Patent Application
20190390834
This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2018-118350, filed on Jun. 21, 2018, the entire contents of which are incorporated herein by reference.
The present invention relates to a vehicular lamp fitting, and more particularly to a vehicular lamp fitting which can form: a low beam light distribution pattern of which length in the vertical direction is longer, density is lower (brightness range is smaller), and maximum luminous intensity is lower compared with an ADB light distribution pattern; and an ADB light distribution pattern of which contour is moderately blurred.
Conventionally a vehicular lamp fitting including: a projection lens constituted by a first lens and a second lens; a light guiding lens disposed behind the projection lens; and a low beam light source that is disposed behind the light guiding lens, and emits light which passes through the light guiding lens and projection lens in this sequence, and is irradiated forward to form a low beam light distribution pattern, has been proposed (e.g. Japanese Laid-open Patent Publication No. 2015-79660 (FIG. 1, etc.)). A focal plane of the projection lens and an exit surface of the light guiding lens, through which the light from the low beam light source exits (and an entry surface of the projection lens through which the light from the low beam light source, which exited through the exit surface of the light guiding lens, enters), are both spherical surfaces (spherical surfaces of which curvature is constant) and match (surface-contacted).
The present inventors examined whether an ADB light source, that emits light which passes through the light guiding lens and projection lens in this sequence and is irradiated forward to form an ADB light distribution pattern, is added to the above mentioned prior art. The focal plane of the projection lens and an exit surface of the light guiding lens, through which the light from the ADB light source exit (and an entry surface of the projection lens through which the light from the ADB light source, which exited through the exit surface of the light guiding lens, enters), are both spherical surfaces (spherical surfaces of which curvature is constant) and match (surface-contacted).
[Patent Document 1] Japanese Laid-open Patent Publication No. 2015-79660
However, through study, the inventors discovered that the low beam light distribution pattern is demanded to have a longer length in the vertical direction, lower density (smaller brightness range) and lower maximum luminous intensity compared with the ADB light distribution pattern, but in the case when the focal plane of the projection lens and the exit surface of the light guiding lens, through which the light from the low beam light source exits (and the entry surface of the projection lens through which the light from the low beam light source, which exited through the exit surface of the light guiding lens, enters), are both spherical surfaces (spherical surfaces of which curvature is constant) and match, and also when the focal plane of the projection lens and the exit surface of the light guiding lens through which the light from the ADB light source exits (and the entry surface of the projection lens through which the light from the ADB light source, which exited through the exit surface of the light guiding lens, enters), are both spherical surfaces (spherical surfaces of which curvature is constant) and match, it turns out that: (1) the low beam light distribution pattern and ADB light distribution pattern have vertically symmetrical shapes and luminous intensity distribution (e.g.
With the foregoing in view, it is an object of the present invention to provide a vehicular lamp fitting which can form: a low beam light distribution pattern of which length in the vertical direction is longer, density is lower (brightness range is smaller) and maximum luminous intensity is lower compared with an ADB light distribution pattern; and an ADB light distribution pattern of which contour is moderately blurred.
In order to achieve the object described above, an aspect of the present invention provides a vehicular lamp fitting, comprising: a projection lens; a separator that is disposed behind the projection lens; a low beam light source that is disposed behind the separator, and emits light which passes through the separator and the projection lens in sequence, and is irradiated forward to form a low beam light distribution pattern,
In addition, in a preferred aspect of the invention described above, the lower portion of the front surface of the upper separator main body is surface-contacted with the lower portion of the upper entry surface of the projection lens,
In addition, in a preferred aspect of the invention described above, the projection lens is constituted by optical surfaces of one or more lenses, except for the back surface of the lens disposed last.
A vehicular lamp 10 (corresponding to a vehicular headlamp according to the present invention) according to an embodiment of the present invention is described below with reference to the attached drawings. Corresponding components in each drawing are denoted by the same reference symbols and overlapping descriptions are omitted.
The vehicular lamp fitting 10 illustrated in
As illustrated in
As illustrated in
The front surface 22a includes a light source module mounting surface 22a1, and a peripheral surface 22a2 surrounding the light source module mounting surface 22a1.
The light source module mounting surface 22a1 and the peripheral surface 22a2 are planes that are parallel with a plane which includes the Y axis and the Z axis, for example.
In the light source module mounting surface 22a1, screw holes 22a5 (three locations in
The peripheral surface 22a2 includes a holder contact surface 22a3 with which the holder 40 contacts, and a retainer contact surface 22a4 with which the retainer 70 contacts.
The retainer contact surface 22a4 is disposed on the left and right side of the peripheral surface 22a2 respectively.
