JPS58211280A - Character reader - Google Patents

Abstract

PURPOSE:To read a character surrounded by a frame, etc. by counting a line containing black, and cutting this inter-line as a character area, when a counting value is within a prescribed range and also no black line exists. CONSTITUTION:In case when a numeral ''2'' and a part of a frame are image- formed on the photodetecting face of a two-dimensional sensor 5, output signals of an OR gate 10 and an AND gate 16 become like B and C shown in the figure, respectively, and are applied to a vertical cutting a circuit 11a. This circuit 11a erases the newest counting value (the number of lines) stored in a memory of the inside, when an output of the AND gate 16 becomes ''1'', therefore, on this picture, only Sj is stored as the number of lines of the uppermost line of a character area. Accordingly, the circuit 11a can set a character area signal VA to ''1'' as shown in the figure D, as to only the part corresponding to the character area, in the following picture. Therefore, a character, a numeral, etc. surrounded by a frame can also be read.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention (1) The present invention relates to a character reading device that can optically read characters surrounded by frames.

BACKGROUND ART AND PROBLEMS In recent years, many devices have come into use that optically read characters, numbers, symbols, etc. written on a sheet of paper while the scanner is held in the hand and moved.

FIG. 1 is a block diagram showing a configuration example of a conventional character reading device using a hand scanner, in which 1 is a hand scanner, 2 is a sheet of paper with numbers written on it, 6 is a lamp that illuminates the sheet of paper 2, and 4 is a lens system, 5 is a two-dimensional centimeter, 6 is an amplifier, 7 is a binarization circuit, 8 is a feature extraction circuit, 9 is an identification circuit, 10 is an OR gate, 11 is a vertical extraction circuit, 12 is a horizontal extraction circuit, 13 and 14 are cutting flags.

Inside the hand scanner 1, there is a lamp 6 that illuminates the paper 2, a lens system 4 that forms an image of the reflected light from the paper 2 onto the light receiving surface of the two-dimensional sensor 9-5, and a lamp 6 that illuminates the paper 2; A two-dimensional sensor that outputs a signal corresponding to the reflected light and an amplifier 6 that amplifies (2) the output signal of the two-dimensional sensor 5 are provided.

The two-dimensional sensor 9-5 is, for example, 11 as shown in FIG.
photoelectric conversion elements (hereinafter referred to as cells) are arranged in a two-dimensional manner, and the signals corresponding to the cells arranged in 81 rows and columns V1 to Vn are parallelized according to the applied clock signal CK. Then output the signals corresponding to the cells arranged in 82 rows and columns V1 to Vn in parallel,
After that, the signals corresponding to the cells arranged in the 83rd row and finally the Sm row and the V1 to Vn columns are output in parallel, thereby completing the scanning for one screen. Note that after the two-dimensional sensor 5 finishes scanning one screen, it starts scanning the next screen, but a flyback period of a certain period of time (for example, one period of the clock signal CK) is provided during this period. It is something that exists.

The binarization circuit 7 converts the signal applied from the two-dimensional sensor 5 via the amplifier 6 into a binary signal corresponding to a character area, ie, "black", and a background area, ie, "white" (in the following description, ,
It is assumed that "1" is output in the case of a character area and "0" is output in the case of a background area. Each signal is binarized and applied to a feature extraction circuit 8, an OR gate 10, and a horizontal extraction circuit 12. The output signal of the OR gate 10 is output from the vertical cutout circuit 1.
Added to 1.

The vertical cutting circuit 11 detects a character area in the vertical direction based on the output signal of the OR gate, and its operation will be explained below.

