JPH05110779A - Original recognition device - Google Patents

Abstract

PURPOSE:To accurately identify an original area by providing a platen cover with three color patterns arranged thereon according to a prescribed rule so as to discriminate a read color pattern. CONSTITUTION:Three-primary color (red, green, blue) dot patterns as color arrangement patterns for a back platen 2 of a platen cover 1 are arranged sequentially periodically in the main scanning direction and the subscanning direction. A comparison discrimination means 11 compares a hue of color picture information read sequentially by an original information read means 10 with that of reference signals R, G, B to detect a color difference between the color picture information and each of the three primary colors (red, green, blue) and discriminates the color picture information to be resident in an original area when a color difference is detected even from any of the three primary colors. Based on a color pattern of the picture information read in this way, since the original area is discriminated, the original area is accurately and surely recognized regardless of the various densities or the color of the original.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document recognition apparatus suitable for a copying machine capable of full-color printing, and more particularly, to accurately recognize a document position and a document size regardless of the color and color density of the document. Document recognition device.

[0002]

2. Description of the Related Art In recent years, so-called digital full-color copying machines have come into widespread use, in which original information is read by a full-color sensor, converted into electric signal image information, and full-color printed.

Further, in such a digital copying apparatus, a document recognition function for detecting the position and size of a document placed at an arbitrary position on the platen glass and selectively printing out only document information. Devices with are emerging.

Conventionally, in this type of document recognition function, as described in, for example, Japanese Patent Laid-Open No. 63-280569,
The platen glass side of the document pressing plate (platen cover) (hereinafter referred to as the back platen) is colored with a specific color, and a filter that cuts the reflected light from this back platen is provided. The position of the document is recognized based on the light emitted, that is, the reflected light from the document.

Further, in Japanese Patent Laid-Open No. 63-41842, the back platen is used as a mirror surface so that the background is black except for the document position, and the document position is detected by detecting the density change of the image information detected by the CCD. A method of recognition is disclosed.

Further, in Japanese Unexamined Patent Publication No. 1-106570, the back platen is made black so that the background is black except for the document position, and the document position is recognized by detecting the density change of the image information detected by the CCD. The method of doing is disclosed.

[0007]

However, in such an original recognition method, since the reflected light is detected by using the black-and-white image sensor, even if the original and the platen cover have different hues, both are black and white. If the shades of the image are close to each other, the two cannot be distinguished from each other, and the original area cannot be accurately recognized.

Further, when copying a thick material such as a book, the platen cover cannot be closed and the back platen cannot be brought into close contact with the platen glass.
Therefore, there is a problem that the focus of the CCD is deviated and the reflected light from the back platen cannot be obtained, so that the original area cannot be accurately recognized.

A first object of the present invention is to solve the above-mentioned problems of the prior art so that regardless of the color or shade of the original,
An object of the present invention is to provide a document recognition device that can accurately recognize a document area.

A second object of the present invention is to provide an original document recognition device which can accurately recognize the original document area even when the platen cover is open.

[0011]

In order to achieve the above-mentioned object, according to the present invention, an original document recognizing apparatus for recognizing an original area based on reflected light of light emitted to an original and a back platen is as follows. It is characterized by taking various measures. (1) A platen cover in which three-color patterns are arranged according to a certain rule in the main scanning direction and the sub-scanning direction of the back platen, and the light reflected from the back platen and the original is optically read and converted into color image information. The original information reading unit, the determination unit that determines whether or not the color image information corresponding to the three colors on the back platen is detected according to the predetermined rule, and the color image information that is out of the predetermined rule. An original area identifying unit that determines the area as an original area when detected is provided. (2) Open / close detection means for detecting the open / closed state of the platen cover, original information reading means for converting the reflected light from the back platen and the original into color image information, and monochrome for converting the color image information into image information of a black and white image Conversion means and original area identification means for identifying the original area based on the color image information when the platen cover is closed, and for identifying the original area based on the black and white image information when the platen cover is open. Equipped.

