JPS6024992B2 - character reading device - Google Patents

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a character reading device using a surface scanner.

[Technical background of the invention and its problems]

In recent years, in the retail industry such as department stores and supermarkets, improvements have been made to improve customer service by shortening the checkout time at the checkout counter, preventing input errors caused by incorrect keys, and improving accounting management, inventory management, and product replenishment operations using computers. In order to achieve automation, a device has been developed and put into practical use that manually scans the characters printed on the price tag of a product, optically reads the characters, and automatically inputs them into a POS device or the like.

On the other hand, the types of characters input into such devices are not only numbers, but also parts of alphabetic characters and symbols such as commas, periods, and /.

This is because, unlike discussions using barcodes, etc., people and character reading devices use the same medium to obtain information, and this is especially necessary for people to accurately obtain information from printed price tags, etc. It is not possible. Furthermore, price tags printed in this manner may be touched by many people and may become dirty when attached to products, and documents other than price tags are generally printed using a line printer.

Unless this line printer is constantly fine-tuned, the print quality tends to be affected by non-character noise such as ghosts and smudges. Regarding discussions on such forms (including price tags),
Due to the demand for smaller size and lower cost, conventional character reading devices detect characters, symbols, etc. by self-scanning inside the scanner, and based on the projection in the width direction of the character and the projected height in the height direction of the character for each line of scanning. When these are detected as patterns that satisfy the detection conditions, the detection conditions are used to distinguish between small patterns such as commas and periods, and other patterns. In the latter case, the type of symbol detected is coded and output to a storage device that stores the identification results, and in the latter case, identification processing is performed and the result is input to the storage device.

Therefore, if the self-scanning direction of the surface scanner is repeated row scanning from top to bottom as shown in Fig. 1a, when an input as shown in Fig. 1b is observed, one pattern of temporal As a result, the recognition result obtained from this observed pattern is determined to be "1" as a result of the character pattern 2 being detected earlier than the character pattern 2. On the other hand, symbols such as commas and periods are edited (checked for digit alignment, etc.) and outputted by the editing section after all the lines have been read, and as a result, symbols such as commas and periods are not output.

Therefore, they are not detected and judged, but as user requirements have improved, unless these things are detected and recognized, it will be difficult to output accurate results.
In particular, accurate detection of these symbols is indispensable for outputting character pitch related to blank detection, control for determining that the end of a field is determined when the same symbol is detected twice, and so on. Therefore, there has been a desire for a high-performance character argumentation device that can recognize symbols and the like as accurately as alphanumeric characters. [Purpose of the Invention] The purpose of the present invention is to be able to recognize symbols, etc. as accurately as alphanumeric characters, etc., and to avoid misrecognizing them, especially when price tags (forms) are mixed with ghosts, noise, etc. Our goal is to provide a high-performance character book.

[Summary of the invention]

The present invention relates to a system that uses two-dimensionally arranged photoelectric conversion devices (hereinafter referred to as surface scanners) to manually scan characters, symbols (those whose character width and height are smaller than alphanumeric characters), etc. Detection/judgment means for detecting character height direction and character width direction projections in synchronization with the video signal during frame scanning, and detecting and determining characters and symbols based on the projection values, as well as determining symbol type codes; an identification means for identifying the character code when a character is detected by the detection and judgment means; and an editing means for editing the character code identified by the identification means and the symbol type code determined by the detection and judgment means. When a symbol is detected, the detection/judgment means stores the type code of the symbol, and when further characters are detected in scanning the same frame, outputs this character pattern to the identification means and clears the stored symbol type code. However, if no character is detected other than the symbol, the stored symbol type code is output to the editing means.

〔Effect of the invention〕

According to the present invention, it is possible to accurately detect characters and symbols even in forms with poor printing quality, so there is no risk of incorrectly inputting alphanumeric characters, symbols, etc., and the practical benefits for the user are enormous. be.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a diagram explaining the outline of a manual scanner incorporating a surface scanner.
The reflected light is projected onto a surface scanner 15 through a lens 14, and the output of the surface scanner 15 is passed through an amplifier 16 to output an analog video signal 17 to the outside.

