Vehicle lighting

Abstract

To provide a vehicular lighting fixture capable of effectively and properly expanding a light distribution pattern.SOLUTION: A vehicular lighting fixture 1 includes: a light source 2; a reflector 3 having a reflection surface R for reflecting light from the light source 2; and a projection lens 4 for forming a light distribution pattern by radiating the reflection light from the reflection surface R frontward of a vehicle. The reflection surface R has a main reflection region X and an expansion region Y in this order from the light source 2 side toward the projection lens 4 direction. The main reflection region X includes: a first focal point F1 positioned at the light source 2 or in the vicinity of the same; and a second focal point F2 positioned further on the projection lens 4 side than the first focal point F1. In the projection lens 4, a rear side focal point is positioned further on the light source 2 side than the second focal point F2, and the expansion region Y is the region in which the light from the light source 2 is reflected in the projection lens 4 direction, passing the position further on the light source 2 side than the second focal point F2.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to vehicle lamps. More specifically, it relates to projector-type vehicle lamps.

Background Art

[0002] A general projector-type vehicle lamp includes a projection lens, a light source disposed on the rear side of the vehicle with respect to the rear focal point of the projection lens, a reflector that reflects light from the light source, and a shade that blocks a part of the reflected light (for example, Patent Document 1). When the light source is lit, the emitted light from the light source is reflected by the reflector, the reflected light enters the projection lens and is irradiated from the projection lens, and a predetermined light distribution pattern is formed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In addition, as a conventional vehicle lamp, the vehicle lamp shown in FIG. 10 is also known. The vehicle lamp 100 in FIG. 10 includes a light source 200, a reflector 300 that reflects light from the light source 200, a projection lens 400, and a shade 500 that blocks a part of the reflected light from the reflector 300. The first focal point F1 and the second focal point F2 of the reflector 300 are located on the optical axis Z of the projection lens 400. The light source 200 is disposed so as to coincide with the first focal point F1 of the reflector 300. The second focal point F2 of the reflector 300 coincides with the rear focal point F3 of the projection lens 400 or is located in the vicinity thereof. The reflecting surface of the reflector 300 is formed of a rotational ellipsoidal surface having the optical axis Z of the projection lens 400 as the rotation axis.

[0005] In the vehicle lighting device 100, when the light source 200 is turned on, the light L0 emitted from the light source 200 is reflected by the reflector 300 and then focused at the second focal point F2. Since the second focal point F2 of the reflector 300 coincides with or is located near the rear focal point F3 of the projection lens 400, the reflected light L1, L2, and L3 reflected by the reflector 300 passes through or near the rear focal point F3 of the projection lens 400. In other words, the reflected light L1, L2, and L3 reflected by the reflector 300 passes through or near the second focal point F2 of the reflector 300. At this time, a portion of the reflected light is blocked by the shade 500. Subsequently, the reflected light L1, L2, and L3 enter the projection lens 400 and are irradiated as a predetermined light distribution pattern P100 above the HL-HR line of the screen (VU side), as shown in Figure 11. The area indicated by the dotted line in Figure 11 shows the area that would have been illuminated by reflected light blocked by the shade 500 if the shade 500 were not present.

[0006] Incidentally, the vehicle lighting fixture shown in Patent Document 1 and Figure 10 is a vehicle lighting fixture that is generally widely used, but in such vehicle lighting fixtures, there are cases where it is necessary to expand the light distribution pattern in order to widen the visible area. Therefore, as a vehicle lighting device that allows for expansion of the light distribution pattern, the vehicle lighting device 110 shown in Figure 12 is known.

[0007] The vehicle light fixture 110 in Figure 12 extends the light distribution pattern (Figure 11) of the vehicle light fixture 100 in Figure 10 upwards. The vehicle light fixture 110 has the same configuration as the vehicle light fixture 100, except that the shape of the reflector 301 is different from that of the reflector 300 of the vehicle light fixture 100. The reflector 301 in Figure 12 differs in shape from the reflector 300 in Figure 11 in that the reflective surface of the reflector 301 in Figure 12 is composed of a free-form surface based on a spheroid, whereas the reflective surface of the reflector 300 in Figure 11 is composed of a spheroid.

