other shortcomings or at least provide a useful alternative.
OBJECT OF THE INVENTION
[0004] The principal object of the embodiments herein is to provide a light source apparatus and a method for manufacturing the light source apparatus.
[0005] Another object of the embodiment herein is to provide a wavelength converter disposed adjacent to a laser diode and a heat sink source in the light source apparatus.
[0006] Another object of the embodiment herein is to provide a light guide for introducing a wavelength of the laser light from the laser diode.

[0007] Another object of the embodiment herein is to provide a phosphor member disposed along a side surface of the light guide.
[0008] Another object of the embodiment herein is to provide the phosphor member for converting the wavelength of the laser light introduced into the light guide and providing the converted wavelength of the laser light.
SUMMARY OF THE INVENTION
[0009] Accordingly, embodiments herein disclose a light source apparatus includes a heat sink source and a laser diode for emitting a wavelength of a laser light. A wavelength converter is arranged adjacent to the laser diode and the heat sink source. The wavelength converter includes a light guide to introduce the wavelength of the laser light from the laser diode. A phosphor member is arranged along a side surface of the light guide to convert the wavelength of the laser light introduced into the light guide and provide the converted wavelength of the laser light.
[0010] In an embodiment, the light guide includes an entry aperture to introduce the wavelength of the laser light from the laser diode into the light guide and an exit aperture to introduce the wavelength of the laser light into the phosphor member.
[0011] In an embodiment, the laser diode comprises at least one high-beam Laser Activated Remote Phosphor (LARP) module to generate a high beam LARP, at least one low beam LARP module to generate a low beam LARP, and a Daytime Running Lamp (DRL).
[0012] In an embodiment, the phosphor member is mounted adjacent to the heat sink source for providing a sharp cut-off.

[0013] In an embodiment, the light guide includes a light reflecting film formed over a surface of the light guide.
[0014] In an embodiment, the light reflecting film is a blue pass dichroic filter.
[0015] In an embodiment, the heat sink source is made of aluminum.
[0016] Accordingly, embodiments herein disclose a method for fabricating a light source apparatus. The method includes providing a heat sink source and providing a laser diode for emitting a wavelength of a laser light. Further, the method includes depositing a laser guide adjacent to the laser diode and the heat sink source. Further, the method includes forming a phosphor member along a side surface of the light guide. Further, the method includes introducing the wavelength of the laser light into the light guide and converting the wavelength of the laser light introduced into the light guide using the phosphor member. Further, the method includes providing the converted wavelength of the laser light.
[0017] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF FIGURES
[0018] This method and system is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in

the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0019] FIG. 1a-FIG. 1e illustrate various arrangements of standard headlight systems;
[0020] FIG. 2 is a schematic side view of a light source apparatus, according to an embodiment as disclosed herein;
[0021] FIG. 3 is a schematic side view of a laser diode included in the light source apparatus, according to an embodiment as disclosed herein;
[0022] FIG. 4a is a front view of a radiator and cooling system with the standard headlight systems;
[0023] FIG. 4b is a back view of the radiator and cooling system, according to an embodiment as disclosed herein;
[0024] FIG. 5a illustrates a low beam projection pattern, according to an embodiment as disclosed herein;
[0025] FIG. 5b illustrates a high beam projection pattern, according to an embodiment as disclosed herein;
[0026] FIG. 6 is a flow chart illustrating a method for fabricating the light source apparatus, according to an embodiment as disclosed herein;
[0027] FIG. 7a and FIG. 7b illustrate various arrangements of proposed headlight systems, according to an embodiment as disclosed herein;
[0028] Fig. 8 illustrates an operation and function of the blue pass dichroic filter, according to an embodiment as disclosed herein; and

[0029] Fig. 9 is a graph illustrating various spectrum characteristics, according to an embodiment as disclosed herein.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The term “or” as used herein, refers to a non-exclusive or, unless otherwise indicated. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0031] The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another.
[0032] Accordingly, embodiments herein achieve a light source apparatus includes a heat sink source and a laser diode for emitting a wavelength of a laser light. A wavelength converter is arranged adjacent to the laser diode and the heat

sink source. The wavelength converter includes a light guide to introduce the wavelength of the laser light from the laser diode. A phosphor member is arranged along a side surface of the light guide to convert the wavelength of the laser light introduced into the light guide and provide the converted wavelength of the laser light.
[0033] Unlike conventional systems, the wavelength converter includes the light guide to introduce the wavelength of the laser light from the laser diode. The phosphor member is arranged along the side surface of the light guide to convert the wavelength of the laser light introduced into the light guide and provide the converted wavelength of the laser light. This results in reducing the size of the light source apparatus (e.g., headlamp system or the like) and achieving a revised front-end package improvement, providing disruptive aesthetic design, improving fuel economy and engine output.
[0034] The light source apparatus is configured to provide a better aerodynamic design and reduce vehicle drag problem and wind induced cabin noise problem. The light source apparatus ensures the safety of human eye.
[0035] Referring now to the drawings, and more particularly to FIGS. 2 through 9, there are shown preferred embodiments.
[0036] FIG. 2 is a schematic side view of a light source apparatus (100), according to an embodiment as disclosed herein. In an embodiment, the light source apparatus (100) includes a heat sink source (112) and a laser diode (104) for emitting a wavelength of a laser light. The laser diode (104) is an edge-emitting semiconductor laser including a semiconductor layer made of Gallium nitride (GaN) or any other suitable nitride-based semiconductor and emitting the light having a wavelength of about 450 nm through an end surface or facet of a semiconductor chip (not shown). The light source apparatus (100) can be