The vertical cutting circuit 11 extracts the two cells corresponding to the rows of the two-dimensional sensor 5 based on the applied clock signal CK (the same clock signal CK applied to the two-dimensional sensor 5). Are you constantly counting whether a value signal is being added? 6. When the output signal of the OR gate 10 changes from MO'' to 1'', the count value (number of rows) at that time is stored in an internal memory (not shown), and the output signal of the OR gate 10 changes from MO'' to 1''. Check whether there are consecutive "1" cells across the lines, that is, how many cells that contain black in the vertical direction exist.Then, the number of cells (number of lines) is determined in advance as the height of the character. Determine whether or not the number (number of rows) is within the range of the number of cells (4) that is being counted, and if it is determined that it is within the range, store the count value (number of rows) in the memory as is. When it is determined that the value is outside the range, the count value stored in the memory 12 is erased.Therefore, the memory provided inside the vertical cutting circuit 11 stores the count value stored in the memory 12. For example, when the number "2" is imaged on the light-receiving surface of the two-dimensional sensor f5 as shown in FIG. It should be noted that the output signal of the OR gate 10 is "0" multiple times.
” to “1”, perform the same operation as described above for each case, and select the last line among the number of lines stored in the memory without being erased at the end of scanning one screen. The number of lines stored in is used as the number of lines in the top line of the character area.

When the scanning for one screen is completed, the vertical cutting circuit 11 repeats the same operation for the next screen, and when scanning the previous screen, the number of (5) top lines of the character area is stored in the memory. If so, the character area signal VA is set to 1'' during the number of cells (number of lines) N corresponding to the predetermined character height from the top row of the character area. (See Figure 2) ) Also, the horizontal cutout circuit 12 detects a character area in the horizontal direction based on the binary signal C2 from the binarization circuit 7, and its operation will be explained below.

The horizontal cutting circuit 12 cuts out a character area in the horizontal direction based on the binary signal applied from the binarization circuit 7 while the character area signal VA from the vertical cutting circuit 11 is "1". For example, when the number "2" is imaged on the light receiving surface of the two-dimensional sensor f5 as shown in FIG.
Between row ECJ1N-1), all the binary signals corresponding to column 21 indicate "white", and some of the binary signals corresponding to column 22 indicate "black". And furthermore, Vi
All the binary signals corresponding to the column are “white” and α(T'i(&
When the condition (α, b are constants determined from the correspondence between the character to be read and the cell) is satisfied, it is assumed that the character area in the horizontal direction has been successfully cut out, and the output signal VH is set to 1'' (6). In other words, for each column V1*V2tV5*...Vn, the logical sum of "black" in the vertical character area VCi=
VWsu-4-VWsu+1+...+VWij+N-1(
VC1=“0”, v
When the conditions c2 = "1", VCi = "0", and α Vi<b are satisfied, it is assumed that the character area in the horizontal direction has been successfully cut out, and the output signal VH is set to #1.

In addition, the horizontal cutting circuit 12 sets VCi="
0" is output. If the vertical extraction is not successful and the signal VA is "0", or if the horizontal extraction does not satisfy the above conditions and the extraction is not successful. Outputs signal VH="0".

The cropping flag 16 stores the content of the signal VH output from the horizontal cropping circuit 12 (“1” for a screen for which horizontal cropping was successful, and 0 for a screen for which horizontal cropping was not successful). ), and the contents of the cut-out flag 13 are set to the cut-out flag 14 during the flyback period (7).
, 14 are "1" and "0", respectively, the identification circuit 9 performs identification processing based on the output of the feature extraction circuit 8. Note that the extraction flags 13, 1
The reason why the identification process is performed when the contents of 4 are "1" and "O", respectively, is to prevent the same character from being identified many times.

The feature extraction circuit 8 extracts the white/black gator features of each line in the character area and adds the extraction results to the identification circuit 9. The detection is based on the signal VCL from 12. In the screen shown in Figure 2, the vertical character area is from line 81 to line S()+N-1), and the horizontal character area is from column 21 to column Vi, so
Extract the features of row 81 and columns V1 to Vi, then S()+1
) row, columns V1 to Vi are extracted, and the following S(j+2)
The features of columns V1 to Vt from row S<j+N-1) are sequentially extracted, and the extraction results are added to the identification circuit 9. The identification circuit 9 determines that the contents of the cutting flags 15 and 14 are "O" and "O", respectively.
At the time of ``(8), the identification process is performed based on the extraction result added from the feature extraction circuit 8.

A conventional character reading device using a hand scanner reads characters as described above, but it has the disadvantage that characters surrounded by a frame 15 as shown in FIG. 3 cannot be read.

