Patent Publication Number: US-2022221123-A1

Title: Vehicle light

Description:
TECHNICAL FIELD 
     The present disclosure relates to a vehicle light. 
     BACKGROUND ART 
     A vehicle light is considered to form an irradiation pattern on a road surface around the vehicle. 
     Here, such a vehicle light is mounted on a vehicle and projects the irradiation pattern in a direction inclined relative to the road surface around the vehicle. Due to this, with the vehicle light, the distance from the installation position of the vehicle to the road surface varies depending on the position in the irradiation pattern, so that the irradiation pattern&#39;s part away from the vehicle becomes extremely dark. 
     Then, it has been considered that a vehicle light uses a micro array lens as a projection lens for projecting a light from a light source (see, for example, Patent Document 1). Then, adjusting a focal position of each lens portion in the micro array lens according to the distance to the road surface in the irradiation pattern can make the luminance distribution in the irradiation pattern as desired. 
     CITATION LIST 
     Patent Literature 
     
         
         PTL 1: Patent No. 2012-530263 
       
    
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     However, the above technology requires use of the micro array lens with the focal position of each lens portion adjusted according to the distance to the road surface, which results in a complicated configuration. 
     The present disclosure has been made in view of the above circumstance, and it is an object of the present invention to provide a vehicle light which, while having a simple configuration, can make a desired luminance distribution in an irradiation pattern. 
     Means for Solving the Problem 
     A vehicle light according to the present disclosure includes: a light source; a light condensing lens that condenses a light emitted from the light source; an irradiation pattern forming member that has an irradiation slit for allowing the light, which is condensed by the light condensing lens, to partially pass through, and that forms the passing light into an irradiation pattern; and a projection lens that projects the irradiation pattern, which is formed by the irradiation pattern forming member, onto a road surface, wherein the irradiation slit has a farthest location that corresponds to a farthest portion projected at a farthest position in the irradiation pattern and a nearest location that corresponds to a nearest portion projected at a nearest position in the irradiation pattern, and the light condensing lens, on the irradiation pattern forming member, makes the farthest location brightest and the nearest location darkest in an upper-lower direction, and diffuses the light emitted from the light source more in a width direction, which is orthogonal to an optical axis direction and to the upper-lower direction, than in the upper-lower direction. 
     Effect of the Invention 
     The vehicle light of the present disclosure, while having a simple configuration, can make a desired luminance distribution in the irradiation pattern. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an explanatory view illustrating how a vehicle light according to the present disclosure is mounted on a vehicle thereby to form an irradiation pattern. 
         FIG. 2  is an explanatory view illustrating the configuration of the vehicle light of Example 1. 
         FIG. 3  is an explanatory view illustrating the configuration of a filter. 
         FIG. 4  is an explanatory view illustrating the progression of the light which passed through a light condensing lens on a transverse cross-section including the optical axis direction and the width direction in the vehicle light. 
         FIG. 5  is an explanatory view illustrating the progression of the light which passed through an upper lens portion of the light condensing lens in a longitudinal cross-section including the optical axis in the vehicle light. 
         FIG. 6  is an explanatory view illustrating the progression of the light which passed through a lower lens portion of the light condensing lens in the longitudinal cross-section including the optical axis in the vehicle light. 
         FIG. 7  is an explanatory view illustrating a light flux distribution on the filter. 
         FIG. 8  is an explanatory view illustrating the relation of a focal plane relative to the parallel rays of light from the filter in a projection lens. 
         FIG. 9  is an explanatory view illustrating a irradiation pattern projected on a screen. 
         FIG. 10  is an explanatory view illustrating the irradiation pattern projected on a road surface. 
         FIG. 11  is a graph illustrating the luminance of each irradiation drawing pattern Di in the irradiation pattern projected on the road surface, illustrating the luminance value on the longitudinal axis and each irradiation drawing pattern Di (its position) on the horizontal axis. 
         FIG. 12  is an explanatory view illustrating an example of using the irradiation pattern formed at the vehicle light. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, Example 1 of a vehicle light  10  as an example of a vehicle light according to the present disclosure will be described with reference to the drawings. In order to make it easier to understand how the vehicle light  10  is installed,  FIG. 1  illustrates the vehicle light  10  in relation to the vehicle  1 , with emphasis on the vehicle light  10 , which does not necessarily correspond to the actual appearance. 
     Example 1 
     The vehicle light  10  of Example 1, which is an embodiment of a vehicle light according to the present disclosure, will be described using  FIGS. 1 to 12 . As illustrated in  FIG. 1 , the vehicle light  10  of Example 1 is used as a light of the vehicle  1  such as a car, and forms an irradiation pattern Pi on a road surface  2  around the vehicle  1  separately from a front light provided on the vehicle  1 . Here, the periphery of the vehicle  1  always includes a proximity area nearer to the vehicle  1  than the front light area illuminated by the front light provided on the vehicle  1 , and may partially include the front light area. In Example 1, the vehicle light  10  is located in a light chamber on both the left and right sides of the front portion of the vehicle. The light chamber is so formed that an open front end of a lamp housing is covered with an outer lens. The vehicle light  10  is provided in the light chamber with an optical axis La inclined relative to the road surface  2 . This is due to the fact that the light chamber is located higher than the road surface  2 . In the following description, in the vehicle light  10 , a direction in which the optical axis La extends, which is the direction to irradiate the light, is referred to as an optical axis direction (Z in the drawing), a vertical direction seen when the optical axis direction is in a state of being along a horizontal plane is referred to as an upper-lower direction (Y in the drawing), and a direction (horizontal direction) orthogonal to the optical axis direction and the upper-lower direction is referred to as a width direction (X in the drawing) (see  FIG. 2 , etc.). 
