Vehicle lamp

Abstract

A vehicle lamp 10 comprises: a projection lens 26 having an incident surface 26b and an emission surface 26a; an LED 16 arranged further to the lamp rear side than a rear focal point F of the projection lens 26; a reflector 18 arranged above the LED 16 and reflecting the light emitted from the LED 16 toward the projection lens 26; a shade 20 arranged between the reflector 18 and the projection lens 26 and blocking a portion of the reflected light from the reflector 18; and a shade reflective surface 20d provided on the upper surface 20a of the shade 20 and reflecting a portion of the reflected light from the reflector 18 upward toward the projection lens 26. The projection lens 26 has, in an upper region of the incident surface 26b, a deflection portion 26c that deflects a portion of the reflected light from the shade reflective surface 20d downward.

Description

Vehicle lighting device

[0001] The present invention relates to a vehicle lighting device.

[0002] Conventionally, a vehicle lighting device has been known that is configured to reflect light from a light source such as an LED with a reflector and irradiate the reflected light in front of the lighting device with a projection lens (see, for example, Patent Document 1). A circular plano-convex lens is used for the projection lens as viewed from the front of the lighting device. In such a vehicle lighting device, a shade is provided between the light source and the projection lens, and a desired light distribution pattern is formed by blocking a part of the reflected light from the reflector with this shade. A reflecting surface is provided near the shade to reflect a part of the reflected light from the reflector upward and make it incident on the projection lens.

[0003] Japanese Patent Application Laid-Open No. 2003-317513

[0004] In recent years, a vehicle lighting device using a narrow-width lens obtained by cutting the upper and lower parts of a conventional circular projection lens has been proposed. When such a projection lens is used, a part of the light incident on the upper region of the incident surface of the projection lens may escape above the projection lens, causing glare.

[0005] The present invention has been made in view of such a situation, and an object thereof is to provide a vehicle lighting device that suppresses the occurrence of glare.

[0006] In order to solve the above problems, a vehicle lighting device according to an aspect of the present invention includes a projection lens having an incident surface and an exit surface, a light source disposed on the rear side of the lighting device with respect to the rear focal point of the projection lens, a reflector disposed above the light source and reflecting the light emitted from the light source toward the projection lens, a shade disposed between the reflector and the projection lens and blocking a part of the reflected light from the reflector, and a shade reflecting surface provided on the upper surface of the shade and reflecting a part of the reflected light from the reflector upward toward the projection lens. The projection lens has a deflection portion in the upper region of the incident surface for deflecting a part of the reflected light from the shade reflecting surface downward.

[0007] According to the present invention, a vehicle lighting device that suppresses the occurrence of glare can be provided.

[0008] This is a schematic vertical cross-sectional view of a vehicle lighting device according to an embodiment of the present invention. The diagram compares a case where a deflection portion is formed in the upper region of the incident surface of the projection lens with a case where no deflection portion is formed.

[0009] The present invention will be described below with reference to the drawings, based on preferred embodiments. The following configurations are illustrative for the purpose of understanding the present disclosure, and the scope of the present disclosure is defined solely by the appended claims. Identical or equivalent components and members shown in each drawing are denoted by the same reference numerals, and redundant descriptions are omitted where appropriate. In addition, the dimensions of members in each drawing are shown enlarged or reduced as appropriate for ease of understanding. Furthermore, some members that are not important for explaining the embodiments are omitted in each drawing.

[0010] Figure 1 is a schematic vertical cross-sectional view of a vehicle lighting device 10 according to an embodiment of the present invention. The vehicle lighting device 10 according to this embodiment is a vehicle headlight positioned at the front of the vehicle.

[0011] As shown in Figure 1, the vehicle light fixture 10 comprises a lamp body 2 having an opening on the front side of the vehicle, and a translucent cover 4 attached to cover the opening of the lamp body 2. The translucent cover 4 is made of a translucent resin, glass, or the like. A light fixture unit 11 is housed in the light chamber 3 formed by the lamp body 2 and the translucent cover 4.

[0012] The lighting unit 11 is a so-called projector-type lighting unit and includes a projection lens 26 having an optical axis Ax extending in the front-to-back direction of the lighting unit, an LED 16 as a light source positioned behind the rear focal point F of the projection lens 26, a reflector 18 positioned to cover the LED 16 from above and reflect the light emitted from the LED 16 toward the projection lens 26, and a shade 20 positioned between the reflector 18 and the projection lens 26 and blocking a portion of the light reflected from the reflector 18.