[0008] The reflector 301 has a gradually changing reflective surface such that light reflected from the side closer to the light source 200 passes near the second focal point F2, and light reflected from the side further away from the light source passes further towards the projection lens 400 (towards the front of the vehicle) than the second focal point F2 on the optical axis Z of the projection lens 400.

[0009] As described above, the reflector 301 has a reflective surface composed of a free-form surface based on a spheroid. Of the reflective surface of the reflector 301, the region located closer to the light source 200 is set with a curvature such that the reflected light L1 passes near the second focal point F2, so that the emitted light L11 from the projection lens 400 is irradiated near the HL-HR line of the screen (mainly the focusing pattern) as shown in Figure 13. On the other hand, of the reflective surface of the reflector 301, the region located further from the light source 200 is set with a curvature such that the reflected light L2 and L3 pass through points F20 and F21, which are farther from the second focal point F2 in the optical axis Z, so that the irradiated farther from the HL-HR line of the screen (mainly the diffusion pattern). In other words, the reflective surface is adjusted so that the light reflected from the side further from the light source 200 passes further forward than the second focal point F2 (in the direction away from the light source 200 in the optical axis, i.e., towards the projection lens 400). The curvature of the reflective surface is determined considering that the reflected light is not obstructed by the shade 500 and is incident on the projection lens 400.

[0010] In the above-described vehicle lighting device 110, when the light source 200 is turned on, the light L0 emitted from the light source 200 is reflected by the reflector 301. The reflected light L1 reflected on the side of the reflector 301 closer to the light source 200 passes through the second focal point F2 or its vicinity (i.e., the rear focal point F3 of the projection lens 400 or its vicinity, which is omitted in Figure 12). The reflected light L2 reflected on the side of the reflector 301 further from the light source 200 passes through a point F20 that is closer to the projection lens 400 (towards the front of the vehicle) than the second focal point F2. The reflected light L3 reflected on the side of the reflector 301 even further from the light source 200 passes through a point F21 that is even closer to the projection lens 400 (further towards the front of the vehicle) than the second focal point F2. In other words, the further the reflected light is reflected from the light source 200 on the reflector 301, the closer the points F20 and F21, where the reflected light intersects with the optical axis Z of the projection lens 400, are to the projection lens 400 side (the front side of the vehicle). This allows the light distribution pattern P200 emitted from the projection lens 400 to be extended upward. As shown by the arrows in Figure 13, the resulting light distribution pattern P200 has a higher upper end than the light distribution pattern P100 shown by the dotted line in Figure 11.

[0011] According to the vehicle lighting device 110 described above, the upper end of the light distribution pattern can be extended upward by adjusting the shape of the reflector 301 so that the light reflected from the side farther from the light source 200 passes forward of the second focal point F2 (in the direction away from the light source 200 in the optical axis, i.e., towards the projection lens 400).

[0012] Incidentally, depending on the type of vehicle, it may be required that the vertical dimension of the lens of this type of vehicle light fixture be made thinner. To make it thinner, for example, by eliminating the shade or changing the position of the rear focal point of the projection lens, however, as shown in the above-mentioned Patent Document 1 and Figures 10-13, the conventional method of gradually changing the second focal point of the reflective surface toward the lens has the problem that it is not possible to expand the light distribution pattern. The object of this disclosure is to provide a vehicle lighting device that can effectively and appropriately extend appropriate parts of the light distribution pattern. [Means for solving the problem]

