Optical system having tapered light transmission element

Abstract

To provide an optical system capable of enhancing coupling of light from a light source to an optical fiber, particularly an optical system that can be incorporated into medical instruments such as endoscopes.SOLUTION: There is provided an optical system. The optical system comprises a lens including an input surface for receiving light from at least one light source and an output surface through which the light exits the lens, the lens further including a peripheral surface extending between the input surface and the output surface and configured to direct, via total internal reflection, at least a portion of the light incident thereon through the output surface to an output focal point. The optical system can further comprise a tapered light pipe optically coupled to the lens and a light guide (e.g., one or more optical fibers) that is optically coupled to the tapered light pipe. The lens directs the received light to an output focal point that is disposed within the tapered light pipe.SELECTED DRAWING: Figure 3A

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of U.S. Provisional Application No. 62 / 890,270, filed August 22, 2019. No. 60 / 313,933, filed on Oct. 13, 2007, which claims priority to this provisional application, which is incorporated herein by reference in its entirety. do. [Technical field]

[0002] The present invention is directed to optical systems, and more particularly to use in medical instruments such as endoscopes. The present invention relates to an optical system that can [Background technology]

[0003] Optical systems are utilized in a variety of medical instruments to illuminate a target area. Many optical instruments, such as a microscope, use optical filters to deliver light from a light source to a target area to be illuminated. As shown in FIG. 1, a light source 1 is coupled to an optical fiber. A common method utilizes a lens 3 having an elliptical total internal reflection (TIR) ​​periphery. , a certain focus (f in ) is optically coupled to the surface of the light source, and is located near the input surface of the optical fiber 2. Another focus (f out ) and point the light at it. Summary of the Invention [Problem to be solved by the invention]

[0004] However, many endoscopes include an integral tapered glass optical element 4 as shown in FIG. The tapered glass optical element 4 is connected to a standard endoscope light source (typically a xenon or halogen The light from the light bulb is sent into the fiber 2. The light that hits the peripheral surface of the tapered glass optical element Typically, many of the rays escape the system due to refraction (e.g., rays A, B, and C) reflected at such an angle.

[0005] Therefore, optical systems that can enhance the coupling of light from a light source to an optical fiber, particularly endoscopes, are required. What is needed is an optical system that can be incorporated into a medical instrument such as a mirror. [Means for solving the problem]

[0006] In one aspect, an optical system is disclosed. The optical system includes: and an output surface where the light exits the lens. extends between the input face and the output face and reflects at least a portion of the light incident through the output face. The optical system further includes a peripheral surface configured to direct the light to an output focal point by total internal reflection. optically coupled to the output surface of the lens to receive at least a portion of the light exiting the lens; and an output surface through which at least a portion of the received light exits the light pipe. and a tapered light pipe having a first end and a second end extending between the input face and the output face. The light pipe further has a peripheral surface that extends from the input surface to the output surface, the cross-sectional area of ​​the light pipe decreasing from the input surface to the output surface. The light guide is tapered to receive at least a portion of the light exiting the output face of the light pipe. The output focal point of the lens is disposed within the tapered light pipe. .

[0007] In some embodiments, the output focal point diverges from the output focal point within the tapered light pipe. Selected to prevent light from exiting the tapered light pipe through the periphery of the tapered light pipe. The sensor is placed in a position where the sensor is to be mounted.

[0008] In some embodiments, the output focal point is located along the optical axis of the tapered light pipe. Additionally, in some embodiments, the location of the output focal point is greater than the input face of the tapered light pipe. , close to the output face of the tapered light pipe.

[0009] By way of example, in some embodiments, the output focus may be located within a tapered light pipe at an output At least about 80% of the light emanating from the focal point does not strike the periphery of the tapered light pipe. The reflector is positioned at a point where it exits the light pipe.

[0010] In some embodiments, the output focal point is a tapered light pipe that emits light from the output focal point. It is positioned such that the diverging light exhibits a divergence angle equal to the numerical aperture of the light guide.

[0011] In some embodiments, the tapered light pipe exhibits a draft angle of from about 1 to about 20 degrees.

[0012] In some embodiments, the input surface of the lens is a cap that receives light emitted by the light source. In some embodiments, such a cavity includes at least one of the light sources. It can be configured to accept some

[0013] In some embodiments, at least a portion of the periphery of the lens is disposed near the input surface of the lens. and an output focus located within the tapered light pipe. In some embodiments, the light emitting surface of the light source (e.g., an LED or a halogen lamp) The light emitting surface of the halogen bulb is placed at or near the input focus.

