3.5 mm endoscope camera

4、How to choose an endoscope camera module?

（1）Endoscope camera module size

The outer diameter of the lens is an important parameter in the selection of industrial endoscopes, and it is also the first condition to pay attention to when selecting an endoscope.

At present, the smallest camera manufactured by EZON has an outer diameter of only 0.65mm, and the largest size is 14mm. There are also other specifications of 1.05, 1.8, 2.0, 3.3, 3.5, 4.5, 5.5, 6, 7, 8, etc., with comprehensive specifications and sizes.

（2）Lens focal length and field of view angle of the endoscopic camera module

According to the distance from the endoscope to the monitored target, the focal length of the lens of the endoscope camera module is selected, and after the lens focal length f is determined, the field of view is determined by the endoscope target surface. Customers need to determine the field of view of the lens based on the application environment of the product. Large angles have a wider observation range and depth of field. Small angles cannot observe close objects. Starting with 30mm or above.

Field of view Depth of field

80° 30-80mm

100° 5-30mm

120° 7-110mm

140° 7-110mm

（3）Aperture or light transmission of the endoscope camera module

The amount of light transmitted through an endoscope is measured by the ratio of the focal length of the lens of the camera module to the clear aperture, marked with F. Each lens is marked with its maximum F value. The amount of light transmitted is proportional to the square of the F value. Inversely proportional to the relationship, the smaller the F value, the larger the aperture. Therefore, you should choose whether to use manual aperture or automatic aperture lens according to the degree of light change of the part being monitored.

（4）Lens resolution of endoscopic camera module

The resolution of a lens refers to the ability of the lens to reproduce the details of an object. Also called resolution or sharpness. It refers to the ability of an optical system to distinguish the minimum distance between two object points or two image points on the image plane. It is also one of the quality indicators for evaluating optical systems. The higher the resolution of the lens, the better it can show the most subtle differences in the image. For digital cameras with higher frame factors, higher resolution is more difficult to achieve. This is because when the sensor area is small, the distance between the photosensitive elements is also very small.

Due to their small size, current endoscopes mostly have resolutions of 720p and 1080p, and mainstream endoscope module chips include OV9734, OV2740, OV6946, OV6930, etc.

（5） Light source: required number of LEDs, such as 2 LEDs, 4 LEDs, or 6 LEDs. Temperature requirements need to be considered at the same time, for example, the temperature should be lower than 50 degrees for 10 consecutive minutes.

In addition to the above basic information, medical camera modules also need to consider the anti-fog treatment, gamma sterilization, IP67 and other propeties of the lens.

After clarifying the above seven elements, the prototype of the endoscopic camera module can be initially designed. EZON can tailor-make the endoscopic camera module that best meets the application requirements according to the needs of the customer.