Abstract:
An illumination device includes a light source positioned on an illumination axis, a lens assembly having at least two biconvex lenses disposed on the illumination axis, and a reflector having a reflecting surface enclosing the lens assembly. The light source emits a first group of light beams which directly impinge of the lens assembly, and a second group of light beams which directly impinge on the reflector. The second group of light beams being reflected by the reflecting surface such that they surround the first group of light beams after being refracted by the lens assembly, without such second group of light beams impinging on the lens assembly.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a projection illumination device, and in more particular to a projection illumination device utilizing a lens assembly and a reflector to project light beams. 
     2. Description of the Related Art 
     U.S. Pat. No. 6,558,032 discloses a LED lighting equipment for vehicle. In  FIG. 1 , the LED lighting equipment comprises a LED lighting equipment  1 ′ comprising a LED lamp  2 ′, a reflection surface of hyperboloid  4 ′ having two focuses f 1  and f 2 , and a reflection surface of paraboloid of revolution  5 ′. Light beams reflected by the reflection surface  4 ′ are emitted outwardly and centrally from the focus f 2 . The focus f 2  of the reflection surface  4 ′ and the focus of the reflection surface  5 ′ are overlapped. The light beams reflected by the reflection surface  5 ′ travel to the remote ahead of the reflection surface  5 ′. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention provides a projection illumination device capable of emitting light in a projecting mode such as distant-light mode. The projection illumination device of the invention comprises a light source, a lens assembly and a reflector. The light source generates a plurality of initial light beams. The initial light beams comprise a first reference light beam traveling in a first direction directed from the light source to the lens assembly and a second reference light beam traveling in a second direction directed from the light source to the reflector. The lens assembly is disposed on an axis. The first reference light beam traveling in the first direction passes through the lens assembly to form a first predetermined light beam traveling away from the light source and a first angle is substantially formed between the first direction and the axis. The reflector comprises a reflective surface. The second reference light beam traveling in the second direction is reflected by the reflecting surface of the reflector to form a second predetermined light beam traveling away from the light source. A second angle is formed substantially between the second direction and the first direction. The first angle is less than or equal to the second angle. The initial light beams are guided by the lens assembly and the reflector to emit light in the projecting mode. 
     A detailed description is given in the following embodiments with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG. 1  is a schematic view of a conventional vehicle light; 
         FIG. 2A  is a schematic view of a projection illumination device (E 1 ) of a first embodiment of the invention, wherein the projection illumination device (E 1 ) is in an operating mode; 
         FIG. 2B  is a schematic view of the projection illumination device (E 1 ) in an operating mode; 
         FIG. 3  is a schematic view of the projection illumination device (E 1 ) in an operating mode; 
         FIG. 4  is a schematic view of a projecting mode (M 1 ) formed by the projection illumination device (E 1 ); 
         FIG. 5  is a schematic view of a varied example (E 1   a ) of the projection illumination device (E 1 ) of the invention; 
         FIG. 6  is a schematic view of a projection illumination device (E 2 ) of a second embodiment of the invention; 
         FIG. 7A  is a schematic view of the projection illumination device (E 2 ) in an operating mode; 
         FIG. 7B  is a schematic view of the projection illumination device (E 2 ) in an operating mode; 
         FIG. 8  is a schematic view of the projection illumination device (E 2 ) in an operating mode; and 
         FIG. 9  is a schematic view of a projecting mode (M 2 ) formed by the projection illumination device (E 1 ). 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims. 
     In  FIG. 2A , a projection illumination device E 1  of a first embodiment of the invention situated in an operating mode comprises a light source  1  provided with longitudinal profile, a lens assembly  2  and a reflector  3 . The light source  1  and the lens assembly  2  disposed in the reflector  3  are spaced apart from each other. A plurality of initial light beams directly radiating from a radiating point  100  of the light source  1  are guided by the lens assembly  2  and the reflector  3  to form a desired projecting mode, e.g. distant-light mode, or other regulated light source distribution. 
