JPS6160186A - Optical character reader - Google Patents

Abstract

PURPOSE:To read both bar codes and characters with a single optical character reader by discriminating whether a detected pattern is equal to the characters or bar codes and executing and each discriminating job according to the result of said discrimination. CONSTITUTION:The output signal of an image sensor 16 is applied to a binary coding circuit 18 for decision of white/black binary coding. Then the binary coded signals are applied to a deciding circuit 19, a horizontal separation circuit 20 and a feature extracting circuit 21. The circuit 19 obtains a black OR of plural columns for each row and discriminates the characters circuit 20 obtains the position information on a pattern and sends it to the circuit 21. A discriminating circuit 22 combines the features of each row given from the circuit 21 to perform discrimination among characters, the bar color and the bar width respectively. When the characters are decided, they are delivered as they are. While the bar codes if decided are discriminated respectively after the emerging orders of each bar are combined by a synthesizing circuit 23.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to an optical reading device that is capable of reading characters written on paper and identifying barcode information.

(b) Prior Art In order to quickly and accurately obtain sales information regarding many products with different unit prices at sales outlets such as department stores and supermarkets, a system called point-op sales (POS) has become widespread.

In this system, product information such as product name code, price, serial number, and manufacturer are recorded for each product.
It is customary to automatically read the necessary items from these with an optical or magnetic character reader, input the results into a computer, and process the data. However, in the actual process of product distribution, the display format of product information written on the tags is not uniform. For example, food products and miscellaneous goods are displayed using barcodes and letters (in this case, numbers), and clothing items are displayed using a combination of letters (in this case, Katakana characters and numbers). Here, written words are used to include numbers and symbols. When the display formats are inconsistent in this way, it is necessary to install multiple reading devices suitable for each display format in order to read product information, and it is necessary to install multiple reading devices suitable for each display format at the same sales location (some devices with the same function There was a problem of having to use them differently.

In addition, as an optical device characterized by having independent identification sections corresponding to characters and barcodes, and performing final recognition based on the identification results of both, Japanese Patent Laid-Open No. 57-1
This is disclosed in Japanese Patent Application Laid-open No. 82284 or Japanese Patent Application Laid-Open No. 182285/1982. For example, the configuration of this device shown in FIG. 9 is known.

That is, in FIG. 9, part A identifies the barcode,
Part B identifies characters. 2 is a two-dimensional image sensor, 2 is an amplifier circuit, o3 and 5 are binarization circuits, and 4 is a bar code identification section. 6 is a character identification part. 7 is a means to determine whether it is a barcode or a character,
It is sent from both the barcode identification unit 4 and the character identification unit 60 (whichever is determined based on the identification results that are carried out at the same time), and the barcode identification A and character identification B are sent from both. Both are running in parallel and at the same time.

H Problems to be Solved by the Invention The optical reading device shown in FIG. 9, which has an identification section that independently identifies characters and barcodes, has a method of simultaneously identifying barcodes and characters with their respective identification sections, Out of both identification results, one of the identification results is output. For this reason, since the object to be identified is identified before distinguishing between characters and barcodes, the object to be identified is easily affected by noise due to dirt, etc., resulting in the problem of erroneous identification. Furthermore, since both barcode and character identification means are required, the apparatus has the disadvantage of being expensive.

An object of the present invention is to provide an optical reading device that can read both characters and barcodes with one device and has excellent reading performance by reducing the influence of noise.

Another object of the present invention is to provide an inexpensive optical reading device by identifying barcodes and characters with one identification section.

B) Means for Solving the Problems In order to solve the above-mentioned problems, the present apparatus is constructed as follows. That is, the output signal of the image sensor is digitized and the number of consecutive lines of 6 black is calculated from the logical sum of the pattern of characters and barcodes, and it is determined whether the pattern is a character or a barcode. means for determining positional information of characters and barcodes in the pattern; feature extracting means for classifying features for each line based on the positional information; an identification means for identifying a color and a bar width, and a means for identifying a barcode from the order of appearance of the identified bar color and bar width, and when the identification result is a character, the identification result of the identification means is It is configured to output it as is, and in the case of a barcode, output the identification result of the barcode.

(e) Before the character or barcode pattern captured by the operational image sensor and further converted into a binary value is specifically identified as a character or pattern, it is determined whether the pattern is a character or a barcode.

Based on this determination result, specific identification is performed in correspondence with characters or barcodes, and further, corresponding identification results are output in accordance with the determination results.

(f) Example The configuration of the present invention is shown in FIG.

It is assumed that a scanner 11 is held by a human hand 12 and an object to be read on a paper 13, such as characters or barcode information, is scanned in the horizontal direction. When the light source 14 illuminates the paper 13 on which objects to be read, such as characters, are written, the pattern of the object to be read written on the paper is imaged onto the image sensor 16 via the lens system 15. The image sensor 16 is one in which photoelectric conversion elements are arranged in a planar (two-dimensional) manner. Since the reflected light from the background area of the paper 13 and the areas such as characters to be read are different from each other, the signals obtained by the corresponding photoelectric conversion elements pass through the amplification circuit 7 and are sent to the binarization circuit 18.
given to. Binarization circuit■8 is white by level judgment,
Performs a binary judgment on black, for example, °0" is the background area (white)
Corresponding to this, II 11+ is output as a signal corresponding to the character area (black).