[0013] The vehicle lighting device according to this disclosure comprises a light source, a reflector having a reflective surface that reflects light from the light source, and a projection lens that projects reflected light from the reflective surface toward the front of the vehicle to form a light distribution pattern, wherein the reflective surface has a primary reflection region and an extended region in that order from the light source side toward the projection lens, the primary reflection region has a first focal point located at or near the light source and a second focal point located toward the projection lens than the first focal point, the projection lens has a rear focal point located toward the light source than the second focal point, and the extended region is a region that reflects light from the light source toward the projection lens through a position toward the light source than the second focal point. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a vehicle lighting device that can effectively and appropriately expand the light distribution pattern. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view of a vehicle light fixture shown as one embodiment of the present disclosure. [Figure 2] Figure 1 is an exploded perspective view of the vehicle's lighting fixture. [Figure 3] This is a cross-sectional view along line AA in Figure 1. [Figure 4] This is a conceptual diagram of a vehicle lighting device as one embodiment of the present disclosure. [Figure 5] This is a magnified view of the portion indicated by the symbol N in Figure 4. [Figure 6] This figure shows the light distribution pattern emitted by the vehicle lighting fixture shown in Figure 4. [Figure 7] This is a conceptual diagram of a vehicle lighting device in which the reflective surface of the reflector does not have an extended region Y. [Figure 8] This figure shows the light distribution pattern of a vehicle light fixture that does not have an extended region Y on the reflector's reflective surface. [Figure 9] This is a conceptual diagram taken from the perspective of arrow A in Figure 2. [Figure 10] It is a conceptual diagram showing a configuration example of a conventional projector-type vehicle lamp. [Figure 11] It is a diagram showing a light distribution pattern irradiated by the vehicle lamp shown in FIG. 10. [Figure 12] It is a conceptual diagram showing a configuration example when expanding the light distribution pattern in a conventional vehicle lamp. [Figure 13] It is a diagram showing an expanded light distribution pattern in the vehicle lamp shown in FIG. 12.

Mode for Carrying Out the Invention

[0016] Hereinafter, an example of an embodiment of a vehicle lamp according to the present disclosure will be described in detail based on the drawings. Note that the present invention is not limited by this embodiment. In FIGS. 6, 8, 11, and 13, the reference numeral "VU - VD" indicates the vertical lines above and below the screen. The reference numeral "HL - HR" indicates the horizontal lines on the left and right of the screen. In this specification, front, rear, up, down, left, and right refer to the front, rear, up, down, left, and right when the vehicle lamp is installed on the vehicle.

[0017] Hereinafter, the configuration and operation of the vehicle lamp in this embodiment will be described based on FIGS. 1 to 9. Here, as an example, the headlamp of a vehicle headlamp, particularly the lamp for irradiating a high-beam (driving beam) light distribution pattern, will be described. The lamp for irradiating a low-beam (passing beam) has a configuration in which the up and down are reversed in the lamp for irradiating a high-beam light distribution pattern.

[0018] (Vehicle lamp 1) In FIGS. 1 to 4, the reference numeral 1 is the vehicle lamp in this embodiment. The vehicle lamps 1 are respectively mounted on both the left and right sides of the front part of the vehicle. The vehicle lamp 1 includes a light source 2, a reflector 3, and a projection lens 4. Further, in FIGS. 1 and 2, the reference numeral 5 is the heat sink member 5, and the light source 2, the reflector 3, and the projection lens 4 are attached thereto. Note that FIGS. 1 and 2 show a configuration example when a plurality of sets of the light source 2, the reflector 3, and the projection lens 4 are provided in the vehicle width direction.

[0019] The light source 2, reflector 3, projection lens 4, and heat sink member 5 constitute a projector-type lamp unit that projects a predetermined light distribution pattern (in this example, the high beam light distribution pattern shown in Figure 6) to the outside, i.e., in front of the vehicle. The light source 2, reflector 3, projection lens 4, and heat sink member 5 are arranged inside the lamp chamber and are attached to the lamp housing via an optical axis adjustment mechanism for the vertical direction (not shown) and an optical axis adjustment mechanism for the horizontal direction (not shown).

[0020] Furthermore, the lamp chamber may contain lamp units other than the light source 2, reflector 3, projection lens 4, and heat sink member 5, such as low beam pattern illumination lamp units, clearance lamp units, turn signal lamp units, and daytime running lamp units. In addition, the lamp chamber may contain inner panels (not shown), inner housings (not shown), inner lenses (not shown), etc.

[0021] (Heat sink component 5) The heat sink component 5 is a component used as needed and is made of a material with high thermal conductivity, such as metal die-casting (aluminum die-casting). The light source 2, reflector 3, and projection lens 4 are attached to the heat sink component 5. In this case, the heat sink component 5 serves as both a heat dissipation component and a mounting component.

[0022] The heat sink member 5 comprises a plate portion 51 as a mounting portion and a plurality of fin portions 52 as a heat dissipation portion. The plurality of fin portions 52 are integrally provided on the upper surface of the plate portion 51 perpendicularly and parallel or substantially parallel in the front-to-back direction.