[0013] The lamp unit 11 is supported by a bracket portion 12. The bracket portion 12 is a roughly plate-shaped member made of a metal material such as aluminum, and is positioned so that its main surface faces the front-to-back direction of the lamp. A light source mounting portion 14 is fixed to the main surface of the bracket portion 12 on the front side of the lamp. A heat dissipation fin 22 is fixed to the main surface of the bracket portion 12 on the rear side of the lamp. The bracket portion 12 has screw holes at predetermined positions on its edges, and an aiming screw 24 that extends forward through the lamp body 2 is screwed into these screw holes. In this way, the bracket portion 12 is attached to the lamp body 2. The vehicle lamp 1 is configured so that the optical axis of the lamp unit 11 can be adjusted horizontally or vertically by the aiming screw 24. Note that the shape of the bracket portion 12 is not particularly limited to this.

[0014] The light source mounting section 14 is made of a metal material such as aluminum and protrudes forward from the main surface of the bracket section 12 on the front side of the luminaire. The light source mounting section 14 has a light source module mounting surface 14a that faces upward in a direction perpendicular to the optical axis of the luminaire unit 11. A substrate 17 on which LEDs 16 are mounted is arranged on the light source module mounting surface 14a.

[0015] The LED 16 is positioned so that its light-emitting surface faces approximately upward in a direction perpendicular to the optical axis of the lighting unit. The substrate 17 is provided with wiring for supplying power to the mounted LED 16. Heat emitted from the LED 16 is transferred to the heat dissipation fins 22 via the light source mounting section 14 and the bracket section 12.

[0016] The reflector 18 is roughly dome-shaped and is positioned above the LED 16 and fixed to the light source mounting section 14. The reflector 18 has an inner reflective surface 18a composed of a free-form surface based on a revolutionary ellipsoid. This reflective surface 18a has a first focal point and a second focal point located further forward than the first focal point. The positional relationship between the reflector 18 and the LED 16 is determined such that the light-emitting surface of the LED 16 substantially coincides with the first focal point of the reflective surface 18a.

[0017] The projection lens 26 has an exit surface 26a at its front and an incident surface 26b at its rear. The exit surface 26a is a convex curved surface, and the incident surface 26b is a convex cylindrical curved surface extending in the left-right direction. The projection lens 26 projects the light source image formed on the rear focal plane, which is the focal plane containing the rear focal point (more precisely, the rear focal point in the vertical cross-section) F, as an inverted image onto a virtual vertical screen in front of the light fixture.

[0018] The projection lens 26 is configured as a narrow lens with a vertical width narrower than its horizontal width, and has a horizontally elongated rectangular shape when viewed from the front of the luminaire. For this reason, vertical wall surfaces 22c and 22d are formed on the top and bottom of the projection lens 22A.

[0019] A shade 20 is provided on the front side of the light source mounting section 14. The shade 20 is fixed to the light source mounting section 14 by fastening members 25 such as screws. The shade 20 has a substantially horizontal shade reflective surface 20d formed on its upper surface 20a, and a curved portion 20b that curves downward on the front side of the light source side of the upper surface 20a so as not to obstruct the incidence of light from the light source onto the projection lens 26. The shade reflective surface 20d reflects a portion of the reflected light from the reflective surface 18a of the reflector 18 upward (away from the optical axis Ax) toward the projection lens 26. The positional relationship between the reflector 18 and the shade 20 is determined such that the ridge line 20c formed by the upper surface 20a and the curved portion 20b of the shade 20 is located near the second focal point of the reflective surface 18a of the reflector 18.

[0020] The shade 20 can also function as a lens holder. A fixing portion (not shown) for the projection lens 26 may be provided at the tip of the curved portion 20b of the shade 20. The projection lens 26 is positioned such that its optical axis Ax coincides with the optical axis of the lamp unit 11, and its rear focal point F substantially coincides with the second focal point of the reflective surface 18a of the reflector 18.

[0021] Light emitted from the LED 16 is reflected by the reflective surface 18a of the reflector 18 and enters the projection lens 26, passing near the second focal point of the reflective surface 18a, i.e., the edge line 20c. The light that enters the projection lens 26 is projected in front of the lamp as approximately parallel light (light ray L1). In addition, a portion of the light reflected from the reflective surface 18a of the reflector 18 is reflected on the shade reflective surface 20d, selectively cutting off the light source light with the edge line 20c as the boundary line. As a result, a light distribution pattern having a cutoff line corresponding to the shape of the edge line 20c of the shade 20 is projected in front of the vehicle.

[0022] In the vehicle light fixture 10 according to this embodiment, a deflection section 26c is provided in the upper region of the incident surface 26b of the projection lens 26, which deflects a portion of the reflected light from the shade reflective surface 20d downward (towards the optical axis Ax). The deflection section 26c may be an inclined plane that is discontinuous with respect to the optical axis Ax and is acute in angle to it. The deflection section 26c is configured so that the reflected light from the shade reflective surface 20d is directly incident on it. "Direct incident" means that the reflected light from the shade reflective surface 20d is incident on the projection lens 26 without passing through the inside of the projection lens 26. In other words, a straight line can be drawn from any point on the shade reflective surface 20d to the deflection section 26c without passing through the inside of the projection lens 26.