Hereinafter, the photoelectric conversion element of the image sensor 16 will be referred to as a cell.

When reading characters, assuming that the image formed on the image sensor 16 is as shown in FIG. 2, this FIG. It will be shown. Now, if we say that the screen is a pattern consisting of nXm cells, the binarization circuit 18 sequentially outputs signals ("O"/ "l"), then output B1, B2, ..., Bn columns of the next row L2, and then 53
Finally, the scanning of one screen is completed by outputting signals corresponding to the 13th matrix, B1, . . ., in the Lm row. Third
The figure shows an example of a barcode marked on a sheet of paper 13, and an example of its correspondence with the binarized signal from the binarization circuit 18 obtained by scanning this with the scanner 11 is shown in FIG. has been done.

The binarized signal from the binarization circuit 18 is sent to a determination circuit 19;
The signal is applied to a horizontal extraction circuit 20 and a feature extraction circuit 21, respectively.

The determination circuit 19 determines whether it is a character or a bar code, and its configuration is shown in FIG. In FIG. 6, numeral 31 is an OR gate, which calculates the "black" logical sum of the binary signals from each cell from the B1 column to the Bn column for each row. That is, the logical sum is ″
In this case, it is assumed that a black spot exists in at least one cell from old to Bn. The output of the OR gate 31 is given to a read-only storage device (hereinafter referred to as ROM) 32.
The output from 32 is provided to register 33. The contents of this register 33 are cleared before scanning of row B1 is started. The ROM 32 is given the result of the logical sum of the output signals of the cells in the B1 row and B1 to Bn columns via the OR game 31 and the contents of the register 33 as an address, and the contents of the ROM 32 read by this address are sent to the register. It is set to 33. Next, the logical sum of the B2 row and the contents of the register 33 are set into the register 33 again as an address. This is sequentially manipulated back to the Lm line. ROM 3
Since the state in which "6 black" exists is coded and written in ROM 32, when the corresponding contents of this ROM 32 are read out and set in the register 33, the register 33 also knows the state of "6 black". The determination of whether it is a 0 character or a barcode is performed as follows. That is, the logical sum of columns Bl to Bn in row B1 is A1, L
Let Am be the result of the logical sum of m rows and columns B1 to Bn. Further, it is assumed that a is the number of consecutive lines of the logical sum ゛■' from Bl to Bn. Here, h.

Let C be a predetermined constant, and the upper and lower rows of consecutive logical sums "1'" are logical sums "°0", and if the object to be read is within the field of view of the image sensor, then the pattern to be read is the character. When h < (L < c holds true).

In addition, df is a predetermined constant, and if the barcode is longer than the field of view of the image sensor, Al or Am is 1'', so if the pattern to be read is a barcode, α
becomes d. In this way, it is determined whether the pattern to be read is a character or a barcode. register 3
3 outputs a signal CHA and a signal VA when it is a character, and outputs a signal BAR when it is a bar code.

As shown in FIG. 1, the signals C)TA and BAR outputted from the determination circuit 19 are sent to a combining circuit 23 and a horizontal cutting circuit 20. In the case of characters, the determination circuit 19 also detects the character area in the vertical direction.

For example, 5 in Figure 2? , if it is a C character screen, Lj
It is determined that the area from line B11 to line B11 is a character, and a signal VA'11 is sent to the horizontal direction cutout circuit 20 and feature extraction circuit 21 so as to be identified within this character area.

Next, character and barcode identification will be explained.

First, character identification will be explained. The signal for one screen is
It is necessary to identify and output the character pattern only when it is correctly within the field of view of the image sensor 16 as shown in FIG. The horizontal cutting circuit 20 is connected to the hand scanner 1
When moving 1, the character pattern will be displayed on image sensor 1.
6 is located at the predetermined position. This position judgment can be performed, for example, if the first row Bl is entirely white and the second row Bl is
2 is the smallest (each line contains 6 black characters and column Bi is all white), the correct position is determined, and the characters are determined to be from B2 to B1-1 column.Then, in the horizontal direction The extraction circuit 20 sends B i-1 from the character position B2 to the feature extraction circuit 21.

Next, barcode identification will be explained. As shown in Figure 4, if the B1 column is 'white' and the B2 column is 'black' and the next 'white' is in the B' column, the position of the black bar is from B2 to Bk-1. shall be. Also, as shown in Figure 4, the B1 column is "black" and the B2 column is "white" and the next °°black' is B1.
In the case of a column, the white bar position is from B2 to R1-1.

The thus identified bar position information, ie, the black bar position B2 to Bk-1 and the white bar position B2 to B1-1, is sent from the horizontal extraction circuit 20 to the feature extraction circuit 21.

