JPH04361473A - Original reader - Google Patents

Abstract

PURPOSE:To easily correct a tilt of an original on an original platen by detecting an edge of the original with an area image sensor and displaying the detected edge coordinate on an LCD. CONSTITUTION:An area image sensor 4 able to scan the entire original face in a short time is provided to an original reader. The scanning signal read by the sensor 4 is converted into a digital signal at a binarizing circuit 6 and an original edge detection circuit 8 generates an edge coordinate data. The data is sent to an LCD 9, on which the data is displayed as an edge coordinate data. The operator checks the tilt of an original by the edge coordinate data displayed on the LCD 9.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an image scanner,
The present invention relates to a manuscript reading device for reading manuscripts containing photographs, characters, etc. in a copying machine or the like.

0002

[Prior Art] In conventional document reading devices such as image scanners and copying machines, the only way to place a document on the document table without tilting it is to carefully place the document by the operator's eye. Ta. However, this installation method takes time and is almost impossible to install completely without tilting.

0003

[Problem to be Solved by the Invention] With the conventional document reading device as described above, it is almost impossible to quickly set up the document without tilting it, and when used for image input of a character recognition device. However, due to the inclination of the manuscript, the character recognition rate decreased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an original reading device that allows originals to be placed without tilting.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an area image sensor that can scan the entire surface of a document in a short time, and a binarization means that binarizes the sensor output. , a document edge detection circuit, and an LCD.

[0006]

[Operation] According to the present invention, with the above-described structure, the original can be placed without being tilted.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view schematically showing a document reading apparatus according to an embodiment of the present invention. As shown in the figure,
An area image sensor 4 capable of scanning the entire surface of a document in a short time is provided to detect edges of a document 10 in a short time. Further, the detected edge coordinates are displayed in real time along with the movement of the document 10 on an LCD 9 installed at the top of the apparatus.

FIG. 2 is a block diagram of the document reading device of this embodiment. In FIG. 2, 1 is a photoelectric conversion element that converts an optical signal obtained by optically scanning a document into an electrical signal;
, 5 is an amplifier circuit that amplifies the electrical signal, and 3 and 6 are amplifier circuits that compare the electrical signal with a certain reference level and convert it into binary values of black and white.
digitization circuit, 7 is a control circuit that controls the entire circuit,
4 is an area image sensor capable of scanning the entire surface of the document in a short time; 8 is a document edge detection circuit that detects the coordinates of two points on the top of the document; and 9 is an LCD. First, the operation when placing a document will be explained. When a document is placed on the document table by an operator, the area image sensor 4 scans the entire surface of the document, converts the signal into a digital signal in the binarization circuit 6, and sends it to the document edge detection circuit 8. send. The document edge detection circuit 8 detects edges based on the digital signal, and sends edge coordinate data to the LCD 9. The LCD 9 displays the edge coordinate data. The operator checks the edge coordinate data displayed on the LCD 9,
If the document is tilted, move the document and set the document so that it is not tilted while watching the display on the LCD 9. In this embodiment, the time required to move the original and display the edge coordinates on the LCD is several tens of milliseconds, and the movement of the original can be displayed in real time. Next, a normal reading operation will be explained. The image data converted into an electrical signal by the photoelectric conversion element 1 is amplified by the amplifier circuit 2, and compared with a predetermined reference voltage by the binarization circuit 3, converted into black and white binary data, and the resulting binary image is Output data.

FIG. 3 is a block diagram of the document edge detection circuit 8. As shown in FIG. The document edge detection operation will be described below with reference to FIG. 4, which shows the positions of edge coordinate data. Figure 4
As shown in , first, as the edge coordinate data of the document,
4 points on the edge of the document (41, 42, 43, 44 in the diagram)
Detect. Next, in order to detect the direction of inclination of the document, the Y coordinate sizes of points 41 and 42 are compared. As a result, when the point 42 is larger, the slope is as shown in FIG. 4(A), and when the point 41 is larger, the slope is as shown in FIG. 4(B). When the slope is as shown in (A), the coordinates of points 41 and 44 are output, and when the slope is as shown in (B), the coordinates of points 43 and 42 are output.

The circuit operation will be explained below with reference to FIG. 11 is a horizontal dot counter that counts the X coordinate, 12 is a vertical dot counter that counts the Y coordinate, and 13 and 14 are X counters that temporarily store the coordinates of white pixels.
These are a coordinate register and a Y coordinate register. First, when the image data sent from the binarization circuit 6 is a white pixel,
It is stored in the X coordinate register 13 and Y coordinate register 14, and the value at this time is compared with the respective values of the X coordinate 41 register 15, the X coordinate 42 register 17, and the Y coordinate 43 register 20. When the value is smaller than the X coordinate 1 register 15, the value at that time is stored in the coordinate 41 register. When the value is larger than the X coordinate 42 register 17, the value at that time is set to the coordinate 42.
Store in register. When it is smaller than the Y coordinate 43 register 20, the value at that time is stored in the coordinate 43 register. When it is the same as the Y coordinate 43 register, the value at that time is stored in the coordinate 44 register. By this operation, when scanning of the original is completed, the coordinate data shown in FIG. 4 is stored in the coordinate 41 register, coordinate 42 register, coordinate 43 register, and coordinate 44 register, respectively. Next, Y
Compare the value of the coordinate 1 register and the value of the Y coordinate 2 register. As a result, when Y coordinate 2 is large, the values of coordinate 1 register and coordinate 4 register are selected and output by the selector, and Y
When coordinate 1 is large, the values of coordinate 3 register and coordinate 2 register are selected and output by the selector.

As described above, according to the document reading apparatus according to the embodiment of the present invention, the edge coordinates of the document are depicted on the LCD, so that the document position can be easily corrected.

Although the display device of the present invention has been described as an LCD in this embodiment, it is not limited to this, and may be any device having an image display function, such as a plasma display, an electroluminescent display, or a CRT. device is available.

[0014]

[Effects of the Invention] As is clear from the above embodiments, according to the present invention, when performing character recognition, an image without tilt can be obtained, so that the character recognition rate can be improved. Readers can be provided.

[Brief explanation of drawings]

FIG. 1 is a perspective view schematically showing a document reading device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a document reading device according to an embodiment of the present invention.

FIG. 3 is a block diagram of a document edge detection circuit in an embodiment of the present invention.

FIG. 4 is a schematic diagram showing the position of edge coordinate data output by the document reading device of the present invention.

[Explanation of symbols]

4 Area image sensor 6 Binarization circuit 8 Original edge detection circuit 9 LCD

Claims (1)

[Claims] 1. An area image sensor that scans a document and outputs an electrical signal; a binarization device that binarizes the electrical signal output; and an edge coordinate of the document from the output of the binarization device. What is claimed is: 1. A document reading device comprising: document edge detection means for detecting the edge coordinates; and a display device for displaying the edge coordinates.