Endoscope Light Guide
An endoscope light guide is a component of endoscopes that provide illumination. This part of the endoscope has several components. The first two are the concave lens and the reflecting surface. The third component is the light guide. The fourth component is the glass panes. These parts help in focusing light.
Concave lens 28
The objective lens used in endoscopes has a simple construction based on three lens elements. It is designed to favorably correct various aberrations. Its spherically and planarly shaped surfaces allow for high precision processing. The lens is preferably made of glass or heat-resistant ceramic. In addition, it is preferred if the lens element is molded.
The lens can be made of a glass material with a high refractive index. It is made of three lens elements: a lens element L1, a concave lens element L2, and a second lens element L3. The concave surface of the lens element is approximately twice the diameter of the first lens element L1.
The light guide can be disposed adjacent or at a distance from the distal end of the endoscope. It can have an end face 6a that is close to the cover glass 2, which enables illuminating light to pass through the cover glass. The light guide can further include an image guide 7 disposed parallel to the light guide and having an end face 7a in opposing relation to the cover glass 3. An observation lens 8 is also disposed between the light guide and the cover glass and can be movable between them.
The negative lens can be fabricated with a step-shaped depression, or may be mounted directly on the entrance face of a deflection prism. This type of lens can be easily fabricated, and offers a well-defined extension of the optical surface. Once positioned on the planar surface, it can then be attached to an endoscope with a deflection prism.
Another method for making an endoscope light guide is by using a negative lens. The negative lens is arranged to define the direction of view and forms an angle with the endoscope objective’s longitudinal axis. It further includes a deflection prism with at least two reflective planes. The first reflective plane forms a plane that is perpendicular to the entrance face of the deflection prism, and the second reflective plane forms a second plane that is inclined at a half angle to the entrance face.
Reflecting surface 20
Reflecting surface 20 covers the illuminating light passing through the central axis of light guide 6. This surface directs intense light to the near object 12, ensuring a satisfactory observation. The light is focused to illuminate a portion of the near object, called area P12, in front of cover glass 3.
The light is reflected back into the observation system, resulting in a bright illumination without parallax. Moreover, the illumination is independent of the distance of the object being observed. The bright illumination illuminates the area of interest in greater brightness than the margins, which eliminates ghosting and provides a sharp image.
A light guide may be any cable or waveguide. In some embodiments, endoscope buttons the light guide is a flexible cable that contains fiber optics. The fiber optics in the light guide transfer the light from a light source 22 to the endoscope. The fiber optics are shown in FIG. 1, but other methods of light transfer may also be used.
Optical devices have been studied for imaging purposes, including optical coherence tomography and confocal microscopy. The actuation method and optical components used in the fabrication process of an endoscopic device will determine its performance. The earliest flexible endoscopes used optical fibers and charge-coupled devices. However, due to the low resolution of coherent optical fiber bundles, the resolution of such imaging systems is limited.
Several researchers have proposed the use of SMA coil actuators to bend optical guide fibers. For instance, Maeda et al. used two SMA coil springs for controlling the bending of optical fibers. One coil is heated by Joule heating and recovers its shape, while the other coil rotates an actuation ring that is attached to the free end of the endoscope.
Light guide 6
The Light guide connector for endoscopic instruments allows the use of a variety of different endoscopic light guides, each of which has different optical characteristics. These connectors feature a lens that helps optimize the angle of light condensing. They also come with a lens adapter that allows different endoscopic light guides to be connected to one another.
The traditional tip of an endoscope includes an imaging area and a light-emitting area. The latter takes up a significant part of the endoscope’s area, and a protective exterior wall also consumes considerable space. This makes it difficult to use the same endoscopic light source for all kinds of endoscopes.
The Light guide is composed of two optical fiber bundles: a first bundle with a first numerical aperture and a second bundle with a second numerical aperture larger than the first. The illumination light is then transmitted through the endoscope’s light guide to illuminate the target site. The first fiber bundle is also used in close-up inspection mode.
Light guide 30 is composed of a first fiber bundle 51 and a second fiber bundle 52. The first bundle is connected to a connection cable 4 and extends through the manipulating head assembly 3 and illumination windows 5. The connection cable is split into two branches. The first fiber bundle acts as the light guide and the second one serves as the electrical signal cable. The latter is connected to a signal processor 17.
The Light guide is an integral part of an endoscope system. It helps in the transmission of illumination light from the source to the subject. The light guide is also used to illuminate the intracavitary area. It extends along the entire length of the endoscope, allowing light to be directed to the target.
Glass panes 21 and 22
An endoscope’s light guide is a series of optical components. Typically, the light guide consists of a cylindrical metal sheath 15 and a bundle of ultra-fine fiber optics. This guide carries illumination light and transmits it through the illumination windows of the endoscope.
The illumination windows of an endoscope are located near the tip of the insertion part 11. The observation window is disposed in an upper position on the insertion part. The illumination window is disposed near the tip of the insertion part, so that it may be seen clearly. The light guide fiber 16 is divided into two pieces at the tip of the insertion part.
One type of endoscope light guide connector has a corrective lens that allows the light to be converged at a specific angle. This enables the light guide to pick up maximum volumes of light and create optimal illumination from the output end. The connector also enables a variety of different light guides to be connected together.
The extension guide also has a hole 19. The opening in the endoscope light guide glass panes 21 is drilled so that they can be removed. Then, the extension guide is fixed to the hole 19 in the endoscope’s housing. In the end, the eyepiece section is fitted into the outer free end portion of the extension guide. The eyepiece section contains the lens cover and eyepiece.
The illumination window of the endoscope emits fluorescent and regular observation light. This light is injected into the endoscope’s operation part to provide a real image of the structure. The light guide glass panes 21 and 22 provide illumination, and the fluorescent and regular observation image is formed on the observation window and the endoscope’s operation part.
Adaptor for endoscope light guide
The adaptor for endoscope light guide is a device used for transmitting light from a light source into an endoscope. The objective of the adaptor is to endoscope buttons increase the acceptance angle of illumination light, which is important for obtaining maximum light pickup volume. It also helps in reducing the light losses during transmission.
The light guide is composed of a metal sheath 15 and a bundle of ultra-fine fiber optics. This guide rod extends through the manipulating head assembly 3 and illumination windows 5. The light guide rod is connected to the manipulating head assembly through a cable that is bifurcated into two cables – one for electrical signals and the other for light. Both are connected to a signal processor through a connector 18.
The adaptor is threaded on the fore end of the light guide rods. The outer diameter of each adaptor pipe is the same as the outer diameter of the light guide. The aperture of the adaptor matches the numerical aperture of the light guide. This allows the light guide to be viewed clearly without any blurred image or light.
The light guide rod is fitted with an adaptor pipe 20. The adaptor is threaded on the light guide rod so that it fits snugly on the connection port. The light guide rod is aligned with the optical axis of the condenser lens 13 using the aligning aperture of the adaptor.
The adaptor allows for uniform illumination across a wider range. It is used for both fixed and flexible endoscopes. Its distal end has an illumination window.