Abstract:
The disclosed technology relates to a system and a method for turning on a lamp linked with a vehicle seat position, capable of: automatically turning on a lamp corresponding to a seat position by moving, forward or backward, the position of a seat on which a driver or a passenger sits in the indoor lighting of a vehicle; and adjusting the lighting of the lamp according to a light distribution standard for a vehicle. The system for turning on a lamp linked with a vehicle seat position, according to the disclosed technology, comprises: a vehicle seat capable of moving forward or backward; a lamp lighting unit provided with one or more lamps corresponding to a stop position according to the movement of the vehicle seat; a seat information memory unit for storing seat position information according to the stop position of the vehicle seat; and a control unit turning on the lamps corresponding to the stop position of the vehicle seat on the basis of the seat position information such that the vehicle seat at the stop position is controlled to be lit.

Description:
PRIORITY CLAIM AND RELATED PATENT APPLICATIONS 
       [0001]    This patent document is a continuation application, under of 35 U.S.C. 120, of International Application No. PCT/KR2014/010365 filed Oct. 31, 2014, which further claims the benefit of priority of Korean Patent Application No. 10-2014-0080991, filed on Jun. 30, 2014 and Korean Patent Application No. 10-2014-0150166, filed on Oct. 31, 2014. The entire content of the above patent applications is incorporated by reference as part of the disclosure of this patent document. 
     
    
     BACKGROUND 
       [0002]    This patent document relates to control illumination at a seat within a vehicle. Lamps are installed in vehicles to illuminate drivers or occupants seated in the interior of the vehicles or to illuminate the interior thereof. 
       SUMMARY 
       [0003]    The disclosed technology can be used to provide a system and method for lighting a lamp operatively connected to a vehicle seat position, in which when the position of a driver seat or an occupant seat is moved forward or rearward in vehicle interior illumination, a lamp located corresponding to the seat position is automatically turned on and the lighting of the lamp is adjustable according to light distribution criteria for vehicle illumination. 
         [0004]    In accordance with one aspect of the disclosed technology, a system for lighting a lamp operatively connected to a vehicle seat position includes a vehicle seat movable forward or rearward, a lamp illumination unit including one or more lamps corresponding to stop positions according to movement of the vehicle seat, a seat information memory unit for storing seat position information according to the stop positions of the vehicle seat, and a control unit for controlling the lamps such that the lamps corresponding to the stop positions of the vehicle seat are turned on for illuminating the vehicle seat corresponding thereto, based on the seat position information. 
         [0005]    The lamp illumination unit may include a second lamp having a second light distribution angle for illuminating a vehicle seat stopped at a reference position, a first lamp having a first light distribution angle for illuminating a vehicle seat which is moved forward from the reference position and is then stopped, and a third lamp having a third light distribution angle for illuminating a vehicle seat which is moved rearward from the reference position and is than stopped. 
         [0006]    The seat information memory unit may store reference position information when the vehicle seat is stopped at a reference position, forward position information when the vehicle seat is moved forward from the reference position and is then stopped, and rearward position information when the vehicle seat is moved rearward from the reference position and is then stopped. 
         [0007]    The control unit may control a first lamp such that the first lamp is turned on for illuminating a vehicle seat, which is moved forward from the reference position and is then stopped, when the seat position information stored in the seat information memory unit is the forward position information, control a second lamp such that the second lamp is turned on for illuminating a vehicle seat, which is stopped at the reference position, when the seat position information stored in the seat information memory unit is the reference position information, and control a third lamp such that the third lamp is turned on for illuminating a vehicle seat, which is moved rearward from the reference position and is then stopped, when the seat position information stored in the seat information memory unit is the rearward position information. 
         [0008]    The control unit may adjust brightness of first, second, and third lamps when they are turned on, and control the first, second, and third lamps for illuminating the associated vehicle seat. 
         [0009]    In accordance with another aspect of the disclosed technology, there is provided a method for lighting a lamp operatively connected to a vehicle seat position in a system having one or more lamps corresponding to stop positions according to movement of a vehicle seat. The method includes (a) stopping the vehicle seat at a reference position or moving the vehicle seat forward or rearward from the reference position, (b) storing seat position information, when the vehicle seat is moved and then stopped, in a seat information memory unit, and (c) lighting lamps corresponding to the positions of the vehicle seat, based on the seat position information stored in the seat information memory unit, by a control unit. 