[0023] (Light source 2) The light source 2 is a semiconductor-type light source, such as an LED, OEL, or OLED (organic light-emitting diode). In this embodiment, the light source 2 is attached to the heat sink member 5 via a plate-shaped substrate 20. The upper surface of the substrate 20 is attached to the lower surface of the plate portion 51 of the heat sink member 5, and the light source 2 is mounted on the lower surface of the substrate 20 at a position facing the reflective surface R of the reflector 3. The light source 2 is supplied with current from a lighting circuit (not shown).

[0024] Light source 2 has a light-emitting surface S. In this example, the light-emitting surface S is downward-facing and square-shaped, as shown in Figures 3 and 4. The light-emitting surface may also be rectangular. The center point of the light-emitting surface S coincides with, or approximately coincides with, the first focal point F1 of the principal reflection region X of the reflecting surface R of reflector 3. When the light-emitting surface S is rectangular, the longitudinal direction of the light-emitting surface S is perpendicular or approximately perpendicular to the optical axis Z of the projection lens 4 in the left-right direction. In the example in Figure 4, the light-emitting surface S is above the optical axis Z of the projection lens 4.

[0025] (Reflector 3) The reflector 3 is made of a material that is highly heat-resistant and opaque, such as a resin component. In this embodiment, the reflector 3 is attached to the heat sink member 5. The reflector 3 has a hollow shape with an open front and upper portion, and closed rear, lower, and left and right portions. The reflector 3 has a reflective surface R that reflects light from the light source 2. The reflective surface R is a converging reflective surface and extends from the vicinity of the light source 2 toward the projection lens 4. The reflective surface R faces the light-emitting surface S of the light source 2.

[0026] As shown in Figure 4, the reflective surface R has a primary reflective region X and an extended region Y in that order, extending from the light source 2 towards the projection lens 4. The primary reflective region X is composed of a spheroidal ellipsoid or a surface based on a spheroidal ellipsoid with the optical axis Z of the projection lens 4 as its axis of rotation, and the extended region Y is composed of a freeform surface. The primary reflective region X is a reflective surface formed such that the radius of curvature gradually increases from the light source 2 towards the projection lens 4, and the extended region Y is a reflective surface with a radius of curvature smaller than the leading edge T of the primary reflective region X on the projection lens 4 side. Under this configuration, as the primary reflective region X is moved from the light source 2 towards the projection lens 4, the radius of curvature gradually increases (the curvature decreases, i.e., the curve becomes gentler), and when it reaches the extended region Y located further ahead on the projection lens 4 side, it becomes a curved surface with a radius of curvature smaller than the radius of curvature of the primary reflective region X (the curvature increases, i.e., the curve becomes steeper). The primary reflective region X and the extended region Y are considered to be smoothly continuous surfaces. In other words, the reflective surface R is composed of a continuous surface without any steps extending from the projection lens 4 towards the light source 2, including the extended region Y.

[0027] (Projection lens 4) The projection lens 4 is, for example, a resin lens made of PC material, PMMA material, etc. In this embodiment, the projection lens 4 is attached to the heat sink member 5 either directly or via a separate holder (not shown).

[0028] The projection lens 4 is an aspherical projection lens. The projection lens 4 consists of an incident surface E1 on the rear and an exit surface E2 on the front. The incident surface E1 faces the reflector 3. The incident surface E1 is a flat surface or is convex or concave relative to the reflector 3. The exit surface E2 is a convex aspherical surface.

[0029] (Description of the optical system, including the light source, reflector, and projection lens) In this explanation, we will identify a single light source and explain the process based on the light emitted from that source, referring to Figure 4.

[0030] In this vehicle lighting device 1, the light source 2 emits light L0 downwards. The projection lens 4 has its rear focal point (the focal point that constitutes the lens image plane M) at the position indicated by the symbol F3 near the light source 2. As described above, the light source 2 coincides with, or nearly coincides with, the first focal point F1 of the main reflection region X of the reflecting surface R of the reflector 3, so the rear focal point F3 of the projection lens 4 is located on the light source 2 side (rear side) of the tip U of the extended region Y (the end of the reflector 3 on the projection lens 4 side). Also, a part of the lens image plane M of the projection lens 4 intersects with a part of the reflector 3. In other words, a part of the lens image plane M of the projection lens 4 crosses a part of the reflector 3. Furthermore, in Figure 4, the extended region Y is located in front of the lens image plane M (on the projection lens 4 side).