This analog signal is input to the doji conversion circuit shown in FIG. 3, and the quantized video signal 19 is input to the character detection circuit 2. Character detection circuit 2 From the projection of the input pattern in the scanning device side area, it is determined whether it is an alphanumeric character or a symbol such as a comma, period, /, etc. according to pre-given conditions, and the detection condition is satisfied. Determine if it was done. Those that satisfy the detection conditions and are determined to be alphanumeric characters are input to the identification circuit 22 through the data line 21, and the character type of the input pattern is encoded and transferred to the editing circuit 25 through the data line 24. On the other hand, character detection circuit 2
01, when a symbol etc. is detected, the data line 23 is sent directly to the editing circuit 25 without being transferred to the identification circuit 22.
The type of symbol detected through the code is encoded and output. The editing circuit 25 checks the result when all the characters in a line have been read, and outputs the data 26 to an external device. Figure 4 explains the processing when a symbol pattern (comma) containing noise is input into the observation area of the scanner.The scanner self-scans horizontally from the top of the observation area and moves downward sequentially. In this case, pattern 21 is detected first. By detecting this pattern,
The value of the character height direction projection 19 of that pattern is obtained. At the same time, the projection in the character width direction projection 23 is obtained, and the character width 25W is inputted to the detection and determination circuit. As a result, if it is determined to be a comma, period, /.fon, or noise based on the determination conditions based on the character width and character height of the pattern shown in FIG. 8, the symbol code excluding the noise is stored in a register prepared in advance. After that, the aircraft is sequentially scanned. In the case of FIG. 4, the height 20 ratio and character width 26W2 are detected and determined in the same manner as described above when the pattern 22 is detected after that. In this way, when noise and symbols are detected in one observation area, the type of symbol detected (register contents)
Only the frame scanning synchronization signal is output in synchronization with the frame scanning synchronization signal. Furthermore, the diagram shown in Fig. 5 explains the case where a symbol and a character pattern are detected in the same frame.
, is detected and determined as a /.fion and stored in the register. However, character pattern 30 detected after that
If it is determined that a character pattern other than a symbol or noise has been detected based on the character height 231 and character width W 232, the determination result based on the previously detected pattern 22 is ignored and priority is given to the identification process of the character pattern. It is something to do. Furthermore, since the pattern 33 subsequently detected by the scanner has been subjected to the above-mentioned identification process,
The detection determination will not be executed. In this way, when a character pattern satisfies the detection conditions in the observation area of the scanner, priority is given to identifying the character pattern, and other patterns are considered to be noise, no matter what other patterns are detected. Furthermore, as shown in Figure 6, symbols (comma, period,
If a pattern 35 that does not satisfy the detection conditions is detected in the same frame in which the pattern was detected, all the contents stored in the register due to the detection are cleared, and the symbol is not output. Not done.

FIG. 7 shows the operation of the detection/judgment circuit, which makes a decision every time a pattern is detected by inputting the character width projection W37, the input data of the character height 36, and the frame scanning synchronization signal EOF38.

The character detection/judgment circuit 39 inputs the quantized video 45 to one of the AND gates 41 and its output to the pattern shift register 401 . When the pattern is a symbol or a pattern excluding noise is satisfied, the AND gate 41 is closed by the control line 43, and the character pattern inputted to the shift register 4 is connected to one of the AND gates 42 to open the control line 44. The information is then transferred to the identification circuit.
On the other hand, if the character detection/judgment circuit 39 detects a symbol satisfying the above conditions, the contents of an internal register (in which the type of symbol is stored) is output to the editing circuit 25 through a line 46.