         [0010]    In the above (a), in a state in which a second lamp having a second light distribution angle for illuminating a vehicle seat stopped at the reference position, a first lamp having a first light distribution angle for illuminating a vehicle seat which is moved forward from the reference position and is then stopped, and a third lamp having a third light distribution angle for illuminating a vehicle seat which is moved rearward from the reference position and is than stopped, are installed to a ceiling of a vehicle, the vehicle seat may be stopped at the reference position or be moved forward or rearward from the reference position. 
         [0011]    In the above (b), the seat information memory unit may store reference position information when the vehicle seat is stopped at the reference position, forward position information when the vehicle seat is moved forward from the reference position and is then stopped, and rearward position information when the vehicle seat is moved rearward from the reference position and is then stopped. 
         [0012]    In the above (c), the control units may control a first lamp such that the first lamp is turned on for illuminating a vehicle seat, which is moved forward from the reference position and is then stopped, when the seat position information stored in the seat information memory unit is the forward position information, control a second lamp such that the second lamp is turned on for illuminating a vehicle seat, which is stopped at the reference position, when the seat position information stored in the seat information memory unit is the reference position information, and control a third lamp such that the third lamp is turned on for illuminating a vehicle seat, which is moved rearward from the reference position and is then stopped, when the seat position information stored in the seat information memory unit is the rearward position information. 
         [0013]    In the above (c), the control unit may adjust brightness of first, second, and third lamps when they are turned on, and control the first, second, and third lamps for illuminating the associated vehicle seat. 
         [0014]    In another aspect, a vehicle is provided to include a vehicle seat in the vehicle that is movable to change a position of the vehicle seat; a lamp illumination unit mounted in the vehicle to provide illumination inside the vehicle, the lamp illumination unit including different lamps that are operable to illuminate the vehicle seat at different stop positions of the vehicle seat, respectively; a seat information memory unit that stores seat position information based on the stop positions of the vehicle seat; and a control unit coupled to the lamp illumination unit to control the lamps in the lamp illumination unit such that the lamps corresponding to the stop positions of the vehicle seat are turned on to illuminate the vehicle seat at a particular seat position based on the seat position information. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The above and other aspects, features and advantages of the disclosed technology are described in conjunction with the accompanying drawings, in which: 
           [0016]      FIG. 1  is a diagram schematically illustrating the configuration of a system for lighting a lamp operatively connected to a vehicle seat position according to an embodiment of the disclosed technology; 
           [0017]      FIG. 2  is a view illustrating examples of a light distribution angle of an interior lamp when a typical vehicle seat is at a stop position; 
           [0018]      FIG. 3  is a view illustrating the structure of a lamp illumination unit and an example in which the light distribution angles of lamps are changed according to the movement of a seat position, according to the embodiment of the disclosed technology; 
           [0019]      FIG. 4  is a flowchart for explaining a method for lighting a lamp operatively connected to a vehicle seat position according to an embodiment of the disclosed technology; 
           [0020]      FIG. 5  is a view illustrating an example in which a second lamp located corresponding to a reference position is turned on and illuminates a vehicle seat located at the reference position, according to the embodiment of the disclosed technology; 
           [0021]      FIG. 6  is a view illustrating an example in which a first lamp is turned on and illuminates a vehicle seat located in front of the reference position, according to the embodiment of the disclosed technology; 
           [0022]      FIG. 7  is a view illustrating an example in which a third lamp is turned on and illuminates a vehicle seat located behind the reference position, according to the embodiment of the disclosed technology; and 
           [0023]      FIG. 8  is a view illustrating examples in which the lamps having respective light distribution angles are adjusted to have different illumination brightness, according to the embodiment of the disclosed technology. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    Exemplary embodiments of the disclosed technology relate to a vehicle, a system and method for lighting a lamp operatively connected to a vehicle seat position, and more particularly, to a system and method for lighting a lamp operatively connected to a vehicle seat position, in which when the position of a driver seat or an occupant seat is moved forward or rearward in vehicle interior illumination, a lamp located corresponding to the seat position is automatically turned on and the lighting of the lamp is adjustable according to light distribution criteria for vehicle illumination. 