[0031] When light source 2 is turned on, the emitted light L0 irradiated downward from light source 2 is reflected by the reflective surface R of reflector 3. The principal reflection region X on the reflective surface R of reflector 3 has a first focal point F1 located at or near light source 2, and a second focal point F2 located closer to the projection lens 4 than the first focal point F1. That is, the first focal point of the principal reflection region X is located at or near light source 2, at the position indicated by the symbol F1. The first focal point of the principal reflection region X is located slightly above the optical axis Z of the projection lens 4.

[0032] The second focal point of the primary reflection region X is located on the optical axis Z of the projection lens 4 at the position indicated by the sign F2, near the projection lens 4. The positions of the second focal point F2 and the rear focal point F3 of the projection lens 4 do not coincide; the second focal point F2 is located in front of the rear focal point F3 of the projection lens 4 (towards the projection lens 4). In other words, the second focal point F2 is located between the projection lens 4 and the rear focal point F3.

[0033] As described above, the extended region Y has a smaller radius of curvature (larger curvature) than the leading edge T of the main reflection region X. Therefore, when it receives the emitted light L0 from the light source 2, the reflected light L3b intersects the main reflection region X at point F20 on the optical axis Z, which is closer to the light source 2 than the second focal point F2, and then proceeds in the direction of the projection lens 4. In other words, the extended region Y reflects the emitted light L0 from the light source 2 through point F20, which is closer to the light source 2 than the second focal point F2 of the main reflection region X, and then proceeds in the direction of the projection lens 4.

[0034] Furthermore, in this embodiment, the extended region Y is formed such that the point where light from the light source 2 intersects the optical axis Z gradually shifts backward (towards the light source 2) from the second focal point F2 of the main reflection region X. That is, as the point where the light from the light source 2 is reflected in the extended region Y shifts (moves) from the light source 2 side towards the projection lens 4 side, the point F20 where the light reflected in the extended region Y intersects the optical axis Z of the projection lens 4 gradually shifts from the projection lens 4 side towards the light source 2 side. In addition, the distance between the first focal point F1 of the main reflection region X and the point F20 where the reflected light L3b from the extended region Y intersects the optical axis Z (the distance between focal points in the extended region Y) is shorter than the distance between the first focal point F1 and the second focal point F2 of the main reflection region X (the distance between focal points in the main reflection region X). Furthermore, the distance between the first focal point F1 and the point F20 where the reflected light L3b from the extended region Y intersects the optical axis Z (the distance between focal points in the extended region Y) decreases as you move further away from the light source 2 in the extended region Y.

[0035] (Function of vehicle lighting device 1) First, to deepen understanding of the contents of this disclosure, we will explain the case where there is no extended region Y on the reflector's reflective surface. Figures 7 and 8 are diagrams to illustrate this. The vehicle lamp 10 shown in Figure 7 has the same configuration as the vehicle lamp 1 in Figure 4, except that the reflective surface R of the reflector 3 is constructed by extending the main reflective region (i.e., using only the main reflective region) instead of the extended region Y. This reflective surface R is composed of a spheroid or a surface based on a spheroid. The vehicle lamp 10 emits the light distribution pattern P1 shown in Figure 8.

[0036] In the vehicle lighting device 10, reflected light L1, reflected from the area of ​​the reflecting surface R of the reflector 3 close to the light source 2, is incident on the area of ​​the projection lens 4 close to the optical axis Z and is emitted as light L11, illuminating the area near the HL-HR line on the screen and forming the central part of the light distribution pattern P1. Reflected light L2, reflected from the area of ​​the reflecting surface R slightly further away from the light source 2, is incident on the area of ​​the projection lens 4 above the optical axis Z and is emitted as light L21, illuminating the area further away from the HL-HR line and forming the area above the central part (VU side) of the light distribution pattern P1. Reflected light L3a, reflected from the area of ​​the reflecting surface R even further away from the light source 2, is incident on the area even further above the optical axis Z of the projection lens 4 and is emitted as light L31, illuminating the area even further away from the HL-HR line and forming the upper end of the light distribution pattern P1 shown in Figure 8.