     The vehicle light  10  has a light source, a light condensing lens that condenses the light emitted from the light source, an irradiation pattern forming member that is provided with an irradiation slit which partially passes the light condensed by the light condensing lens and that forms the passing light into an irradiation pattern, and a projection lens that projects, on the road surface, the irradiation pattern formed by the irradiation pattern forming member. An example of the irradiation pattern forming member includes a filter. 
     As illustrated in  FIG. 2 , in the vehicle light  10 , a light source portion  11 , a light condensing lens  12 , a filter  13 , and a projection lens  14  are housed in a housing  15 , and a heat radiation member  16  is attached to the housing  15 , constituting a projector-type road surface projection unit. The housing  15  includes a lower member  15   a  and an upper member  15   b , and the upper member  15   b  is fitted to the lower member  15   a  with each of the above members ( 11  to  14 ) installed in the lower member  15   a . In the housing  15 , a light condensing lens groove  15   c  to fit the light condensing lens  12  therein, a filter groove  15   d  to fit the filter  13  therein, and a projection lens groove  15   e  to fit the projection lens  14  therein are provided (illustrated only on the lower member  15   a  side). 
     In the light source portion  11 , a light source  21  is mounted on a substrate  22 . The light source  21  is composed of a light emitting element such as an LED (Light Emitting Diode), and is provided with an emission optical axis coinciding with the optical axis La. In Example 1, the light source  21  emits amber monochromatic light (having a single peak in a graph in which the longitudinal axis is the light amount and the horizontal axis is the wavelength) in a Lambertian distribution with the optical axis La centered. The light source  21  is not limited to the configuration of Example 1, as long as the color (wavelength band), mode of distribution, and the number of colors (the number of peaks in the graph described above) in the emitted light can be set as appropriate. 
     The substrate  22  lights the light source  21  by appropriately supplying the power from a lighting control circuit. In a state of being mounted on an installation face (a light source installation portion  16   a ) of the heat radiation member  16 , the substrate  22  is housed in the rear end portion of the housing  15  (the end portion opposite to the projection lens groove  15   e  in the optical axis direction). 
     The light condensing lens  12  condenses the light emitted from the light source  21  and condenses the light on the filter  13 . The light condensing lens  12  is formed by a biconvex lens in Example 1, and an incident face  12   a  and an emission face  12   b  (see  FIG. 4 , etc.) are each a free curved face. The optical setting in the light condensing lens  12  will be described below. In the light condensing lens  12 , mount flange portions  12   c  are provided at both ends in the width direction. Each of the mount flange portions  12   c  can be fitted into the light condensing lens groove  15   c  of the housing  15 . The light condensing lens  12  has a lens axis extending in the optical axis direction. That lens axis is an optical axis line that passes through the position of the largest thickness in the optical axis direction in the light condensing lens  12 . In the light condensing lens  12 , when the mount flange portion  12   c  is fitted into the light condensing lens groove  15   c , the extending direction of the lens axis is caused to coincide with the optical axis La. The incident face  12   a  and the emission face  12   b  may be convex or concave, and are not limited to the configuration of Example 1, as long as the light condensing lens  12  is a convex lens and satisfies the optical setting described below. 
     The filter  13  transmits the light from the light source  21  condensed by the light condensing lens  12  thereby to form the irradiation pattern Pi. As illustrated in  FIG. 1  and the like, the irradiation pattern Pi has four irradiation drawing patterns Di aligned at equal intervals in a direction away from the vehicle  1 . Each irradiation drawing pattern Di is of a large open V-shape and is of a substantially equal size each other. When each irradiation drawing pattern Di is individually illustrated, the one farthest from the vehicle  1  is designated as a first irradiation drawing pattern al, and the second, third, and fourth irradiation drawing patterns Di 2 , Di 3 , and Di 4 , respectively, are designated as they sequentially approach the vehicle  1  from there. Due to this, in the irradiation pattern Pi, the first irradiation drawing pattern Di 1  is the farthest portion and the fourth irradiation drawing pattern Di 4  is the nearest portion. The irradiation pattern Pi can be made to look like an arrow pointing in a predetermined direction from the vehicle  1  by arranging each of the four irradiation drawing patterns Di with the vertices of the V-shaped pattern positioned in a substantially straight line. In Example 1, the vehicle light  10  is provided at each of the left and right tip portions of the vehicle  1 , and forms the irradiation pattern Pi on the surrounding road surface  2  so as to point diagonally toward the front side of the vehicle  1  in the front/rear direction and toward the outside in the width direction. This irradiation pattern Pi can inform the surroundings of the direction in which the vehicle  1  is proceeding, and is formed in conjunction with a turn lamp in Example 1. 