[0014] In some embodiments, the maximum distance from the output face of the tapered light pipe to the output focal point (x max ) is given by the following relation:

[0015]

number

[0016] Here, R out denotes the radius of the output face of the light pipe, and α denotes the amount of light propagating beyond the output focus. This indicates the divergence angle of the light.

[0017] In a related aspect, a light source is provided that receives light from at least one light source and illuminates the body portion. An endoscope is disclosed that includes an optical system directed to a body portion. The optical system includes at least A lens having an input surface that receives light from a single light source and an output surface where the light exits the lens. The lens may extend between the input face and the output face and direct the input light through the output face. and a peripheral surface configured to direct at least a portion of the light incident thereon toward an output focal point by total internal reflection. The optical system further comprises a lens for receiving at least a portion of the light exiting the lens. and at least a portion of the received light is guided through the output surface. and an output face at which the light pipe exits the light pipe. a peripheral surface extending between the input surface and the output surface, the cross-sectional area of ​​the light pipe extending from the input surface to the output surface. The light guide receives at least a portion of the light that exits the output face of the light guide. The output focus of the lens is optically coupled to the tapered light guide so as to be incident on the tapered light guide. It is placed within the ID.

[0018] In some embodiments of the endoscope, the output focus is located within a tapered light pipe. At least about 80% of the light emanating from the force focus is tapered through the circumference of the tapered light pipe. The light is placed in a position selected to prevent it from exiting the light pipe. The point may be located along the optical axis of the tapered light pipe, e.g., closer to the tapered light pipe than to the input face of the tapered light pipe. In some endoscope applications, the optical fiber may be positioned close to the output face of the light pipe. In an embodiment, the output focal point is at least part of the light within the tapered light pipe that diverges from the output focal point. At least about 80% (e.g., at least about 90% or 100%) of the circumference of the tapered light pipe. The light can be placed in a position where it exits the tapered light pipe without hitting the endoscope. In some embodiments, the output focal point is a tapered light pipe with a diverging light beam from the output focal point. The light guide is positioned such that the light emitted by the guide exhibits a divergence angle equal to the numerical aperture of the light guide. In some embodiments, the tapered light pipe may be characterized by a draft angle of about 1° to about 20°. This can be done.

[0019] Various aspects of the present invention are best understood with reference to the following detailed description taken in conjunction with the associated drawings, which are briefly described below. This can be further understood by [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 shows a schematic of a prior art system for coupling light from a light source into a light guide (eg, an optical fiber). [Diagram 2] FIG. 2 illustrates generally an optical system for use in an endoscope that delivers light from a light source to a target area. [Diagram 3] 3A and 3B show a schematic diagram of an optical system according to an embodiment of the present invention. [Figure 4] FIG. 4 shows a schematic diagram of an endoscope incorporating an optical system according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present invention generally relates to a method for detecting light emitted by a light source to illuminate a target area of ​​interest. The present invention relates to an optical system that enables efficient coupling of various optical fibers to an instrument such as an endoscope. Such terms are used herein in accordance with their ordinary meaning in the art. As used herein, "numerical aperture" refers to the number of apertures a system can receive light through. This refers to a dimensionless number that characterizes the range of angles that can be captured or emitted.

[0022] As used herein, "about" refers to a variation (e.g., of a numerical value) of up to 5%. It is intended to.

[0023] 3A and 3B, an optical system 100 according to one embodiment includes a lens 10 4. A light source 102 is optically coupled to transmit light to the light source 4. By way of example, in some embodiments, the light source may be a light emitting diode. (LED or halogen bulb). In some embodiments, the light source 102 They emit light in the visible portion of the electromagnetic spectrum, for example in the wavelength range from about 450 nm to about 700 nm. However, in other embodiments, light sources producing light having other wavelengths may be utilized. do.

[0024] The lens 104 is optically coupled to the light source 102 and has an input surface for receiving light from the light source 102. 104a, and the received light, or at least a portion of it, passes through the lens via output surface 104b. The peripheral surface 104c is disposed between the input surface 104a and the output surface 104b. In this embodiment, the peripheral surface 104c extends along two focal points f in and f out Have In this embodiment, the light is an ellipsoid (a three-dimensional shape whose plane cross section is an ellipse). Source 102 is at focus fin (also referred to herein as the "input focal point") at or near and the focus f out (also referred to herein as the "output focus") is outside of lens 104. do.

