JPS5866173A - Line reader - Google Patents

Abstract

PURPOSE:To make the device small-sized and low-cost and reduce the power consumption, by storing a character pattern in a line buffer memory divisionally while offsetting the visual field of a photoelectric transducer in accordance with the inclination direction and the inclination angle of a character line to be read. CONSTITUTION:A character line is scanned and read along this character line by a photoelectric transducer 2, and the photoelectric conversion signal is inputted and stored in a line buffer memory 3 through a visual field controlling circuit 5 for the photoelectric transducer. An inclination angle detecting circuit 6 detects the inclination direction and the inclination angle of the character line to the scanning direction on a basis of the output from a line detecting circuit 4. A line dividing calculator 7 calculates coordinates of division points in accordance with this detected inclination angle. The visual field controlling circuit 5 offsets the visual field of the photoelectric transducer 2 in the form feed direction at coordinates of division points of the character line in accordance with the detected inclination angle.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for inputting a pattern by scanning a horizontally written form with a photoelectric converter in the row direction using an optical character reading device or the like.
The present invention relates to a line reading device with a reduced memory capacity.

A conventional optical character reading system will be explained with reference to FIG. In Figure 1, form 1 has many lines of horizontally written characters.
．． A2. ...It is written by printing or handwriting, and at the left end of this form 1, each character line A, , A2
．． A line mark C1 indicating the approximate center position in the width direction of...
C2, . . . are each character line A, , A2. ... are marked correspondingly. When this form 1 is set in the reading device, the character lines A, , A, ,...
・It is sent in the Y direction almost perpendicular to . Form 10 line mark C
A photoelectric converter 2 composed of a plurality of (for example, (m+1) photodiode arrays from 0 to Ym) is placed at a position where it can read 1°C2, . is the predetermined height, i.e. the size of the field of view)
It has MY, width, and depth. When feeding the form 1 in the Y direction, when the line mark corresponding to the character line to be extracted matches the center position Y of the photoelectric converter 2, the feeding of the form 1 is stopped, and then the line mark corresponding to the character line to be extracted matches the center position Y of the photoelectric converter 2. , photoelectric converter 2 in the X direction
scan and read a line of characters. The photoelectric conversion signal of the character line pattern read by the photoelectric converter 2 is stored in a line buffer memory 3 connected to the photoelectric converter 2.

Like the photoelectric converter 2, this line buffer memory 3 also has elements in three directions: height, ie, X address), M1 width (ie, X address), and depth. Normally, the field of view size MY of the photoelectric converter 2 is set larger than the height (X address) M of the line buffer memory 3.

In such a character reading method, it would be ideal if the direction of the character line to be read always coincided with the scanning direction X of the photoelectric converter 2. In this case, only the width B of the character line should be scanned. Therefore, the height MY of the photoelectric converter and the height M of the line buffer memory are minimized, and the capacity of the line buffer memory 3 is also minimized.

However, each character line A, , A, , to form 1
The direction of the text lines and the photoelectric converter may vary due to reasons such as how to print or handwrite, how to cut the form 1 with the text lines written on it, how to set the form 1 on which the text lines have been written into the reading device, etc. In many cases, an inclination occurs with respect to the scanning direction X of No. 2.

Furthermore, even in the same form, the line direction may change for each character line written, and in this case also, an inclination occurs.

Now, if the angle of this inclination is θ upward to the right (the same applies to the case upward to the left), and the length of the character line is L, the field of view My of the photoelectric converter 2 is My = L 5iIIθ + Bcosθ ・−
----<1), and accordingly, the height M (the number of X addresses) of the line buffer memory 3 must also be increased. In the conventional method, the field of view of the photoelectric converter 2 and the number of X addresses of the line buffer memory 3 are set in advance to be thicker than the minimum width B of the character line, taking into account a certain degree of inclination of the character line. However, if this set value is small, it is not possible to read a character line with a larger inclination angle and store it in the line buffer memory 3.

Therefore, if the set value is increased according to the maximum possible tilt angle, the line buffer memory 3 will have a large capacity, and the amount of memory that is not used will increase, so the mechanical loss of the photoelectric converter 2 will increase. However, there is a drawback that the efficiency of using the line buffer memory 3 is reduced.

The purpose of the present invention is to eliminate the drawbacks of these conventional devices.The purpose of the present invention is to detect the direction and amount of inclination of character lines on a form with respect to the scanning direction of a photoelectric converter, and to convert the characters according to the detected amount. By dividing lines and storing them in line buffer memory, line memory is used efficiently and economically.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, the line reading device of the present invention includes a photoelectric converter 2
, line buffer memory 3, center position Y of photoelectric converter 2
, set the field of view of the line detection circuit 4 and photoelectric converter 2 that detect the line mark of the character line to be read, and set the field of view to Y.
A field of view control circuit 5 that offsets in the direction, a tilt angle detection circuit 6 that detects and calculates the tilt angle and tilt direction of a character line, and coordinates for dividing the character line and offset of the photoelectric converter 2 according to the tilt angle of the character line. The line division calculator 7 determines the amount, the memory table 8 stores the coordinates of division points and the amount of offset, and the line buffer memory 3 also corrects the character pattern to be read out according to the coordinates and offset amount of the memory table 8. The pattern normalization circuit 9 to
They are connected and configured as shown in the figure, and their output (that is, the output of the pattern normalization circuit 9) is sent to the next OCR system.

Next, the operation will be explained.

In FIGS. 1 and 2, while the form 1 is being sent in the Y direction, the row detection circuit 4 receives the output of the photoelectric converter 2, and marks the line (for example, C1
) is detected, and when the character line A1 corresponding to this line mark C1 is exactly at this center position Y1, the feeding of form 1 is stopped. Then, in synchronization with the X (line) clock Cx, the photoelectric The converter 2 is moved in the X direction, scans the character line A, and sends the photoelectric conversion signal of the field of view to the line buffer memory 3.