In other words, in a character reading device using a hand scanner, it is necessary to make the field of view larger than the character area from the viewpoint of operability of the hand scanner. When reading the numbers shown in Figure 4 (A), CC) on the light receiving surface of the two-dimensional sensor 5,
An image as shown in will be formed. At this time, the signals output from the OR gate 10 are as shown in CB) and CD> in the same figure, so the vertical cutout circuit 11 extracts the output signal from the OR gate 10 (A), Naka). It becomes impossible to detect which one indicates the vertical character area. That is, in the conventional device, the fourth
When an image like the one shown in Figures (A) and (C) is formed, it is difficult to accurately determine the vertical character area (9), so it is difficult to read nine numbers, etc. surrounded by a frame. There were no drawbacks.

Purpose of the Invention The present invention is to improve the above-mentioned drawbacks, and its purpose is to make it possible to read characters, numbers, etc. surrounded by frames. .

Embodiment of the invention FIG. 5 is a block diagram of an embodiment of the invention, and 11α
is a vertical cutting path, 16 is an AND gate, and the other first
The same reference numerals as in the figures represent the same parts.

Incidentally, the output of the AND gate 16 of the vertical cutout circuit 11α is “
1", the operation is the same as that of the vertical cutout circuit 11 shown in FIG. It is something to do.

Now, for example, as shown in FIG. 6 CA), the two-dimensional sensor 5
Assuming that the number "2" and a part of the frame are imaged on the light-receiving plane of It is added to the output circuit 11α. As mentioned above, the vertical cutout circuit 11α erases the newest count value (number of rows) stored in the internal memory (not shown) when the output of the AND gate 16 becomes "1". Therefore, on this screen, only "Sノ" is stored as the number of lines at the top of the character area. Therefore, the vertical cutting circuit 11α can set the character area signal VA to "1" only in the part corresponding to the character area on the next screen (C2) as shown in FIG. It becomes possible.

In this way (2. In this embodiment (2), the ORGATE 10
Even if the output is "1" continuously over the corresponding number of rows, if there is a row in which the output of the AND gate 16 is "1" between the rows, that is, all columns is “black”
If there is a line, the line spacing is a frame (= assuming that they correspond,
The character area signal VA is not set to "1", the output of the OR gate 10 is continuously "1" over the number of lines that are two windows in height of the character, and the output of the AND gate 16 is "1" between the lines. When no line is included, the character area signal VA is set to 1, assuming that the line spacing corresponds to the character area.
”, it is possible to read characters, numbers, etc. surrounded by frames.

In addition, in the embodiment, the case where the present invention is applied to a character reading device using a hand scanner has been explained.
It is not limited to this.

As described in the detailed description of the invention, the present invention provides that when the number of rows containing black that are continuous in the vertical direction is within a predetermined range, and there are no rows that are all black between the rows, Since the line spacing is used as a vertical character area, there is an advantage that characters, symbols, etc. surrounded by frames can be read.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional example, Fig. 2 is an explanatory diagram of a two-dimensional sensor, Figs. The figure is a block diagram of an embodiment of the present invention, and FIGS. 6(A) to 6(CD) are explanatory diagrams of the operation of FIG. 5. 1 is a hand scanner, 2 is paper, a roller lamp, 4 is a lens system, 5 is a two-dimensional centimeter, 6 is an amplifier, 7 is a binarization circuit, 8 is a feature extraction circuit, 9 is an identification circuit, 10 is an OR gate, 11.11a is a vertical cutout circuit, 12 is a horizontal cutout circuit,
13 and 14 are cutting flags, 15 is a frame, and 16 is an AND gate. Patent Applicant Sumitomo Electric Industries Co., Ltd. Agent Patent Attorney Gobe Tamamushi (16) Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A two-dimensional sensor converts the reflected light from a sheet of paper with letters, symbols, etc. It has a binarization circuit that performs two conversions, and an extraction circuit that detects vertical and horizontal character work 1 noa based on the output signal of the binary conversion circuit. A character reading device (=approximately 1.N) for identifying characters, symbols, etc., using the binary signal (2-based) in the character area, It counts whether there are consecutive rows containing at least one "black" character, and if the count value is within a predetermined range, and if there is no row car that is all "black" between the counted rows. ,), the counted line spacing is used as a vertical character area.