JPH03232080A - Bar code reader - Google Patents

Abstract

PURPOSE:To improve the read rate of a bar code of low quality by main- scanning the inside of a memory in plural subscanning directions at a time and using the true value of a notices picture element out of plural obtained picture elements to generate new scanning data. CONSTITUTION:A scanning means main-scans the inside of a memory 5 in plural subscanning directions at a time at the time of scanning a bar code image in the memory 5. An arithmetic means uses picture element information around the noticed picture element out of plural picture elements obtained by the scanning means to calculate the true value of the noticed picture element. A scanning data generating means uses the true value of the noticed picture element calculated by the arithmetic means to generate new scanning data. A recognizing part 6 constitutes the scanning means, the arithmetic means, and the scanning data generating means. Thus, the read rate of the bar code of low quality is improved to increase the recognition speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a barcode reading device that optically reads barcodes.

(Prior Art) When reading a barcode as shown in FIG. 6 with a conventional barcode reading device, first, a barcode image 20 stored in a memory is scanned with a 1-bit width.
1, and the number of 1 and 0 pixels corresponding to the barcode image obtained by this scanning is counted to create run length data. The barcode is read by matching the run length data thus obtained with the barcode pattern. However, if the barcode read by the above-mentioned scanning of the conventional barcode reading device is not correctly coded, the 1-bit width scanning 21 has to be performed again to read the barcode again.

However, with the conventional barcode reading method as described above, when the barcode shown in Figure 6 is dirty or faded, the recognition rate is poor with the 1-bit width scanning, and rescanning is required several times. The disadvantage was that it had to be repeated.

Therefore, there is an inconvenience that the recognition is not completed in one scan, resulting in a decrease in throughput and a decrease in the recognition speed.

(Problems to be Solved by the Invention) According to the conventional barcode reading device as described above, only 1-bit width scanning is performed on the barcode image in the memory, so the barcode may be smudged or blurred. If this happens, the recognition rate decreases, the scanning is often repeated, the throughput decreases, and the recognition speed deteriorates.

SUMMARY OF THE INVENTION The present invention aims to eliminate the above-mentioned drawbacks and to provide a barcode reading device that improves the reading rate for low-quality barcodes and improves the recognition speed.

[Structure of the Invention] (Means for Solving the Problems) The present invention photoelectrically converts a barcode written on a form, etc., stores a good barcode image in a memory, and then converts the barcode image in this memory into a memory. In a barcode reading device that recognizes the barcode based on scan data obtained by scanning, when scanning the barcode image in the memory, the barcode image in the memory is scanned at once in a plurality of sub-scanning directions. a scanning means for main-scanning a pixel of interest, a calculation means for calculating a true value of the pixel of interest using pixel information in the vicinity of the pixel of interest among the plurality of pixels obtained by the scanning means; The scan data generating means generates new scan data using the true value of the pixel of interest.

(Function) In the barcode reading device of the present invention, when scanning the barcode image in the memory, the scanning means performs main scanning in the memory at once in a plurality of sub-scanning directions. The calculation means calculates the true value of the pixel of interest using pixel information in the vicinity of the pixel of interest among the plurality of pixels obtained by the scanning means.

The scan data raw sphere means generates new scan data using the true value of the pixel of interest calculated by the calculation means.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the barcode reading device of the present invention. 1 is a form on which a barcode is written; 2 is a photoelectric conversion unit that photoelectrically converts the barcode image on the form 1 and reads it as image data; 3 is an amplifier that amplifies the image data output from the photoelectric conversion unit 2. , 4 is an A/D converter that quantizes the image data (analog data) inputted from the amplifier 3 and converts it into a digital signal; 3 is a memory unit that stores the digitized image data, that is, the barcode image; 6 is a recognition unit that reads the barcode image stored in the memory unit 5 and performs barcode recognition processing.

Here, the recognition unit 6 constitutes a scanning means, a calculating means, and a scanning data generating means.