[0037] Next, referring to Figures 4-6, we will explain the operation when the configuration shown in Figure 7 above is modified to form an extended region Y on the reflecting surface of the reflector. The extended region Y has the effect of extending an appropriate part of the light distribution pattern (in this example, the upper end) by reflecting light from the light source 2 through a position closer to the light source 2 than the second focal point F2 of the main reflection region X towards the projection lens 4. The vehicle lamp 1 illuminates with the light distribution pattern P2 shown in Figure 6.

[0038] As shown in Figures 4-6, of the emitted light L0 from the light source 2, the reflected light L1 reflected near the light source 2 in the main reflection region X of the reflecting surface R of the reflector 3 passes through the first focal point of the main reflection region X, passing near the optical axis Z, and is incident on the region of the projection lens 4 close to the optical axis Z (near the center of the projection lens 4), where it is emitted as light L11 and irradiates the area near the HL-HR line on the screen, forming the area near the center of the light distribution pattern P2 shown in Figure 6. The reflected light L2 reflected in the main reflection region X, which is slightly further away from the light source 2, passes through, for example, the second focal point F2, and is incident on the region slightly above the optical axis Z of the projection lens 4, where it is emitted as light L21 and irradiates the region further away from the HL-HR line, forming the area slightly above the center (towards the VU side) of the light distribution pattern P2. Then, the reflected light L3b reflected in the extended region Y, which is further away from the light source 2, passes through the optical axis Z of the projection lens 4 at point F20, which is closer to the light source 2 than the second focal point F2 of the main reflection region X. It then enters a region even higher than the optical axis Z of the projection lens 4 and is emitted as light L31, illuminating the area even higher (towards the VU direction) than the HL-HR line, forming the vicinity of the upper end of the light distribution pattern P2. At this time, the reflected light L3b shown in Figure 4 intersects the optical axis Z at a larger angle than the reflected light L3a shown in Figure 7 when the extended region Y does not exist. Also, the position at which the reflected light L3b enters the projection lens 4 is higher than that of the reflected light L3a when the extended region Y does not exist. As a result, it is possible to illuminate a light distribution pattern P2 that extends the upper end of the light distribution pattern P1 (shown by a dotted line in Figure 6) illuminated by the vehicle lamp 10 in Figure 7 upwards (in the direction of the arrow in Figure 6; the VU direction of the screen). In other words, the vehicle light fixture 1 can move the upper end of the light distribution pattern P1 of the vehicle light fixture 10 further away from the HL-HR line.

[0039] Furthermore, the operation of the vehicle light fixture 1 will be explained in more detail with reference to Figure 5, which is an enlarged view of the part labeled N in Figure 4. In Figure 5, the dotted line labeled K indicates an extended region K, which is an extension of the main reflection region X from the tip T towards the projection lens 4. The reflective surface having the extended region K has the same shape as the reflective surface of the reflector when the extended region Y shown in Figure 7 does not exist. The extended region K is formed so that the radius of curvature gradually increases from the tip T toward the projection lens 4, following the main reflection region X. As shown in Figure 5, the emitted light L0 toward the extended region K is reflected at a small angle (reflected light L3a) and moves toward the direction labeled D1. On the other hand, the extended region Y, as shown by the white arrow in Figure 5, has a smaller radius of curvature (larger curvature) than the extended region K and is curved upwards from the extended region K. The emitted light L0 directed toward the extended region Y is reflected upward at a larger angle than the reflected light L3a reflected in the extended region K (reflected light L3b), and is directed in the direction of sign D2, which is higher than the direction of D1. As a result, in a configuration with an extended region Y, a light distribution pattern P2 can be projected, in which the upper end of the light distribution pattern irradiated from the projection lens 4 is extended upward.

[0040] Furthermore, in Figure 5, the dotted line indicated by symbol A is the line (back path) of the reflected light L3b reflected in the extended region Y, extended toward the lens image plane M of the projection lens 4, and the dotted line indicated by symbol B is the line (back path) of the reflected light L3a reflected in the extended region K, extended toward the lens image plane M. As shown in Figure 5, the point where the back path A of the reflected light L3b reflected in the extended region Y intersects with the lens image plane M is further from the light source than the point where the back path B of the reflected light L3a reflected in the extended region K intersects with the lens image plane M. This makes it possible to project a light distribution pattern P2, which is the upper end of the light distribution pattern P1 emitted from the projection lens 4 extended upward.