     The reflector  3  comprises a light-emitting opening  300  and a conical continuous reflective surface  30  having a main focus  300   f  located at an axis a 1 -a 1 . The light source  1  enclosed by the reflector  3  therein and transversely crossing the axis a 1 -a 1  at the radiating point  100  is located at the main focus  300   f  of the continuous reflective surface  30  of the reflector  3 , and the shape of the light-emitting opening  300  is dependent on the curvature of the continuous reflective surface  30 . In this embodiment, the longitudinal profile of the light source  1  is perpendicularly transverse to the axis a 1 -a 1 , the main focus  300   f  of the conical continuous reflective surface  30  of the reflector  3  and the radiating point  100  of the light source  1  are overlapped or actually the same one, and the continuous reflective surface  30  is a parabolic surface and the light-emitting opening  300  is symmetrical. The continuous reflective surface  30  can be an elliptical or hyperbolic surface. 
     The lens assembly  2  comprises a first lens unit  21  and a second lens unit  22  enclosed by the reflector  3  therein. The first lens unit  21  has a front convex side  210   c , a first outer end  210  and a first focus  210   f . The second lens unit  22  substantially located at the first focus  210   f  of the first lens unit  21  has a second outer end  220 . The first and second lens units  21  and  22  disposed on the axis a 1 -a 1  are spaced from each other, and the first lens unit  21  is located between the light source  1  and the second lens unit  22 . The first lens unit  21  and the second lens unit  22  sequentially guide the initial light beams  11   a   0  directly radiating from the radiating point  100  of the light source  1  to form a first predetermined light beam  11   a   1  traveling away from the light source  1 . That is, the front convex side  210   c  of the first lens unit  21  is a back side opposite to the second lens unit  22 , and the continuous reflective surface  30  of the reflector  3  is concave to the front convex side  210   c  of the lens assembly  2 . Two vertical assist lines AL 1  and AL 2  are utilized to geometrically define the light source  1  and the lens assembly  2 . The vertical assist line AL 1  is composed of a first line segment s 11  and a second line segment s 12  vertically intersected with the first line segment s 11  at a corner point c 1 , and the vertical assist line AL 2  is composed of a first line segment s 21  and a second line segment s 22  vertically intersected with the first line segment s 21  at a corner point c 2 . With respect to the vertical assist line AL 1 , the first line segment s 11  is perpendicular to the axis a 1 -a 1  and passes through the light source  1 , and the second line segment s 12  is parallel to the axis a 1 -a 1  and tangent to an outermost end (first outer end  210 ) of the first lens unit  21  of the lens assembly  2  with respect to the axis a 1 -a 1 . With respect to the vertical assist line AL 2 , the first line segment s 21  is perpendicular to the axis a 1 -a 1  and passes through the light source  1 , and the second line segment s 22  is parallel to the axis a 1 -a 1  and tangent to an outermost end (second outer end  220 ) of the second lens unit  22  of the lens assembly  2  with respect to the axis a 1 -a 1 . Note that the corner point c 1  of the vertical assist line AL 1  and the corner point c 2  of the vertical assist line AL 2  are located within the reflector  3 . 
     With respect to an effective area of the first lens unit  21 , a conical initial light beams  11   a   0  directly radiating from the radiating point  100  of the light source  1  received by the first lens unit  21  are guided to the second lens unit  22 . The outer conical surface of the conical initial light beams  11   a   0  is defined as a first position r 11 , and a first angle θ 11  is substantially formed between the first position r 11  and the axis a 1 -a 1  with respect to the radiating point  100  of the light source  1 . The initial light beams  11   a   0  located on the first position r 11  are defined as a first reference light beam  11   a   0 ( r   11 ) traveling in a first direction d 11  directed from the light source  1  to the first lens unit  21  of the lens assembly  3 . That is to say, the first angle θ 11  is a first boundary effective angle θm 1  (shown in  FIG. 3 ) for the lens assembly  2  capable of guiding the initial light beams  11   a   0  directly radiating from the radiating point  100  of the light source  1  with respect to the axis a 1 -a 1 . 