The thickness between the retainer contact surface 22a4 and the back surface 22b (thickness in the X axis direction) is thicker than the thickness between the holder contact surface 22a3 and the back surface 22b (thickness in the X axis direction), whereby a step difference is formed.
In the base 22, screw holes 22c (two locations in
On the left and right sides of the base 22, the first extended portion 24 which is extend backward (X axis direction) from the left and right sides of the base 22 respectively is formed. On the front end of the first extended portion 24, a second extended portion 26 which is extend sideways (Y axis direction) is formed.
A radiation fin 28 is disposed on the back surface 22b of the base 22.
The light source module 30 includes: a plurality of low beam light sources 32a; a plurality of ADB light sources 32b; and a substrate 34 on which the plurality of low beam light sources 32a, the plurality of ADB alight sources 32b and a connector 34c are mounted.
As illustrated in
Each of the light sources 32a and 32b is a semiconductor light-emitting element (e.g. LED or LD) having a rectangular light-emitting surface (e.g. 1 millimeter square). Each of the light sources 32a and 32b is mounted on the substrate 34 in a state of each light-emitting surface facing forward (front surface). Each of a plurality of rectangles in
In the substrate 34, through holes 34a (two locations in
The light source module 30 having the above configuration is fixed to the heat sink 20 (light source module mounting surface 22a1) by screwing the screws N2 inserted in the notches S1 into the screw holes 22a5 of the heat sink 20 in a state where the positioning pins 22a6 of the heat sink 20 are inserted into the through holes 34a of the substrate 34.
As illustrated in
A front surface 42a of the holder main body 42 is configured as a surface (a concave spherical surface facing backward) having an inverted shape of the back surface of the separator 50 (back surface 52b of an upper separator main body 52 and a back surface 53b of the lower separator main body 53), so that the back surface of the separator 50 is surface-contacted.
In the holder main body 42, a through hole 42c, to which a first light guiding unit 52d and a second light guiding unit 53d of the separator 50 are inserted, is formed.
In the holder main body 42, a cylindrical unit 44 which is extend backward (X axis direction) from the outer periphery of the holder main body 42 is disposed. In the front end of the cylindrical unit 44, a flange unit 46, which contacts a holder contact surface 22a3 of the heat sink 20, is disposed.
In the holder main body 42 (and the cylindrical unit 44), a notch S4 is disposed.
In the front opening end face 40a of the holder 40, a convex portion 48 and a convex portion 49 are disposed.
As illustrated in
As illustrated in
A front surface 52a of the upper separator main body 52 is configured as a surface having an inverted shape of the upper half above the reference axis AX of a back surface 60b of the primary lens 60 (spherical surface which is concave in the backward direction), so that the upper half of the back surface 60b of the primary lens 60 (spherical surface which is convex in the backward direction) is surface-contacted.
The back surface 52b of the upper separator main body 52 (see
As illustrated in
The stepped edge 52a1 includes an edge e1 corresponding to the left horizontal cut-off line CL1, an edge e2 corresponding to the right horizontal cut-off line CL2, and an edge e3 corresponding to the diagonal cut-off line CL3 connecting the left horizontal cut-off line CL1 and the right horizontal cut-off line CL2.
The extended edge 52a2 is disposed at a same position as the edge el with respect to the Z axis direction, and the extended edge 52a3 is disposed at a same position of the edge e2 with respect to the Z axis direction.
A lower end face 52c of the upper separator main body 52 (see
As illustrated in
At the front end of the first light guiding unit 52d, a first entry surface 52e is disposed. The first entry surface 52e is in a plane that is parallel with the plane which includes the Y axis and the Z axis, for example.
The first entry surface 52e is disposed at a position facing the light source module 30 (light-emitting surfaces of the plurality of light sources 32a) in a state where the first light guiding unit 52d is inserted into the through hole 42c of the holder 40 (see
As illustrated in
The front surface 53a of the lower separator main body 53 is configured as a surface having an inverted shape of the lower half below the reference axis AX of the back surface 60b of the primary lens 60 (spherical surface which is concave in the backward direction), so that the lower half of the back surface 60b of the primary lens 60 (spherical surface which is convex in the backward direction) is surface-contacted.
The back surface 53b of the lower separator main body 53 (see
As illustrated in
The extended edge 53a2 is disposed at the same position as the edge e1′ with respect to the Z axis direction. The extended edge 53a3 is disposed at the same position as the edge e2′ with respect to the Z axis direction.