         [0025]    In various automobiles or vehicles, the light distribution angles of lamps may not be adjusted according to the body types or tastes of drivers or occupants since the lamps are fixed even when the driver or occupant seats are moved forward or rearward so as to be suitable for the body sizes of drivers or occupants, in conventional vehicle illumination. 
         [0026]    That is, since the light distribution angles of vehicle interior lamps are fixed, it is impossible to change the light distribution angles of the fixed lamps even when seat positions are changed according to the body types of drivers or occupants. 
         [0027]    In addition, when the seat positions are moved forward or rearward, the lighting of the fixed lamps may be blocked by the bodies of drivers or the fixed lamps may illuminate unnecessary places due to the light distribution of the fixed lamps. 
         [0028]    Accordingly, in order to resolve light distribution angle problems according to seat movement, widening light distribution angles may adversely affect drivers and occupants. 
         [0029]    Meanwhile, the method of manually adjusting light distribution angles in a vehicle interior causes inconvenience for a user to use lamps, and is difficult to adjust light distribution angles defined by light distribution criteria for vehicle illumination. 
         [0030]    Bulb lamps are less affected by seat movement since they have wide light distribution angles, but the light distribution angles of LED lamps may be significantly affected due to straightness of LEDs 
         [0031]    Since various modifications may be performed on the exemplary embodiments according to the concept of the disclosed technology and the embodiments of the disclosed technology can be implemented in a wide range of varied forms, specific exemplary embodiments of the disclosed technology will be described herein in detail with reference to the accompanying drawings of the exemplary embodiments of the disclosed technology. However, the disclosed technology will not be limited only to the specific exemplary embodiments of the disclosed technology which are disclosed herein. Therefore, it should be understood that the scope and spirit of the disclosed technology can be extended to all variations, equivalents, and replacements in addition to the accompanying drawings of the disclosed technology. 
         [0032]    A system for lighting a lamp operatively connected to a vehicle seat position according to exemplary embodiments of the disclosed technology will be described below in more detail with reference to the accompanying drawings. Throughout the disclosure, like reference numerals refer to like parts throughout the various figures and embodiments of the disclosed technology, and redundant description thereof will be omitted. 
         [0033]      FIG. 1  is a diagram schematically illustrating the configuration of a system for lighting a lamp operatively connected to a vehicle seat position according to an embodiment of the disclosed technology. 
         [0034]    Referring to  FIG. 1 , the system for lighting a lamp operatively connected to a vehicle seat position, which is designated by reference numeral  100 , according to the embodiment of the disclosed technology includes a vehicle seat  110 , a lamp illumination unit  120 , a seat information memory unit  130 , and a control unit  140 . 
         [0035]    The vehicle seat  110  is a seat in which a driver or an occupant boarding a vehicle is seated, and is mounted to be movable forward or rearward. 
         [0036]    The lamp illumination unit  120  includes one or more LED lamps having light distribution angles which correspond to seat positions according to the movement of the vehicle seat. 
         [0037]    The lamp illumination unit  120  is configured such that one or more LED lamps having light distribution angles are installed at different light distribution angles. 
         [0038]    The lamp illumination unit  120  includes one or more lamps corresponding to positions when the vehicle seat  110  is moved and stopped. 
         [0039]    That is, as illustrated in  FIG. 3 , the lamp illumination unit  120  includes a second lamp  220  having a second light distribution angle for illuminating a vehicle seat  110  stopped at a reference position, a first lamp  210  having a first light distribution angle for illuminating a vehicle seat  110  which is moved forward from the reference position and is then stopped, and a third lamp  230  having a third light distribution angle for illuminating a vehicle seat  110  which is moved rearward from the reference position and is than stopped. 
         [0040]    The seat information memory unit  130  stores seat position information when the vehicle seat  110  is moved and stopped. 
         [0041]    That is, the seat information memory unit  130  stores reference position information when the vehicle seat  110  is stopped at the reference position, forward position information when the vehicle seat  110  is moved forward from the reference position and is then stopped, and rearward position information when the vehicle seat  110  is moved rearward from the reference position and is then stopped. 
         [0042]    The control unit  140  controls lamps such that a lamp corresponding to a vehicle seat  110 , which is stopped at any position, is turned on for illuminating the vehicle seat corresponding thereto, based on the seat position information stored in the seat information memory unit  130 . 