constructed which is capable of securing a uniform luminance distribution and a uniform luminous color.
[0037] In an embodiment, the heat sink source (112) is made of aluminum, copper or any other material having high heat conductivity to allow the heat from the laser to be removed. A wavelength converter (114) is arranged adjacent to the laser diode (104) and the heat sink source (112). The wavelength converter (114) includes a light guide (102) to introduce the wavelength of the laser light from the laser diode (104). A phosphor member (110) is arranged along a side surface (108) of the light guide (102) to convert the wavelength of the laser light introduced into the light guide (102) and provide the converted wavelength of the laser light. The light guide (102) is formed of a light-transmissive cylindrical glass member.
[0038] Further, arranging the wavelength converter (114) and the laser diode 104 adjacent to each other allows the size of the light source apparatus (100) to be compact and the time of flight of the laser light required to reach the light source apparatus (100) to be shortened.
[0039] In an embodiment, the light guide (102) is configured to side pump the phosphor member (110) mounted adjacent to a corner of the heat sink source (112).
[0040] The phosphor member (110) has a particle diameter of 10 μm or less or, more favorably, 5 μm or less, so that the phosphor member (110) absorbs a blue light with a wavelength of around 450 nm that is outputted from the laser diode (104) into a yellow light having a luminescence peak at a wavelength of around 560 nm.
[0041] In an embodiment, the light guide (102) includes an entry aperture (not shown) to introduce the wavelength of the laser light from the laser diode

(104) into the light guide (102) and an exit aperture (not shown) to introduce the wavelength of the laser light into the phosphor member (100).
[0042] The laser beam introduced into the light guide (102) is diffused in random directions by internal arrangements of the light guide (102), and is outputted as a diffused light from a light-emitting region (not shown) at which is not covered by the light reflecting film (106) and enters into the phosphor member (110).
[0043] In an embodiment, the laser diode (104) comprises at least one high-beam LARP module (116) to generate a high beam LARP, at least one low beam LARP module (120) to generate a low beam LARP, and a Daytime Running Lamp (DRL) (118) as shown in the FIG. 3. The at least one low beam LARP module (120) will adopt a number of elements, as shown in the FIG. 2, in order to develop the low beam pattern as required by legislation (as shown in the FIG. 5a).
[0044] The at least one low beam LARP module (120) provides the required beam pattern, as per ECE R20. The at least one high-beam LARP module (116) provides the long distance headlamp pattern as shown in the FIG. 5b. The daytime running lamp (118) can be an LED marker lamp, as seen on a number of traditional headlamp vehicles.
[0045] In an example, as shown in the FIG. 3, the size of the visible lamp is 25cm2 and lamp maximum boundary is 35 x 200 CM2.
[0046] In an embodiment, the phosphor member (110) is mounted adjacent to the heat sink source (112) for providing a sharp cut-off. The sharp cut¬off enable the light source apparatus (100) to provide the beam pattern as required in regulations (as shown in the FIG. 5a).

[0047] In an embodiment, the light guide (102) includes a light reflecting film (106) formed over a surface of the light guide (102). The light reflecting film is a blue pass dichroic filter. The light reflecting film (106) is made of a material having a high reflectance and a high thermal conductivity such as Silver (Ag), Aluminum (Al), or other metals.
[0048] In an embodiment, size and usage of the light guide (102), the laser diode (104), and the phosphor member (110) are adjusted based on the implementation.
[0049] FIG. 4a is a front view of a radiator and cooling system with the standard headlight systems. The radiator and cooling system includes an aperture (140) for flow path over engine compromised by height of radiator pack and slam panel and convoluted package (128) for top hose, header tank, etc.
[0050] FIG. 4b is a back view of the radiator and cooling system, according to an embodiment as disclosed herein. FIG. 4b illustrates the radiator and cooling system after the standard headlamp systems has been replaced by a smaller package LARP unit. The radiator and cooling system includes a package opportunity (130) for improved ducting all around matrix, possible increased aperture (132) arranged above the radiator, convoluted flow path if slam panel is relocated, hoses arrangement (134), bumper beam arrangement (136) and revised matrix aspect, reduced area (138).
[0051] The proposed light source apparatus (100) removes a radiator condenser and reduces the cooling drag that substantial saves 2-3% fuel usage. The proposed light source apparatus (100) changes in the number of 3 cooling matrix to 2 matrix which leads approximately 30% reduction in cooling drag.
[0052] FIG. 5a illustrates a low beam projection pattern, according to an embodiment as disclosed herein. The legal requirement for the low beam