The upper end face 53c of the lower separator main body 53 (see
As illustrated in
At the front end of the second light guiding unit 53d, a second entry surface 53e is disposed. The second entry surface 53e is a surface that is adjusted such that a plurality of regions constituting the ADB light distribution pattern (e.g. a plurality of regions A1 to A4 which are independently turned ON/OFF) are formed in a state of being divided by the vertical edges, as illustrated in
The second entry surface 53e is disposed at a position facing the light source module 30 (light-emitting surfaces of the plurality of ADB light sources 32b) in a state where the second light guiding unit 53d is inserted into the through hole 42c of the holder 40 (see
As illustrated in
In the lower separator main body 53, a notch S5 is formed so that the connector 34c of the light source module 30 does not contact (interfere) with the lower separator main body 53.
As illustrated in
The separator 50 having the above configuration is disposed in a state where the first light guiding unit 52d of the upper separator main body 52 and the second light guiding unit 53d of the lower separator main body 53 are inserted (e.g. press-fitted or engaged) into the through holes 42c of the holder 40, the first entry surface 52e of the upper separator main body 52 (first light guiding unit 52d) and the light source module 30 (light-emitting surfaces of the plurality of low beam light sources 32a) face each other, the second entry surface 53e of the lower separator main body 53 (second light guiding unit 53d) and the light source module 30 (light-emitting surfaces of the plurality of the ADB light sources 32b) face each other (see
Here the convex portions 48 of the holder 40 are inserted into the through hole 52f1 of the upper separator main body 52 and the through holes 53f1 of the lower separator main body 53 (see
As illustrated in
As illustrated in
As illustrated in
The lens main body 82 includes a front surface 82a and a back surface 82b on the opposite side of the front surface 82a (see
On the outer periphery of the lens main body 82, a tubular unit 84, which extends from the outer periphery of the lens main body 82 in the backward direction (X axis direction), is disposed.
The primary lens 60 and the secondary lens 80 constitute the projection lens of which focal point F (see
For the primary lens 60 and the secondary lens 80 constituting this projection lens, the spherical lens and the plano-convex lens according to Japanese Patent Application Publication No. 2015-79660, for example, can be used.
The secondary lens 80 having the above configuration is disposed in a state where the lens main body 82 is disposed ahead of the primary lens 60; and the pressor/screw receiving unit 86 is in contact with the flange unit 76 of the retainer 70 (see
In the case of the vehicular lamp fitting 10 having the above configuration, when the plurality of low beam light sources 32a are turned ON, the lights from the plurality of low beam light sources 32a enter through the first entry surface 52e of the first light guiding unit 52d of the upper separator main body 52, are guided inside the first light guiding unit 52d, and exit through the front surface 52a of the upper separator main body 52. Thereby a luminous intensity distribution corresponding to the low beam light distribution pattern is formed on the front surface 52a of the upper separator main body 52. This luminous intensity distribution includes the edges e1 to e3 (see
When the plurality of ADB light sources 32b are turned ON, the lights from the plurality of ADB light sources 32b enter through the second entry surface 53e of the second light guiding unit 53d of the lower separator main body 53, are guided inside the second light guiding unit 53d, and exit through the front surface 53a of the lower separator main body 53. Thereby a luminous intensity distribution corresponding to the ADB light distribution pattern is formed on the front surface 53a of the lower separator main body 53. This luminous intensity distribution includes the edges e1′ to e3′ (see
When the plurality of low beam light sources 32a and the plurality of ADB light sources 32b turn ON, a composite light distribution pattern, including the low beam light distribution pattern PLo and the ADB light distribution pattern PADB, is formed, as illustrated in
According to the study by the present inventors, in the case of the vehicular lamp fitting 10 having the above configuration, the regulations specified for the low beam distribution pattern are satisfied, but the luminous intensity of a part of the low beam light distribution pattern (e.g. area around 4° below the horizontal line) becomes relatively high, and luminous intensity unevenness (brightness unevenness) is generated, and as a result, the naturalness of the light distribution is diminished.
A part of the low beam light distribution pattern (e.g. area around 4° below the horizontal line) becomes high because light, of which luminous intensity is relatively strong (e.g. light in the narrow angle direction with respect to the optical axis AX32a of the low beam light source 32a (see
As shown in
The specific reason as to why the thickness TC at the center portion of the low beam light distribution pattern PLo becomes thinner than the thicknesses TL and TR on the left and right sides thereof, is unknown, but the following may be possible.
