Composition of rigid endoscope

Rigid endoscope is composed of three parts:mechanical system,optical system, and light guide system.

Mechanical system: it consists of stainless steel alloy mirror outer tube, inner tube, endoscope body, light cone, eyepiece cavity, eyepiece, etc.

Optical system: it consists of objectives, rod lens, and Ocular Lens. 

The mechanical system of rigid endoscop:

The mechanical system of rigid endoscope, the endoscope body, the outer tube, the inner tube, the light cone, and the eyepiece cavity are all made of stainless steel alloy materials. The eyepieces of the rigid endoscope is a black polymer high temperature resistant material.

The connection between the outer tube of the mirror and the various parts of the mirror body is seamlessly welded by laser to ensure the sealing of the entire mirror.

The endoscope body and eyepieces are tightly fixed and sealed by precision instruments, so that they will not fall off and leak during use.

The lens tube and objective lens are sealed by adhesive or welding technology, and there will be no leakage during use. The objective lens of metal welding technology has better sealing.

The Optical system of rigid endoscope :

The optical system of a rigid endoscope consists of objective lens, rod lens group, and Ocular Lens.

The objective lens determines the viewing angle and field of view of the endoscope, and is responsible for collecting images; the rod lens group is responsible for transmitting images, the Ocular Lens magnifies the image and transmits the image through the eyepieces.

Direction of View: The incident light of the object image first passes through the objective lens glass (sapphire material), and then enters the objective lens and conducts in parallel. The angle between the incident light entering the objective lens and the horizontal line, that is, the viewing angle (DOV), Direction of View.  The viewing angle of the endoscope is generally 0°，12°，30°，70°，90°。

Field of View: The range that the objective lens can observe, called the field of view (FOV), Field of View.  The field of view of the endoscope is generally divided into wide angle and standard angle. The wide angle is suitable for endoscopes with relatively large cavities, such as laparoscopy, hysteroscopy, and cystoscopy, which are all wide-angle; the standard angle is used for endoscopes with relatively small cavities, such as prostate electrosurgery, which is the standard angle.

Welding: The objective lens glass is the most advanced endoscope, made of sapphire. The degree of sealing between the objective lens glass and the metal tube determines the life of the endoscope. A good hard mirror uses metal welding method, which has strong sealing.

The light guide system of rigid endoscope:

The optical guide system is composed of very fine optical fibers with a diameter of 0.03mm. The main function of optical fiber is to conduct light. One end of the optical fiber system is connected to the light cone of the endoscope, and the other end is connected to the objective lens end. Light is emitted from the objective lens end of the endoscope to illuminate the body.

Manual: The light guide system and the optical system are all assembled by hand. The internal assembly of each endoscope is done manually.

Objective lens Tip: The optical fiber needs to be woven into a number of small strands before it is loaded into the endoscope. There are usually one share, two shares, and three shares. A strand of optical fiber presents a semicircle or a whole circle at the objective lens end. The two-strand optical fiber presents the left and right directions at the objective lens end, and the three-strand optical fiber presents the upper, left, and right directions at the objective lens end.