JPS644387B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a document processing device that processes a document placed on a document table.

Conventionally, image reading devices that scan and read images using an optical system using a solid-state sensor array, etc., unconditionally scan and read a predetermined area, making it difficult to determine the image area within the scanning area. It was difficult. Therefore, the image data that is subsequently captured includes unnecessary parts other than the original, and if the original is not placed in the specified position, the periphery of the image reproduced by a printer etc. may be black or the image may be reproduced diagonally. There were some drawbacks.

The present invention has been made in view of the above points, and includes a document table on which a document is placed, a solid-state scanning element that scans an image of the document placed on the document table, and an output data of the solid-state scanning device. The object of the present invention is to provide a document processing apparatus having a detection means for detecting a plurality of corner coordinates of the document itself on the document table based on the present invention.

Embodiments of the present invention will be described below with reference to the drawings. Figure 1 shows a document placed on the document platen glass.
An image reading device is shown in which the document is held down by a document table cover and a solid-state scanning element is used to scan and read the image of the document through an optical system. is a document, 4 is a scanning area, 5 is a lens, 6 is a sensor array, D ₁ is a main scanning direction, and D ₂ is a sub-scanning direction.

A unique pattern is provided on the surface of the document table cover 2, and means is provided for detecting the position of the document by detecting this pattern when scanning the document. In the illustrated embodiment, this unique pattern consists of a repeating pattern of N bits of pixels printed on the surface of the document table cover 2 at right angles to the main scanning direction. When scanning is performed using the document table cover 2, the repeating pattern described above can be obtained in the main scanning direction in the scanning area other than the document. Therefore,
The digital pixel data obtained by A/D conversion also has a repeating pattern of N bits. In the scanning device installed as described above, up to N types of predicted N-bit pixel patterns are stored in registers, and sequentially compared with the serial pixel data of every N bits obtained by scanning. Only when the pixel data does not match the register, it can be determined that the pixel data is true pixel data.

The principle of detecting the position of a document using the above pattern is shown in a block diagram in FIG.

In the figure, 11, 12, 13 are a document, a lens, a sensor array, 14 is an A/D converter, 1
5 and 16 are registers that can store N-bit serial data, 17 is a maximum of N types of N-bit patterns R1 to RN that can be predicted in advance, and 18 is a comparator that compares registers 15 and 16 with R1 to RN. 19 is a read/write controller, and 20 is a counter.

First, a digital signal obtained by the A/D converter 14 is inputted into the registers 15 and 16 alternately as N-bit serial data by the counter 20 and the read/write controller 19. When N-bit data is input to one register, the other register is set up so that it sequentially compares with up to N types of N-bit patterns set in advance and outputs it. Only the image information of the original can be output by outputting it as pixel data only when it does not match any of the bit patterns, and excluding it as data other than the original when it matches any of the patterns. In the figure,
21 is a gate circuit, from which an image signal output 22 with unnecessary portions erased is obtained. As described above, this apparatus is equipped with a means for determining the position of the original by detecting a unique pattern printed on the original platen cover. Therefore, by detecting the position of the document, it is possible to correct a document that is not placed at a predetermined position, such as if it is tilted.

This embodiment further includes means for correcting the position of the document. Examples thereof will be described with reference to the drawings.

Figure 3 shows a device for storing image data, in which 31 is a document, 32 is a lens, 33 is a sensor array, 34 is an A/D converter, 35 is a minicomputer, and 35A is included therein. A first image memory, 35B a second image memory, 35C a third image memory, and 36 a document position detector. In this device, analog image information obtained by scanning a document 31 is converted into a digital signal by an A/D converter 34, and one is sent directly to a minicomputer 35.
The document position information is stored in the first image memory 35A, and the document position information is stored in the second image memory 35B by the document position detection means 36. At this time, X-Y coordinates are assigned to the addresses of the image memories 35A and 35B as shown in FIG. In Figure 4,
The shaded area is the area other than the original in the scanning area. Second
In the image memory 35B, information for distinguishing between the document portion and other portions is stored in the memory as shown in FIG. The address coordinates of the four points are determined by determining the maximum and minimum of the addresses X and Y of the original portion using a minicomputer from the information in the second image memory 35B. This is shown in FIG. Inclination θ of the manuscript in Figure 5
can be calculated from the coordinates using a minicomputer. If we rotate the coordinate system using θ and let the rotated coordinate system be (X', Y'), then X'Y' = cosθ sinθ sinθ sinθ (Y). Therefore, by converting the address of pixel data using equation (1), the tilt of the document can be corrected. In other words, the pixel data in the first image memory 35A and the second image memory 35B are compared, and if it is original data, the coordinates are converted using the minicomputer using equation (1), and the converted addresses are sequentially stored in the third image memory 35C. If you store it with the camera side up, you can correct the slanted original.

As described above, according to the present invention, multiple corner coordinates of the document itself on the document table are detected based on the output data of the solid-state scanning element that scans the document image. It is possible to recognize the positioning state, and for example, use these coordinates to perform unnecessary data removal, positional deviation correction, etc.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the device of the present invention;
FIG. 2 is a block diagram showing the principle of document position detection according to the present invention, FIG. 3 is a diagram showing a device for storing image data, and FIGS. 4 and 5 are diagrams explaining correction of the document position. DESCRIPTION OF SYMBOLS 1...Original platen glass, 2...Original platen cover, 3...Original, 4...Scanning area, 5...Lens, 6...Sensor array, 11...Original, 12...Lens, 13...Sensor array, 14...A/D converter , 15, 16...Register, 17...N bit pattern, 18...Comparator, 19...Read/write controller, 20
...Counter, 21...Gate circuit, 22...Output, 3
1... Original, 32... Lens, 33... Sensor array, 34... A/D converter, 35... Mini computer, 35
A, 35B, 35C...image memory, 36...document position detection means.

Claims (1)

[Scope of Claims] 1. A document table on which a document is placed; a solid-state scanning element that scans an image of the document placed on the document table; What is claimed is: 1. A document processing device comprising: a detection means for detecting a plurality of corner coordinates of the document itself.