A reason may be because, firstly, the thickness of the upper separator main body 52 along the reference axis AX becomes thicker in the horizontal direction as departing from the reference axis AX (see thicknesses T1 and T2 in
For example, a portion of the upper separator main body 52 that is distant from the reference axis AX (e.g. portion at thickness T2 in
According to the study by the present inventors, the low beam light distribution is demanded that the length in the vertical direction is longer, the density is lower (brightness range is smaller) and the maximum luminous intensity is lower, compared with the ADB light distribution pattern, but the low beam light distribution pattern that is demanded is not formed in the cases when: the focal plane FP of the projection lens 90 and the front surface 52a of the separator 50, through which the light from the low beam light source 32a exits (and the back surface 60b of the primary lens 60 through which the light from the low beam light source 32a, which exited through the front surface 52a of the separator 50, enters), are both spherical surfaces (spherical surfaces of which curvature is constant) and match (surface-contacted); and the focal plane FP of the projection lens 90 and the front surface 53a of the separator 50 through which the light from the ADB light source 32b exits (and the back surface 60b of the primary lens 60 through which the light from the ADB light source 32b, which exited through the front surface 53a of the separator 50, enters), are both spherical surfaces (spherical surfaces of which curvature is constant) and match (surface-contacted), as illustrated in
Now as Embodiment 2, a vehicular lamp fitting 10A which forms: a low beam light distribution pattern of which length in the vertical direction is longer, density is lower (brightness range is smaller) and maximum luminous intensity is lower compared with an ADB light distribution pattern; and an ADB light distribution pattern of which contour is moderately blurred, will be described.
The differences of the vehicular lamp fitting 10A of the present embodiment from the above mentioned vehicular lamp fitting 10 of Embodiment 1 are: a separator 50A is used instead of the separator 50; and a primary lens 60A is used instead of the primary lens 60. The rest of the configuration is the same as Embodiment 1. In the following, the differences from Embodiment 1 will be primarily described, and a composing element the same as Embodiment 1 is denoted with the same reference sign, and description thereof may be omitted.
As illustrated in
Similarly to Embodiment 1, the low beam light source 32a, the ADB light source 32b, the separator 50A, the primary lens 60A and the secondary lens 80 are maintained in a positional relationship illustrated in
The secondary lens 80 (front surface 82a and back surface 82b) and the primary lens 60A (front surface 60a) constitute the projection lens 90. In concrete terms, out of one or more lenses (primary lens 60A and secondary lens 80 in the present embodiment), optical surfaces other than the back surface of the lens disposed last (the back surface 60Ab of the primary lens 60A in the present embodiment), that is, the front surface 60a of the primary lens 60A and the front surface 82a and the back surface 82b of the secondary lens 80 in Embodiment 2, constitute the projection lens 90. The focal plane FP of the projection lens 90 is a spherical surface of which curvature is constant, for example (see
As illustrated in
The separator 50A is a cup-shaped member which is made of silicon resin, and of which front side is open and back side is closed, as illustrated in
As illustrated in
The upper separator main body 52A is disposed above the reference axis AX, and the lower separator main body 53 is disposed below the reference axis AX.
The upper separator main body 52A is a thin plate type light guiding unit which includes the front surface 52Aa and the back surface 52Ab on the opposite side of the front surface 52Aa. In concrete terms, in the horizontal cross-sectioned view, the upper separator main body 52A, which is a thin plate type light guiding unit, curves along the back surface 60Ab (upper entry surface 60Ab1) of the primary lens 60A (see
As illustrated in
The lower portion of the front surface 52Aa of the upper separator main body 52A is surface-contacted with the lower portion of the back surface 60Ab (upper entry surface 60Ab1) of the primary lens 60A. Further, the space S is formed between a portion above the lower portion of the front surface 52Aa of the upper separator main body 52A and a portion above the lower portion of the back surface 60Ab (upper entry surface 60Ab1) of the primary lens 60A.
The interval (space S) between the front surface 52Aa of the upper separator main body 52A and the back surface 60Ab (upper entry surface 60Ab1) of the primary lens 60A increases in the upward direction. The relationship between the front surface 52Aa of the upper separator main body 52A and the rear focal plane FP of the projection lens 90 (curvature of field, see
The light from the low beam light source 32a, which exits through the first light guiding unit 52d (front surface 52Aa) of the upper separator main body 52A, becomes diffused light, hence the light that reaches the back surface 60Ab (upper entry surface 60Ab1) of the primary lens 60A becomes weaker as the distance (space S) between the front surface 52Aa of the upper separator main body 52A and the back surface 60Ab (upper entry surface 60Ab1) of the primary lens 60A increases (that is, in the upward direction from the reference axis AX). As a result, the low beam light distribution pattern has an ideal luminous intensity distribution which gradually decreases in the downward direction from the upper edge.