     In the filter  13 , as illustrated in  FIG. 3 , a filter portion  23  is provided in a filter frame portion  24 . The filter frame portion  24  is in the form of a frame surrounding the filter portion  23  and can be fitted into the filter groove  15   d  of the housing  15  (see  FIG. 1 ). 
     The filter portion  23  is basically formed of a plate-shaped film member that blocks the transmission of light, and is provided with an irradiation slit  25 . The irradiation slit  25  partially transmits the light from the light source  21  condensed by the light condensing lens  12  thereby to form the light into the shape of the irradiation pattern Pi. The irradiation slit  25  is caused to correspond to the irradiation pattern Pi, and, in Example 1, is composed of four slit portions  26 . The four slit portions  26  correspond, one-to-one, to the four irradiation drawing patterns Di, and are each made in the form of a V-shape that largely opens as each irradiation drawing pattern Di, and are made to have different sizes and different intervals from each other, unlike each irradiation drawing pattern Di. In detail, the vehicle light  10  is provided with the optical axis La inclined relative to the road surface  2 , so that the distance from the filter  13  and the projection lens  14  to the road surface  2  differs, so that with a projection on the road surface  2  by the projection lens  14 , each slit portion  26  (each irradiation drawing pattern Di which is the light transmitted therethrough) has a size and an interval which correspond to the distance. Due to this, the size and interval of each slit portion  26  are set according to the distance to the road surface  2  so that each slit portion  26  (each irradiation drawing pattern Di) has substantially equal size and substantially equal interval on the road surface  2 . 
     Further, each of the slit portions  26  is in a positional relation of a rotational symmetry around the optical axis La, relative to the positional relation of each irradiation drawing pattern Di of the irradiation pattern Pi. In detail, the vehicle light  10  is provided with each slit portion  26  in a positional relation of a rotational symmetry around the optical axis La relative to each irradiation drawing pattern Di, so that each irradiation drawing pattern Di is in a targeted positional relation on the road surface  2  because the projection lens  14  reverses and projects the filter  13  (irradiation slit  25 ) on the road surface  2 . Due to this, concerning each slit portion  26 , a first slit portion  261  at the lowermost side in the upper-lower direction is the farthest location that corresponds to the first irradiation drawing pattern Di 1  (farthest portion) of the irradiation pattern Pi. Then, concerning each slit portion  26 , a second slit portion  262  thereabove corresponds to the second irradiation drawing pattern Di 2 , a third slit portion  263  thereabove corresponds to the third irradiation drawing pattern Di 3 , and an uppermost fourth slit portion  264  is the nearest location that corresponds to the fourth irradiation drawing pattern Di 4  (nearest portion) of the irradiation pattern Pi. In the filter  13  of Example 1, in the upper-lower direction, the third slit portion  263  is provided across the optical axis La, the fourth slit portion  264  is provided thereabove, and the second slit portion  262  and the first slit portion  261  are provided below the third slit portion  263 . 
     Herein, as illustrated in  FIG. 1 , the vehicle light  10  is designed to form, on both right and left sides of the vehicle  1 , the irradiation pattern Pi symmetrically with respect to a plane orthogonal to the width direction of the vehicle  1 . Due to this, as illustrated in  FIG. 3 , the vehicle light  10  has two filters, that is, a filter  13 R for the right side when installed in front of the right side of the vehicle  1 , and a filter  13 L for the left side when installed in front of the left side of the vehicle  1 . The two filters  13 R and  13 L have the same configuration as each other, except that the irradiation slit  25  (each slit portion  26  thereof) is provided symmetrical with respect to the plane orthogonal to the width direction. The filter  13  (light transmitted through each slit portion  26  of the irradiation slit  25 ) is projected on the road surface  2  by the projection lens  14 . 
     As illustrated in  FIG. 2 , the projection lens  14  has a lens body portion  27 , which is a circular convex lens when viewed in the optical axis direction, and a flange portion  28  surrounding a periphery of the lens body portion  27 . In Example 1, the lens body portion  27  is a free curved face in which an incident face  27   a  and an emission face  27   b  are each a convex face. The optical setting in the lens body portion  27  of the projection lens  14  will be described below. The projection lens  14  has a lens axis extending in the optical axis direction. This lens axis is an optical axis that passes through the position where the thickness in the optical axis direction is the largest in the lens body portion  27 . The incident face  27   a  and the emission face  27   b  each may be convex or concave, and are not limited to the configuration of Example 1, as long as the lens body portion  27  is a convex lens and satisfies the optical setting described below. 
     The flange portion  28  protrudes from the lens body portion  27  in a radial direction with the optical axis La centered, and extends around the entire circumference in a circumferential direction with the optical axis La centered. The flange portion  28  is capable of being fitted into the projection lens groove  15   e  of the housing  15 . Concerning the projection lens  14 , when the flange portion  28  is fitted into the projection lens groove  15   e , the extending direction of the lens axis is caused to coincide with the optical axis La. 
     The heat radiation member  16  is a heat sink member for releasing, to the outside, the heat generated at the light source  21 , and is formed of an aluminum die-casting or resin having thermal conductivity. This heat radiation member  16  has a light source installation portion  16   a  in which the light source portion  11  (substrate  22  thereof) is installed, and a plurality of heat radiation fins  16   b . To the outside from each heat radiation fin  16   b , the heat radiation member  16  radiates the heat generated by the light source portion  11  installed at the light source installation portion  16   a.    