headlight beam pattern per ECE R20 for a right hand drive vehicle is depicted in the FIG. 5a. FIG. 5b illustrates high beam projection pattern, according to an embodiment as disclosed herein. The proposed LARP headlamp will meet both of these requirements.
[0053] FIG. 6 is a flow chart 600 illustrating a method for fabricating the light source apparatus (100). At 602, the method includes providing the heat sink source (112). At 604, the method includes providing the laser diode (104) for emitting the wavelength of the laser light. At 606, the method includes depositing the laser guide (102) adjacent to the laser diode (104) and the heat sink source (112). At 608, the method includes forming the phosphor member (608) along the side surface (108) of the light guide (102). At 610, the method includes introducing the wavelength of the laser light into the light guide (102). At 612, the method includes converting the wavelength of the laser light introduced into the light guide (102) using the phosphor member (110). At 614, the method includes providing the converted wavelength of the laser light.
[0054] The various actions, acts, blocks, steps, or the like in the flow diagram 600 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some of the actions, acts, blocks, steps, or the like may be omitted, added, modified, skipped, or the like without departing from the scope of the invention.
[0055] FIG. 7a and FIG. 7b illustrate various arrangements of proposed headlight systems, according to an embodiment as disclosed herein.
[0056] Fig. 8 illustrates an operation and function of the blue pass dichroic filter, according to an embodiment as disclosed herein. The blue pass dichroic filter is also called as a phosphor conversion plate. The blue pass dichroic filter converts the light from a blue spectrum (resultant from the high power laser diode (104)) to mixed white light. This is shown in the FIG. 8. This then converts the

blue light to one whose spectrum more closely matches daylight as shown in the FIG. 9.
[0057] The FIG. 9a-9g shows graphs illustrating various spectrum characteristics, according to an embodiment as disclosed herein. FIG. 9a shows the spectrum for the LARP system with the blue pass filter. FIG. 9b shows the spectrum of visible daylight. FIG.9c shows the spectrum of an incandescent bulb. FIG.9d shows the spectrum for a fluorescent tube. FIG. 9e shows the spectrum for a halogen bulb. FIG. 9f shows the spectrum for a cool white LED. It is to be noted that this spectrum is the closest to natural daylight and closely matches that achieved by FIG. 9a. Further, FIG. 9g shows the spectrum for a warm white LED.
[0058] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

We Claim:
1. A light source apparatus (100), comprising:
a heat sink source (112);
a laser diode (104) for emitting a wavelength of a laser light; and a wavelength converter (114), disposed adjacent to the laser diode (104) and the heat sink source (112), comprising:
a light guide (102) to introduce the wavelength of the laser light from the laser diode (104), and
a phosphor member (110), disposed along a side surface (108) of the light guide (102), to convert the wavelength of the laser light introduced into the light guide (102) and provide the converted wavelength of the laser light.
2. The light source apparatus (100) of claim 1, wherein the light guide (102) comprises an entry aperture to introduce the wavelength of the laser light from the laser diode (104) into the light guide (102) and an exit aperture to introduce the wavelength of the laser light into the phosphor member (110).
3. The light source apparatus (100) of claim 1, wherein the laser diode (104) comprises at least one high-beam Laser Activated Remote Phosphor (LARP) module (116) to generate a high beam LARP, at least one low beam LARP module (120) to generate a low beam LARP, and a Daytime Running Lamp (DRL) (118).
4. The light source apparatus (100) of claim 1, wherein mounting the phosphor member (110) adjacent to the heat sink source (112) provides a sharp cut-off.

5. The light source apparatus (100) of claim 1, wherein the light guide (102) comprises a light reflecting film (106) formed over a surface of the light guide (102).
6. The light source apparatus (100) of claim 6, wherein the light reflecting film (106) is a blue pass dichroic filter.
7. The light source apparatus (100) of claim 1, wherein the heat sink source (112) is made of aluminum.
8. A method for fabricating a light source apparatus (100), comprising:
providing a heat sink source (112);
providing a laser diode (104) for emitting a wavelength of a laser light;
depositing a laser guide (102) adjacent to the laser diode (104) and the heat sink source (112);
forming a phosphor member (110) along a side surface of the light guide (102);
introducing the wavelength of the laser light into the light guide (102);
converting the wavelength of the laser light introduced into the light guide (102) using the phosphor member (110); and
providing the converted wavelength of the laser light.
9. The method of claim 8, wherein the light guide (102) comprises an entry aperture to introduce the wavelength of the laser light from the laser diode (104) into the light guide and an exit aperture to introduce the wavelength of the laser light into the phosphor member (110).
10. The method of claim 8, wherein the laser diode (104) comprises at least one high-beam Laser Activated Remote Phosphor (LARP) module to

generate a high beam LARP, at least one low beam LARP module (120) to generate a low beam LARP, and a Daytime Running Lamp (DRL).
11. The method of claim 8, wherein mounting the phosphor member (110) adjacent to the heat sink source (112) provides a sharp cut-off.
12. The method of claim 8, wherein comprising forming a light reflecting film (106) over a surface of the light guide (102).
13. The method of claim 12, wherein the light reflecting film (106) is a blue pass dichroic filter.