A length H1 in the vertical direction (see
The front surface 52Aa of the upper separator main body 52A is formed as a curved surface which is slightly convex in the forward direction, for example (see
The thickness T of the upper separator main body 52A (see
As illustrated in
The first extending unit 54 and the second extending unit 55 are connecting portions which have no optical function. The first extending unit 54 extends forward from the upper end portion of the upper separator main body 52A. The second extending unit 55 extends along the back surface 60Ab of the primary lens 60A, from the front end portion of the first extending unit 54.
The lower separator main body 53 is a thin plate type light guiding unit which includes the front surface 53a and the back surface 53b on the opposite side of the front surface 53a. The upper edge of the front surface 53a of the lower separator main body 53 includes the stepped edge 53a1 (not illustrated in
The second light guiding unit 53d extends toward the ADB light source 32b from the upper portion of the lower separator main body 53 (back surface 53b), and, at the front end, has a second entry surface 53e which faces the ADB light source 32b. The second entry surface 53e is a surface through which the light from the ADB light source 32b enters the separator 50A (second light guiding unit 53d), and is a plane that is parallel with the plane including the Y axis and the Z axis, for example.
As illustrated in
The primary lens 60A is made of transparent resin, such as acrylic and polycarbonate, and is a spherical lens including the front surface 60a and the back surface 60Ab on the opposite side of the front surface 60a, as illustrated in
The back surface 60Ab of the primary lens 60A includes the upper entry surface 60Ab1 which is disposed above the reference axis AX and the lower entry surface 60Ab2 which is disposed below the reference axis AX.
The upper entry surface 60Ab1 is a surface through which the light from the low beam light source 32a, which exits through the front surface 52Aa of the upper separator main body 52A, enters the primary lens 60A. The upper entry surface 60Ab1 is disposed in a region facing the front surface 52Aa of the upper separator main body 52A, out of the back surface 60Ab of the primary lens 60A.
The lower portion of the upper entry surface 60Ab1 matches with the rear focal plane FP of the projection lens 90. The portion above the lower portion of the upper entry surface 60Ab1, however, does not match with the rear focal plane FP of the projection lens 90, and is inclined forward from the rear focal plane FP.
The surface shape of the upper entry surface 60Ab1 is adjusted so as to: satisfy the regulations specified for the low beam light distribution pattern; suppress the luminous intensity of a part of the low beam light distribution pattern (e.g. area around 4° below the horizontal line) from becoming relatively high; and make the thickness in the vertical direction uniform with respect to the horizontal direction (that is, suppress the diminishing of the naturalness of the light distribution). For example, the surface shape of the upper entry surface 60Ab1 is adjusted such that the luminous intensity distribution of the low beam light distribution pattern gradually decreases in a downward direction from the upper edge of the low beam light distribution pattern. In some cases, the surface shape of the front surface 52Aa of the upper separator main body 52A may be adjusted in the same manner. In this description, “uniform” is not limited to the meaning of uniform in the strict sense. In other words, “uniform” includes a state of being visually uniform or being approximately uniform.
The surface shape of the upper entry surface 60Ab1 adjusted like this becomes a complicated free form surface, hence it is difficult to express the surface shape of the upper entry surface 60Ab1 by concrete numeric values.
However, by adjusting the surface shape of the upper entry surface 60Ab1 using predetermined simulation software, and confirming the low beam light distribution pattern (e.g. luminous intensity distribution) each time adjustment is performed, it becomes possible to discern a surface shape of the upper entry surface 60Ab1 to form a low beam distribution pattern which: satisfies the regulations specified for the low beam light distribution pattern; suppresses the luminous intensity of a part of the low beam light distribution pattern (e.g. area around 4° below the horizontal line) from becoming relatively high; and makes the thickness in the vertical direction uniform with respect to the horizontal direction (that is, suppresses the diminishing of the naturalness of the light distribution).
The lower entry surface 60Ab2 is a surface through which the light from the ADB light source 32b, which exits through the front surface 53a of the lower separator main body 53, enters the primary lens 60A. The lower entry surface 60Ab2 is disposed in a region facing the front surface 53a of the lower separator main body 53, out of the back surface 60Ab of the primary lens 60A. The lower entry surface 60Ab2 matches with the rear focal plane FP of the projection lens 90.
As illustrated in
As illustrated in
The interval between the second region B2 and the focal plane FP of the projection lens 90 increases in the upward direction from the reference axis AX. In contrast, the interval between the third region B3 and the focal plane FP of the projection lens 90 increases in the downward direction from the reference axis AX.
By adjusting the first region B1, the vertical length of the high luminous intensity zone in the vicinity of the cut-off line of the low beam light distribution pattern where the luminous intensity is high, and the vertical length of the high luminous intensity zone in the vicinity of the lower edge of the ADB light distribution pattern where the luminous intensity is relatively high, can be adjusted. Further, by adjusting the second region B2, the vertical length of the low beam light distribution pattern can be adjusted. Furthermore, by adjusting the third region B3, the vertical length of the ADB light distribution can be adjusted.
