JPH07154594A - Image forming device - Google Patents

Abstract

PURPOSE:To perform a decision with a high accuracy without hindrance to reading of an ordinary source document by deciding whether or not the source document is a special one based on received infrared ray information with an image sensor having sensitivity to the infrared rays. CONSTITUTION:Light of a halogen lamp 103 containing infrared rays is applied to a source document pressing face 101a of a source document press plate 101 and a source document 102 onto a contact glass 201. A reflected light from the face of the source document 102 reaches a CCD image sensor 107 and image information or infrared ray information is received. In this case, the reflected light passes through a source document read filter 105a or an infrared ray detection filter 105b to eliminate light of an undesired area at the time of source document reading or special source document detection. The face 101a absorbs infrared rays and no reflected light is in existence thereon. Furthermore, since an infrared ray absorbing mark 102a in the special source document absorbs infrared rays, no reflected light is in existence. The size of the source document 102 and the position and the size of the mark 102a are recognized depending on the presence of the infrared reflected light to make decision on a special source document.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a function of discriminating special documents such as banknotes and securities, and more particularly, a special document using ink that absorbs or reflects infrared light. The present invention relates to an image forming apparatus having a mechanism for detecting

[0002]

2. Description of the Related Art In recent years, due to improvements in image processing technology and image forming technology, it has become possible to perform image formation so finely that copy bills copied by a color copying machine and actual bills cannot be easily distinguished. For this reason, a device has been developed that determines special documents such as bills and securities, and prohibits illegal copying in the case of special documents. An image forming apparatus equipped with a function of determining a special document in a copying machine. Is also provided.

In such an image forming apparatus, as a method for determining a special document, for example, a method using a pattern matching method as disclosed in Japanese Patent Laid-Open No. 2-83571 "Image recording apparatus" is generally used. In this apparatus, it is determined whether the original is a special original based on the input image data and the pattern data registered in advance.

On the other hand, even in the case of special manuscripts such as bills and securities, in order to make it possible to easily judge them as ordinary manuscripts (manuscripts which are not special manuscripts), ink which absorbs or reflects infrared light One in which a specific mark for determination is formed on a special document has been developed. Corresponding to this, for example, as shown in Japanese Patent Laid-Open No. 4-367082, a special document using ink that simultaneously detects infrared wavelengths by a CCD image sensor and absorbs or reflects infrared light. There is also disclosed an apparatus capable of making the determination.

[0005]

However, according to Japanese Patent Laid-Open No. 4-367082, a special document using an ink that absorbs or reflects infrared light by simultaneously detecting infrared wavelengths with a CCD image sensor. However, since it is necessary to increase the infrared sensitivity of the CCD image sensor, there is a problem in that reading of a normal document is hindered.

On the other hand, when the infrared sensitivity of the CCD image sensor is set to such an extent that reading of a normal document is not hindered, a problem arises in that high-precision determination cannot be performed.

The present invention has been made in view of the above, and it is an object of the present invention to make it possible to make a highly accurate determination without hindering the reading of a normal document.

[0008]

In order to achieve the above-mentioned object, the present invention provides an image forming apparatus having a mechanism for detecting a special document using ink that absorbs or reflects infrared light. Based on the infrared light information input by the image sensor, a light source that irradiates the original with light including the The present invention provides an image forming apparatus provided with a special original document determination means for determining whether or not an original document is a special original document.

The special manuscript judging means detects the manuscript area and the infrared color mark in the manuscript from the infrared light information, and judges whether the manuscript is a special manuscript or not.

In order to achieve the above object, the present invention provides an image forming apparatus having a mechanism for detecting a special document using ink that absorbs or reflects infrared light,
A light source that irradiates a document with light including infrared light, a document pressure plate whose document pressing surface has an infrared reflection color, an image sensor having sensitivity to infrared light, and infrared light information input by the image sensor. Based on the above, there is provided an image forming apparatus provided with a special document determining means for determining whether or not a document is a special document.