[0023] Figure 1 illustrates how a portion of the reflected light from the shade reflective surface 20d of the shade 20 enters the deflection portion 26c of the projection lens 26 (light ray L2). This reflected light is refracted downward by the deflection portion 26c and emitted from the emission surface 26a in front of the lamp.

[0024] Figure 2 compares the case where a deflection portion 26c is formed in the upper region of the incident surface 26b of the projection lens 26 and the case where the deflection portion 26c is not formed. In the projection lens 26 shown in Figure 2, the dashed line 27 indicates the incident surface 26b and vertical wall surface 22c when the deflection portion 26c is not formed.

[0025] Figure 2 illustrates how reflected light from the shade reflective surface 20d incident on the upper region of the projection lens 26 propagates when a deflection portion 26c is not formed in the upper region (ray L3). As shown by ray L3 in Figure 2, reflected light incident on the upper region of the incident surface 26b is refracted at the incident surface 26b, but escapes upward from the vertical wall surface 22c before reaching the exit surface 26a. This is because the projection lens 26 is configured as a narrow lens. The presence of light escaping from the upper end of the projection lens 26 in this way is undesirable because it generates glare. To prevent glare, it is necessary to provide a separate light-shielding member, which can lead to increased costs.

[0026] To solve these problems, the vehicle light fixture 10 according to this embodiment is provided with a deflection section 26c in the upper region of the incident surface 26b, so that the reflected light from the shade reflective surface 20d is refracted downward (light ray L2). As a result, the reflected light is guided to the exit surface 26a and emitted from the exit surface 26a, so that the reflected light does not escape from the vertical wall surface 22c and cause glare.

[0027] The deflection portion 26c may be formed on an inclined surface that is tilted at 15° to 25° with respect to the optical axis Ax of the projection lens 26. In this case, the reflected light from the shade reflection surface 20d can be preferably deflected downward and directed toward the emission surface 26a.

[0028] The present invention has been described above based on the embodiments. These embodiments are illustrative, and it will be understood by those skilled in the art that various modifications are possible in combinations of each component and each processing process, and that such modifications also fall within the scope of the present invention.

[0029] Embodiments can also be expressed as follows, numbered: (Item 1) A vehicle lamp comprising: a projection lens having an incident surface and an outgoing surface; a light source positioned behind the rear focal point of the projection lens; a reflector positioned above the light source and reflecting the outgoing light from the light source toward the projection lens; a shade positioned between the reflector and the projection lens and blocking a portion of the reflected light from the reflector; and a shade reflective surface provided on the upper surface of the shade, which reflects a portion of the reflected light from the reflector toward the projection lens, wherein the projection lens has a deflection portion in the upper region of the incident surface that deflects a portion of the reflected light from the shade reflective surface toward the projection lens. (Item 2) The vehicle lamp according to Item 1, wherein the deflection portion includes an inclined surface that is tilted at 15° to 25° with respect to the optical axis of the projection lens. (3) The vehicle lamp according to item 1 or 2, characterized in that the deflection portion is configured so that reflected light from the shade reflective surface is directly incident upon it. (4) The vehicle lamp according to any one of items 1 to 3, characterized in that the projection lens is configured as a narrow lens with a vertical width narrower than its horizontal width. (5) The vehicle lamp according to item 4, characterized in that vertical wall surfaces are formed above and below the projection lens.

[0030] This invention can be used in vehicle lighting fixtures.

[0031] 1. Vehicle lighting fixture, 2. Lamp body, 3. Light chamber, 4. Light-transmitting cover, 10. Vehicle lighting fixture, 11. Light fixture unit, 12. Bracket section, 14. Light source mounting section, 16. LED, 17. Circuit board, 18. Reflector, 20. Shade, 26. Projection lens.

Claims

1. A vehicle lamp comprising: a projection lens having an incident surface and an outgoing surface; a light source positioned behind the rear focal point of the projection lens; a reflector positioned above the light source and reflecting the outgoing light from the light source toward the projection lens; a shade positioned between the reflector and the projection lens and blocking a portion of the reflected light from the reflector; and a shade reflective surface provided on the upper surface of the shade, which reflects a portion of the reflected light from the reflector upward toward the projection lens, wherein the projection lens has a deflection portion in the upper region of the incident surface that deflects a portion of the reflected light from the shade reflective surface downward.

2. The vehicle lamp according to claim 1, characterized in that the deflection portion includes an inclined surface that is tilted at an angle of 15° to 25° with respect to the optical axis of the projection lens.

3. The vehicle lamp according to claim 1 or 2, characterized in that the deflection portion is configured so that reflected light from the shade reflective surface is directly incident upon it.

4. The vehicle lighting device according to claim 1 or 2, characterized in that the projection lens is configured as a narrow lens with a vertical width narrower than its horizontal width.

5. The vehicle lighting device according to claim 4, characterized in that vertical wall surfaces are formed above and below the projection lens.

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