The secondary lens 80 is made of transparent resin, such as acrylic and polycarbonate, and is a plano-convex lens which includes the front surface 82a and the back surface 82b on the opposite side of the front surface 82a. The front surface 82a is a plane that is parallel with a plane including the Y axis and the Z axis, and the back surface 82b is a spherical surface which is convex in the backward direction.
In the vehicular lamp fitting 10A having the above mentioned configuration, when the low beam light source 32a is turned ON, the light from the low beam light source 32a enters the separator 50A (first light guiding unit 52d) through the first entry surface 52e.
As illustrated in
Further, another part of the light from the low beam light source 32a which entered the separator 50A (first light guiding unit 52d), such as the light Ray 2 of which luminous intensity is relatively low (e.g. light in the wide angle direction with respect to the optical axis AX32a of the low beam light source 32a) is guided inside the upper separator main body 52A while repeating the total reflection between the front surface 52Aa and the back surface 52Ab of the upper separator main body 52A, and exits through the front surface 52Aa of the upper separator main body 52A, then enters the primary lens 60A through the upper entry surface 60Ab1 of the primary lens 60A, and is projected by the projection lens 90 constituted by the primary lens 60A and the secondary lens 80, so as to form the low beam light distribution pattern.
The present inventors confirmed that the low beam light distribution pattern formed as described above: satisfies the regulations specified for the low beam light distribution pattern; suppresses the luminous intensity of a part of the low beam light distribution pattern (e.g. area around 4° below the horizontal line H) from becoming relatively high; and makes the thickness in the vertical direction uniform with respect to the horizontal direction (that is, the thicknesses TC, TL and TR become uniform, and the diminishing of the naturalness of the light distribution is suppressed), as illustrated in
An exact reason as to why the luminous intensity of a part of the low beam light distribution pattern (e.g. area around 4° below the horizontal line) does not become high is unknown, but the following is possible.
Since the space S is formed between the front surface 52Aa of the upper separator main body 52A and the back surface 60Ab (upper entry surface 60Ab1) of the primary lens 60A, the light Ray 1 of which luminous intensity is relatively high, out of the light from the low beam light source 32a which enters the separator 50A (first light guiding unit 52d), is refracted (diffused) when the light Ray 1 exits through the front surface 52Aa of the upper separator main body 52A and when the light Ray 1 enters the primary lens 60A through the back surface 60Ab (upper entry surface 60Ab1) of the primary lens 60A respectively, and is then Fresnel-reflected. As a result, the light directed to a part of the low beam light distribution pattern (e.g. area around 4° below the horizontal line) decreases.
A precise reason as to why the thickness in the vertical direction becomes uniform with respect to the horizontal direction is unknown, but the following is possible.
That is, since the space S is formed between the front surface 52Aa of the upper separator main body 52A and the back surface 60Ab (upper entry surface 60Ab1) of the primary lens 60A, the light Ray 1 of which luminous intensity is relatively high, out of the light from the low beam light source 32a which enters the separator 50A (first light guiding unit 52d) is refracted (diffused) when the light Ray 1 enters the primary lens 60A through the back surface 60Ab (upper entry surface 60Ab1) of the primary lens 60A, and a part of the light Ray 1 is projected to a region of the low beam light distribution pattern of which luminous intensity is relatively low (mainly the lower region of the center portion) by the projection lens 90 constituted by the primary lens 60A and the secondary lens 80.
Another possible reason is that the light from the low beam light source 32a, which is guided inside the upper separator main body 52A while repeating the total reflection between the front surface 52Aa and the back surface 52Ab of the upper separator main body 52A and exits through the front surface 52Aa of the upper separator main body 52A, is projected to a region of the low beam light distribution pattern of which luminous intensity is relatively low (mainly the lower region of the center portion) by the projection lens 90 constituted by the primary lens 60A and the secondary lens 80.
The present inventors confirmed that the low beam light distribution pattern formed as described above has a longer vertical direction (T3<T4 in
A possible reason as to why the low beam light distribution pattern has the longer vertical length compared with the ADB light distribution pattern is because the second region B2 is disposed ahead of (or behind) the focal plane FP of the projection lens 90, hence the light from the low beam light source 32a, which exist through the front surface 52Aa of the upper separator main body 52A and enters the primary lens 60A through the upper entry surface 60Ab1 of the primary lens 60A, is projected in a blurred state by the projection lens 90 constituted by the primary lens 60A and the secondary lens 80.
