JPS6273390A - Optical character reader - Google Patents

Abstract

PURPOSE:To read a character with good operability at a high speed by a handy device, by storing digital outputs of plural characters by an image sensor, in a memory, reading out a signal of a one character portion and positioning the character end, and shifting in a lump the number of picture elements. CONSTITUTION:All characters of a form 23 are read by an image sensor 26 of a handy optical character reader, and a digital output of the senser 26 passing through a binary- coding circuit 27 is stored in a memory 28. Next, (m)X(n) dot picture elements of a one character portion are read out and accumulated in a buffer register 8 of a discriminating circuit 30 provided with vertical/horizontal segmenting circuits 9, 16, etc., and an intercharacter detecting circuit 32 detects the number of picture elements l1 extending to the left end of the character and supplies it to a controlling circuit 31. As a result, the portion of the number of picture elements l1 is shifted to the left by the circuit 31, and subsequently, in the same way, the number of picture elements l2 between said character and the adjacent character is detected by the circuit 32, and thereafter, the number of picture element l2 is shifted by the circuit 31 and the adjacent character is identified. In such a way, a character can be read with a good operability at a high speed by only placing a handy device on a character recording paper.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an optical character reading device that reads the character t by scanning a sheet with a hand-held scanner.

Conventional technologies and their problems > At supermarkets, department stores, etc., POS (Point of Sale) collects sales information for each item and manages inventory.
5ales) system is widespread.

Hand-held optical character readers are often used in these POS systems.

FIG. 5 is a block diagram of an example of a conventional optical character reading device.
We have a character reading device that identifies characters while moving horizontally on the sheet of paper 3. The rung 4 illuminates the paper 3, and the characters and patterns on the paper 3 are irradiated through the lens system 5.
An image is formed on an image sensor 6 in which photoelectric conversion elements are arranged in a planar (two-dimensional) manner. Since the reflected light from the background area and the reflected light from the text area of 1tt3 are different from each other, the signals obtained by the corresponding photoelectric conversion elements are applied to the control and binarization circuit 7 to determine the level. A determination is made as to whether to binarize white or black.

For example, the binarization determination result is output with a signal corresponding to the background area, ie, white, of the paper 3 as 10, and a signal corresponding to the character area, ie, black, as ki 1. Signal whisper O/! which is binarized by the control and binarization circuit 7! , %1# are stored in the buffer register 8.

Here, the method of character f&tori will be explained.

The photoelectric conversion element of the image sensor 6 will be referred to as a cell, and the area where data is compressed to the resolution required for recognition will be referred to as a unit area.

Assuming that the characters and patterns on the paper 3 are imaged on the image sensor 6 as shown in FIG. 6, FIG. As an example of the correspondence, a screen consisting of p and nXm cells is called a screen. The control and binarization circuit 7 sequentially performs B2 r Bs ! from the B2 column of the superlative L1. ...outputs the signal corresponding to the Bn column, and then outputs the signal corresponding to the Bn column, and then the BIT B of the next row.
The scanning of one screen is completed by outputting signals corresponding to the I r B3 r...Bn columns, the &Lj rows, and finally one Bl r...Bn column. The vertical extraction circuit 9 after the buffer register 8 in FIG. 5 is a circuit that detects the character area in the vertical direction, and checks whether there is one black I cell from the Bi column to the Bn column for each row.
If the number of consecutive rows containing 1 black L cells (determined from the size of the characters) is determined as a vertical character area. In Fig. 6, the vertical character area signal VA indicating this range is horizontally cut out from the line where one black character exists continuously from the L line to the 10th N line.
and output to the job-specific circuit 13. The horizontal cutting circuit 16 is a circuit that judges whether or not a character has reached a predetermined position in the horizontal direction.
For example, when the 87th column is all Kijiro I and a part of the B2 column is Higashiguro I, a horizontal cutout signal VH indicating that the characters are placed in a predetermined position is output to the identification circuit 13.

