Light guide for coupling differently shaped light source and receiver

#The present invention relates to fiber optics, and more specifically to a light guide between differently shaped light source and light receivers.

#Fiber-optic light sources are generally well known and are used in a broad range of applications. For example, in the medical field, fiber-optic illuminators such as various light sources, fiber-optics, and endoscopes are widely used in endoscopy. Bulb-based medical fiber sources are currently manufactured by Stryker, Smith-Nephew, Storz, Olympus, and others. Light sources and fiber-optics are commonly used for microscopy illumination, with lamp-based products offered by Zeiss, Welch-Allyn, Dolan-Jenner, and others. Fiber-optic illumination systems are also used with industrial boroscopes and machine vision systems. While the preceding devices primarily provide ‘white’ light for illumination, other fiber-optic light sources providing ‘blue’ light in the wavelength range 420-490 nm are used in photodynamic therapy for pediatric hyperbilirubinemia.

#Systems having light sources and fiber-optics for light transmission can also provide one or more defined wavelengths of light for fluorescent excitation in biological and other research fields. For many applications, a round beam spot is desired, for example, an exam light, a spot light and a fiber optic light. In the case of a fiber optic light, the goal is to deliver more light through a fiber bundle. A fiber bundle is comprised of numerous fiber strands tightly packed together. All the fiber strands end at a cylindrical metal ferell. The fiber strands are then bound and polished. Light comes in from one end of the fiber bundle and is emitted out from the other end of the fiber bundle. When the fiber bundle end is round, the effective light transmission area is round. If the incoming light beam is from a rectangular or square shaped light source, depending on the size, only portion of the light is transmitted or portion of the fiber strands are utilized resulting in inefficiency.

#FIG. 1A is a perspective diagram of an example fiber optic interface involving a different shaped light source and receiver;

#FIG. 1B is a perspective diagram of an example fiber optic interface involving a different shaped source and receiver;

#FIG. 2 is a side view of a light guide that allows efficient light transmission between different shaped light source and receiver surfaces in FIGS. 1A-1B;

#While these examples are susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail preferred examples with the understanding that the present disclosure is to be considered as an exemplification and is not intended to limit the broad aspect to the embodiments illustrated.

#FIG. 1A shows an example prior art fiber optic system 100 including an incoming light source 102 that includes a rectangular shaped light emitting surface 104. The rectangular shaped surface 104 may be a result of an LED package that is typically fabricated in a square or rectangular shape. The light is emitted from the light emitting surface 104 to a fiber bundle 106 via an interface surface 108 that is in a circular shape. Since the interface surface 108 at the end of the fiber bundle 106 is circular, the effective light transmission area is circular. If the incoming light beam is from a rectangular or square such as the light emitting surface 104, depending on the size, only portion of the light is transmitted or portion of the fiber strands are utilized resulting in inefficiency in light transmission. The grid sections of the light emitting surface 104 in FIG. 1A represent the portion of light that is not transmitted to the fiber bundle 106.

#FIG. 1B shows another example prior art fiber optic system 150 that suffers from inefficiency in light transmission. The system 150 includes an incoming light source 152 that includes a rectangular shaped light emitting surface 154. The light from the light emitting surface is transmitted through a fiber bundle 156 that includes a circular end surface 158. In this example, the circular end surface 158 is larger in area than the square shaped light emitting surface 154 and therefore the fiber 154 is only partially illuminated by the light from the light source 152. The grid sections of the light emitting surface 158 in FIG. 1A represent the portion of the fiber optic bundle that is not illuminated by the light source 152.