A possible reason as to why the low beam light distribution pattern has the lower density (smaller brightness range) and lower maximum luminous intensity compared with the ADB light distribution pattern is the same as the above mentioned reason as to why the luminous intensity of a part of the low beam light distribution pattern (e.g. area around 4° below the horizontal line) does not become high.
The reason why the width W2 of the low beam light distribution pattern PLo becomes wider than the width W1 of the ADB light distribution pattern PADB in
When the ADB light source 32b is turned ON, the ADB light distribution pattern PADB is formed, and when the low beam light source 32a and the ADB light source 32b are turned ON, a composite light distribution pattern, which includes the low beam light distribution pattern PLo and the ADB light distribution pattern PADB, is formed. Since this aspect is the same as Embodiment 1, description thereof is omitted.
Furthermore, the present inventors confirmed that the contour of the ADB light distribution pattern formed as described above is moderately blurred.
A possible reason as to why the contour of the ADB light distribution pattern is moderately blurred is because the third region B3 is disposed behind (or ahead of) the focal plane FP of the projection lens 90, hence the light from the ADB light source 32b, which exits through the front surface 53a of the lower separator main body 53 and enters the primary lens 60A through the lower entry surface 60Ab2 of the primary lens 60A, is projected in the blurred state by the projection lens 90 constituted by the primary lens 60A and the secondary lens 80.
As described above, according to the present embodiment, the vehicular lamp fitting 10A, which forms a low beam light distribution pattern which has a longer vertical direction, lower density (smaller brightness range) and lower maximum luminous intensity compared with the ADB light distribution pattern, and an ADB light distribution pattern of which contour is moderately blurred, can be provided.
Further, according to the present embodiment, the vehicular lamp fitting 10A forms a lower beam light distribution pattern which suppresses the luminous intensity of a part of the low beam light distribution pattern (e.g. area around 4° below the horizontal light), from becoming relatively high, and makes the thickness in the vertical direction uniform with respect to the horizontal direction (that is, suppresses the diminishing of the naturalness of the light distribution), can be provided.
According to the study of the present inventors, it was discovered that in the vehicular lamp fitting 10A having the above configuration, a space S13 may be generated in some cases between the front surface 52Aa of the upper separator main body 52A through which the light from the low beam light source 32a and the front surface 53a of the lower separator main body 53 through which the light from the ADB light source 32b exits, due to the molding variations of the separator 50A and the change in temperature, as illustrated in
Now as Embodiment 3, a vehicular lamp fitting 10B, which makes the luminous intensity change between the low beam light distribution pattern PLo and the ADB light distribution pattern PADB become smooth and suppresses the diminishing of the naturalness of the light distribution, even if the space S13 is generated between the front surface 52Aa of the upper separator main body 52A through which the light from the low beam light source 32a exits and the front surface 53a of the lower separator main body 53 through which the light from the ADB light source 32b exits, will be described.
A difference of the vehicular lamp fitting 10B of the present embodiment from the above described vehicular lamp fitting 10A of Embodiment 2 is that a separator 50B is used instead of the separator 50A. The rest of the configuration is the same as Embodiment 2. In the following, the differences from Embodiment 2 will be primarily described, and a composing element the same as Embodiment 2 is denoted with the same reference sign, and description thereof may be omitted.
The separator 50B illustrated in
As illustrated in
As illustrated in
The thickness T3 of the overlap unit 57 is 0.2 mm, for example. In order to suppress a drop in the transmittance of the light from the low beam light source 32a, which exits through the front surface 52Aa of the upper separator main body 52B, it is preferable that the thickness T3 of the overlap unit 57 is as thin as possible.
The overlap unit 57 is disposed in a state where the space S15 is formed between the back surface 57b of the overlap unit 57 and the front surface 52Aa of the upper separator main body 52B so that a light Ray 3 from the ADB light source 32b, which is guided inside the overlap unit 57 while repeating the total reflection between the front surface 57a and the back surface 57b of the overlap unit 57, exits through the front surface 57a of the overlap unit 57. The space S15 is about 0.02 mm, for example.
In the vehicular lamp fitting 10B having the above mentioned configuration, when the low beam light source 32a and the ADB light source 32b are simultaneously turned ON, the light from the low beam light source 32a enters the separator 50B (first light guiding unit 52d) through the first entry surface 52e.
A part of the light from the low beam light source 32a which entered the separator 50B (first light guiding unit 52d), such as the light Ray 1 of which luminous intensity is relatively high (e.g. see
Further, another part of the light from the low beam light source 32a which entered the separator 50B (first light guiding unit 52d), such as the light Ray 2 of which luminous intensity is relatively low (see
Meanwhile, the light from the ADB light source 32b enters the separator 50B (second light guiding unit 53d) through the second entry surface 53e.