     The vehicle light  10  is assembled as follows with reference to  FIG. 2 . First, the light source  21  is mounted on the substrate  22  thereby to assemble the light source portion  11 , and the light source portion  11  is fixed to the light source installation portion  16   a  of the heat radiation member  16 . Then, in the lower member  15   a  of the housing  15 , the light condensing lens  12  is fitted into the light condensing lens groove  15   c , the filter  13  is fitted into the filter groove  15   d , and the projection lens  14  is fitted into the projection lens groove  15   e . Then, with the emission optical axis of the light source  21  coincided with the optical axis La and positioned, the light source installation portion  16   a  of the heat radiation member  16  is fixed to the rear end of the lower member  15   a  of the housing  15  while the substrate  22  is housed in the rear end portion of the lower member  15   a . Then, fitting the upper member  15   b  on the upper side of the lower member  15   a  mounts the heat radiation member  16  while housing the light source portion  11 , the light condensing lens  12 , the filter  13 , and the projection lens  14  in the housing  15 . With this, the light condensing lens  12 , the filter  13 , and the projection lens  14  are arranged on the optical axis La of the light source  21  of the light source portion  11  in the above order from the light source  21  side in a predetermined positional relation, and the heat radiation member  16  is fixed to the light source portion  11  thereby to assemble the vehicle light  10 . 
     The vehicle light  10  is installed in the light chamber in a state in which the optical axis La is inclined relative to the road surface  2  around the vehicle  1  while being directed diagonally to the front side outside the vehicle  1  (see  FIG. 1 ). The vehicle light  10  can turn the light source  21  on and off as appropriate by supplying, from the substrate  22  to the light source  21 , the power from the lighting control circuit. The light from the light source  21  is condensed by the light condensing lens  12  thereby to irradiate the filter  13 , and after passing through the irradiation slit  25  (each slit portion  26 ) thereof, is projected by the projection lens  14  thereby to form, on the road surface  2 , the irradiation pattern Pi in which the four irradiation drawing patterns Di are arranged in a substantially straight line. 
     Next, the optical setting of the light condensing lens  12  will be described using  FIGS. 4 to 7 .  FIG. 7  shows that the darker the color, the relatively brighter, and the lighter the color, the relatively darker. First, the light condensing lens  12  basically irradiates within a setting range Sr (see  FIG. 3 ) in the filter  13  by condensing the light from the light source  21 . The setting range Sr is, in Example 1, a range in which the irradiation slits  25  (each slit portion  26  thereof) of both the filter  13 R for the right side and the filter  13 L for the left side are provided, that is, a range covering the irradiation slits  25  of the filters  13 R and  13 L for both the left and right sides. The setting range Sr is an elliptical shape with the optical axis La at a center thereof (see  FIG. 7 ), and the light condensing lens  12  is also an elliptical shape with the optical axis La at a center thereof in accordance with the setting range Sr. Note that the setting range Sr is not limited to the configuration of Example 1, as long as the shape of the setting range Sr is set according to the shape of the irradiation slit  25 , and the shape of the light condensing lens  12  is be set according to the setting range Sr. In the following, a direction orthogonal to the optical axis La is defined as a radial direction. 
     As illustrated in  FIG. 4 , in a transverse cross-section including the optical axis direction and the width direction, within the range from the emission face  12   b  to the filter  13 , the light condensing lens  12 , concerning the light from the light source  21 , diffuses a light flux passing near the optical axis La in the radial direction, and parallelizes the light flux passing through the position away from the optical axis La in the radial direction. That is, the light condensing lens  12  diffuses the light near the optical axis La where the light amount is high due to being the Lambertian distribution, and condenses the light as outward from near the optical axis La. Then, in the transverse cross-section, that is, in the width direction, the light condensing lens  12  substantially evenly diffuses the light from the light source  21  within the setting range Sr of the filter  13 , so that the light amount distribution becomes substantially equal. 
     As illustrated in  FIGS. 5 and 6 , the light condensing lens  12  is a free curved face including an upper lens portion  31  and a lower lens portion  32  in the upper-lower direction with the optical axis La at the center. The upper lens portion  31  condenses the light from the light source  21  so as to cause the light to intersect with the optical axis La in a longitudinal cross-section including the optical axis direction and the upper-lower direction, as illustrated in  FIG. 5 . The upper lens portion  31  causes at least the light flux near the optical axis La of the rays of light from the light source  21  to intersect with the optical axis La at the most filter  13  side, than other light fluxes, between the filter  13  and the projection lens  14 . Then, the upper lens portion  31  causes the majority of the light fluxes, excluding the light flux near the optical axis La, to intersect with the optical axis La beyond the projection lens  14 . As long as causing at least the light flux near the optical axis La to intersect with the optical axis La at the most filter  13  side, than other light fluxes, between the filter  13  and the projection lens  14 , the upper lens portion  31  may cause any light flux other than the above to intersect with the optical axis La either before or after the projection lens  14 . With this, above the optical axis La in the setting range Sr, the upper lens portion  31  evenly diffuses, in the upper-lower direction, the light from the light source  21  passing through the upper lens portion  31 ; meanwhile, as nearer to the optical axis La in the radial direction, the upper lens portion  31  condenses more rays of light. In  FIG. 5 , it appears that more light fluxes are condensed on the upper side, but this is because the light flux from the light source  21  is described according to the shape of the light condensing lens  12 , and in reality, according to the above setting, more rays of light are condensed as nearer to the optical axis La. 
