JP-7856440-B2 - Endoscope illumination optical system, optical adapter, and endoscope

JP7856440B2JP 7856440 B2JP7856440 B2JP 7856440B2JP-7856440-B2

Inventors

高橋進

Assignees

ワブテック・インスペクション・テクノロジーズ・ジャパン株式会社

Dates

Publication Date: 20260511
Application Date: 20220131
Priority Date: 20210528

Claims (15)

An illumination optical system for an endoscope having an insertion portion that is inserted into a subject, An optical element having an incident surface into which light enters as incident light, and an exit surface from which the light exits as illumination light, The emission surface has a diffusion region that diffuses the emitted light, The diffusion region has a plurality of recesses and a plurality of peripheral regions arranged on the emission surface. Each recess has a plurality of total reflection surfaces that are inclined with respect to the exit surface and cause total internal reflection of the incident light. At least one of the plurality of total reflective surfaces is inclined at a first angle with respect to the emission surface, Each peripheral region is formed to surround the opening of each recess , I: After passing through the incident surface, the reflected light that has been totally reflected by the total reflection surface, and II: Having a transmissive surface that transmits and emits the incident light that, after passing through the incident surface, was not totally reflected by the total reflection surface, Endoscope illumination optical system.
Each of the aforementioned recesses has a triangular pyramidal shape with its apex being the deepest part and its base being an equilateral triangle with an opening. The aforementioned plurality of total reflective surfaces are the three planes excluding the base surface of the triangular pyramidal shape. The illumination optical system for endoscopes according to claim 1.
The angle of each total reflecting surface with respect to the aforementioned emission surface is an angle between 85 degrees and greater than 70 degrees. The illumination optical system for endoscopes according to claim 2.
Each of the aforementioned peripheral regions is parallel to the emission surface. The illumination optical system for endoscopes according to claim 1.
Each of the aforementioned peripheral regions has a second angle with respect to the emission surface that is greater than 0 degrees and smaller than the first angle. The illumination optical system for endoscopes according to claim 1.
The plurality of recesses are arranged on the ejection surface such that two adjacent sides of two adjacent recesses are parallel to each other. The illumination optical system for endoscopes according to claim 1.
When the exit surface is viewed from a direction perpendicular to the exit surface, the projected areas of each peripheral region and each total reflecting surface onto the exit surface are denoted as the first area and the second area, respectively, and the ratio of the first area to the second area is a value greater than (1/3) and less than 3. The illumination optical system for endoscopes according to claim 1.
Each of the aforementioned recesses has a square pyramidal shape with its apex being the deepest part and its square or rectangular base being an opening. The aforementioned plurality of total reflective surfaces are the four planes excluding the base surface of the square pyramidal shape. The illumination optical system for endoscopes according to claim 1.
The angle of each total reflecting surface with respect to the aforementioned emission surface is an angle between less than 85 degrees and greater than 65 degrees. The illumination optical system for endoscopes according to claim 8.
Each of the aforementioned recesses has a hexagonal pyramidal shape with its apex being the deepest part and its base being an opening, The aforementioned plurality of total reflective surfaces are the six planes excluding the base surface of the hexagonal pyramidal shape. The illumination optical system for endoscopes according to claim 1.
The angle of each total reflecting surface with respect to the aforementioned emission surface is an angle between less than 87 degrees and greater than 70 degrees. The illumination optical system for endoscopes according to claim 10.
Each of the aforementioned recesses has a polygonal pyramidal shape with its apex being the deepest part and its base being an opening. When the ejection surface is viewed from a direction perpendicular to the ejection surface, the vertex is located at the centroid of the regular polygon. The illumination optical system for endoscopes according to claim 1.
The aforementioned endoscope is a direct-viewing endoscope, In the optical element, the incident surface and the exit surface are parallel. The illumination optical system for endoscopes according to claim 1.
An optical adapter that can be attached to the tip of an insertion part inserted into a subject, An optical element having an incident surface into which light enters as incident light, and an exit surface from which the light exits as illumination light, The emission surface has a diffusion region that diffuses the emitted light, The diffusion region has a plurality of recesses and a plurality of peripheral regions arranged on the emission surface. Each recess has a plurality of total reflection surfaces that are inclined with respect to the exit surface and cause total internal reflection of the incident light. At least one of the plurality of total reflective surfaces is inclined at a first angle with respect to the emission surface, Each peripheral region is formed to surround the opening of each recess , I: After passing through the incident surface, the reflected light that has been totally reflected by the total reflection surface, and II: Having a transmissive surface that transmits and emits the incident light that, after passing through the incident surface, was not totally reflected by the total reflection surface, Optical adapter.
An optical element having an incident surface into which light enters as incident light, and an exit surface from which the light exits as illumination light, The emission surface has a diffusion region that diffuses the emitted light, The diffusion region has a plurality of recesses and a plurality of peripheral regions arranged on the emission surface. Each recess has a plurality of total reflection surfaces that are inclined with respect to the exit surface and cause total internal reflection of the incident light. At least one of the plurality of total reflective surfaces is inclined at a first angle with respect to the emission surface, Each peripheral region is formed to surround the opening of each recess , I: After passing through the incident surface, the reflected light that has been totally reflected by the total reflection surface, and II: Having a transmissive surface that transmits and emits the incident light that, after passing through the incident surface, was not totally reflected by the total reflection surface, Endoscope illumination optical system, The insertion part that is inserted into the subject, An endoscope having

