JPH0578065B2 - - Google Patents

Description

[Detailed Description of the Invention] [1] Technical Field The present invention relates to an optical reading device that is capable of reading characters, codes, etc. written on paper and identifying code information such as barcodes. It is.

[2] Prior art and its problems A system called Point of Sales (POS) has become widespread in order to quickly and accurately obtain sales information about many products with different unit prices at department stores, supermarkets, etc. In this system, each product has a product name code, price,
A "product tag" containing product information such as the serial number and manufacturer is attached, and the necessary items from these are automatically read with an optical or magnetic reader and the results are input into a computer. , it is customary to process data. However, in the actual process of product distribution, the display format of product information on the tags described above is inconsistent; for example, food items and miscellaneous goods are displayed using barcodes and numbers, and clothing items are displayed using a combination of letters and numbers. It is displayed by. In such cases, in order to read product information, it is necessary to install multiple reading devices suitable for each display format, and several devices with the same function must be used at the same sales location. There was a problem.

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. 182284/1984 or Opening 57
-There is one disclosed in Publication No. 182285. However, by identifying barcodes and characters in parallel,
Since it outputs only one of the two identification results, it may be affected by noise such as dirt, resulting in incorrect identification, and the equipment may be expensive as both types of identification means are required. It had some drawbacks.

FIG. 1 is an example of a conventional bar code and character reading device. A identifies the barcode and B
identifies characters. 1 is a two-dimensional image sensor, and 2 is an amplifier circuit. 3 and 5 are binarization circuits, and 4 is a barcode identification section. 6 is a character identification part. 7 is a means for determining whether it is a barcode or a character, which is determined based on the identification results sent from both the barcode identification section 4 and the character identification section 6 and carried out at the same time. barcode identification A and character identification B
Both are running in parallel. For this reason, as described above, it is susceptible to noise such as dirt and requires two series of identification sections, which makes it expensive.

[3] Purpose of the invention The purpose of the present invention is to solve the problems of the prior art described above, and to print both characters and barcodes using the same image sensor without replacing or adding any other parts. An object of the present invention is to provide an improved optical reading device that can be read automatically.

Another object of the present invention is to provide a device with good reading performance by first determining whether it is a bar code or a character and then identifying it. Still another object is to provide an inexpensive reading device by identifying barcodes and characters with one identification section.

[4] Disclosure of the invention 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, codes, 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 objects 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, the signals obtained by the corresponding photoelectric conversion elements are transmitted to the amplifier circuit 1.
7, the signal is added to the binarization circuit 18, and the level is determined to determine whether the signal is converted into white or black. For example, "0" is output as a signal corresponding to the background area (white), and "1" is output as a signal corresponding to the character area (black).
Hereinafter, the photoelectric conversion element of the image sensor 16 will be described as a cell.

Image sensor 1 when reading characters or codes
If the image formation on 6 is as shown in Figure 3, then
FIG. 3 shows an example of the correspondence between each cell of the image sensor and the binarized signal from the binarization circuit 18. Now, if a pattern consisting of n×m cells is called a screen, the binarization circuit 18 is
Outputs signals (“0”/“1”) corresponding to columns B2, B3, ...Bn sequentially from column B1 of L1, and then outputs signals (“0”/“1”) corresponding to columns B2, B3, ...
B1, B2, ...Bn columns, then L3 rows, and finally Lm rows
Scanning of one screen is completed by outputting signals corresponding to columns B1, . . . Bn.

Next, one row of the barcode is shown in FIG. 5, and an example of the binarized data obtained by scanning this barcode is shown in FIG. 4. The determination circuit 19 determines whether it is a character (including symbols) or a bar code. Barcode identification is as shown in Figure 4.
The following explanation assumes that cell 30 located in row Bk is used. The configuration of the determination circuit 19 is shown in FIG.