     As illustrated in  FIG. 6 , in the longitudinal cross-section illustrated above, the lower lens portion  32  condenses the light from the light source  21  so as to cause the light to intersect with the optical axis La. The lower lens portion  32  causes the light flux, of the rays of light from the light source  21 , which passes through the position farthest away from the optical axis La in the radial direction, to intersect with the optical axis La at the most filter  13  side between the filter  13  and the projection lens  14 . That is, concerning the light from the light source  21 , the lower lens portion  32  causes the light flux, which passes through the farthest away position from the optical axis La, to intersect with the optical axis La at the nearest position, and causes the light flux nearer to the optical axis La, to intersect with the optical axis La at the position away from the filter  13 . Then, the lower lens portion  32  causes the majority of the light fluxes, including the light flux near the optical axis La, to intersect with the optical axis La between the filter  13  and the projection lens  14 . As long as causing at least the light flux passing through the position farthest away from the optical axis La to intersect, between the filter  13  and the projection lens  14 , with the optical axis La, the lower lens portion  32  may cause any light flux other than the above to intersect with the optical axis La either before or after the projection lens  14 . With this, below the optical axis La in the setting range Sr, the lower lens portion  32  evenly diffuses, in the upper-lower direction, the light from the light source  21  passing through the lower lens portion  32 ; meanwhile, as away from the optical axis La in the radial direction, the lower lens portion  32  condenses the light. 
     This light condensing lens  12 , with the optical setting described above, causes the light from the light source  21  passing through the light condensing lens  12  to be irradiated to the filter  13  (filter  13 L for the left side in the example illustrated in the figure) within the setting range Sr, as illustrated in  FIG. 7 . In that setting range Sr, according to the setting in the upper-lower direction in the light condensing lens  12  (its upper lens portion  31  and lower lens portion  32 ), the first to fourth slit portions  261 ,  262 ,  263 , and  264  gradually change in brightness in the above order, so that the first slit portion  261  which becomes the farthest location is the brightest, and the fourth slit portion  264  which becomes the nearest location is the darkest, in the upper-lower direction. That is, the light condensing lens  12 , in the upper-lower direction, makes the position where the first slit portion  261  which becomes the farthest location is provided the brightest (as a peak), while gradually darkening as away from there, thereby to irradiate an area within the setting range Sr with the light from the light source  21 . Due to this, the light condensing lens  12 , by condensing the light from the light source  21 , gradually changes, in the longitudinal cross-section of the filter  13 , that is, in the upper-lower direction, the brightness across the optical axis La so as to make the farthest location brightest and the nearest location darkest. 
     Further, in the setting range Sr, with the setting in the transverse cross-section (width direction) in the light condensing lens  12 , the brightness in the width direction is made substantially uniform at each slit portion  26 , that is, at each position in the upper-lower direction. That is, the light condensing lens  12 , in the width direction, diffuses the light in a manner not to cause a difference in brightness compared to in the upper-lower direction, and causes the light from the light source  21  to irradiate within the setting range Sr. And, since the setting range Sr is set as described above, the irradiation slit  25  (each slit portion  26 ) can be irradiated in a similar light flux distribution even when either of the filters  13 R or  13 L of the left or right side is used. The light transmitted through the filter  13 , that is, each slit portion  26  which is deemed as the light flux distribution is projected on the road surface  2  by the projection lens  14 . 
     Next, the optical setting of the projection lens  14  will be described using  FIG. 8 . In  FIG. 8 , (a) illustrates the case of the emission from a radial position of 6 mm, (b) illustrates the case of the emission from a radial position of 4 mm, and (c) illustrates the case of the emission from a radial position of 2 mm. The lens body portion  27  (projection lens  14 ) sets a focal plane Fp, as illustrated in  FIG. 8 . The focal plane Fp is a plane on which a point for condensing parallel rays of light from on the optical axis La and from a radial position d, which is defined as a predetermined interval and from the optical axis La in the radial direction, is located, at a position in the optical axis direction where the filter  13  is provided (the plane indicated by a sign  13 ). The radial position d is the position in all radial directions, up, down, left, and right, with respect to the optical axis La, and the lens body portion  27  is similarly set in any direction orthogonal to the optical axis La. The lens body portion  27  is set so that as the radial position d becomes larger, a curvature radius r of the focal plane Fp becomes smaller that is, the curvature of the focal plane Fp becomes larger. Then, the lens body portion  27  sets the curvature center Cc (described at the top and in the middle) on the opposite side to the filter  13  (on the left of the focal plane Fp in  FIG. 8 ) relative to the focal plane Fp, regardless of the radial position d, and makes the focal plane Fp convex toward the projection lens  14  side. That is, the lens body portion  27  does not reverse the convex direction of the focal plane Fp even when the radial position d changes. 
