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JP-7855997-B2 - Optical components

JP7855997B2JP 7855997 B2JP7855997 B2JP 7855997B2JP-7855997-B2

Inventors

  • 安藤 浩
  • 舘 鋼次郎

Assignees

  • 株式会社デンソー
  • トヨタ自動車株式会社
  • 株式会社ミライズテクノロジーズ

Dates

Publication Date
20260511
Application Date
20221221

Claims (11)

  1. An optical component that reflects ambient light internally to guide it, The light guide (2) comprises an incident surface (2a) into which the ambient light is incident, an exit surface (2b) to which the incident light incident from the incident surface first reaches and which reflects and emits the incident light to the outside, and a reflective surface (2c) positioned opposite to the exit surface which reflects the reflected light from the exit surface toward the exit surface. The injection surface has a plurality of prism sections (3) which are composed of a plurality of inclined surfaces (31, 32, 33) that have different inclination angles and are inclined with respect to a reference surface of the injection surface . The optical member has a reflective surface which is the same inclined surface (41) as one of the plurality of inclined surfaces, with the same inclination angle .
  2. The optical member according to claim 1, wherein one of the multiple inclined surfaces that emits a portion of the incident light to the outside is designated as an emission section (33), and the emission section is parallel to the incident surface.
  3. The plurality of prism sections constituting the ejection surface are referred to as the first prism section. The optical member according to claim 1, wherein the reflective surface has a plurality of second prism portions (4) having a reflective portion (41) which is a surface that reflects the light reflected from the incident light at the exit surface back to the exit surface, and adjacent surfaces (42) adjacent to the reflective portion.
  4. The optical member according to claim 3, wherein the reflective portion is parallel to one of the plurality of inclined surfaces (31) that reflects the incident light.
  5. Let n be the refractive index of the light guide, and let δ be the angle between the direction normal to one of the plurality of inclined surfaces that reflects the incident light (31) and the reflecting surface, and the direction in which the incident light travels. The optical member according to claim 1, wherein the one inclined surface and the reflective surface are inclined such that sinδ > 1/n.
  6. The direction connecting the ejection surface and the reflecting surface , perpendicular to the reference plane of the ejection surface, is defined as the thickness direction (D2), the angle between the incident direction of the ambient light on the incident surface and the thickness direction is defined as θ, the angle between the direction in which the incident light traveling toward the ejection surface travels and the thickness direction is defined as φ, and the angle between the direction in which the incident light traveling toward the reflecting surface travels and the thickness direction is defined as ε. The optical member according to claim 1, wherein one of the plurality of inclined surfaces that reflects the incident light (31), and the incident surface are inclined such that ε > φ > θ.
  7. The direction connecting the ejection surface and the reflective surface , which is perpendicular to the reference plane of the ejection surface, is defined as the thickness direction (D2), the angle between the direction in which the incident light traveling toward the ejection surface propagates and the thickness direction is defined as φ, and the angle between the incident surface and the thickness direction is defined as ψ. The optical member according to claim 1, wherein the incident surface is inclined such that ψ < φ.
  8. The optical member according to claim 1, wherein the injection surface has three or more of the inclined surfaces.
  9. In the light guide, the direction in which the incident light is reflected and propagated by the emission surface and the reflection surface, and which is parallel to the reference surface of the emission surface, is defined as the light guide direction (D1), and of the plurality of inclined surfaces, one surface that reflects a portion of the incident light is defined as the first inclined surface (31), the surface adjacent to the first inclined surface is defined as the second inclined surface (32), and the surface located on the opposite side of the second inclined surface from the first inclined surface, which emits a portion of the incident light to the outside, is defined as the third inclined surface (33). The ejection surface has a plurality of regions (2ba to 2bc) in which the ratio of the first width (Pa1 to Pa(m+1)) of the first inclined surface in the light guide direction to the second width (Pb1 to Pb(m+1)) from the second inclined surface to the third inclined surface in the light guide direction is different. The optical member according to claim 8, wherein the ratio of the first width to the second width is smaller for each of the multiple regions that are located further from the incident surface.
  10. The direction connecting the injection surface and the reflective surface , which is perpendicular to the reference plane of the injection surface, is defined as the thickness direction (D2), and the distance from the injection surface to the end of the incident surface opposite to the injection surface (2a1) is defined as the incident surface height (Td). The incident surface height is greater than the distance (Ts) between the injection surface and the reflective surface in the thickness direction. Let ξ be the angle between the imaginary straight line (VL) connecting the end portion and the end portion of the reflective surface on the incident surface side (2c1) and the thickness direction, and let φ be the angle between the direction in which the incident light traveling toward the emission surface propagates and the thickness direction. The optical member according to claim 1, wherein the light guide satisfies ξ < φ.
  11. With the aforementioned reflective surface as the first reflective surface, the light guide has a second reflective surface (5a, 8) inside that reflects the incident light to the first reflective surface. The optical member according to claim 1, wherein the second reflective surface is parallel to the same inclined surface among the first reflective surfaces.