[0025] The optical system 100 includes a light guide 106 and a lens 104 disposed between the light guide 106. The tapered light pipe 108 is a light pipe extending from a lens. The input surface 108a receives light from the output surface 108b. The light exiting the input surface 108b is optically coupled to the light guide 106 so that the light exiting the input surface 108b enters the light guide 106. The cross-sectional area of ​​the tapered light pipe 108 is a to output surface 108b. More specifically, in this embodiment, The tapered light pipe 108 has substantially circular input and output faces, with the input of the light pipe The radius (Rin) of the input surface is smaller than the radius (Rout) of the output surface. The taper of the light pipe 108 extends between the input face 108a and the output face 108b. The draft angle can be, for example, from about 1° to about 20°. .

[0026] In this embodiment, a lens 104 and a tapered light pipe for the lens 104 The position 108 is the output focus f out is configured to be located within the tapered light pipe 108. More specifically, in this embodiment, the output focal point f out is the optical axis of the light pipe ( OA) closer to the output face 108b of the light pipe than to the input face 108a. do.

[0027] As shown in FIG. 3A, light rays entering the light pipe 108 converge at an angle (β) to an output focus (f ou t ) and then converges to the output focus (f out ) towards the output face of the light pipe. As the light moves, it diverges (the divergence angle is equal to the convergence angle). The lens 104 has an output focal point f out The divergence angle of the light rays propagating beyond the numerical aperture of the light guide 106 This allows the light exiting the tapered light guide 108 to have a substantially equal Light entering the light guide 106 can be efficiently coupled out.

[0028] In some embodiments, the output surface 108a of the tape light pipe is connected to the output focal point f ou t Maximum distance to (x max ) is given by the following relation:

[0029]

number

[0030] Here, R out denotes the radius of the output face of the light pipe, and β denotes the light propagating beyond the output focus. This indicates the divergence angle of the light.

[0031] As discussed herein, an output focal point f out By placing Light entering the light pipe will not exit the light pipe through its periphery, and therefore Light can be efficiently coupled into the optical waveguide 106 .

[0032] The lens 104, light pipe 108, and light guide 106 may be formed from a variety of suitable materials. By way of example, in some embodiments, the lens 104 may be made of PMMA. It is made of polymer materials such as polymethyl methacrylate (PC) or polycarbonate (PC). Alternatively, the lens 104 may be configured such that the lens 104 is a high-output light source (e.g., The device may be made of glass so that it can be coupled to a thermal head (power LED). The perforated light pipe 108 is formed from glass, although in other embodiments it may be formed from any suitable polymer as described above. Further, in this embodiment, the shape of the light guide can be an optical fiber. A light guide is a fiber optic cable that transmits light introduced into a light guide to a target area. The optical fiber can be bent when being guided to the optical fiber.

[0033] The optical system according to the invention can find various applications. Such an optical system can be incorporated into an endoscope as an illumination source. An endoscope 400 is shown having a mirror body 402, which extends from a proximal end (PE) to a distal end (F). The flexible elongate element 404 extends to the distal end (DE). The exemplary endoscope is configured to be inserted into a patient's body using a handle 4 for manipulating the device. Also includes 06.

[0034] The optical system according to the present invention is adapted to be mounted on an endoscope to provide light for illuminating a target area. The optical system can be coupled to the body 402. In this embodiment, the optical system can be a light guide. The light source 102, the lens 404, and the optical fiber 406 are connected to the endoscope body via an adapter 406. More specifically, 104, tapered light pipe 108, and a portion of light guide 106 are attached to the housing of optical adapter 406. The light guide 106 extends from the optical coupler to the flexible element 404. and the distal end of the light guide is located near the distal end (DE) of the flexible element, so that Light traveling through the light guide 106 exits the distal end of the flexible element and illuminates the target area of ​​interest. Can be illuminated.