     The lens body portion  27  of Example 1 sets the focal plane Fp as follows as an example. The lens body portion  27  has the curvature radius r of the focal plane Fp of about 7 mm for the parallel rays of light emitted from the radial position d of 6 mm and from on the optical axis La, as illustrated at the top of  FIG. 8 . Further, the lens body portion  27  has the curvature radius r of the focal plane Fp of about 14 mm for the parallel rays of light emitted from the radial position d of 4 mm and from on the optical axis La, as illustrated in the middle of  FIG. 8 . Then, the lens body portion  27  has the curvature radius r of the focal plane Fp of about 128 mm for the parallel rays of light emitted from the radial position d of 2 mm and from on the optical axis La, as illustrated at the bottom of  FIG. 8 . When the lens body portion  27  reduces the curvature radius r of the focal plane Fp as the radial position d increases, it is sufficient that the value of the curvature radius r relative to the radial position d is appropriately set, and the lens body portion  27  is not limited to the configuration of Example 1. In particular, the lens body portion  27  has the above setting of the focal plane Fp (relation between the radial position d and the curvature radius r), at a position (outside the near-axis area) where the radial position d is larger than the near-axis area (less than 2 mm at the radial position d in Example 1). With this, the lens body portion  27  can suppress blurring by clarifying a contour of the irradiation pattern Pi with almost no change compared to the case where the lens body portion  27  is set on the entire surface including the near-axis area, thus making an efficient optical setting. 
     The projection lens  14  projects the irradiation slit  25  (each slit portion  26  thereof) of the filter  13  which is defined as the light flux distribution described above, thereby to form the irradiation pattern Pi, as illustrated in  FIGS. 9 and 10 .  FIG. 9  illustrates the irradiation pattern Pi formed on a screen arranged orthogonally to the optical axis La, and  FIG. 10  illustrates the irradiation pattern Pi formed on the road surface  2  inclined relative to the optical axis La. The contour of the irradiation pattern Pi is made clear on the screen, thus suppressing the blurring. This is due to the fact that setting the projection lens  14  (lens body portion  27 ) as described above can reduce the effect of an image face curve of the projection lens  14 . 
     In addition, the contour of the irradiation pattern Pi is clear on the road surface  2  as well, thus preventing the blurring. This is due to the fact that setting the projection lens  14  (lens body portion  27 ) as described above can reduce the effect that the distance to the road surface  2  changes due to the inclination of the road surface  2  relative to the optical axis La. 
     In particular, in the vehicle light  10  of Example 1, since the light source  21  is a monochromatic light, the effect of chromatic aberration in the projection lens  14  can be greatly suppressed. Due to this, the projection lens  14  can form the irradiation pattern Pi with a clear contour and suppressed blurring. 
     In this irradiation pattern Pi, each irradiation drawing pattern Di, on the road surface  2 , is set to the luminance value illustrated in  FIG. 11 .  FIG. 11  illustrates the luminance values in the vicinity of the V-shaped vertex in each irradiation drawing pattern Di. In  FIG. 11 , the luminance values on the longitudinal axis are logarithmic because it is generally known that the sense of brightness is proportional to the logarithm of luminance. As illustrated in  FIG. 11 , the irradiation pattern Pi is logarithmically linear in the degree of change in brightness relative to the change in distance from the vehicle  1 , with the first irradiation drawing pattern Di 1  farthest from the vehicle  1  being the darkest and the fourth irradiation drawing pattern Di 4  nearest to the vehicle  1  being the brightest. That is, in the irradiation pattern Pi, each irradiation drawing pattern Di is arranged at an equal interval from each other, and the brightness is linearly increased in the order of the first irradiation drawing pattern al, the second irradiation drawing pattern Di 2 , the third irradiation drawing pattern Di 3 , and the fourth irradiation drawing pattern Di 4 . 
     To explain this operation, a vehicle light of a comparative example is used. The vehicle light of the comparative example shall be the same in configuration as the vehicle light  10 , and the setting range Sr of the filter  13 , that is, each slit portion  26 , shall be irradiated at uniform brightness with the light that is from the light source  21  and passed through the light condensing lens  12 . The vehicle light of the comparative example is similar to the vehicle light  10  of Example 1 in that at the projecting on the road surface  2 , it becomes darker in the order from the fourth irradiation drawing pattern Di 4  at the nearest location to the third irradiation drawing pattern Di 3 , the second irradiation drawing pattern Di 2 , and the first irradiation drawing pattern Di 1 , but the change is not linear and it darkens rapidly nearer to the farthest location (the first irradiation drawing pattern Di 1 ). This is due to the fact that in the irradiation pattern Pi projected by the projection lens  14 , the brightness changes in proportion to the square of the distance from the projection lens  14  to the projection face (in this example, the road surface  2 ). Due to this, the vehicle light of the comparative example deteriorates the visibility of the farthest location (first irradiation drawing pattern Di 1 ), and gives the viewer a sense of discomfort due to the rapid change in brightness. 