The special manuscript judgment means judges the infrared reflected light level by comparing the infrared light information with a plurality of judgment threshold values set in advance, and judges the manuscript area and the red color in the manuscript from the judgment result. The external color mark is detected to determine whether or not the original is a special original. Further, the special document determining means changes a plurality of determination threshold values for determining the infrared reflected light level when the document pressure plate is opened.

[0012]

In the image forming apparatus of the present invention, an original pressing plate whose original pressing surface has an infrared absorbing color is used to press the original, and a light source applies infrared light to the original and the original pressing surface of the original pressing plate. By irradiating, infrared reflected light with a lower reflection level of infrared light outside the original area can be obtained. By inputting this infrared reflected light as infrared light information with an image sensor having sensitivity to infrared light, the infrared light information ( The original area (size) and the position and size of the infrared color mark can be recognized by the presence / absence of infrared reflected light.

Further, in the image forming apparatus of the present invention, an original pressing plate whose original pressing surface has an infrared reflection color is used to press the original, and the light source and the original pressing surface of the original pressing plate contain infrared light. By irradiating with light, infrared reflected light with a higher reflection level of infrared light outside the original area can be obtained. By inputting this infrared reflected light as infrared light information with an image sensor having sensitivity to infrared light, the infrared light information ( With or without infrared reflected light)
The original area (size) and the position and size of the infrared color mark can be recognized.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming apparatus of the present invention will be described below in detail in the order of [Embodiment 1] and [Embodiment 2] with reference to the drawings.

[Embodiment 1] FIG. 1 is a block diagram of an image forming apparatus according to Embodiment 1, in which an original pressing plate 101 whose original pressing surface has an infrared light absorbing color and a light containing infrared light are used as an original. 1
Halogen lamp 103 for irradiating 02, a lamp driving unit 104 for driving the halogen lamp 103, a document reading filter 105a for reading a document, an infrared light detection filter 105b for detecting a special document, A filter driving unit 106 that moves the document reading filter 105a and the infrared light detection filter 105b up and down to switch the filter, and the document 1 that has passed through the document reading filter 105a or the infrared light detection filter 105b.
The reflected light from 02 is received, photoelectric conversion is performed, and R, G,
CCD image sensor 107 for generating B image data
And an A / D converter 1 for converting image data (analog signal) from the CCD image sensor 107 into a digital signal.
08, a shading correction circuit 109 for performing shading correction, and R, G, and B image data after shading correction are input to perform various image processing such as color conversion processing and gradation processing, and Y, An image processing circuit 110 for transmitting as M and C image data, and R and R after shading correction.
Based on a special manuscript determination unit 111 that determines whether the manuscript 102 is a special manuscript by inputting G and B image data and an output prohibition signal of the special manuscript judgment unit 111 described later,
An output prohibition circuit 112 that prohibits output of image data sent from the image processing circuit 110, a printer unit 113 that forms an image on recording paper according to Y, M, and C image data input from the image processing circuit 110, A system controller 114 for controlling each of the above units is provided.

FIG. 2A shows the structure of the optical system of the image forming apparatus according to the first embodiment, and FIG. 2B shows the original pressure plate 101 having the original pressing surface 101a of the infrared absorption color and the infrared light. Documents with absorption marks 102a (here, special documents)
102 is shown.

As shown in FIG. 2A, the light (including infrared light) emitted from the halogen lamp 103 is applied to the original 102 placed on the contact glass 201 and the original pressing surface of the original pressing plate 101. It is irradiated to 101a. In addition,
The document pressing surface 101a of the document pressing plate 101 and the document 10
Since the infrared light absorption mark 102a on 2 absorbs infrared light, the reflected infrared light emitted to this portion disappears.
Next, the reflected light reflected by the surface of the original 102 is reflected by the mirrors 202, 203, 204 and the lens 205 to C
It is guided to the CD image sensor 107 and input as image information or infrared light information. At this time, the reflected light passes through the document reading filter 105a or the infrared light detection filter 105b arranged between the lens 205 and the CCD image sensor 107 to detect the case of reading the document or detecting the special document. Light in unnecessary areas is removed depending on each case. The document reading filter 105a and the infrared light detection filter 105
b is moved up and down as needed by the filter driving unit 106 so that any of the corresponding filters can be moved to the CCD.
It is arranged in the optical path in front of the image sensor 107.