[0041] According to the above-described vehicle lighting device 1, the reflective surface R of the reflector 3 is formed at or near the projection lens 4 side end, and has an extended region Y that reflects light from the light source 2 towards the projection lens 4 through a position on the light source 2 side of the second focal point of the reflective surface R, thereby extending the upper end of the light distribution pattern upward. By reversing the orientation of the light source and reflector, it is also possible to extend the light distribution pattern downward. In this way, by reflecting light from the light source 2 towards the projection lens 4 through a position on the light source 2 side of the second focal point F2, the appropriate parts of the light distribution pattern can be effectively and appropriately extended.

[0042] Furthermore, in the above-described vehicle light fixture 1, the expanded region Y is formed such that the point where light from the light source 2 intersects the optical axis Z gradually shifts backward (towards the light source 2) from the second focal point F2 of the main reflection region X. Therefore, the further away the point in the expanded region Y that reflects light from the light source 2 is toward the projection lens 4, the more the light is reflected toward the upper side of the projection lens 4, thus extending the upper end of the light distribution pattern upward. The extent to which it is extended upward can be appropriately adjusted by changing the length and curvature of the expanded region Y, depending on the position and direction of the object for which improved visibility is required.

[0043] Furthermore, in the above-described vehicle light fixture 1, the rear focal point F3 of the projection lens 4 is located close to the reflective surface R of the reflector 3, so the pattern projected onto the reflector 3 approximates the light distribution pattern that is emitted. This eliminates the need for a shade to adjust the shape of the light distribution pattern by blocking some of the reflected light from the reflective surface R of the reflector 3, thus enabling miniaturization of the vehicle light fixture. In addition, because the distance between the light source 2 and the reflector 3 is short, the illuminance value hitting the reflector 3 can be increased, thereby increasing the luminous intensity of the emitted light. Furthermore, since the reflective surface R of the reflector 3 consists of a continuous surface without any steps between the main reflective area X and the extended area Y, streaks are less likely to occur within the light distribution pattern.

[0044] In the above embodiment, the second focal point of the main reflection region X that constitutes the reflective surface R of the reflector 3 is provided near the projection lens 4, but its position is not limited and can be appropriately changed in front of the rear focal point F3 of the projection lens 4 (on the projection lens 4 side). The first focal point of the main reflection region X is located slightly above the optical axis Z of the projection lens 4, but it may also be located on the optical axis Z of the projection lens 4. Furthermore, although the extended region Y is composed of freeform surfaces, it may also be a freeform surface based on a spheroidal ellipsoid (with the optical axis Z of the projection lens 4 as the axis of rotation) with a smaller radius of curvature than the principal reflection region X. Furthermore, although the light source 2 is attached to the heat sink member 5 via a plate-shaped substrate 20, it may be attached to another mounting member instead of the heat sink member 5. Furthermore, the rear focal point F3 of the projection lens 4 is located near the light source 2, but it may be in front of the light source 2 (towards the projection lens 4) or behind it. Furthermore, the vehicle light fixture 1 may have a shade that blocks a portion of the reflected light from the reflective surface R of the reflector 3, but it is preferable not to have a shade for forming the light distribution pattern, as this allows for miniaturization. Furthermore, although a portion of the lens image plane M of the projection lens 4 intersects with a portion of the reflector 3, it may also be located on the rear side of the reflector.

[0045] In the above embodiment, an example of extending the light distribution pattern in the vertical direction was described, but it is also possible to extend the light distribution pattern in the horizontal direction by forming the extended region Y to a position close to the horizontal cross-section of the optical axis Z. As explained in detail with reference to Figure 9, by forming the extended region Y to a height close to the light source 2, the curvature of the extended region Y becomes greater than the curvature of the main reflection region X in region O close to the light source 2. The light reflected in the extended region Y of region O is reflected towards the projection lens 4, passing through a position closer to the light source 2 than the second focal point F2, and can illuminate the HL and HR sides of the VU-VD line of the screen in Figure 6. This makes it possible to extend the light distribution pattern in the horizontal direction.