         [0043]    In addition, the control unit  140  controls LED lamps such that an LED lamp corresponding to a vehicle seat, which is moved and then stopped in any position, and having a light distribution angle corresponding thereto are turned on or off, or the LED lamps having respective light distribution angles are adjusted to have different illumination brightness. 
         [0044]    Thus, the control unit  140  automatically changes the light distribution angles of the vehicle lamps using the seat position information. 
         [0045]      FIG. 2  is a view illustrating examples of a light distribution angle of an interior lamp when a typical vehicle seat is at a stop position. 
         [0046]    As illustrated in  FIG. 2 , the LED lamp provided within the vehicle is installed to illuminate the upper surface of the seat according to light distribution criteria for vehicle illumination. The LED lamp is attached to the ceiling of the vehicle interior so as to illuminate a portion in front of a driver or an occupant, as illustrated in  FIG. 2( a ) , when the driver or the occupant is seated in the seat. 
         [0047]    When the seat is moved forward as illustrated in  FIG. 2( b )  in order for the driver or occupant boarding the vehicle and seated in the seat to adjust the position of the seat so as to be suitable for the body type thereof, the driver or occupant seated in the seat is moved forward, but the LED lamp, which is fixedly attached to the ceiling of the vehicle, immediately illuminates the head of the driver or occupant rather than the front portion of the driver or occupant, thereby causing inconvenience for the driver or the occupant. 
         [0048]    In addition, when the seat is moved rearward as illustrated in  FIG. 2( c )  in order for the driver or occupant boarding the vehicle and seated in the seat to adjust the position of the seat so as to be suitable for the body type thereof, the driver or occupant seated in the seat is moved rearward, but the LED lamp, which is fixedly attached to the ceiling of the vehicle, illuminates a portion directed further forward than the front portion of the driver or occupant, thereby causing inconvenience for the driver or the occupant. 
         [0049]      FIG. 3  is a view illustrating the structure of the lamp illumination unit and an example in which the light distribution angles of the lamps are changed according to the movement of the seat position, according to the embodiment of the disclosed technology. 
         [0050]    Referring to  FIG. 3 , the lamp illumination unit  120  attached to the ceiling of the vehicle according to the embodiment of the disclosed technology includes the first lamp  210 , the second lamp  220 , and the third lamp  230  such that the LED lamps of the lamp illumination unit  120  vertically illuminate the vehicle seat  110  in which the driver or occupant boarding the vehicle is seated. 
         [0051]    Here, the first lamp  210  of the lamp illumination unit  120  is installed to the ceiling of the vehicle so as to have a first light distribution angle (15°) for illuminating a vehicle seat  110  which is moved forward and is then stopped. 
         [0052]    In addition, the second lamp  220  of the lamp illumination unit  120  is installed to the ceiling of the vehicle so as to have a light distribution angle (0°) for vertically illuminating a vehicle seat  110  which is stopped at the reference position. 
         [0053]    In addition, the third lamp  230  of the lamp illumination unit  120  is installed to the ceiling of the vehicle so as to have a light distribution angle (15°) for illuminating a vehicle seat  110  which is moved rearward from the reference position and is then stopped. 
         [0054]    That is, when the state in which the second lamp  220  is installed to the ceiling of the vehicle so as to vertically illuminate the vehicle seat  110  is regarded as a reference state (a light distribution angle of 0°), the first lamp  210  is installed so as to be inclined upward and directed forward such that the light distribution angle thereof is, e.g., an angle of 15° with respect to the reference state, and the third lamp  230  is installed so as to be inclined upward and directed rearward such that the light distribution angle thereof is, e.g., an angle of 15° with respect to the reference state. Here, although the embodiment describes that the light distribution angles of the first and third lamps  210  and  230  have, e.g., an angular difference of 15° with respect to the light distribution angle (0°) of the second lamp  220  as the reference state such that the first and third lamps  210  and  230  are respectively directed forward and rearward, the disclosed technology is not limited thereto. For example, the first and third lamps  210  and  230  may be installed to have different angles between 0° and 90° according to positions in which the vehicle seat  110  is moved forward or rearward and is then stopped. 