Now, with reference to FIG. 2 (b), the state of reflection and absorption of infrared light on the document pressing surface 101a and the document 102 will be described. On the original pressing surface 101a of the original pressing plate 101, infrared light is absorbed, so that there is no reflected light. Further, when the original 102 is a special original such as a bill, since the contour portion and the background portion of the bill are white, infrared light is reflected to some extent. Further, since the infrared light absorption mark 102a in the bill absorbs infrared light, there is no reflected light. In this way, the area (size) of the original 102 and the position and size of the infrared light absorption mark 102a can be recognized depending on the presence or absence of the infrared reflected light.

Even when the original pressure plate 101 is opened, there is no reflected light from the position of the original pressing surface 101a. Therefore, the area (size) of the original 102 and infrared light absorption are exactly the same. The position and size of the mark 102a can be recognized. In addition, the infrared light absorption mark 102a
If an infrared light reflection mark is used instead of the infrared light reflection mark, the area (size) of the original 102 is changed by making its reflection level different from the original area other than the infrared light absorption mark 102a.
Then, the position and size of the infrared light absorption mark 102a can be recognized.

FIG. 3 shows the photosensitivity of the RGB output of the CCD image sensor 107 when a light source containing infrared light is used,
The characteristics of the original reading filter 105a and the infrared light detection filter 105b are shown. Since the visible light wavelength region of 400 nm to 750 nm is used during normal document reading, the document reading filter 105a causes 750n.
Cut light above m. On the other hand, when infrared light is detected, conversely, the infrared light detection filter 105b causes 750 nm.
Cut the following light. This makes it possible to detect reflected light in the near infrared region and the far infrared region when detecting infrared light.

The operation of the above configuration will be described. In the first embodiment, before reading a document with visible light, a pre-scan is executed to read image data (infrared light information) in the infrared light region, and whether the special document determining unit 111 is a special document. It is to be determined whether or not.

FIG. 4 shows a flowchart of the special document detection routine. First, the system controller 114
During the prescan, the lamp driving unit 104 is controlled to turn on the halogen lamp 103, and at the same time, the filter driving unit 1
06 is controlled to switch to the infrared light detection filter 105b (S401), document scanning is performed, and infrared light information is read by the CCD image sensor 107 (S402).

The infrared light information read by the CCD image sensor 107 is input to the special document determination section 111 via the A / D converter 108 and the shading correction circuit 109. The special document determination unit 111 executes the infrared light level determination process based on the input infrared light information to determine the presence or absence of infrared reflected light (S403), and the region (size) of the document 102, Infrared light absorption mark 10 which is a specific mark
The position and size of 2a are recognized (S404).

Next, the recognized area (size) of the original 102 is compared with the size of the special original stored in advance to determine whether or not the size is the same as the special original (S405). Here, if the size is not the same as the size of the special document, the process proceeds to step S408, and normal copy processing is executed.

On the other hand, it is determined whether or not the specific mark is at a predetermined position based on the position and size of the infrared light absorption mark 102a which is the specific mark (S406). Here, the special manuscript judgment unit 111 judges that the read manuscript 102 is a special manuscript when the specific mark is at a predetermined position, and outputs a copy prohibition signal to the output prohibition circuit 112 and the system controller 114. , Copy prohibition processing is performed (S407). If the specific mark is not at the predetermined position, the process proceeds to step S408, and the normal copy process is executed.

As described above, in the first embodiment, the original pressure plate 1
Since the original pressing surface 101a of No. 01 has an infrared light absorbing color, both the size of the original 102 and the position and size of the infrared light absorbing mark 102a in the original can be easily recognized by detecting the infrared light. Thus, the special document can be determined with high accuracy. Further, even when the original pressure plate 101 is opened, highly accurate determination can be similarly performed with the same configuration.