For an arbitrary column, for example, the Bk column or three columns including the left and right sides of Bk, the number of consecutive black rows is determined as follows. Reference numeral 31 denotes an OR gate, which calculates the logical sum of "black" of the binary signals from the cells in the Bk column and the cells before and after it, that is, in the Bk-1 and Bk+1 columns, for each row. If the logical sum is 1 for a certain row, Bk-1 of that row,
This indicates that "black" existed in at least one cell of Bk and Bk+1. This row is called a row where black exists. 32 is a read-only storage device (hereinafter referred to as
(referred to as ROM) and 33 is a register. Line L1
The result of the logical sum of the output signals of the cells in columns Bk-1, Bk, and Bk+1 and the contents of the register 33 are input into the ROM 32 as addresses, and the contents of the ROM 32 are read and set in the register 33. However, the contents of the register 33 are cleared before scanning the L1 line. Next, the logical sum of the L2 row and the contents of the register 33 are input to the ROM 32 as an address, and the contents are read out and set in the register 33 again. Repeat this sequentially up to the Lm line. The state in which "black" exists, that is, the number of consecutive "black" lines and the position in which "black" exists, are coded and written in the ROM 32, so when this is read and set in the register 33, it is written from the register 33. It is possible to know the number of consecutive lines of "black" and the position where "black" exists.

Determination as to whether the recognition result is a character or a barcode is performed as follows. Columns Bk−1, Bk of row L1, and
The logical sum in Bk+1 is A1, column Bk− of row Lm
Let Am be the result of the logical sum of 1, Bk, and Bk+1.

Also, “1” of the logical sum of Bk−1, Bk, and Bk+1
Let a be the number of consecutive lines. Since the height of the barcode is greater than the height of the characters, check whether a is the size of the characters or the size of the barcode.
Let b, c, and d be predetermined constants, where b corresponds to the minimum size of a character, c corresponds to the maximum size of a character, and d corresponds to the minimum height of a barcode. Let c>b. In the case of characters, the upper and lower rows of consecutive logical sums of "1" have a logical sum of "0" and are within the field of view of the image sensor, and b = a
〓c, when it is a barcode, it becomes ad. This allows you to distinguish between characters and barcodes, and when it is a character, the signal CHA is used, and when it is a barcode, the signal is
Output BAR.

The explanation was given by calculating the logical sum of Bk-1, Bk, and Bk+1, but regardless of the number of columns, the logical sum of columns B1 to Bn is calculated for each row to determine whether it is a character or a barcode. You can also do this without looking for a logical sum.
It is also possible to use a binary signal of only the Bk column. The determination circuit 19 determines whether it is a character or a barcode, and sends the determination result to the identification circuit 22. In the case of characters, the determination circuit 19 also detects the character area in the vertical direction. For example, in a drawing like Figure 3, start from the Lj line.
It is determined that the area up to the Ls line is a character, and a signal VA is sent to the character cutout circuit 20 to identify it within this character area. The identification circuit 22 uses a read-only storage device (hereinafter referred to as barcode ROM) 23 for barcode identification based on the signal sent from the determination circuit 19.
A read-only storage device for character identification (hereinafter referred to as character identification)
24 (referred to as ROM) is selected, the contents are read out, and identification processing is performed.

Next, the methods for identifying characters and barcodes will be explained first, starting with character identification.

Assume that a screen as shown in FIG. 3 is obtained.

This signal for one screen needs to be identified and output only when the character pattern is correctly within the field of view of the image sensor 16 as shown in FIG. Therefore, when the hand scanner 11 is moved, the character cutting circuit 20 determines whether the character pattern is at a predetermined position on the image sensor 16. This position judgment is determined to be correct when, for example, the first column B1 is all "white", the second column B2 contains "black" in at least one row, and the last column Bn is all "white". By known methods such as The character cutting circuit 20 operates only when a signal indicating that it is a character is sent from the determination circuit 19, and when the signal indicating a character is not sent, that is, when it is a bar code, the position is detected. do not have.

Therefore, the character is recognized by the identification circuit 22 at the correct position corresponding to the pattern shown in FIG. Identification is obtained by known techniques, for example Japanese Patent Application Laid-Open No. 16133/1983.
According to the technology disclosed in Japanese Patent Application No. 52-81181, it is as follows. That is, for each line L1 to Lm, the characteristics of the line are classified based on the length of consecutive "black" or "1"s obtained in each row and the number of consecutive occurrences. For example, in the character pattern in Figure 3, the jth line Lj
is the horizontal line "-", and the j+2nd line Lj+2 is the rightmost point "・"
It will be classified as follows. Next, classification is performed by combining the features classified in order from the top row. For example, the combination of "-" on the Lj line and "-" on the Lj+1 line is the same "-", and when combined with the "・" on the Lj+2 line, it becomes "¬", and this combination is used to identify characters. If the range is narrowed, and then the features in the Lj+3 row are sequentially combined with the features up to "-" in the LsN row, the range can be finally identified as the number "2".