[0046] In the above embodiment, one example configuration was shown in which multiple sets of light sources 2, reflectors 3, and projection lenses 4 are provided in the width direction of the vehicle. However, it is sufficient to have one or more sets of light sources 2, reflectors 3, and projection lenses 4, and the number can be appropriately selected according to the vehicle type, etc. Furthermore, one or more sets of light sources 2, reflectors 3, and projection lenses 4 can be used in combination with different optical systems.

[0047] The structure of this disclosure can be summarized as follows: [1] A light source, a reflector having a reflective surface that reflects light from the light source, and a projection lens that projects the reflected light from the reflective surface toward the front of the vehicle to form a light distribution pattern, The reflective surface has a primary reflective region and an extended reflective region in this order, extending from the light source side toward the projection lens. The main reflection region has a first focal point located at or near the light source, and a second focal point located closer to the projection lens than the first focal point. The projection lens has a rear focal point located closer to the light source than the second focal point. The extended region is a region that reflects light from the light source towards the projection lens, passing through a position closer to the light source than the second focal point, in a vehicle lighting device. [2] The main reflection region is composed of a spheroid or a surface based on a spheroid, The vehicle lamp according to [1], wherein the radius of curvature of the extended region is smaller than the radius of curvature of the projection lens side end of the main reflection region. [3] The vehicle lamp according to [1] or [2], wherein the extended region is configured such that as the location that reflects light from the light source shifts from the light source side toward the projection lens side, the location where the light reflected in the extended region intersects with the optical axis of the projection lens gradually changes from the projection lens side toward the light source side. [4] The reflective surface is a continuous surface without steps extending from the projection lens toward the light source, including the extended region, as described in any of [1] to [3]. [5] The vehicle lamp according to any one of [1] to [4], wherein the rear focal point of the projection lens is located on the light source side of the tip of the extended region. [6] A vehicle lamp according to any one of [1] to [5], wherein a part of the image plane of the projection lens intersects with the reflector. [Explanation of Symbols]

[0048] 1, 10, 100, 110 Vehicle lighting fixtures 2, 200 light sources 3,300,301 reflector 4,400 projection lenses 5 Heat sink component 20 circuit boards 51 Board part 52 Fin section 500 Shade E1 entrance plane E2 exit surface F1 1st focal point F2 2nd focal point F3 projection lens rear focus K extension area Light emitted from the L0 light source L1, L2, L3, L3a, L3b reflected light L11, L21, 31 Output light M lens image plane P1, P2, P100, P200 light distribution patterns R reflective surface S Illuminating surface T tip X Main reflection area Y Extension Region Z optical axis

Claims

1. The system comprises a light source, a reflector having a reflective surface that reflects light from the light source, and a projection lens that projects the reflected light from the reflective surface toward the front of the vehicle to form a light distribution pattern. The reflective surface has a primary reflective region and an extended reflective region in this order, extending from the light source side toward the projection lens. The main reflection region has a first focal point located at or near the light source, and a second focal point located closer to the projection lens than the first focal point. The projection lens has a rear focal point located closer to the light source than the second focal point. The extended region is a region that reflects light from the light source towards the projection lens, passing through a position closer to the light source than the second focal point, in a vehicle lighting device.

2. The aforementioned primary reflection region is composed of a spheroid or a surface based on a spheroid, The vehicle lamp according to claim 1, wherein the radius of curvature of the extended region is smaller than the radius of curvature of the projection lens side end of the main reflection region.

3. The vehicle lighting device according to claim 1 or 2, wherein the expanded region is configured such that, as the portion that reflects light from the light source shifts from the light source side toward the projection lens side, the portion where the light reflected in the expanded region intersects with the optical axis of the projection lens gradually changes from the projection lens side toward the light source side.

4. The vehicle lamp according to claim 1 or 2, wherein the reflective surface is composed of a continuous surface without steps extending from the projection lens toward the light source, including the extended region.

5. The vehicle lamp according to claim 1 or 2, wherein the rear focal point of the projection lens is located on the light source side of the tip of the extended region.

6. The vehicle lighting device according to claim 1 or 2, wherein a portion of the image plane of the projection lens intersects with the reflector.

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