Automatic focusing method and system of scanning code device

Abstract

The invention belongs to the focal length adjustment technical field and relates to an automatic focusing method of a scanning code device. The method includes the following steps that: the running speed value of a conveyor belt is preset, and the focal length of the lens of the scanning code device is adjusted to be a default focal length; images are acquired according to a fixed time interval, measured objects on the conveyor belt in the images are judged, and the characteristic position of each measured object is calibrated; the deviation pixel values of the measured objects are obtained according to the deviation of the characteristic positions of the measured objects in the fixed time interval; vertical distances between the measured objects and the lens are calculated; and the focallength of the lens is automatically adjusted according to the vertical distances between the measured objects and the lens. The present invention also provides an automatic focusing system corresponding to the automatic focusing method. According to the automatic focusing method of the invention, a distance measuring device such as a distance sensor is not required to be additionally adopted, thedistances between the measured objects and the scanning lens can be quickly determined, and the focal length of the lens can be quickly adjusted.

Description

technical field [0001] The invention belongs to the technical field of focus adjustment, and in particular relates to an automatic focus method and system for a code scanning device. Background technique [0002] Barcodes are widely used in product manufacturing process, and the emerging two-dimensional code can store more information, so its application in product manufacturing process is more in-depth. For example, in automobile manufacturing, DPM two-dimensional codes, that is, direct parts marking two-dimensional codes, can be used to mark auto parts with needle marking machines, laser marking machines, inkjet printers and even chemical etching technology. Has been widely used in the automotive industry. The American Automobile Manufacturers Association (AIAG) has also specially formulated relevant standards, from the steel body, steel cover, crankshaft, connecting rod, camshaft of the engine to the valve body, valve seat, valve cover of the gearbox, and then to the key...

AI Technical Summary

Problems solved by technology

Although this method can realize the function of autofocus, it has the following disadvantages: 1. The overall cost of the system is increased; 2. The overall complexity of the system is increased; 3. The position of the distance sensor is fixed, so it is impossible to realize the prediction of the motion trajectory of the object to be measured; 4. , unable to achieve multi-objective simultaneous measurement

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