     The initial light beams  11   a   0  located inside the first position r 11  and the first reference light beam  11   a   0 ( r   11 ) located on the first position r 11 , i.e., the initial light beams  11   a   0  located in the range of the first angle θ 11  with respect to the axis a 1 -a 1 , are converted into a plurality of refracted light beams  11   a   01  by the first lens unit  21 , and the refracted light beams  11   a   01  guided by the second lens unit  22  forms the first predetermined light beam  11   a   1  traveling away from the light source  1 . 
     In  FIG. 2B , to specify the distribution of the light beams reflected by the continuous reflective surface  30  of the reflector  3 , the initial light beams  11   a   0  located within the first position r 11  guided by the first and second lens units  21  and  22  of the lens assembly  2  and the first predetermined light beam  11   a   1  formed by the first and second lens units  21  and  22  are omitted. 
     The initial light beams  12   a   0  directly radiating from the radiating point  100  of the light source  1  perpendicular to the axis a 1 -a 1  is reflected by the continuous reflective surface  30  of the reflector  3  to form a second predetermined light beam  12   a   1  traveling away from the light source  1 . The second predetermined light beam  12   a   1  substantially has a round structure defined as a second position or an effective position r 12  which is perpendicularly intersected with the axis a 1 -a 1  by passing through the site of the light source  1 , i.e., the light source  1  is located at the intersection of the effective position r 12  and the axis a 1 -a 1 , and a second angle θ 12  is substantially formed between the second position r 12  and the first position r 11 . The initial light beams  12   a   0  located on the second position r 12  are defined as a second reference light beam  12   a   0 ( r   12 ) traveling on the second position r 12 . In this embodiment, the first angle θ 11  is less than or equal to the second angle θ 12 , and the sum of the first angle θ 11  and the second angle θ 12  is substantially equal to 90 degrees. The second reference light beam  12   a   0 ( r   12 ) has an initial direction substantially perpendicular to the axis a 1 -a 1 . 
     The second angle θ 12  is a second boundary effective angle θm 2  for the continuous reflective surface  30  of the reflector  3  capable of guiding the initial light beams  12   a   0  directly radiating from the radiating point  100  of the light source  1  not passing through lens assembly  2  with respect to the axis a 1 -a 1 . The first angle θ 11  is less than or equal to 45 degrees or ranging from about 0 to 30 degrees. The second angle θ 12  is less than 90 degrees or ranging from about 20 to 90 degrees. 
     The initial light beams  11   a   0  and  12   a   0 , the first reference light beam  11   a   0 ( r   11 ) and the second reference light beam  12   a   0 ( r   12 ) substantially travel along the same direction. 
     Note that the second reference light beam  12   a   0 ( r   12 ) traveling in the second direction r 12  is not interfered by the first and second outer ends  210  and  220  of the lens assembly  2 . That is to say, part of the second predetermined light beam  12   a   1  formed by the initial light beams  12   a   0  moving on the second position r 12  encloses the lens assembly  2  therein, so that the structure of the first and second lens  21  and  22  of the lens assembly  2  is limited within the light paths formed by the second reference light beam  12   a   0 ( r   12 ), or the initial light beams  11   a   0  directly radiating from the radiating point  100  and away from the rectangular profile of the light source  1  travel along a longitudinal direction of the longitudinal profile of the light source  1  to strike the reflector  3 , so that the reflected light beams  11   a   01  are formed not to impinge upon the lens assembly  2 . 
     In  FIG. 3 , the initial light beams  11   a   0  and  12   a   0  directly radiating from the radiating point of the light source  1  are guided by the lens assembly  2  and the reflector  3  to emit light in a desired projecting mode M 1  (shown in  FIG. 4 ) at a desired distance in front of the projection illumination device E 1  according to related regulations. In this embodiment, the projecting mode M 1  is a distant-light mode formed on a plane W 1 , at a predetermined distance, e.g., 25 meters in front of the projection illumination device E 1 . 