     Contrary to this, in the vehicle light  10  of Example 1, the light from the light source  21  irradiates the filter  13  in a manner to gradually change the brightness of the setting range Sr of the filter  13  in the order of the first to fourth slit portions  261 ,  262 ,  263 ,  264  so that the first slit portion  261  is the brightest and the fourth slit portion  264  is the darkest. That is, the vehicle light  10  brightens the first slit portion  261  most that corresponds to the first irradiation drawing pattern Di 1  at the farthest location and darkens the fourth slit portion  264  most that corresponds to the fourth irradiation drawing pattern Di 4  at the nearest location, contrary to the brightness in each irradiation drawing pattern Di of the irradiation pattern Pi. Then, the vehicle light  10 , by setting the brightness in the filter  13 , can mitigate the rapid change in brightness caused by the change in distance attributable to projection on the road surface  2  by the projection lens  14 , thus making it possible to linearize the change in brightness of each irradiation drawing pattern Di. Due to this, the vehicle light  10  can ensure the visibility of the farthest location (the first irradiation drawing pattern Di 1 ), and can suppress a sense of discomfort of the viewer by making the linear change in brightness. 
     Next, the operation of this vehicle light  10  will be described using  FIG. 12 . The vehicle light  10  is interlocked with the turn lamp, and when any of the left and right turn lamps is turned on, the light source  21  of the one on the turned-on side is turned on thereby to form the irradiation pattern Pi on the road surface  2 . For example, the example illustrated in  FIG. 12  illustrates a scene in which the vehicle  1  is coming out of an alley with poor visibility and is about to turn left. In the vehicle  1 , the turn lamp on the left side is flashed, and thereby the vehicle light  10  installed on the front left forms the irradiation pattern Pi on the road surface  2 . Then, the driver of a vehicle  1 A proceeding from the right side in front view of  FIG. 12  can see the irradiation pattern Pi formed on the road surface  2 , even if the driver cannot see the vehicle  1 . 
     Further, in the vehicle  1 , the left and right vehicle light rays  10  are interlocked with the turn lamps, so that when a hazard lamp is turned on, the left and right vehicle light rays  10 , two in number, simultaneously form the irradiation patterns Pi on the road surface  2  (see  FIG. 1 ). Due to this, the vehicle light  10  can make a person around the vehicle  1  more reliably aware that the hazard lamp is turned on, compared to the case where only the left and right turn lamps are blinking. 
     The vehicle light  10  of Example 1 can obtain each of the following operational effects. 
     The vehicle light  10  is provided with the light condensing lens  12  that condenses the light emitted from the light source  21 , the filter  13  provided with the irradiation slit  25  that partially transmits the light condensed by the light condensing lens  12 , and the projection lens  14  that projects the light through the filter  13  thereby to form the irradiation pattern Pi. In the vehicle light  10 , the light condensing lens  12 , on the filter  13 , brightens the farthest location of the irradiation slit  25  most and darkens the nearest location of the irradiation slit  25  most in the upper-lower direction, and diffuses the light emitted from the light source  21  more in the width direction than in the upper-lower direction. Due to this, by setting the brightness in the filter  13 , the vehicle light  10  can mitigate the rapid change in brightness caused by the change in the distance from the projection lens  14  to the projection face. With this, in the vehicle light  10 , even when the optical axis La is provided in a manner to be inclined relative to the road surface  2 , the brightness distribution in the irradiation pattern Pi can be made as desired by the light condensing lens  12  setting the brightness on the filter  13 . And, since the vehicle light  10  makes the irradiation pattern Pi a desired luminance distribution by means of the light condensing lens  12  which is composed of the single incident face  12   a  and the emission face  12   b , and the projection lens  14  which is composed of the single emission face  27   b  and the incident face  27   a , the vehicle light  10  can be easily configured. 
     The vehicle light  10  has a plurality of irradiation drawing patterns Di in which the irradiation patterns Pi are arranged, and the irradiation slit  25  has the slit portion  26  that individually corresponds to the irradiation drawing patterns Di. With this, the vehicle light  10  can make each irradiation drawing pattern Di at a desired brightness by setting the brightness of each slit portion  26  with the light condensing lens  12 , making it possible to improve the visibility of the irradiation pattern Pi. 
     Further, in the vehicle light  10 , the light condensing lens  12 , on the filter  13 , diffuses the light from the light source  21  within the setting range Sr where the slit portion  26  is provided in the width direction. Due to this, the vehicle light  10 , as long as within the setting range Sr, can make the similar light flux distribution even if the position of each slit portion  26  is changed, for example, by using the left and right filters  13  in which the irradiation slits  25  (each slit portion  26 ) are provided symmetrical with respect to the plane orthogonal to the width direction in Example 1. With this, the vehicle light  10  can have a simple configuration while increasing the versatility. 
     In the vehicle light  10 , a plurality of slit portions  26  are arranged in the upper-lower direction, with the nearest location being the upper side and the farthest location being the lower side, in the irradiation slit  25 . Further, in the vehicle light  10 , the slit portion  26  is made smaller from the nearest location to the farthest location, and the number of slit portions  26  located below the optical axis La is larger than the number of slit portions  26  located above the optical axis La. Then, the vehicle light  10  is composed of the upper lens portion  31  and the lower lens portion  32  in the upper-lower direction. Additionally, in the vehicle light  10 , the upper lens portion  31  causes at least the light flux near the optical axis La to intersect with the optical axis La between the slit portion  26  and the projection lens  14 , and the lower lens portion  32  causes the light flux, which passes through the position farthest from the optical axis La, to intersect with the optical axis La on the most slit portion  26  side between the slit portion  26  and the projection lens  14 . Due to this, even when the vehicle light  10  is provided with the optical axis La inclined relative to the road surface  2 , the vehicle light  10  can make the plurality of irradiation drawing patterns Di of equal size and make each of them have a desired brightness. In addition, since the vehicle light  10  has a larger number of slit portions  26  on the lower side, which is the farthest location, than on the upper side, which is the nearest location, all the slit portions  26  can be put within an equal range from the optical axis La in the radial direction, thus making it possible to efficiently use the light from the light source  21 . 
