JP-7856695-B2 - Optical unit and method for determining the reflective surface

Inventors

• 田中 秀忠
• 櫻井 一利

Assignees

• 株式会社小糸製作所

Dates

Publication Date

20260511

Application Date

20240513

Priority Date

20181225

Claims (5)

1. A method for determining the reflective surface of a rotating reflector that rotates in one direction around a rotation axis while reflecting light emitted from a light source, A step of setting the optical surface of a projection lens capable of achieving a desired light distribution pattern in front, A step of setting up a region of a virtual light source from which light projected as the aforementioned light distribution pattern is considered to have been emitted, A step of setting the angle of the rotation axis of the rotating reflector with respect to a straight line passing through the focal point of the projection lens, The step of setting the position of the light source, A step of setting the range of the reflection angle of the rotating reflector such that the virtual image position of the light source falls within the region of the virtual light source, The process of setting multiple divided cross-sections within the range of the aforementioned reflection angle, and connecting the multiple divided cross-sections that have been rotated by a predetermined angle around the rotation axis, thereby setting the reflective surface of the rotating reflector, A method for determining a reflective surface, characterized by including the following:
2. The method for determining a reflective surface according to claim 1, characterized in that the plurality of divided cross-sections are set so that the reflection angles are equally spaced.
3. The method for determining a reflective surface according to claim 1 or 2, characterized in that the range of the reflection angle is set within a range of ±5° to ±10° with respect to the plane perpendicular to the rotation axis.
4. A method for determining a reflective surface according to any one of claims 1 to 3, characterized in that the reflective surface is set such that the light from the light source, reflected while rotating, forms a desired light distribution pattern.
5. The rotating reflector has blades that function as reflective surfaces arranged around the axis of rotation. The blade has a twisted shape such that the angle between the axis of rotation and the reflective surface changes as it moves in the circumferential direction around the axis of rotation. The method for determining a reflective surface according to any one of claims 1 to 4.

Description

This invention relates to an optical unit usable in lighting fixtures such as vehicle lights. Furthermore, this invention relates to a method for determining the reflective surface of a rotating reflector or the like. (1) (2) In recent years, devices have been devised that reflect light emitted from a light source forward of a vehicle and scan the area in front of the vehicle with the reflected light to form a predetermined light distribution pattern. For example, such a device comprises a rotating reflector that rotates in one direction around a rotation axis while reflecting light emitted from a light source, and a light source consisting of a light-emitting element. The rotating reflector is provided with a reflective surface so that the light from the light source reflected while rotating forms a desired light distribution pattern. Furthermore, the light from the light source reflected by the reflective surface is projected forward as a light source image via a projection lens (see Patent Documents 1 and 3). (3) As described above, various optical components such as lenses and reflectors are used in vehicle lighting fixtures. The shapes of the reflective and refractive surfaces of these optical components are designed to meet the optical performance requirements of the lighting fixture in which they are used. For example, a design method has been devised for a headlight reflector in which the reflective surface is divided into upper, lower, left, and right sections. The left and right reflective surfaces are curved surfaces with quadratic cross-sections in their vertical and horizontal directions, respectively, and have a focal point. The light source placement point is positioned forward of the focal point and offset towards the reflective surface. The light source placement points on the left and right reflective surfaces are aligned, and the optical axis of the left reflective surface is tilted to the left, while the optical axis of the right reflective surface is tilted to the right (see Patent Document 2). International Publication No. 11/129105Japanese Patent Application Publication No. 2-129803International Publication No. 15/122304 This is a schematic horizontal cross-sectional view of a vehicle headlight according to this embodiment.This is a front view of a vehicle headlight according to this embodiment.This is a perspective view showing the main parts of the optical unit according to this embodiment.This is a perspective view of the rotating reflector according to this embodiment.This is a side view of the rotating reflector according to this embodiment.This is a front view of a rotating reflector for the right-side headlight, illustrating the shape of the reflective surface.Figure 7(a) is a schematic diagram illustrating the positional relationship between the light source, the virtual image of the light source, and the focal point of the lens when the rotating reflector of the optical unit according to this embodiment is in the first rotation position; Figure 7(b) is a schematic diagram illustrating the positional relationship between the light source, the virtual image of the light source, and the focal point of the lens when the rotating reflector of the optical unit according to this embodiment is in the second rotation position; and Figure 7(c) is a schematic diagram illustrating the positional relationship between the light source, the virtual image of the light source, and the focal point of the lens when the rotating reflector of the optical unit according to this embodiment is in the third rotation position.Figures 8(a) to 8(c) are schematic diagrams illustrating the light distribution patterns formed by the optical units shown in Figures 7(a) to 7(c).Figure 9(a) is a side view showing the schematic configuration of an optical unit according to the reference example, and Figure 9(b) is a schematic diagram for explaining the light distribution pattern formed by the optical unit according to the reference example.Figures 10(a) to 10(c) are diagrams illustrating the trajectory of the area in which the light source image is projected onto the reflective surface of a rotating reflector according to a reference example.Figure 11(a) is a side view showing the schematic configuration of the optical unit according to this embodiment, and Figure 11(b) is a schematic diagram for explaining the light distribution pattern formed by the optical unit according to this embodiment.Figures 12(a) to 12(c) are diagrams illustrating the trajectory of the area in which the light source image is projected onto the reflective surface of the rotating reflector according to this embodiment.This is a schematic diagram illustrating a method for determining the reflective surface in the optical unit according to this embodiment.This diagram shows a flowchart of the method for determining the reflective surface according to this embodiment.Figures 15(a) to 15(f) are schematic diagrams to further explain the proc