Blind spot monitor lens

Abstract

[Purpose of Use] The subject article is a lens that constitutes a component of a light-emitting device for a blind spot monitor (hereinafter referred to as "BSM"). The BSM is a vehicle accessory, mounted, for example, on a door mirror, that detects approaching vehicles and alerts the driver by illuminating a predetermined icon. The BSM's light-emitting device includes the subject article's lens, which receives light from a light source and emits it as a surface light. This surface-emitted light is shaped by passing it through a light-transmitting section bearing an icon, resulting in an illuminated display in the shape of the icon. [Structure] The subject design's lens is a one-piece molded product made of a translucent, milky-white, or other opaque plastic material that diffuses and transmits light. The subject design's lens has a bag-like structure with an upwardly opening cavity behind the front panel that forms the light-emitting surface. A prior design of a lens with the same application as the subject design is described in U.S. Patent Application Publication No. 2016 / 0209000. However, the lens in this prior design has a solid structure made of a single thick plate, not a bag-like structure with a cavity. (<State of Use>> One example of the configuration of a BSM equipped with the lens in the design at issue and its state of use are described with reference to Reference Figures 1 and 2. The light-emitting device 12 of the BSM 10 is composed of a housing 14, a printed circuit board 16, and a lens 18 in the design at issue, assembled together. When the light-emitting device 12 is assembled, the light-emitting surface 20a of the LED 20 mounted on the underside of the printed circuit board 16 faces the opening 22a of the cavity 22 in the lens 18. The light-emitting device 12 is attached to the back of the mirror plate 26 using double-sided adhesive tape 28, with the front plate 24 (light-emitting surface) of the lens 18 facing the mirror plate 26. A triangular icon-shaped window 28a is formed within the surface of the double-sided adhesive tape 28. A light-transmitting portion 30a is formed on the back surface of the mirror plate 26 at a position overlapping the window 28a of the double-sided adhesive tape 28, by removing the reflective film 30 in the shape of a triangular icon by etching or the like. When the LED 20 emits light, the light is incident into the cavity 22 through the opening 22a. A portion of the light incident into the cavity 22 is reflected by the rear plate 25 of the lens 18 and is irradiated onto the rear surface of the front plate 24, and another portion is irradiated directly onto the rear surface of the front plate 24.The light irradiated onto the back surface of the front panel 24 is diffused and transmitted through the front panel 24, shaped into an icon shape by the light transmitting portion 30a, and emitted to the outside through the mirror panel 26. As a result, the illuminated display of the icon is visible from the driver's viewpoint.

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