Next, the operation of this embodiment will be explained. First, the barcode portion written on the form 1 is photoelectrically converted by the photoelectric conversion unit 2, and the obtained image data is sent to the A/D converter via the amplifier 3.
Output to converter 4. The A/D converter 4 digitizes the input image data, and stores the digitized image data, that is, the barcode image, in the memory section 5. The recognition unit 6 main-scans the barcode image stored in the memory unit 5 by 3 bits in the sub-scanning direction as shown in FIG.

FIG. 3 is a diagram showing details of the scanning method of the barcode image by the recognition section 6. As shown in FIG. The recognition unit 6 has Nl, N, N
Main scanning for 3 bits is performed at one time in the sub-scanning direction of +1 line. At this time, the recognition unit 6 applies mask a to the Mth bit (
Then, each bit is scanned by sequentially applying mask b to the M+1 bit, and as a result, the recognition unit 6 obtains scan data (pixel data) as shown by 10 in the figure. As a result, if the recognition unit 6 performs normal recognition, the process ends, and if normal recognition cannot be performed, another recognition process as described below is performed.

In another recognition process, the recognition section 6 scans the memory section 5 with a mask 11 as shown in FIG. 4 and applies the mask 11 to the desired data.

Thereafter, the recognition unit 6 applies the data obtained by applying the mask 11 to the following equation to obtain the sum of pixels within the mask. At this time, black circles are counted as 1 and white circles as 0.

Y=X+A+B+C+D (1) However, X is the pixel of interest.

As a result, if ¥≧3, the pixel of interest is recognized as X=1, and in other cases, the pixel of interest is recognized as X=0. In this way, the recognition unit 6
obtains scanning data as shown at 10 in FIG. 3 and performs barcode recognition. Here, in the example of Fig. 3, A=1,
Since B=1, C=1, D=O1X=0, substituting these relationships into equation (1) yields Y=3, and therefore,
=1 is determined.

However, if correct recognition cannot be performed even with this method, the recognition section 6 applies a mask 12 as shown in FIG. 5 to the data obtained by scanning the inside of the memory section 5. after that,
The recognition unit 6 applies the mask 12 to the data obtained by (
1) Find the total sum of pixels within the mask by applying the equation. As a result, if Y≧3, the pixel of interest is set to X=1; otherwise, the pixel of interest is set to X=0, and scanning data as shown at 10 in FIG. 3 is obtained to perform barcode recognition.

Even with this method, if the recognition unit 6 is unable to recognize the barcode, the scanning position in the memory 5 is changed and the above operation is repeated.

According to this embodiment, the barcode image stored in the memory 5 is main-scanned for 3 bits at a time in the sub-scanning direction, and the barcode is normally scanned based on the scanning data for 1 bit of the scanned image. Recognition is performed, but if recognition fails, the recognition unit 6 uses memory in order to correctly recognize the barcode by calculating the true value of the pixel of interest in consideration of data surrounding the pixel of interest. A low-quality barcode can be read accurately with one access to the section 5, and the number of retries can be reduced and recognition speed can be improved.

〔Effect of the invention〕

As described above, according to the barcode reading device of the present invention, the reading rate for low-quality barcodes can be improved and the recognition speed can be improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the barcode reading device of the present invention, FIG. 2 is a diagram showing a scanning method for the memory section of the recognition section shown in FIG. 1, and FIG. Figures 4 and 5 are diagrams explaining the details of the scanning method shown in the figure, Figures 4 and 5 are diagrams showing examples of masks applied to scanned data by the recognition unit shown in Figure 1, and Figure 6 is a diagram illustrating the conventional masking method. It is a figure showing an example of a scanning method of a code reading device. 1... Concern vote 2... Photoelectric conversion section 4...
A/D converter 5...Memory section 6...Recognition section

Claims (1)

[Claims] After storing a barcode image obtained by photoelectrically converting a barcode written on a form or the like into a memory, the barcode is recognized based on the scan data obtained by scanning the barcode image in the memory. In the barcode reading device, when scanning the barcode image in the memory, a scanning means for main scanning the memory in a plurality of sub-scanning directions at once; A calculation means for calculating the true value of the pixel of interest using pixel information in the vicinity of the pixel of interest among the pixels, and scanning for generating new scanning data using the true value of the pixel of interest calculated by the calculation means. A barcode reading device comprising data generation means.