[Embodiment 2] In Embodiment 2, as shown in FIG. 5, the document pressing surface 501a is replaced with infrared light instead of the document pressure plate 101 whose infrared pressing color is used as the document pressing surface of Embodiment 1. The original pressure plate 501 having a reflection color is used. Further, as shown in FIG. 6, the special document determination section 111 is configured by an infrared light level determination circuit 601 and a recognition determination circuit 602. Note that other configurations are common to those of the first embodiment, and illustration and description thereof are omitted.

FIG. 5 shows a document pressure plate 501 having a document pressing surface 501a of an infrared light reflection color according to the second embodiment, a document having an infrared light reflection mark 502a and a watermark portion 502b (here, a special document). 502 is shown. With reference to the figure, the state of reflection and absorption of infrared light on the document pressing surface 501a and the document 502 will be described.

On the document pressing surface 501a of the document pressing plate 501, infrared light is reflected with a predetermined reflectance. Also, manuscript 5
When 02 is a special document such as a banknote, since the outline and the background of the banknote are white, infrared light is reflected to some extent. Also,
In the bill watermark portion 502b, the total of the reflected light from the watermark portion itself and the reflected light of the transmitted light reflected by the document pressing surface 501a and the light transmitted through the watermark portion 502b again becomes the reflected light. In addition, the infrared light reflection mark 502a in the bill
However, infrared light is reflected with a predetermined reflectance.

Here, if the reflection level of the infrared reflected light at each of the above parts is made different, the determination of each part becomes possible by identifying the reflected light level.

FIG. 7 shows the infrared reflected light levels of the respective parts shown in FIG. 5, and if the thresholds are set to the levels Th1 to Th4 shown by the broken lines in the figure, the judgment of each part becomes possible.

FIG. 8A shows the infrared reflected light level of each part when the document pressure plate 501 is opened. In this case, the reflected light from the document pressure plate 501 disappears and the watermark portion 502 is shown.
The reflected light from b is reduced. To open the original pressure plate 501,
Since it can be easily detected through a pressure plate opening / closing sensor (not shown), when the pressure plate is opened, each part can be determined by changing the threshold value or changing the object to be identified by each threshold value. Specifically, for example, the threshold may be changed to levels Th5 to Th7 indicated by broken lines in FIG. 8B so that the background portion of the document, the watermark portion 502b, and the infrared light reflection mark 501a can be determined.

Therefore, the infrared light level determination circuit 60 of FIG.
In 1, the above-mentioned thresholds are set to judge each part from the infrared reflected light level. Information on the determination result is input to the recognition determination circuit 602. Here, the size of the document area and the mark position are recognized to determine whether or not the document is a special document.

With the above configuration, the flowchart of the special document detection routine of FIG. 4 shown in the first embodiment is similarly executed. However, in this case, in the infrared light level determination processing in step S403, the infrared light level determination circuit 6
In 01, the threshold value is changed depending on whether or not the document pressure plate 501 is opened, and each part is judged from the infrared reflected light level. Further, in step S404, the recognition determination circuit 60
It is assumed that the area (size) of the document 502 and the position and size of the infrared light reflection mark 502a which is a specific mark are recognized by the method 2 described above.

As described above, in the second embodiment, the document pressure plate 5
Since the document pressing surface 501a of No. 01 has an infrared reflection color, both the size of the document 502 and the position and size of the infrared reflection mark 102a in the document can be easily recognized by detecting the infrared light. Thus, the special document can be determined with high accuracy.

Even when the original pressure plate 501 is opened,
By changing the threshold value in the infrared light level determination circuit 601, similarly highly accurate determination can be performed.

[0037]

As described above, the image forming apparatus of the present invention is an image forming apparatus having a mechanism for detecting a special document using ink that absorbs or reflects infrared light, and includes infrared light. A document source based on a light source for irradiating the document with a light source, a document pressure plate with a document pressing surface having an infrared light absorbing color, an image sensor sensitive to infrared light, and infrared light information input by the image sensor. Since the special document determining means for determining whether or not the document is a special document is provided, it is possible to make a highly accurate determination without hindering reading of a normal document.