     Concerning the vehicle light  10 , in the projection lens  14 , the focal plane Fp for the parallel rays of light from the filter  13  has the curvature radius that decreases as away in the radial direction from the vicinity of the optical axis La. Due to this, the vehicle light  10  can project the filter  13  (irradiation slit  25  (each slit portion  26 )) on the road surface  2  by reducing the effect of the image face curve of the projection lens  14  even when the optical axis La is provided in a manner to be inclined relative to the road surface  2 , and can form the irradiation pattern Pi on the road surface  2  with a clear contour and suppressed blurring. 
     In the vehicle light  10 , the focal plane Fp has the curvature center Cc set on the opposite side to the filter  13  regardless of the distance from the optical axis La in the radial direction. Due to this, the vehicle light  10  can form the irradiation pattern Pi on the road surface  2  with a clearer contour and more suppressed blurring, even when the optical axis La is provided in a manner to be inclined relative to the road surface  2 . 
     Accordingly, the vehicle light  10  of Example 1 as the vehicle light according to the present disclosure can make the luminance distribution in the irradiation pattern Pi as desired while having the simple configuration. 
     Although the vehicle light of the present disclosure has been described above based on Example 1, the specific configuration is not limited to Example 1, and design changes, additions, and the like are allowed as long as they do not depart from the gist of the invention pertaining to each claim of the scope of the patent claims. 
     Further, in Example 1, the irradiation pattern Pi is constituted by aligning four irradiation drawing patterns Di at substantially equal intervals in the direction away from the vehicle  1 . However, provided that the irradiation pattern Pi is formed on the road surface  2  around the vehicle  1  and is the one that informs any person around the vehicle  1  of some intention of the driver, such as the one indicating the turn lamp and the hazard lamp in Example 1, the pattern and the like may be anything as long as being set as appropriate and is not limited to the configuration of Example 1. For example, the irradiation pattern Pi may be formed by the single irradiation drawing pattern Di, or may be formed by respective irradiation drawing patterns Di having different patterns from each other, or may vary in size and pattern in the arrangement order. 
     Further, in Example 1, in order to make the light condensing lens  12  corresponding to the left and right filters  13 R and  13 L, the light condensing lens  12  diffuses the light from the light source  21  within the setting range Sr in which each slit portion  26  is provided in the width direction. However, the light condensing lens  12  is not limited to the configuration of Example 1, as long as the light condensing lens  12  diffuses the light in the width direction thereby to make the luminance of the light, which transmits through each slit portion  26 , substantially equal. As an example of this, the light condensing lens  12  may be one that diffuses, in the width direction, the light from the light source  21  within the slit portion  26  of the filter  13  on any one of left and right sides, that is, may be one that condenses the light to a range caused to match the size of the slit portion  26  in the width direction and meanwhile that diffuses the light in the range, and is not limited to the configuration of Example 1. In this way, when the light is condensed in the range of the slit portion  26  in the width direction, the light condensing lens  12  can gradually perform the brightening in the order of the fourth to first slit portions  264 ,  263 ,  262 ,  261  more efficiently because the slit portion  26  is made smaller as the slit portion  26  approaches the farthest location. 
     Further, in Example 1, in each slit portion  26 , the brightness in the width direction is made substantially uniform. However, the brightness in the width direction at each slit portion  26  may be anything as long as being appropriately set and is not limited to the configuration of Example 1. For example, in each slit portion  26 , the vicinity of the apex that is made into the V-shape can be brightened. In this case, in the transverse cross-section, within the range from the emission face  12   b  to the filter  13 , the light condensing lens  12  shall, concerning the light from the light source  21 , with the light flux passing near the optical axis La in the radial direction being parallel, diffuses the light flux outside of it in the radial direction, and parallelizes the light flux passing through the position away from the optical axis La in the radial direction. In this way, the irradiation pattern Pi can emphasize the way in which the four irradiation drawing patterns Di point the direction of being arranged on a substantially straight line. 
     In Example 1, in the light condensing lens  12 , the upper lens portion  31  and the lower lens portion  32  are set in the upper-lower direction around the optical axis La. However, as long as the light condensing lens  12  has the upper lens portion  31  set on the upper side and the lower lens portion  32  set on the lower side in the upper-lower direction, the respective positions can be set as appropriate, and are not limited to the configuration of Example 1. 
     DESCRIPTION OF REFERENCE NUMERALS 
     
         
         
           
               10  vehicle light 
               12  light condensing lens 
               13  filter 
               14  projection lens 
               21  light source 
               25  irradiation slit 
               26  slit portion 
               31  upper lens portion 
               32  lower lens portion 
             Cc curvature center 
             d radial position 
             Di irradiation drawing pattern 
             Fp focal plane 
             La optical axis 
             Pi irradiation pattern 
             r curvature radius 
             Sr setting range