Patent EP-2993392-A1 (EP)
Inventor: OWADA RYOTARO
IPC: F21S8/12
Filed: 2015-08-25
Abstract: A lens member (14) to be disposed in front of a light source (12) can include a front end portion (14BB) and a rear end portion (14AA), and be configured to form a predetermined light distribution pattern (P) including a cut-off line at its upper edge by causing light rays emitted from the light source (12) and entering the lens member (14) to exit through the front end portion (14BB) for irradiation. The lens member (14) can include: an incident portion (14a) configured to allow the light rays from the light source (12) to enter the lens member (14) while dividing the entering light rays into first light rays (Ray1) that travel obliquely upward and forward and second light rays (Ray2) that travel obliquely upward and rearward; a first reflecting surface (14b1) configured to internally reflect the first light rays (Ray1); a second reflecting surface (14b2) configured to internally reflect the second light rays (Ray2); a third reflecting surface (14b3) configured to internally reflect the second light rays (Ray2) that have been internally reflected by the second reflecting surface (14b2); a fourth reflecting surface (14b4) configured to internally reflect at least part of the first light rays (Ray1) that have been internally reflected by the first reflecting surface (14b1) and the second light rays (Ray2) that have been internally reflected by the third reflecting surface (14b3); and a light exiting surface (14c) disposed at the front end portion (14BB) and configured to be a convex lens surface having a rear-side focal point (F 14c ). In the lens member (14), the fourth reflecting surface (14b4) is configured to be a reflecting surface having a front end edge (14b5) and extending rearward from a position at or near the rear-side focal point (F 14c ) of the light exiting surface (14c). The incident portion (14a), the first reflecting surface (14b1), the fourth reflecting surface (14b4), and the light exiting surface (14c) can constitute a first optical system configured to form a first partial light distribution pattern (P1) including a cut-off line at its upper end edge defined by the front end edge (14b5) of the fourth reflecting surface (14b4), the first partial light distribution pattern (P1) formed by irradiating, forward through the light exiting surface (14c), light rays not shielded by the fourth reflecting surface (14b4) and light rays internally reflected by the fourth reflecting surface (14b4) out of the first light rays (Ray1) having entered the lens member (14) through the incident portion (14a) and been internally reflected by the first reflecting surface (14b1). The incident portion (14a), the second reflecting surface (14b2), the third reflecting surface (14b3), the fourth reflecting surface (14b4), and the light exiting surface (14c) can constitute a second optical system configured to form a second partial light distribution pattern (P2) including a cut-off line at its upper end edge defined by the front end edge (14b5) of the fourth reflecting surface (14b4), the second partial light distribution pattern (P2) formed by irradiating, forward through the light exiting surface (14c), light rays not shielded by the fourth reflecting surface (14b4) and light rays internally reflected by the fourth reflecting surface (14b4) out of the second light rays (Ray2) having entered the lens member (14) through the incident portion (14a) and been internally reflected by the second reflecting surface (14b2) and the third reflecting surface (14b3) in order. The predetermined light distribution pattern (P) can be formed by superposing the first partial light distribution pattern (P1) and the second partial light distribution pattern (P2) upon each other as a synthetic light distribution pattern.