When the character pattern result is input from the identification circuit 22 and it is detected that all of the scanned character lines have been scanned, the editing circuit 25 edits the result by checking the number of digits, etc., and outputs the result 26 to the outside. FIG. 8 is an example of reference data for determining whether the character width projection described above satisfies the detection condition depending on its width and position, where the hatched area is black and the x area is white or black. When the character width direction detection conditions 1} to '41 are satisfied, it is determined that the detection condition for the character width is satisfied.

This is based on the condition that if the scanner observation area is 12 bits in the character width direction, the observation pattern is centered on the approximate center, and the same idea is used for other observation areas as well.

Furthermore, Fig. 9 shows an example in which symbols (comma, period, /.), noise, and characters are determined based on the values of the character width W and character height H when the character width direction projection satisfies the detection conditions described above. It is something. With this invention, even in the case of a form with poor printing quality, such as a form with a ghost in a form printed by a line printer, a form with a ghost in FIG. It is possible to obtain a character reading device that achieves high performance, miniaturization, and low cost, and can easily detect and recognize characters.

In the present invention, when a plurality of symbols are detected in one frame, the type of symbol detected last in the frame may be output. This facilitates editing by referring to information regarding the position of adjacent characters in the observation area (the center or upper end of commas and dots is below the center of adjacent characters). In addition, there is a method of outputting the detected pattern by attaching stricter conditions (increasing certainty) to the determination conditions in Figure 9, and distinguishing and outputting ambiguous areas in the area determination of such a size through identification processing. is also easily considered. Furthermore, once a symbol is detected, its first symbol code is sent to the editing circuit, but it may be processed so that the same type of symbol is not output continuously in this frame scan. When a plurality of recognition results are obtained in the same row scanning range of the same symbol, a method of making a final judgment based on majority vote and outputting the result to the outside may be considered.

[Brief explanation of drawings]

Figures 1a and 1b are diagrams explaining how a conventional device of this type outputs incorrect recognition results in the scanning direction of the surface scanner and observation patterns in which ghosts, etc. occur. Diagram explaining the configuration of the illumination system, optical system, etc. of the scanner, Part 3
The figure is a block diagram of this character reading device, and Figure 4 shows an example where noise and symbols are detected in the same frame. Figure 5 is a diagram that explains how character patterns with ghosts are detected and recognized as only characters, regardless of other noises, based on the explanation in Figure 4. Figure 6 shows the character pattern after a symbol is detected. A diagram illustrating a state in which a symbol detection result is not output when a part of the pattern is detected and the pattern does not satisfy the detection conditions. FIG. 7 is an explanation of the operation of a character detection judgment circuit as an embodiment of the present invention. Figure 8 shows an example of character width direction detection judgment conditions, and Figure 9 shows a pattern in which the character width and character height in the 12-bit observation area in the character width direction satisfy the detection conditions. A map of the separation detection conditions for symbols, noise, and characters to be identified, Figure 10a,
b is a diagram showing an example of printed characters that can be read by the present invention. 11... surface scanner, 18... quantization circuit,
20...Character detection circuit, 22...Identification circuit, 25...Editing circuit. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10

Claims (1)

[Claims] 1. An area scanning means that scans the characters and symbols on the paper in rows frame by frame and sequentially converts and outputs them into video signals, and detects the vertical and horizontal projection values of the pattern area from the video signal output by the area scanning means. and a detection/judgment means that compares this with a predetermined value to determine whether the pattern area is a character or a symbol, and if it is a symbol, determines the symbol type code; If it is determined that this is the case, an identification means is used to identify the character code using the video signal of the pattern area, and a check is performed on the character code identified by this identification means and the symbol type code determined by the detection and determination means. and editing means for editing and outputting the edited data, and the detection and determination means stores the symbol type code when a symbol is detected in row scanning of the same frame by the area scanning means, and subsequently stores the symbol type code in another pattern area. is determined to be a character, the stored symbol type code is cleared and the character pattern is output to the identification means, and if the other pattern area is not determined to be a character, only the stored symbol type code is edited by the editing means. A character reading device characterized by outputting.