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DE-112016002315-B4 - Headlight module and headlight assembly

DE112016002315B4DE 112016002315 B4DE112016002315 B4DE 112016002315B4DE-112016002315-B4

Abstract

Headlight module (100), which features: a light source (1) configured to emit light; a light distribution control element (4) configured to form a light distribution pattern by changing a divergence angle of the incident light; and an optical projection element (8) configured to project the light distribution pattern, wherein the light distribution control element (4) includes a first light distribution forming part (41) configured to form an area of high brightness in the light distribution pattern and a second light distribution forming part (42) configured to form an area of low brightness in the light distribution pattern, where the low brightness area has a lower brightness than the high brightness area, characterized by that the first light distribution formation part (41) is a light-refracting surface in a convex shape as seen from the side of the light source (1), the second light distribution formation part (42) is a light-refracting surface in a concave shape as seen from the side of the light source (1), and that the headlight module (100) still exhibits: a condensing optical element (2) configured to convert the light emitted by the light source (1) into condensed light, wherein the first light distribution formation part (41) is arranged on an optical axis of the condensing optical element (2).

Inventors

  • Masashige Suwa
  • Ritsuya Oshima
  • Keiji Nakamura
  • Kuniko Kojima
  • Muneharu Kuwata

Assignees

  • MITSUBISHI ELECTRIC CORPORATION

Dates

Publication Date
20260513
Application Date
20160517
Priority Date
20150522

Claims (13)

  1. Headlight module (100) comprising: a light source (1) configured to emit light; a light distribution control element (4) configured to form a light distribution pattern by changing a divergence angle of the incident light; and an optical projection element (8) configured to project the light distribution pattern, wherein the light distribution control element (4) comprises a first light distribution forming part (41) configured to form a high-brightness area in the light distribution pattern, and a second light distribution forming part (42) configured to form a low-brightness area in the light distribution pattern, the low-brightness area having a lower brightness than the high-brightness area, characterized in that the first light distribution forming part (41) is a refractive surface in a convex shape as seen from the side of the light source (1), and the second light distribution forming part (42) is a refractive surface in a shape as seen from the side seen from the light source (1), is of a concave shape, and the headlight module (100) further comprises: a condensing optical element (2) configured to convert the light emitted by the light source (1) into condensed light, wherein the first light distribution forming part (41) is arranged on an optical axis of the condensing optical element (2).
  2. Headlight module (100) according to Claim 1 , in which the first light distribution formation part (41) is arranged on an optical axis of the light source (1).
  3. Headlight module (100) according to Claim 2 , in which the second light distribution formation part (42) is arranged outside the first light distribution formation part (41) with reference to the optical axis of the light source (1).
  4. Headlight module (100) according to Claim 1 , in which the second light distribution formation part (42) is arranged outside the first light distribution formation part (41) with reference to the optical axis of the condensing optical element (2).
  5. Headlight module (100) according to Claim 1 , in which the first light distribution forming part (41) transmits a mean ray emitted by the light source (1).
  6. Headlight module (100) according to Claim 5 , in which the second light distribution formation part (42) is arranged outside the first light distribution formation part (41) with reference to the central ray.
  7. Headlight module (100) according to one of the Claims 1 until 6 , in which the first light distribution formation part (41) has a greater refractive power than the second light distribution formation part (42).
  8. Headlight module (100) according to one of the Claims 1 until 7 , in which the light distribution pattern is formed in a plane located at a focal point position of the optical projection element.
  9. Headlight module (100) according to Claim 8 , in which the plane is perpendicular to an optical axis of the optical projection element (8).
  10. Headlight module (100) according to Claim 8 or 9 , in which the light emitted by the first light distribution formation part (41) condenses in the plane.
  11. Headlight module (110) according to Claim 10 , further comprising an optical element comprising the light distribution control element (4) and a reflective surface (32).
  12. Headlight module (110) according to Claim 11 , in which the optical element contains the optical projection element (8).
  13. Headlight device (10), comprising the headlight module (100, 110) according to one of the Claims 1 until 12 .

Description

TECHNICAL AREA The present invention relates to a headlight module and a headlight device for illuminating an area in front of a vehicle or the like. STATE OF THE ART A headlight device for a vehicle is required to meet the conditions for a prescribed light distribution pattern as required by road traffic regulations or the like. As one of the rules of the road, the predetermined light distribution pattern concerning the low beam of a car, for example, is in a laterally long shape that is narrow in the vertical direction. Furthermore, it is required that an area on the lower side of a cut line (on the inside of the light distribution pattern) has maximum illuminance. The area with maximum illuminance is referred to as a "high illuminance area." Here, the "area on the lower side of the cut line" means an upper part of the light distribution pattern, corresponding to a portion that illuminates a distant area in the case of a headlight device. Furthermore, it is necessary that any light distribution irregularity in the light distribution pattern be suppressed. This irregularity appears as a dark or bright line when the headlight illuminates the road surface. Such irregularities can impair the driver's sense of distance. Therefore, the headlight must provide a light distribution with less light distribution irregularity. Patent document 1 discloses a technology for generating an area of high brightness using a convex lens. A bright light source image is formed near the upper edge of a shadow by using the convex lens, and the light source image is projected by a projection lens. Accordingly, the area of high brightness is formed near the line of intersection. Patent document 2 describes a lighting unit for a vehicle headlight. The lighting unit is provided with a projection lens, a light source, a reflector, an aperture, and a convex lens. Patent document 3 discloses a vehicle headlight module. The vehicle headlight module comprises a light source, a light guide component, and a projection lens. Patent document 4 describes a vehicle lamp. The vehicle lamp has a light source and a lens arranged on the front of the light source. The lens deflects the light emitted by the light source and directs it toward the front of the vehicle lamp. State of the art documentation PATENT DOCUMENTS Patent document 1: JP 2008-288010 APatent document 2: US 2008 / 0 285 297 A1Patent document 3: DE 11 2014 002 157 T5Patent document 4: US 2007 / 0 127 253 A1 SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION However, in the configuration described in patent document 1, the light source image formed by the convex lens is projected forward by the image projection lens as an inverted image. The light source causes a brightness irregularity depending on the electrode pattern or similar characteristics of the light source. Furthermore, the light source causes a brightness irregularity depending on its configuration, shape, or similar characteristics. Thus, the brightness irregularity of the light source is directly projected as a brightness irregularity in the light distribution pattern. In other words, the brightness irregularity of a light-emitting surface of the light source is directly projected as a brightness irregularity in the light distribution pattern. This means that the brightness irregularity of the light source is directly projected, and this causes the light distribution irregularity in the light distribution pattern. One object of the present invention, which was undertaken in view of the problem with conventional technology, is to provide a headlight device that is capable of generating the area of high illuminance while reducing the light distribution irregularity by using a segmented optical surface. MEANS TO SOLVE THE PROBLEM A spotlight module contains a light source configured to emit light, a light distribution control configured to create a light distribution pattern by changing the divergence angle of the incident light, and an optical projection element configured to project the light distribution pattern. The light distribution control includes a first light distribution forming part configured to create a high-brightness area within the light distribution pattern, and a second light distribution forming part configured to create a low-brightness area within the light distribution pattern. The low-brightness area has a lower brightness than the high-brightness area. EFFECTS OF THE INVENTION According to the present invention, a headlight module or headlight device with lower light distribution irregularity can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS 1 is a configuration diagram showing a configuration of a headlight module 100 according to a first embodiment.2 is a configuration diagram showing the configuration of the headlight module 100 according to the first embodiment.3 is a perspective view of a light distribution control element 4 of the headlight module 100 according to the first embodi