[0012]

According to the above configuration (1), outside the original area,
As the color image information, the color pattern arranged on the back platen according to a certain rule is detected, and the color pattern arranged according to the certain rule is not detected in the original area. Therefore, by determining the color pattern of the read color image information, the original area can be accurately identified regardless of the lightness or color of the original.

According to the above configuration (2), when the platen cover is in the open state, the original area is identified not by the color image information but by the shade of the image information of the black and white image. However, the original area can be accurately identified.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing a color arrangement pattern of a back platen 2a of a platen cover 1 according to a first embodiment of the present invention. In this embodiment, a red color having a diameter of 0.2 to 5 mm,
Dot patterns of the three primary colors of green and blue are periodically and sequentially arranged in the main scanning direction and the sub scanning direction.

FIG. 2 is a view showing a color arrangement pattern of a back platen 2b which is another embodiment of the present invention. In this embodiment, there are three primary colors of red, green and blue having a width of 0.5 to 5 mm. Line-shaped patterns are sequentially arranged in the main scanning direction and the sub scanning direction at a predetermined angle (for example, 45 °) in sequence.

FIG. 3 is a functional block diagram of the original document recognition function of the present invention for recognizing the original document area based on the reflected light of the light applied to the original document 3 and the back platen 2.

The document information reading means 10 optically reads the reflected light 4 from the back platen 2 of the platen cover 1 and the document 3 and converts it into color image information of an electric signal.
The comparing / determining means 11 compares the hue of the read color image information with the reference signals R, G, B in response to the hues of the three primary colors on the back platen 2, and the same hue as the three primary colors on the back platen 2. It is determined whether the image information of is detected by a certain rule.

When the color image information that deviates from the predetermined rule is detected, the original area identifying means 12 determines the area as the original area. The image information extracting means 13 selectively extracts, from the color image information output from the original information reading means 10, only the color image information in the range determined to be the original area by the original area identifying means 12 and the recording means. It outputs to 14.

In such a configuration, the comparison / determination means 11 compares the hue of the color image information sequentially read by the document information reading means 10 with the reference signals R, G, B to obtain the color image information. If a color difference from the three primary colors of red, blue, and green is detected and a color difference is detected between any of the three primary colors, the color image information is determined to be the original area.

When no color difference is detected between any of the three primary colors, the color image information read next is again compared with the three primary colors, and the thus obtained color image information is obtained.
If the detection order of the three primary colors that does not cause color difference is in accordance with the certain rule (that is, the pattern of red, blue, and green),
The color image information is recognized as that of the back platen, and if it does not follow a certain rule, the image information is recognized as that of the document.

According to such an identification method, even if there is the same color as the three primary colors on the back platen in the original, the image information will not be erroneously determined to be outside the original area. ..

In the above-mentioned embodiment, the arrangement pattern of the three primary colors on the back platen is described as the dot pattern (FIG. 1) or the line pattern (FIG. 2), but the present invention is only this. However, the arrangement pattern is not limited to this, as long as the patterns of three different colors are arranged in the main scanning direction and the sub scanning direction of the back platen according to a certain rule. May be.

In each of the above-described embodiments, the patterns of three different colors are red (R), green (G), and blue (B).
However, the present invention is not limited to this, and any three different primary colors may be used.
It may be color.

According to the present embodiment, the original area is identified based on the color pattern of the read image information, so that the original area can be recognized accurately and reliably regardless of the lightness or color of the original. Become.

By the way, with the above-described structure, when the platen cover 1 is not completely closed during copying, such as when copying a book or a thick original, the color arrangement pattern on the back platen 2 can be detected. Since it is not possible, the original area cannot be recognized. Therefore, in the second embodiment of the present invention described below with reference to FIG. 4, the method of identifying the document area is changed according to the opening / closing of the platen cover.

In the figure, the color image information read by the color sensor 41 is input to the color difference determination section 42 and the black and white pixel conversion section 43.