For the contents of the features extracted for each line and the contents of the result of combining the features of each line,
It is stored in ROM24. When the identification circuit 22 receives a signal indicating a character from the determination circuit 19, it reads out the contents of features and combinations of features from the character ROM 24 and identifies the character.

Next, the identification operation when code information written in a barcode is scanned by the hand scanner 11 will be explained using FIG. 4. The scanning from line L1 to line Lm of the screen showing the pattern in Figure 4 is repeated at extremely short intervals (for example, 200 μsec), as in the case of the character pattern in Figure 3, until the image sensor passes through one character. During this time, multiple scans will be performed.

When identifying a barcode, use at least one cell out of n x m cells, count the number of times "black" or "white" appears in this cell, and use this count to determine the length of the long width. Determine and identify whether it is a black bar, a short black bar, a long white bar, or a short white bar.

21 is a white/black bar counter, and the judgment circuit 1
It operates only when a signal is sent from 9 when it is determined to be a bar code, and counts the number of "white" and "black" scans.

An example of the configuration of the white/black bar counter 21 is shown in FIG.

As mentioned above, cell 30 located in row Lh, column Bk
Explain as if you are using .

In the configuration example shown in FIG. 2, the binarization circuit 18 determines whether a predetermined cell 30 is "white" or "black" and sets the corresponding signal "0" or "1" to the color flag (1) 13. do. When scanning the next screen, when setting the signal of the cell 30 to the color flag (1) 43, the contents of the previous color flag (1) 43 are set to the color flag (2) 44. Now, the content of color flag (2) 44 is color flag (1)
This indicates the scanning state prior to the state of No. 43.

In the matching circuit 45, color flag (1) 43 and color flag (2)
44, and if they are the same, the contents of the counter 46 are added based on whether "white" or "black" continues. When the contents of color flag (1) 43 and color flag (2) 44 are different, it means that "white" and "black" have changed, that is, it indicates that scanning of the bar width has been completed. In this case, the verification circuit 45 sends a signal to the normalization circuit 48, and also sends the contents of the counter 46 to the normalization circuit 48.
Clear the contents of.

If the paper 13 has foreign matter such as dust attached or is dirty, it may be mistakenly added as a barcode.

In the present invention, in order to prevent such errors, the contents of the counter 46 are incremented when the determination circuit 19 determines that it is a bar code and the signal is sent from the determination circuit 19 to the verification circuit 45. This prevents errors caused by small noises.

Also, since the hand scanner 11 is moved by hand,
The number of counts for each bar will be different because different people or even the same person move their hands at different speeds each time. In the present invention, the influence of the moving speed of the scanner is solved as follows.

That is, barcode information as shown in FIG. 5 has a start mark and a stop mark at both ends, and the width thereof is predetermined.

When reading while moving the hand scanner 11, this start mark or end mark is scanned first, but first the contents of the counter 46 in the initial "black" state are stored in the reference number memory 47, This count corrects for differences in hand movement speed.

Next, the normalization circuit 48 receives the count number B for each white and black state from the counter 46 according to the content A of the reference number memory 47, which is the count number at the start mark or end mark. /A×a (where a is a predetermined constant). is normalized to eliminate the influence of the hand scanner's movement speed.

As the output from the normalization circuit 48, values corresponding to each bar width are obtained.

The bar classification circuit 49 selects "white" and "black" from the value corresponding to the bar width obtained from the normalization circuit 48 and the signal corresponding to "white" and "black" obtained from the matching circuit 45.
The bars are distinguished and the bar widths are distinguished and sent to the identification circuit 22. The identification circuit 22 outputs "white" when information is obtained from the start mark to the end mark or conversely from the end mark to the start mark.
Numbers, depending on the order of appearance of each width of the “black” bar,
Identify symbols, etc.

At the time of identification, the content corresponding to the identification is read from the barcode ROM 23 and identified.

For example, scan the barcode in Figure 5 using the scanner 11.
FIG. 8 shows a part of the explanation of the operation when moving from left to right.