Description

This invention relates to an optical component that reflects a portion of the light incident from an incident surface internally, and emits the incident light and the reflected light to the outside from a surface different from the incident surface. Conventionally, an example of this type of optical element is the one described in Patent Document 1. The optical element described in Patent Document 1 includes a light guide having an incident surface to which ambient light enters, a first surface to which ambient light entering from the incident surface first turns, and a second surface opposite the first surface, and a semi-transparent mirror positioned on the first surface side. In this optical element, a portion of the ambient light entering from the incident surface is reflected by the semi-transparent mirror to the second surface, the remainder is absorbed or transmitted by the semi-transparent mirror, and the light reflected by the semi-transparent mirror is reflected back to the second surface side. Furthermore, this optical element has a prism sheet with multiple prisms positioned on the first surface, and the light transmitted through the semi-transparent mirror is emitted to the outside via the multiple prisms. Patent No. 6372305 This is a cross-sectional view showing an optical member of the first embodiment.This is an explanatory diagram of the light guide in the optical member of the first embodiment.This is an enlarged cross-sectional view showing region III in Figure 1.This is a schematic diagram showing the relationship between the inclination angle of each inclined surface constituting the prism section of the emission surface and the light guide.This is an explanatory diagram showing the tilt angle of the back and the resulting suppression of gaps in the light guide.This is a schematic diagram showing the optical components and light guide of a comparative example.This is a cross-sectional view showing the optical member of the second embodiment.This is a schematic diagram showing the prism portion and width of the first to third regions of the injection surface in the second embodiment.This is an explanatory diagram of the light guide in the optical member of the second embodiment.This is a cross-sectional view showing a first modified example of the optical member of the second embodiment.This is a cross-sectional view showing a second modified example of the optical member of the second embodiment.Figure 11 is an explanatory diagram of the light guide in the optical component.This is an explanatory diagram illustrating the gap in light rays caused by a reflective surface having a prism section.This is a cross-sectional view showing a third modified example of the optical member of the second embodiment.This is an enlarged cross-sectional view showing region XV in Figure 14.This figure corresponds to Figure 15 and is an enlarged cross-sectional view showing the cavity layer formation process.This is a diagram corresponding to Figure 15, and is an enlarged cross-sectional view showing a modified example in which a reflective layer is provided instead of a cavity layer.This is a cross-sectional view showing an optical component of another embodiment. The embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, parts that are identical or equivalent to each other will be denoted by the same reference numerals. (First Embodiment) The optical member 1 of the first embodiment will be described with reference to the drawings. The optical member 1 of this embodiment can be used as a blind spot assisting device, which is attached to, for example, a member or obstacle that obstructs the user's field of view and creates a blind spot, and allows the user to see the scenery in the blind spot area. For example, in the case of an in-vehicle application, the optical member 1 is attached to the pillar of the vehicle on which it is mounted, and guides ambient light from the area that becomes a blind spot due to the pillar towards the user, allowing the user to see the scenery in the blind spot area. In Figure 4, hatching is applied to the light incident on the optical component 1 and the light emitted from the optical component 1 to the outside, in order to make the light guidance within the optical component 1 easier to understand. The optical component 1 includes a light guide 2 made of a translucent material, as shown in Figure 1, for example. The light guide 2 includes an incident surface 2a that allows external light to enter the interior, an exit surface 2b adjacent to the incident surface 2a, a reflective surface 2c facing the exit surface 2b, an end surface 2d connecting the exit surface 2b and the reflective surface 2c, and a back surface 2e connecting the incident surface 2a and the reflective surface 2c. The optical component 1 allows external light to enter the interior of the light guide 2 through the incident surface 2a, and whi