The color difference determining section 42 determines the color difference between the color image information and the reference signals R, G, B. The black and white pixel conversion unit 43 converts color information into image information of a black and white image. The density determination unit 44 determines the density of image information of a black and white image.

The open / close sensor 46 detects the open / closed state of the platen cover 1. When the open / close sensor 46 detects that the platen cover 1 is in the closed state, the document area determination unit 45 determines the document area based on the determination result by the color difference determination unit 42, and determines that the platen cover 1 is in the open state. When detected, the document area is determined based on the determination result by the density determination unit 44.

According to the present embodiment, when the platen cover is in the open state, the original area is identified based on the shading of the image information of the black and white image instead of the color image information.
The original area can be accurately and reliably identified regardless of the open / closed state of the platen cover.

[0031]

As described above, according to the present invention, the following effects can be achieved. (1) Since the original area is determined based on the color pattern of the read image information, the original area can be recognized accurately and reliably regardless of the shade or color of the original. (2) When the platen cover is open, the original area is identified based on the contrast of the image information of the black and white image, not the color image information, so the original area is accurately identified regardless of the open / closed state of the platen cover. become able to.

[Brief description of drawings]

FIG. 1 is a color pattern of a back platen that is an embodiment of the present invention.

FIG. 2 is a color arrangement pattern of a back platen which is another embodiment of the present invention.

FIG. 3 is a functional block diagram of the present invention.

FIG. 4 is a block diagram of a copying machine that is a second embodiment of the present invention.

[Explanation of symbols]

1 ... Platen cover, 2 ... Back platen, 3 ... Original,
4 ... Reflected light, 10 ... Original information reading means, 11 ... Comparison / determination means, 12 ... Original area identification means, 13 ... Image information extraction means, 14 ... Recording means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroshi Hayashi, 3-7-1, Fuchu, Iwatsuki City, Saitama Prefecture, Iwatsuki Plant, Fuji Zerox Co., Ltd. (72) Makoto Watanabe 3-7-1, Fuchu, Iwatsuki City, Saitama Prefecture No. Fuji Xerox Co., Ltd. Iwatsuki Plant (72) Inventor Koji Ymoto Moto 3-7-1, Fuchu, Iwatsuki City, Saitama Prefecture Fuji Zerox Co., Ltd. Iwatsuki Plant (72) Inventor, Takashi Nakajima 3-Chome, Iwatsuki City, Saitama Prefecture 7th-1 Fuji Xerox Co., Ltd. Iwatsuki Office

Claims (4)

[Claims] 1. A document recognition device for recognizing a document area based on reflected light of light emitted to a document and a back platen, wherein patterns of three different colors are provided in a main scanning direction and a sub scanning direction of a back platen. A platen cover arranged according to a certain rule, a document information reading unit that optically reads reflected light from the back platen and a document and converts the reflected light into color image information of an electric signal, and responds to three colors on the back platen. A determination unit that determines whether color image information is detected according to the predetermined rule, and a document area identification unit that determines the area as a document region when color image information that is out of the predetermined rule is detected. A document recognition device comprising: 2. The original according to claim 1, wherein the predetermined rule is that dot patterns of three colors different from each other are periodically arranged in the main scanning direction and the sub scanning direction. Recognition device. 3. The fixed rule is that line-shaped patterns of three different colors are sequentially arranged at predetermined angles in a main scanning direction and a sub-scanning direction. The document recognition device according to Item 1. 4. An open / close detecting means for detecting an open / closed state of a platen cover in an original recognition device for recognizing an original area based on reflected light of light applied to the original and the back platen, and reflection from the back platen and the original. An original information reading unit that optically reads light and converts it into color image information of an electrical signal, a black-and-white conversion unit that converts color image information into image information of a monochrome image, and color image information when the platen cover is closed. An original document identifying device for identifying the original document area based on the image information of the black-and-white image when the platen cover is in an open state.