knowledge of barcode scanner

- Dec 04, 2019-

Bar code scanners are also called bar code readers, bar code scanners, bar code scanners, bar code scanners, bar code scanners, and bar code readers, but they are called differently. It is a reading device used to read the information contained in a bar code. Using the {optical} principle, the content of the bar code is decoded and transmitted to a computer or other device via a data line or wirelessly. The structure of a barcode scanner is usually as follows: light source, receiving device, photoelectric conversion component, decoding circuit, and computer interface.


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There are many types of bar code scanners, and the following are common:

(1) Handheld barcode scanner.

(2) Small roller barcode scanner.

(3) Platform type barcode scanner.



The resolution of the bar code scanning gun should be determined from three aspects: the optical part, the hardware part and the software part. That is, the resolution of the scanning gun is equal to the resolution of its optical components plus its own resolution obtained through processing and analysis by hardware and software.


Optical resolution is the actual number of light spots that can be captured by the optical components of the scanning gun per square inch. It refers to the physical resolution of the scanning gun CCD (or other optoelectronic devices), and also the true resolution of the scanning gun. The value of is the value obtained by dividing the number of pixels that can be captured by the photoelectric element by the maximum scannable size of the scanning gun level. For example, a scanning gun with a resolution of 1200 DPI often has a resolution of only 400 to 600 DPI. The resolution of the extended part is generated jointly by hardware and software. This process is generated by computer analysis of the image and mathematically filling the blank part (this process is also called interpolation processing).


Optical scanning and output are one-to-one. What is scanned is what is output. After processing by computer software and hardware, the output image will become more realistic and the resolution will be higher. Most of the scanners currently on the market have software and hardware expansion functions for resolution. Some scanning gun advertisements write 9600 × 9600DPI. This is only the maximum resolution obtained through software interpolation, not the true optical resolution of the scanning gun. So for the scanning gun, its resolution has optical resolution (or optical resolution) and maximum resolution. Of course, what we care about is optical resolution. This is the hard work.

We say that the resolution of a certain scanning gun is as high as 4800 DPI (this 4800 DPI is the sum of optical resolution and software difference processing), which means that when an image is input with the scanning gun, 4800 × can be collected on a 1-inch-inch scanning format. 4800 pixels. Scanning area of 1 inch square, the image size after scanning with 4800DPI resolution is 4800Pixel × 4800Pixel. When scanning an image, the higher the scanning resolution is set, the finer the effect of the generated image and the larger the image file generated, but the more the interpolation components are.


There are several reasons why a barcode scanner cannot read a barcode:

(1) The function of reading this barcode is not turned on.

(2) The bar code does not meet the specifications. For example, the required blank space is missing, the contrast between the bar and the space is too low, and the width / narrow ratio of the bar and the space is inappropriate.

(3) The surface of the bar code is covered with a transparent material and the reflectance is too high. Although the bar code can be seen by the eyes, the data collector has strict reading conditions and cannot be read.

(4) Direct sunlight, the photosensitive device enters the saturation region.

(5) Hardware failure, contact your dealer for repair.