Description

This invention relates to an endoscopic illumination optical system, an optical adapter, and an endoscope, and more particularly to an endoscopic illumination optical system, an optical adapter, and an endoscope having the illumination optical system, having an insertion portion that is inserted into a subject. Endoscopes are widely used in industrial and medical fields. An endoscope has an insertion tube from which illumination light is emitted. The reflected light from the subject is received by an observation window, and by acquiring an image of the subject, an endoscopic image of the subject within the subject is obtained. An illumination optical system, which includes optical elements that diffuse light so that the illumination light has a desired beam angle, is provided within the optical adapter attached to the tip of the insertion part, or within the tip of the insertion part itself. Multiple inclined surfaces are formed on the incident surface of the optical element, and these inclined surfaces diffuse the light. This diffusion causes illumination light with a desired beam angle to be emitted from the exit surface of the optical element. For example, in the optical element disclosed in Japanese Patent Publication No. 2015-226712, a prism surface is provided on the incident surface of the optical element, in which multiple prisms, each having multiple inclined surfaces, are regularly formed. Japanese Patent Publication No. 2015-226712 This is a configuration diagram showing the configuration of an endoscope device according to an embodiment of the present invention.This is a perspective view of the tip portion to which an optical adapter is attached, according to an embodiment of the present invention.This is a cross-sectional view of the tip portion to which an optical adapter is attached, according to an embodiment of the present invention.This is a perspective view of the tip portion to which an optical adapter is attached, according to an embodiment of the present invention, in which the shape of the illumination window is ring-shaped.This is a cross-sectional view of the tip portion to which an optical adapter is attached, according to an embodiment of the present invention, in which the shape of the illumination window is ring-shaped.This is a diagram of a rod lens viewed from the tip side, according to an embodiment of the present invention.This is a perspective view of the tip portion of a rod lens as seen from the oblique tip side, according to an embodiment of the present invention.This is a diagram of a cylindrical rod lens viewed from the tip side, according to an embodiment of the present invention.This is a diagram illustrating the shape of a recess according to an embodiment of the present invention.This is a cross-sectional view showing the cross-sectional shape of a recess according to an embodiment of the present invention.This is a diagram illustrating the light transmission region of each recess according to an embodiment of the present invention.This is a diagram illustrating the peripheral region from which totally reflected light is emitted, according to an embodiment of the present invention.This is a diagram illustrating a peripheral region having an inclined surface according to an embodiment of the present invention.This is a diagram illustrating the direction of light emission according to an embodiment of the present invention.This is a diagram illustrating the position of the deepest part of the recess, according to Modification 1 of the embodiment of the present invention.This is a diagram illustrating a recess according to a modified example 2 of the present invention.This figure illustrates a modified example 2 of the present invention, showing the position of the deepest part of a recess that is offset from the centroid of a square.This is a diagram illustrating a recess according to a third modified embodiment of the present invention.This is a diagram illustrating a recess according to a third modified embodiment of the present invention.This is a plan view of an inclined surface and a part of the surrounding area relating to a modified example 3 of the present invention.This figure illustrates the configuration of the optical path of illumination light within an optical adapter, according to a modified example 7 of the embodiment of the present invention. The embodiments of the present invention will be described below with reference to the drawings. In the diagrams used in the following explanation, the scale of each component is different in order to make each component recognizable on the diagram. The present invention is not limited to the quantity of components, the shape of the components, the ratio of the sizes of the components, and the relative positional relationship of each component as shown in these diagrams. (Configuration of the endoscope device) Figure 1 is a configuration diagram showing the endoscopic device according to this embodiment. As show