For identification, a part of the technology disclosed in Japanese Patent Application Laid-open No. 16133/1983 is used. JP-A-54-1.6133 discloses a method for identifying only characters, but the present invention identifies characters, bar code bar color, and bar width.

The feature extraction circuit 21 extracts character or barcode position information from the determination circuit 19 and the horizontal extraction circuit 20, and determines the length and number of consecutive occurrences of black and white spaces for each line. Classify by characteristic. Figure 7 shows an example of classification by characteristics.
CO to 07 are for character identification, and C8 to C15 are for barcode identification. In this way, the features of each row classified by the feature extraction circuit 21 are sent to the identification circuit 22.

For example, in the character pattern shown in Figure 2, C6y is extracted from the Lj line and Lj+1 line, C3Y is extracted from L'+2, and then C3, C3, C3, C6, C6, C1, C is extracted from the Lj+3 to Ls line.
1,.

CI, C1, C6, and C6 are sequentially extracted.

The identification circuit 22 performs identification by combining the features sent from the feature extraction circuit 21. For example, when characters C6, C6, C6, etc. of the character pattern shown in Figure 2 are sent, as shown in Figure 8, they are sent one after another (combining the features) to finally form the character 112 I+. In the case of the barcode pattern shown in Fig. 4, C8 is sequentially sent from the feature extraction circuit 21 in each row as the black bar of the module, so the identification circuit 22 recognizes that a combination of only C8 is one module. In the case of the barcode pattern shown in FIG. 5, the feature extraction circuit 21 extracts C8, which indicates a 3-module white bar in each row, and the identification circuit 22 identifies it as a 3-module white bar. The identification result of the identification circuit 22 is sent to the synthesis circuit 23.

In the case of a barcode to which the signal BAR is applied, the synthesis circuit 23 combines the appearance order of each bar of the identified barcode sent from the identification circuit 22 and identifies it as a final barcode. For example, if the barcode pattern changes from Figure 4 to Figure 5,
Module/l/(7) White bar, similar identification results are sequentially provided from the identification circuit 22 to the synthesis circuit 23, and the synthesis circuit 23 synthesizes these to determine which number or symbol the barcode corresponds to. decide. The synthesis circuit 23 receives the signal CI(A
In the case of a character that is given, the identification result sent from the identification circuit 22 is output as is.

(G) Effect □ The optical reading device of the invention can read both barcode display tags and text display tags with the same device, so it speeds up the checkout process in POS systems that use both barcode display and text display. becomes possible.

Furthermore, since the present invention identifies patterns after distinguishing between characters and barcodes, it is possible to accurately read tags with less erroneous identification due to noise such as dirt.

Furthermore, since the present invention treats characters and bar codes in the same way and identifies them using one identification means, an inexpensive device can be realized.

Furthermore, the present invention determines and processes the positions of characters and barcodes to be identified, and treats them as two-dimensional information, so it is not affected by the operation of the scanner being operated.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing an image on an image sensor that has been binarized and corresponds to each other, and Fig. 3 is a diagram showing an example of a barcode marked on paper. , Fig. 4 and Fig. 5 are diagrams in which the image on the image sensor in Fig. 3 is binarized and corresponded to each other, Fig. 6 is a configuration diagram of the determination circuit, and Fig. 7 is an example of feature classification by the feature extraction circuit. FIG. 8 is an explanatory diagram for identifying characters using an identification circuit, and FIG. 9 is a configuration diagram of a conventional optical reading device. 11... Scanner, 13... Paper, 14... Light source, ■5... Lens system, 16... Image sensor, 17... Amplification circuit, 18. ... Binarization circuit, 19 ... Judgment circuit, 20 ... Horizontal extraction circuit, 21 ... Feature extraction circuit, 22 ... Identification circuit, 23 ... Synthesis circuit . Patent applicant: Sumitomo Electric Industries, Ltd. (5 others) Figure 2 Br BzBs ---1 ------Bj ---
--Bn JP-A-Sho Gl-GO18G (6) 4 Fig. 5 BtBz BI L+ non-H type pot W wing Fig. 7 Fig. 7 Blasphemy bud size 1J opening #JH61-60186'J) Fig. 8 Fig. 9 figure

Claims (1)

[Claims] (1) In a hand-held optical reading device that optically reads characters and barcodes using an image sensor consisting of a plurality of photoelectric conversion elements arranged in a planar arrangement, characters and barcodes are detected within the field of view of the image sensor. imaging means for forming an image of the object to be read; means for digitizing the output signal of the image sensor to form a character or barcode pattern; determining means for determining whether the pattern is a character or a barcode by determining the number of consecutive rows of "black" from a logical sum of "black" in a plurality of columns; and means for determining position information of characters and barcodes in the pattern. and,
patent extraction means for classifying features for each line based on the position information; identification means for identifying bar colors and bar widths of characters and barcodes based on the information on the feature classification;
means for identifying a barcode from the order of appearance of the identified bar color and bar width; if the determination result is a character, the identification result of the identification means is output as is, and if it is a barcode, the identification result is output as is; An optical reading device characterized in that it outputs an identification result.