A part of the light from the ADB light source 32b which entered the separator 50B (second light guiding unit 53d) directly exits through the upper portion of the front surface 53a of the lower separator main body 53B, then enters the primary lens 60A through the lower entry surface 60Ab2 of the primary lens 60A, and is projected by the projection lens 90 constituted by the primary lens 60A and the secondary lens 80, so as to form the ADB light distribution pattern.
Further, as illustrated in
The present inventors confirmed that the composite light distribution pattern, including the low beam light distribution pattern and the ADB light distribution pattern which is formed as above, makes the luminous intensity change between the low beam light distribution pattern PLo and the ADB light distribution pattern PADB become smooth, and suppresses the diminishing of the naturalness of the light distribution, as illustrated in
As described above, according to the present embodiment, the vehicular lamp fitting 10B, which makes the luminous intensity change between the low beam light distribution pattern PLo and the ADB light distribution pattern PADB become smooth, and suppresses the diminishing of the naturalness of the feeling of light distribution, even if the space S13 is formed between the front surface 52Aa of the upper separator main body 52B through which the light from the low beam light source 32a exits and the front surface 53a of the lower separator main body 53B through which the light from the ADB light source 32b exits, can be provided.
Modifications will be described next.
The overlap unit described in Embodiment 3 is the overlap unit 57 of which upper portion of the front end of the lower separator main body 53B extends upward, but the present invention is not limited to this. For example, as illustrated in
The overlap unit 58 is a thin film type light guiding unit, which includes: a front surface 58a facing the lower entry surface 60Ab2 (not illustrated in
The thickness T4 of the overlap unit 58 is 0.2 mm, for example. In order to suppress the drop in transmittance of the light from the ADB light source 32b which exits through the front surface 53a of the lower separator main body 53B, it is preferable that the thickness T4 of the overlap unit 58 is as thin as possible.
The overlap unit 58 is disposed in a state where the space S16 is formed between the back surface 58b of the overlap unit 58 and the front surface 53a of the lower separator main body 53B, so that the light from the low beam light source 32a, which is guided inside the overlap unit 58 while repeating the total reflection between the front surface 58a and the back surface 58b of the overlap unit 58, exits through the front surface 58a of the overlap unit 58. The space S16 is about 0.02 mm, for example.
In this modification, when the low beam light source 32a and the ADB light source 32b are simultaneously turned ON, the light from the low beam light source 32a enters the separator 50B (first light guiding unit 52d) through the first entry surface 52e.
The light Ray 1 of which luminosity intensity is relatively high (see
The light Ray 2 of which luminous intensity is relatively low (see
Further, another part (Ray 4 in
Meanwhile, the light from the ADB light source 32b enters the separator 50B (second light guiding unit 53d) through the second entry surface 53e.
A part of the light from the ADB light source 32b, which entered the separator 50B (second light guiding unit 53d), directly exits through the upper portion of the front surface 53a of the lower separator main body 53B, then enters the primary lens 60A through the lower entry surface 60Ab2 of the primary lens 60A, and is projected by the projection lens 90 constituted by the primary lens 60A and the secondary lens 80, so as to form the ADB light distribution pattern.
The present inventors confirmed that the composite light distribution pattern including the low beam light distribution pattern and the ADB light distribution pattern, which is formed as described above, makes the luminous intensity change between the low beam light distribution pattern PLo and the ADB light distribution pattern PADB become smooth, and suppresses the diminishing of the naturalness of the light distribution, as illustrated in
In the description of Embodiment 3, the overlap unit 57 is applied to the separator 50A of the vehicular lamp fitting 10A of Embodiment 2, but the present invention is not limited to this. For example, the overlap unit 57 may be applied to the separator 50 of the vehicular lamp fitting 10A of Embodiment 1, or other separators. This is the same for the overlap unit 58 as well.
In the description of the above embodiments, the projection lens is the projection lens 90 constituted by two lenses (the primary lens 60A and the secondary lens 80), but the present invention is not limited to this. For example, the projection lens may be a projection lens constituted by one lens, or a projection lens constituted by three or more lenses (not illustrated).
Further, in the description of the above embodiments, the focal plane FP of the projection lens 90 is a spherical surface of which curvature is constant (see
All the numeric values of each of the embodiments are given only for illustration purpose, and appropriate numeric values different from these numeric values can be, of course, used.
Each of the embodiments is given only for illustration purpose in all respects. The present invention is not limited to each of the embodiments in its interpretation. The present invention can be carried out in various ways without departing from its spirit or principal feature.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-118350 | Jun 2018 | JP | national |