         [0055]    Accordingly, as illustrated in  FIG. 3 , the first lamp  210  is turned on for illuminating a vehicle seat  110  which is moved forward from the reference position and is then stopped, the second lamp  220  is turned on for illuminating a vehicle seat  110  which is stopped at the reference position, and the third lamp  230  is turned on for illuminating a vehicle seat  110  which is moved rearward from the reference position and is then stopped. 
         [0056]    In this case, each of the first, second, and third lamps  210 ,  220 , and  230  illuminates the vehicle seat  110  at angles of 60° in left and right directions to a vertical line. 
         [0057]      FIG. 4  is a flowchart for explaining a method for lighting a lamp operatively connected to a vehicle seat position according to an embodiment of the disclosed technology. 
         [0058]    In the system for lighting a lamp operatively connected to a vehicle seat position  100  according to the embodiment of the disclosed technology, the second lamp  220  for illuminating the vehicle seat  110  located at the reference position, the first lamp  210  for illuminating the vehicle seat  110  which is moved forward from the reference position and is then stopped, and the third lamp  230  for illuminating the vehicle seat  110  which is moved rearward from the reference position and is then stopped, are installed to the ceiling of the vehicle, as illustrated in  FIG. 3 . 
         [0059]    Referring to  FIG. 4 , in the system for lighting a lamp operatively connected to a vehicle seat position  100  according to the embodiment of the disclosed technology, when the vehicle seat  110  is first stopped at the reference position (S 410 ) as illustrated in  FIG. 5 , the seat information memory unit  130  stores seat position information when the vehicle seat  110  is in a stop state (S 420 ).  FIG. 5  is a view illustrating an example in which the second lamp located corresponding to the reference position is turned on and illuminates the vehicle seat located at the reference position, according to the embodiment of the disclosed technology. 
         [0060]    Accordingly, the control unit  140  lights the second lamp of the lamp illumination unit  120  so that the second lamp illuminates the vehicle seat  110  located at the reference position, as illustrated in  FIG. 5 , based on the seat position information stored in the seat information memory unit  130  (S 430 ). 
         [0061]    As illustrated in  FIG. 6 , when the vehicle seat  110  is moved forward of the vehicle by the driver or the occupant and is located in front of the reference position (S 440 ), the seat information memory unit  130  stores forward position information when the vehicle seat  110  is moved and then stopped (S 450 ).  FIG. 6  is a view illustrating an example in which the first lamp is turned on and illuminates the vehicle seat located in front of the reference position, according to the embodiment of the disclosed technology. 
         [0062]    Accordingly, the control unit  140  lights the first lamp  210  of the lamp illumination unit  120  located corresponding to a current vehicle seat  110  so that the first lamp  210  illuminates the vehicle seat  110 , as illustrated in  FIG. 6 , based on the forward position information (S 460 ). 
         [0063]    However, as illustrated in  FIG. 7 , when the vehicle seat  110  is moved rearward of the vehicle by the driver or the occupant and is located behind the reference position (S 470 ), the seat information memory unit  130  stores rearward position information when the vehicle seat  110  is moved rearward from the reference position and is then stopped (S 480 ).  FIG. 7  is a view illustrating an example in which the third lamp is turned on and illuminates the vehicle seat located behind the reference position, according to the embodiment of the disclosed technology. 
         [0064]    Accordingly, the control unit  140  lights the third lamp  230  of the lamp illumination unit  120  located corresponding to a current vehicle seat  110  so that the third lamp  230  illuminates the vehicle seat  110  located behind the reference position, as illustrated in  FIG. 7 , based on the rearward position information (S 490 ). 
         [0065]    In this case, the control unit  140  may light one of the first, second, and third lamps  210 ,  220 , and  230  according to the position of the moved seat, and adjust the light distribution angle of the lamp illumination unit  120 . As illustrated in  FIG. 8 , the lamps having respective light distribution angles are adjusted to have different illumination brightness when they are turned on.  FIG. 8  is a view illustrating examples in which the lamps having respective light distribution angles are adjusted to have different illumination brightness, according to the embodiment of the disclosed technology. 