     In  FIG. 5 , a projection illumination device E 1   a  is a varied example of the illumination device E 1 . The illumination device E 1   a  differs from the projection illumination device E 1  in that the projection illumination device E 1   a  further comprises at least one connecting portion  4  disposed between the lens assembly  2  and the reflector  3 , i.e., the lens assembly  2  is positioned on the reflector  3  via the connecting portion  4 . In the projection illumination device E 1   a , two connecting portions  4  are applied to be disposed between the reflector  3  and the first lens unit  21  and between the reflector  3  and the second lens unit  22 , respectively. The installation of the connecting portions  4  does not affect projecting mode M 1 . In other embodiments, the first and second lens units  21  and  22  of the lens assembly  2  are spherical or non-spherical lenses, and the continuous reflective surface  30  of the reflector  3  can be a parabolic surface or formed by multiple of curved surfaces. 
     In  FIG. 6 , a projection illumination device E 2  of a second embodiment of the invention comprises the light source  1 , a reflector  5  and a lens assembly  6 .  FIGS. 7A and 7B  are two sectional views along an axis a 2 -a 2  and a direction N-N of  FIG. 6 , respectively specifying two main parts of the light paths of the projection illumination device E 2 . The geometrical structure of projection illumination device E 2  is defined by a three-dimensional, or XYZ, Cartesian coordinate system comprising three axes X, Y and Z. The axis a 2 -a 2  is parallel to the axis X. 
     The light source  1  and the lens assembly  6  disposed in the reflector  5  along the axis a 2 -a 2  are spaced from each other. 
     The reflector  5  comprises a reflective surface  50  having a first reflecting region  501  and a second reflecting region  502  and a light-emitting opening  500  formed on the edges of the first and second reflecting regions  501  and  502 . The second reflecting region  502  is not connected to the first reflecting region  501 , i.e., the reflector  5  is a device comprising a semi-opened structure. The shape of the light-emitting opening  500  is dependent on a curvature of the reflective surface  50 . 
     A plurality of initial light beams  11   b   0  and  12   b   0  directly radiating from the radiating point of the light source  1  are guided by the reflector  5  and/or the lens assembly  6  to form a desired projecting mode, e.g. distant-light mode, except the initial light beams traveling along the axis Z. That is to say, the initial light beams traveling along the axis Z are directly emitted toward the remote. In this embodiment, the first and second reflecting regions  501  and  502  are cylindrical curved surfaces, and the two axes of the first and second reflecting regions  501  and  502  are formed by the parabolic lenses having the same curvature, thus, symmetrical light-emitting opening  500  is obtained. Conversely, if the two axes of the first and second reflecting regions  501  and  502  are formed by the parabolic lenses having two distinct curvatures, the profile of the light-emitting opening of the reflector  5  is asymmetrical (not shown in Figs.). 
     The lens assembly  6  comprises a first lens unit  61  having a first focus  610   f  and a second lens unit  62  substantially located at the first focus  610   f  of the first lens unit  61 . The first and second lens unit  61  and  62  are disposed apart from each other on the axis a 2 -a 2 , and the first lens unit  61  is disposed between the light source  1  and the second lens unit  62 . The first lens unit  61  comprises a first cylindrical lens  6100  and the second lens unit  62  comprises a second cylindrical lens  6200 . The first and second cylindrical lenses  6100  and  6200  of the first and second lens units  61  and  62  sequentially guide the initial light beams  11   b   0  directly radiating from the radiating point  100  of the light source  1  to form a first predetermined light beam  11   b   1  traveling toward the remote. 