[0035] Those skilled in the art will appreciate that various modifications may be made to the above embodiments without departing from the scope of the present invention. You will understand that you can add

Claims

1. 1. An optical system comprising: an input surface for receiving light from at least one light source and an output surface where said light exits the lens; a lens extending between the input surface and the output surface and having a front surface; and directing at least a portion of the light incident through said output face to an output focal point by total internal reflection. The present invention further includes a peripheral surface configured as follows: at the output surface of the lens to receive at least a portion of the light exiting the lens. and an input surface for optically coupling at least a portion of the received light to an output surface for optical transmission. and an output face exiting the input end of the light pipe, the light pipe having a tapered light pipe having an output face exiting the input end of the light pipe. a circumferential surface extending between said input surface and said output surface, said light pipe having a cross-sectional area of ​​about 100 mm; from the output surface, The tapered light pipe is adapted to receive at least a portion of the light exiting the output face of the light pipe. a light guide optically coupled to the light source; an output focus of the lens is disposed within the tapered light pipe; Optical system.

2. The output focal point is at least a fraction of the light within the tapered light pipe that diverges from the output focal point. Approximately 80% of the light exits the tapered light pipe through the periphery of the tapered light pipe.

13. The optical system of claim 1 , wherein the optical system is positioned at a location selected to prevent:

3. 2. The optical fiber of claim 1, wherein the output focal point is disposed along the optical axis of the tapered light pipe. Optical system.

4. The position of the output focal point is located at a position closer to the taper than the input face in the tapered light pipe.

13. The optical system of claim 1 near the output face of a tubular light pipe.

5. The output focus is a small amount of light diverging from the output focus within the tapered light pipe. At least about 80% of the light emitted from the tapered light pipe is directed toward the tapered light pipe without hitting the peripheral surface of the tapered light pipe. The optical system of claim 1 , wherein the optical system is disposed at a position exiting the optical path.

6. The output focus is a light diverging from the output focus in the tapered light pipe.

10. The optical system of claim 1, wherein the light guide is positioned at a position that exhibits a divergence angle equal to the numerical aperture of the light guide. Tem.

7. 10. The optical element of claim 1, wherein the tapered light pipe exhibits a draft angle of about 1° to about 20°. system.

8. The input surface of the lens receives light emitted by the at least one light source. The optical system of claim 1 comprising a cavity.

9. At least a portion of the periphery of the lens is disposed within the cavity and has an input focus and a front focus. the output focus being disposed within the tapered light pipe; 9. The optical system of claim 8, comprising:

10. 10. The optical system of claim 9, wherein at least a portion of the light emitting surface of the light source is located at the input focal point. Optical system.

11. The maximum distance from the output face of the tapered light pipe to the output focal point (x ｍａｘ )teeth, The following relationship: [0010] is given by Where: R ｏｕｔ denotes the radius of the output face of the light pipe, α denotes the half angle of divergence of light propagating beyond the output focus; 4. The optical system of claim 3.

12. An endoscope comprising: an optical system, the optical system comprising: an input surface for receiving light from at least one light source and an output surface where said light exits the lens; a lens extending between the input face and the output face, the lens having to direct at least a portion of the light incident through said output face to an output focal point by total internal reflection. The present invention further has a peripheral surface configured as follows: the output surface of the lens for receiving at least a portion of the light exiting the lens. and an input surface for optically coupling at least a portion of the received light through an output surface. a tapered light pipe having an output face exiting the pipe, the light pipe having an input a circumferential surface extending between the input surface and the output surface, the cross-sectional area of ​​the light pipe being decreasing from said surface to said output surface; The taper is adapted to receive at least a portion of the light exiting the output face of the light pipe. a light guide optically coupled to the light pipe; an output focus of the lens is disposed within the tapered light pipe; Endoscope.

13. The output focus is a light diverging from the output focus in the tapered light pipe. and preventing light from exiting the tapered light pipe through the peripheral surface of the tapered light pipe.

13. The endoscope of claim 12, wherein the endoscope is positioned at a position selected as follows:

14. 14. The optical fiber of claim 13, wherein the output focal point is disposed along the optical axis of the tapered light pipe. Endoscope.

15. The location of the output focal point is located closer to the tapered light pipe than to the input face of the tapered light pipe. The endoscope of claim 13 proximate the output face of a light pipe.

16. The output focus is a small amount of light diverging from the output focus within the tapered light pipe. At least about 80% of the light is directed through the tapered light pipe without hitting the peripheral surface of the tapered light pipe. The endoscope of claim 13 , wherein the endoscope is positioned to exit the

17. The output focus is a light diverging from the output focus in the tapered light pipe.

14. The endoscope of claim 13, wherein the light guide is positioned at a position that exhibits a divergence angle equal to the numerical aperture of the light guide. 。

18. 14. The optical fiber of claim 13, wherein the tapered light pipe exhibits a draft angle of about 1° to about 20°. Endoscope.

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