The identification circuit 13 is a circuit that identifies characters in a vertical character area (for example, from line Lj to line Lj+N) when the horizontal position is determined to be correct, and the line feature extraction circuit 1
0. It has a partial fault extraction circuit 11 and a discrimination processing circuit 12. The new feature extraction circuit 10 detects and extracts and classifies the feature C1 of each line within the t character area. Partial % fine output circuit 11
further performs all feature classifications from the plurality of signals Ci sent from the new feature extraction circuit 10 and outputs Di. The identification processing circuit 12 receives the signal D sent from the partial feature extraction circuit 11.
Identify the characters from the order of i and output the result Dout k. To be more specific, the feature extraction circuits 10 and 11 classify the relevant features 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 noturn shown in Figure 6, line Lj and line Lj+1 are horizontally long lines % p,
The line Lj+2 is classified as a horizontal short line ゝ-〃. Next, classification is performed by combining the features classified in order from the top row. For example, Lj line Lj 11th line whisper-I and Lj
+2 lines of lt -1 are combined to make ^1'', and this combination narrows the character identification range, and then the characteristics of Lj 10s lines,
By sequentially combining the features and narrowing the range down to Lj+N lines of whisper-〃, it can finally be identified as the honorific character 12''.

In this way, by moving the scanner 1 laterally with the hand 2 and scanning it, characters are read one by one.

However, in the conventional technique shown in FIG. 5, it is difficult to move the scanner 1 accurately in the horizontal direction, so it is difficult to read the scanner correctly, and furthermore, it has the disadvantage that it is difficult to operate because it is operated with the hand 2. Ta.

On the other hand, in order to improve operability, a wide-area image sensor is used so that multiple characters and symbols to be read can be contained within the field of view. An optical character reading device for this purpose was also developed. A conventional optical character filling device of this type is shown in FIG.

In FIG. 7, reference numeral 21 denotes a scanner, which reads characters, symbols, etc. written on the paper 23 by simply placing it on the paper 23 with the hand 22.

The paper 23 is, for example, a price tag on which information for a POS system is written. 24 is a light source, 1.25 is a lens system, 26 is an image sensor, and the field of view is approximately the same size as the information writing tab 9 of the paper 23 and the price tag. 27
is a control and digitizing circuit which converts the analog signal 18, which is the output signal of the sensor 26, into a binary signal <g, and sends it to the memory 28. The memory 28 stores binarized data of almost the entire field of view of the sensor 26.

The eighth factor shows an explanation of the binary data of the image sensor 26. It is a pXq image sensor 26 and has a field of view of the entire information writing area of the paper 23.

Characters and symbols are identified by the identification circuit 30, and since the identification circuit 30 identifies each character, the memory 28
Extract data for one character from inside. The control circuit 29 takes out data equivalent to mXn pixels, which is the processing capacity of the identification circuit 30, from the memory 28 and stores it in the buffer register 8.

In FIG. 8, first, data from BI to Bn column B1 row to Lm row is taken out from memory 28, and... Sofa register 8
Transfer to. Processing of character lines after buffer register 8 is the same as in the conventional case. Next, data from columns B1+1 to Bn+1 and from the 7th row to the Lm row are transferred from the memory 28 to the 9th sofa reno star 8. Similarly, transfer Ll row to Lm row of columns B, + 2 to Bn+2, repeat this, and transfer L
Transfer data from l to B1 column of row Lm.

This data transfer results in the same scanning as moving the conventional scanner 1 by hand 2.

When the 58th row to the Bq column in Lm row 1 is completed, the rows are shifted downward. For example, if the field of view from L to Lm lines is about twice the width of the letters, shift about two pixels,
That is, from row LT to row L3m, data from column B1 to column Bn is first transferred, and the same operation is repeated thereafter.