     With respect to an effective area of the first lens unit  61 , conical initial light beams  11   b   0  directly radiating from the radiating point of the light source  1  received by the first lens unit  61  are guided to the second lens unit  62 . The outer conical surface of the conical initial light beams  11   b   0  is defined as a first position r 21 , and a first angle θ 21  is substantially formed between the first position r 21  and the axis a 2 -a 2 . The initial light beams  11   b   0  located on the first position r 21  are defined as a first reference light beam  11   b   0 ( r   21 ) traveling on the first position r 21 . That is to say, the first angle θ 21  is a first boundary effective angle θn 1  for the lens assembly  2  capable of guiding the initial light beams  11   b   0  directly radiating from the radiating point of the light source  1  with respect to the axis a 2 -a 2 . 
     The initial light beams  11   b   0  located inside the first position r 21  and the first reference light beam  11   b   0 ( r   21 ) located on the first position r 21 , i.e., the initial light beams  11   b   0  located in the range of the first angle θ 21  with respect to the axis a 2 -a 2 , are converted into a plurality of refracted light beams  11   b   01  by the first lens unit  61 , and the refracted light beams  11   b   01  guided by the second lens unit  62  forms the first predetermined light beam  11   b   1  traveling away from the light source  1 . 
     In  FIG. 7B , to specify the distribution of the light beams reflected by the reflective surface  50  of the reflector  5 , the initial light beams  11   b   0  located within the first position r 21  guided by the first and second lens  61  and  62  of the lens assembly  6  and the first predetermined light beam  11   b   1  formed by the first and second lens  61  and  62  are omitted. 
     The initial light beams  12   b   0  directly radiating from the radiating point of the light source  1  perpendicular to the axis a 2 -a 2  is reflected by the reflective surface  50  of the reflector  5  to form a second predetermined light beam  12   b   1  traveling away from the light source  1 . The second predetermined light beam  12   b   1  substantially has a round structure defined as a second position r 22 , and a second angle θ 22  is substantially formed between the second position r 22  and the first position r 21 . The initial light beams  12   b   0  located on the second position r 22  are defined as a second reference light beam  12   b   0 ( r   22 ) traveling on the second position r 22 . In this embodiment, the first angle θ 21  is less than or equal to the second angle θ 22 , and the sum of the first angle θ 21  and the second angle θ 22  is substantially equal to 90 degrees. The second reference light beam  12   b   0 ( r   22 ) has an initial direction substantially perpendicular to the axis a 2 -a 2 . 
     The second angle θ 22  is a second boundary effective angle θn 2  for the reflective surface  50  of the reflector  5  capable of guiding the initial light beams  12   a   0  radiating from the radiating point of the light source  1  not passing through lens assembly  6  with respect to the axis a 2 -a 2 . The first angle θ 21  is less than or equal to 45 degrees or ranging from about 0 to 30 degrees. The second angle θ 22  is less than 90 degrees or ranging from about 20 to 90 degrees. 
     Note that the first and second outer ends  610  and  620  of the lens assembly  6  do not interfere with the second reference light beam  12   b   0 ( r   22 ) traveling on the second position r 22 . That is to say, the structure of the first and second lens units  61  and  62  of the lens assembly  6  is limited within the light paths formed by the second reference light beam  12   b   0 ( r   22 ). 
     In  FIG. 8 , the initial light beams  11   b   0  and  12   b   0  radiating from the radiating point of the light source  1  are guided by the lens assembly  6  and the reflector  5  to form a desired projecting mode M 2  (shown in  FIG. 9 ) at a desired distance in front of the projection illumination device E 2  according to the related regulations. In this embodiment, the projecting mode M 2  is a signal-light mode or signal formed on a plane W 2 , at a predetermined distance, e.g., 25 meters, away from the projection illumination device E 2 . 
     In addition, the connecting portion  4  can be disposed between the reflector  5  and the lens assembly  6  (not shown in Figs.). 
     In other embodiments, the first and second lens units  61  and  62  of the lens assembly  6  are spherical or non-spherical lenses, and the reflective surface  50  of the reflector  5  can be a cylindrical surface having a parabolic or other curvature. 
     While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.