         [0066]    That is, the control unit  140  may control the lighting of the first and second lamps  210  and  220  when the vehicle seat  110  is located in front of the reference position as illustrated in  FIG. 8( a )  such that the luminous intensity of the first lamp  210  is 100% and the luminous intensity of the second lamp  220  is 30%. Here,  FIG. 8  is a view illustrating examples in which the luminous intensities of the respective lamps of the lamp illumination unit are adjusted according to the embodiment of the disclosed technology. In addition, the control unit  140  may also control the lighting of the first and second lamps  210  and  220  such that the luminous intensities of the first and second lamps  210  and  220  are 60% and 60%, respectively. 
         [0067]    Meanwhile, the control unit  140  may control the lighting of the second and third lamps  220  and  230  when the vehicle seat  110  is stopped at the reference position as illustrated in  FIG. 8( b )  such that the luminous intensity of the second lamp  220  is 100% and the luminous intensity of the third lamp  230  is 20%. Of course, the control unit  140  may also control the lighting of the second and third lamps  220  and  230  such that the luminous intensities of the second and third lamps  220  and  230  of the lamp illumination unit  120  are 60% and 60%, respectively. 
         [0068]    In addition, the control unit  140  may control the lighting of the third lamp  230  when the vehicle seat  110  is located behind the reference position as illustrated in  FIG. 8( c )  such that the luminous intensity of the third lamp  230  is 100% and the luminous intensity of the second lamp  220  adjacent thereto is 30%. 
         [0069]    Meanwhile, although the lamp located corresponding to the associated seat position is automatically turned on based on the seat position information according to the movement of the vehicle seat, and illuminates the associated vehicle seat at the light distribution angle corresponding thereto, the user may set the lamps so as to arbitrarily adjust the light distribution angles. That is, when the seat is moved forward from the reference position and is then located in front of the reference position, the user may manually light the first lamp such that the first lamp illuminates the seat located in front of the reference position. 
         [0070]    In addition, the user may directly rotate a wheel having a rotary shaft and adjust a light distribution angle through matrix control. That is, the user may rotate the wheel of the second lamp  220  corresponding to the seat located at the reference position so as to adjust and set the illumination angle thereof, may rotate the wheel of the third lamp  230  corresponding to the seat located behind the reference position so as to adjust and set the illumination angle thereof, or may rotate the wheel of the first lamp  210  corresponding to the seat located in front of the reference position so as to adjust and set the illumination angle thereof. 
         [0071]    In connection with LED lamps installed corresponding to a driver seat and an occupant seat, the LED lamp corresponding to the driver seat may be turned on for illuminating the driver seat when a driver is seated in the driver seat, as described above. In addition, when no one is seated in the occupant seat, the LED lamp corresponding to the occupant seat may not be turned on or may be turned on for illumination at the low level of brightness. 
         [0072]    In accordance with the disclosed technology described above, it is possible to realize the system and method for lighting a lamp operatively connected to a vehicle seat position, in which when the position of the driver seat or the occupant seat is moved forward or rearward in vehicle interior illumination, the lamp located corresponding to the seat position is automatically turned on and the lighting of the lamp is adjustable according to light distribution criteria for vehicle illumination. 
         [0073]    As is apparent from the above description, in accordance with the disclosed technology, it is possible to increase convenience since the turn-on position and brightness of a lamp vary according to a change in position of a vehicle seat varying according to the body type and driving habit of a driver. 
         [0074]    In addition, it is possible to reduce costs of products by the application of the matrix beam pattern manner of an LED lamp, without using separate motors, actuators, and optical lenses for changing light distribution angles. 
         [0075]    The disclosed technology can be applied to a vehicle since having a structure in which the light distribution angles are changed using existing memory seat information without using separate measurement sensors and devices for sensing the movement of the vehicle seat. 
         [0076]    Various embodiments have been described in the best mode for carrying out the disclosed technology. It will be understood that the above-mentioned technical configurations of the exemplary embodiments may be executed in order to enable those of ordinary skill in the art to embody and practice the disclosed technology in other specific forms without changing the spirit or essential features of the disclosed technology. Although the disclosed technology has been described with respect to the illustrative embodiments, it will be apparent to those skilled in the art that various variations and modifications may be made. 
         [0077]    The disclosed technology is applicable to a system and method for lighting a lamp operatively connected to a vehicle seat position, in which when the position of a driver seat or an occupant seat is moved forward or rearward in vehicle interior illumination, a lamp located corresponding to the seat position is automatically turned on and the lighting of the lamp is adjustable according to light distribution criteria for vehicle illumination.