By the way, in the conventional technology shown in FIG.
The data for one character is extracted by moving each pixel horizontally and then processed for identification. For this reason, the same part of the pixel must be identified many times, and there is a drawback that it takes a long time to identify the entire field of view.

The present invention is based on the above-mentioned conventional technology, and simply by placing the scanner on the paper, the curve selection field is written on the paper and includes most of the next characters, symbols, etc., making it easy to operate and fast. The overall objective is to provide a hand-held optical character reader capable of processing.

<Measures to Solve the Problems> The present invention achieves the above object by scanning and capturing characters, etc. using an image sensor consisting of a curved array of light α-variable elements. A hand-held optical character reading device includes the above-mentioned image sensor having a field of view corresponding to a plurality of characters, means for digitizing and storing the output signal of the image sensor, and means for digitizing and storing the output signal of the image sensor, and digitizing and storing the output signal of the image sensor. means for extracting a signal equivalent to one character; means for recognizing a character, etc. for one character from this extraction ratio signal; means for detecting the location Vt of the character, etc.; and the location of the detected character, etc. The present invention is characterized in that it has a means for determining a position from which a signal is to be extracted in the next adjacent character, etc., and shifting the number of pixels all at once vertically or horizontally to this position.

Embodiment An embodiment of the present invention is shown in FIG. 21 is a suno yana, which can be read by simply placing it on the paper 23 with the hand 22 to read the next letters, symbols, etc. written on the paper 23. The paper 23 is, for example, a price tag on which information for a POS system is written. 24 is a light source, 1.25 is a lens system, and 26 is an image sensor, which has a field of view that is approximately the same size as the information written on the paper 23, that is, the price tag. A control and binarization circuit 27 converts the analog signal, which is the output signal of the image sensor 26, into a fully binarized signal and sends it to the memory 28. The memory 28 stores binarized data of almost the entire field of view of the image sensor 26.

Characters and symbols are identified by separate f-IR circuits 30, and since the identification circuit 30 identifies one character at a time, data for one character is extracted from the memory 28. Control circuit 29
m is the processing capacity of the identification (b) path 30 from the memory 28.
Increase the data equivalent to xn pixels and store it in buffer register 8.
It is stored in

The vertical cutting circuit 9 is a circuit for detecting a character area in the vertical direction, the horizontal cutting circuit 16 is a circuit for determining whether a character etc. has reached a predetermined position in the horizontal direction, and the line feature extraction circuit 10 is a circuit for detecting a character area in the vertical direction. A partial % fine output circuit 11 extracts and divides the feature Ct of each line within the character area, a circuit that further performs feature division from the feature C1 and outputs Di, and an identification processing circuit 12 identifies characters from the order of the signal Di. Result Dout
This is a circuit that outputs .

Now, in FIG. 1, vertical cutting circuit 9 and horizontal cutting circuit 1
6, and the character amount detection circuit 3 similarly to the line feature extraction circuit 10.
2 also receives data from the buffer register 8. This character amount detection circuit 32 detects l! from the corresponding character using mXn pixel data for one character! It detects the number of pixels up to the next character that matches 4 and outputs the pixel vSLN up to mXn pixel data, which is data for the next one character.

This will be explained using a cutout screen in Figure 2.
When data of mXn pixels for one character is first extracted as shown in FIG. As l! I is output to the control circuit 31.

In this case, since the output VA of the vertical cutting circuit 9 is input to the character spacing calculation circuit 32, the pixel data sent to this character amount detection circuit 32 indicates that the character after vertical cutting exists approximately in the center of the basement. become.

The output SLN of the character amount detection circuit 32 is 1 time 31 on the open side.
In this 1tilJ + wholesale circuit 31, S L
After shifting the screen by a few strokes based on the NK, mXn pixel data for one character is extracted and stored in the buffer register 8. This state is shown in FIG. 2(b).