Reference numeral 51 indicates a clock for the scanning period of the screen, and reference numeral 52 indicates a signal binarized into "black" and "white", that is, "1" and "0" by the control and binarization circuit 7. The count of the number of scans for “black” is shown at 53, the count number of the number of scans for “white” is shown at 54, and 5
5 and 56 show the normalized values of "black" and "white", respectively.

The first “black” and the second “black” are a start mark or an end mark, and one character starts from the next “white” and continues with “black”, “white”, “black”, and the second “ It is predetermined that one character ends with "black". In this case, the appearance order is “white”
1, "black" 4, "white" 1, and "black" 1 appear, which corresponds to the number "9", so the identification result is "9", and so on.

Output more accurate results by removing mixtures of characters and barcodes.

Although the case where one cell is used for barcode identification has been described, a plurality of cells may be used.
In barcode identification, the method of counting the number of scans of "white" and "black" has been described, but the scanning time of the appearance of "white" and "black" may be held and counted.

In addition, as a method of normalizing barcodes, we have explained that normalization is performed using the start mark and end mark, but as in Japanese Patent Application No. 1982-99611, the "white" mark immediately before the barcode is
It may be normalized by comparing it with "black".

As explained above, according to the optical reading device of the present invention, both barcode display tags and text display tags can be read by the same device. It is possible to increase the speed at

In the present invention, the tags can be read more accurately because the identification is performed after distinguishing between characters and barcodes.

Furthermore, in the present invention, since characters and barcodes are each identified by one identification means, an inexpensive device can be realized.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional OCR and barcode reading device, FIG. 2 is a diagram showing a configuration example of the present invention,
FIG. 3 is a diagram showing an image of a character or code on a sensor;
Figure 4 is a diagram showing an image of barcode information on a sensor, Figure 5 is an example of barcode information, Figure 6 is a configuration diagram of a determination circuit, and Figure 7 is an example configuration of a white/black bar counter. 8 are explanatory diagrams in the case of barcode reading. DESCRIPTION OF SYMBOLS 1... Two-dimensional image sensor, 2... Amplification circuit, 3... Binarization circuit, 4... Barcode identification section, 5... Binarization circuit, 6... Character identification section, 7
...Means for determining, 11...Sukiyana, 12...
Hand, 13... Paper, 14... Light source, 15... Lens system, 16... Image sensor, 17... Amplification circuit, 18... Binarization circuit, 19... Judgment circuit, 2
0...Character cutting circuit, 21...White/black bar counter, 22...Identification circuit, 23...Read-only storage device for barcode identification, 24...Read-only storage device for character identification, 30...Cell, 31...OR gate, 32...Read-only storage device (ROM), 33
... Register, 43 ... Color flag (1), 44 ... Color flag (2), 45 ... Verification circuit, 46 ... Counter, 47 ... Reference number memory, 48 ... Normalization circuit, 49 ... Bar division circuit, 51...Screen scanning period clock, 52...Binarized signal, 53...Count the number of black scans, 54...Count the number of white scans,
55... Black normalized value, 56... White normalized value.

Claims (1)

[Claims] 1. In a hand-held optical reader that optically reads characters, symbols, etc. and barcodes using an image sensor consisting of a plurality of photoelectric conversion elements arranged in a planar arrangement, characters, symbols, etc. are detected within the field of view of the image sensor. and a means for forming an image of a barcode; a means for digitizing the output signal of each pixel of the image sensor; and a means for performing a black logical sum for each row of the digital signals of any column or any adjacent columns of the image sensor. means for determining the number of consecutive rows in which black exists by sequentially checking whether or not black pixels exist in each row from top to bottom; and a constant predetermining the number of consecutive rows in which black exists. A combination of a determination means for determining whether it is a character, symbol, etc. or a barcode by comparing it with a character, one identification means for identifying both a character symbol and a barcode, and a signal to be referred to when identifying a character, symbol, etc. and a second identification storage device that stores a combination of signals to be referred to when identifying a barcode code. The identification means reads the content of the signal combination from the first identification storage device and identifies it as a character, symbol, etc. while referring to it, and when the determination means determines that it is a barcode, the identification means An optical reading device characterized in that the combination of signals is read out from the second identification storage device and identified as a barcode while being referenced.