Common parameters of industrial endoscope lenses
Industrial endoscopes mainly include lenses, probes, controllers, and light sources. Their composition can deeply explore the internal components of the equipment and capture and record images and videos. Using endoscopes for auxiliary inspections helps reduce mechanical failures and machine maintenance costs. The lens is one of the most important components in an endoscope. If you want to choose a lens suitable for product applications, you must first have a certain understanding of the common parameters of the lens.
1. Interface:
Common interface specifications are: M5, M5.5, M6, M6.5, M7, M8, M9, M12, M16, C, CS
P0.35 represents the thread pitch of 0.35mm, and 0.23mm and 0.5mm are also common
2. Optical focal length:
Refers to the distance from the main surface of the image to the focus of an optical system.
The shorter the focal length, the wider the view, the more framing, but the more blurred the local area;
The longer the focal length, the narrower the view, the less framing, but the closer it is, the clearer the local area.
3. Aperture:
"relative aperture", is an indicator of the imaging brightness of the optical system.
Under the same light environment, the smaller the F value of this parameter, the brighter the monitoring imaging screen. For example, the starlight lens is generally around F1.0, and the night vision effect is much better than F2.0.
4. Total optical length:
refers to the distance from the surface of the first lens of the optical system to the image plane.
5. Lens structure:
Refers to the structure of each component of the optical system. 6G represents 6 pieces of optical glass, P represents plastic glass, and IR represents filter.
6. Field of view:
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The angle range that the optical system can image. Generally, it is necessary to take different chips as an example. The final imaging angle formed by different chip assemblies is different. H represents horizontal view, V represents vertical view, and D represents diagonal view. |
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7. Relative illumination:
The brightness ratio of the imaging edge to the imaging center.
The illumination of the imaging edge must be darker than that of the imaging center. Generally, the lens requires this ratio to reach more than 50%.
8. Distortion:
| refers to the degree of distortion of the image formed by the optical system on the object relative to the object itself. The distortion of the lens exists, and the difference lies in the size. Generally, the larger the field of view, the greater the distortion. |  |
9. CRA: From the sensor side of the lens, the maximum angle of light that can be focused on the pixel is defined as a parameter, called the chief ray angle (CRA)
10. Back focus:
Optical back focus BFL (O) refers to the distance from the last side of the last lens of the lens to the image plane
Mechanical back focus BFL (M) refers to the distance from the mechanical rear end face of the lens to the image plane.