Next, in Figure 2(b), the number of pixels to adjacent characters l
! , and outputs No. 1d SLN as an output from the all-character spacing detection circuit 32 to the control J output circuit 31. In the control circuit, the screen is shifted as shown in FIG. Data will be retrieved. In this way, the adjacent 9
The entire number of pixels up to a character is detected and the screen is shifted by that pixel at once to speed up the extraction of data for one character.

FIG. 3 shows an example of purchasing the character spacing calculation circuit 32.
OR circuit 33, soft register 34, control ROM3
Indicates that it consists of 5.

The binarized data of each column for each row on the screen is sequentially input to the OR circuit 33, and this OR circuit 33 performs a logical OR with the output of the shift register 34 of one stage corresponding to the n column of one horizontal digit on the screen. is stored in the shift register 34 again, and the logical sum is calculated in the vertical direction for each column in all rows. In other words, the first step is to find a column containing pixels that will become a character. The result of the logical sum is R for control.
The signal is input to the OM 35, and the ROM 35 creates and reads out a control signal according to the number of pixels.

The ROM 35 also detects and removes noise (such as noise smaller than characters), and the program also determines whether or not it is noise. In the case of noise, the SLN is designed not to output.

In this way, the characters start in the horizontal direction of the screen! L9, the screen can be detected by the number of pixels, and the screen can be shifted all at once at that position.

In the explanation of FIG. 2, we have described the case where pixels are shifted horizontally, but they may also be shifted vertically as in the fourth example.
It is also possible to detect the vertical pixel n ls in WJ4 (a) and extract data by shifting the number of pixels as shown in FIG. 4 (b).

<Effects of the Invention> The present invention improves the visibility of almost all information written on paper such as price tags.
By using a scanner with a sensor having f and reading characters, which are information written on the paper, simply by placing the scanner on the paper, it is possible to realize an optical reading device with very good operability.

Furthermore, when identifying characters one by one, the end of each character is detected and all data in the character area is processed, making it possible to perform both speed processing.

[Brief explanation of drawings]

1 to 4 show the implementation of the present invention, in which FIG. 1 is a configuration diagram, FIGS. The figure is a block diagram of an example of a character amount detection circuit, Figures 4(a) and 4(b) are state diagrams showing a state in which the screen is shifted, Figures 5 to 8 are conventional examples, and the fifth figure is a block diagram of an example. , No. 6 is an explanatory diagram of binary data, FIG. 7 is a configuration diagram of another example, and FIG. 8 is an explanatory diagram of binary data. In the figure, ■...Scanner, 2...Hand, 3...Paper, 4...
・Lamp, 5... Lens system, 5... Image sensor, 7... Control and binarization circuit, 8... Buffer register, 9... Vertical extraction circuit, lO... Row feature extraction Circuit, 11... Partial feature extraction circuit, 12... Identification circuit, 13... Identification circuit, 16... Horizontal cutting circuit, 21... Scanner, 22... Hand, 23... Paper , 24...Light source, 25, L/lens system, 26
...Image sensor, 27...Control and binarization circuit, 28...Memory, 29...Control circuit, 30...
-Identification circuit, 31...control circuit, 32...character amount detection circuit. % Applicant Sumitomo Electric Industries, Ltd.

Claims (1)

[Claims] In a hand-held optical character reading device that scans and reads characters, etc. using an image sensor consisting of a plurality of photoelectric conversion elements arranged in a planar manner, the above-mentioned image sensor having a field of view equivalent to a plurality of characters, and this image sensor are used. means for digitizing and storing the output signal of the sensor; means for extracting a signal equivalent to one character, etc. from the stored digital signal; and means for recognizing one character, etc. from the extracted signal; The detection means detects the position of the above-mentioned character, etc., and the position from which the signal of the next character, etc. adjacent to the detected character, etc. is located is determined, and the number of pixels is batched vertically or horizontally to this position. 1. An optical character reading device comprising: means for shifting the character.