When the row detection circuit 4 detects the row mark C1, it starts the visual field control circuit 5, resets the visual field control register (not shown) in the visual field control circuit 5 to the initial value, and sets the initial value and the Y (width) clock Cy. Based on the height of the field of view of 20 character lines of the photoelectric converter, Y2~(Y, +
K), and the photoelectric conversion signals of the character patterns within the viewing range begin to be stored in the line buffer memory 3. The size of the field of view in one direction of the photoelectric converter (K+1) set by the field of view control circuit 5 matches the number of X addresses of the line buffer memory 3. The line buffer memory 3 stores each (K+1) photoelectric conversion signal in correspondence with one X address.

The tilt angle detector 6 converts the output of the visual field control circuit 5 into Y
Start detecting the distribution of black dots by projecting it onto the axis, and when you have counted the passage of X clocks Cx equivalent to an appropriate fraction (for example, 1/6) of the length of the character line, the distribution of black dots and the X clock Cx Information indicating the inclination direction and inclination angle .theta. of the character line A being read and scanned is calculated from the count value of , and this information is provided to the line division calculator 7.

The line division calculator 7 also calculates whether the transmitted inclination angle θ and the height M of the line buffer memory 3 should be divided, and further calculates the length l in the X direction at which the character pattern information overflows. -1 . . . (3) (However, this l is a length with a margin) to predict and determine the X coordinates X, , X, , . . . to be divided. However, in the first section of this division, the character line starts from approximately the center position in the Y direction and continues at an inclination angle θ.
The length is -l, and each section after the second section has a length of l. The line division calculator 7 calculates the calculated X coordinate value X, ,
X2. . . . When the values obtained by counting the passage of the X clock Cx match, a planned amount R for offsetting (moving) the photoelectric converter 2 in the Y direction is given to the visual field control circuit 5, and according to the inclination direction of the character line, The value of the register (not shown) in the visual field control circuit 5 is set to be added (when the character line is on the upper right side) or subtracted (when the character line is on the upper left side)', and the visual field of the photoelectric converter 2 is set to It is offset by the planned amount R in the same direction as the feed direction Y (in the case of upward movement to the right) or in the opposite direction (in the case of upward movement to the left).

Even after the photoelectric converter 2 is offset, the size of the field of view in the Y direction of the field of view control circuit 5 is the same as before offset.
(K1i), and in the line buffer memory 3, each (K+l) photoelectric conversion signal is stored in correspondence with each X address.

As a result, the character pattern A is divided and stored in the line buffer memory 3, as shown in FIG.

Note that if the inclination angle θ of the character line A is small and the number of divisions N calculated by equation (2) is less than 1/2, the character line A1 is not divided as shown in Figure 4. , one stroke portion are successively stored in the line buffer memory 3.

The coordinates of these division points X, , For character reading, when the character pattern divided and stored in the line buffer memory 3 is read out to the pattern normalization circuit 9 in amounts equivalent to one character at a time, the division point coordinates of the memory table 8 are . . . and the planned offset amount 10R are also given to the pattern normalization circuit 9,
The pattern normalization circuit 9 corrects the X coordinate value for each divided section of the character pattern and then normalizes it. Through this normalization, it is possible to reproduce a continuous character pattern substantially parallel to the Y axis, and this is sent to the next OCR system for character recognition or the like.

As explained above, according to the present invention, the inclination direction and inclination angle of a character line to be read on a form with respect to the scanning direction of a photoelectric converter are detected, and the character pattern is detected while offsetting the field of view of the photoelectric converter accordingly. Since the image is divided and stored in the line buffer memory, the size of the field of view of the photoelectric converter and especially the capacity of the line buffer memory can be reduced (up to 1/the number of divisions), and the line reading device It is possible to achieve smaller size, lower price, and power saving. In addition, even if the inclination angle of the character line is large, the character line can be read easily and reliably, so there is no need to take care to adjust the form to the line reading device so that the character line and the scanning direction match. This makes handling and operation of the device easier. Furthermore, since the same form is read while detecting the inclination of each character line, even forms with changes in the inclination of each character line can be easily and accurately read, and dummy scanning is not required. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the outline of a conventional line reading device and the present invention, FIG. 2 is a block diagram of the device of the present invention, and FIGS. 3 and 4 show character patterns written in the line buffer memory according to the present invention. FIG. 1... Ledger, 2... Photoelectric converter, 3...
・Line buffer memory, 5... Visual field control circuit, 6... Tilt angle detection circuit, 7... Line division calculator, 8...
...Memory table, 9...Pattern normalization circuit, A4, A2 r...Character line, R...Offset amount, X...Scanning direction, X, , X,, ,...
Dividing point coordinates, Y... feed direction, θ... tilt angle. Patent applicant Oki Electric Industry Co., Ltd. Nippon Telegraph and Telephone Public Corporation Patent application agent Megumi Yamamoto -

Claims (1)

[Claims] Charging conversion of a character pattern read by scanning a form with many character lines written on it in a direction almost perpendicular to the character lines and scanning the character lines with a photoelectric converter. In a line reading device that stores signals in a line buffer memory, a tilt angle detection circuit detects a tilt direction and a tilt angle of the character line with respect to the scanning direction;
a line division calculator that calculates the dividing point coordinates of the character line according to the detected inclination angle; and a line division calculator that calculates the dividing point coordinates of the character line according to the detected inclination direction; A line reading device comprising: a field of view control circuit that offsets in a form feeding direction.