Further, the image forming apparatus of the present invention is an image forming apparatus having a mechanism for detecting a special document using ink that absorbs or reflects infrared light, and irradiates the document with light containing infrared light. Whether the original is a special original based on the light source, the original pressure plate whose original pressing surface has an infrared reflection color, the image sensor sensitive to infrared light, and the infrared light information input by the image sensor Since the special document determining unit for determining whether or not the document is provided, it is possible to perform high-precision determination without hindering reading of a normal document.

[Brief description of drawings]

FIG. 1 is a block diagram of an image forming apparatus according to a first exemplary embodiment.

FIG. 2A is an explanatory diagram showing the configuration of an optical system of the image forming apparatus of the first embodiment, and FIG. 2B is a document having a document pressing surface of the infrared light absorbing color of the first embodiment. FIG. 6 is an explanatory diagram showing a document (here, a special document) having a pressure plate and an infrared light absorption mark.

FIG. 3 shows the photosensitivity of RGB outputs of a CCD image sensor when a light source including infrared light is used, and the characteristics of a document reading filter and an infrared light detecting filter.

FIG. 4 is a flowchart of a special document detection routine according to the first exemplary embodiment.

5A and 5B are explanatory views showing a document pressure plate having a document pressing surface of an infrared light reflection color and a document having an infrared light reflection mark and a watermark portion (here, a special document) according to the second embodiment. .

FIG. 6 is an explanatory diagram illustrating a configuration of a special document determination unit according to a second exemplary embodiment.

FIG. 7 is an explanatory diagram showing infrared reflected light levels of respective portions shown in FIG.

8A is an explanatory diagram showing the infrared reflected light level of each part when the document pressure plate is opened in FIG. 5, and FIG. 8B is an example of changing the threshold value when the document pressure plate is opened. FIG.

[Explanation of symbols]

 101 Document Platen 101a Document Pressing Surface 102a Infrared Light Absorption Mark 103 Halogen Lamp 104 Lamp Driving Unit 105a Document Reading Filter 105b Infrared Light Detection Filter 106 Filter Driving Unit 107 CCD Image Sensor 111 Special Document Judgment Unit 114 System Controller 501 Document Pressure plate 501a Original pressing surface 502a Infrared light reflection mark 601 Infrared light level determination circuit 602 Recognition determination circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G06T 7/00 G07D 7/00 E H04N 1/00 108 H 9287-5L G06F 15/62 410 Z 9061 -5L 15/70 455 A (72) Inventor Hitoshi Nakamura 1-3-6 Nakamagome, Ota-ku, Tokyo Stock company Ricoh Company (72) Midori Aida 1-3-3 Nakamagome, Ota-ku, Tokyo Share Company Ricoh

Claims (5)

[Claims] 1. An image forming apparatus having a mechanism for detecting a special document using ink that absorbs or reflects infrared light, wherein a light source for irradiating the document with light including infrared light and a red document pressing surface. Special original determination that determines whether the original is a special original based on the original pressure plate having an external light absorption color, an image sensor having sensitivity to infrared light, and infrared light information input by the image sensor And an image forming apparatus. 2. The special document determination means detects the document region and an infrared color mark in the document from the infrared light information, and determines whether or not the document is a special document. The image forming apparatus according to claim 1. 3. An image forming apparatus having a mechanism for detecting a special document using ink that absorbs or reflects infrared light, wherein a light source for irradiating the document with light including infrared light and a red document pressing surface. Special original determination that determines whether an original is a special original based on an original pressure plate having an external light reflection color, an image sensor having sensitivity to infrared light, and infrared light information input by the image sensor And an image forming apparatus. 4. The special manuscript judgment means judges the infrared reflected light level by comparing the infrared light information with a plurality of judgment threshold values set in advance, and judges the manuscript area and the red color in the manuscript from the judgment result. 4. The image forming apparatus according to claim 3, wherein the external color mark is detected to determine whether the original is a special original. 5. The special document determination means changes a plurality of determination threshold values for determining the infrared reflected light level when the document pressure plate is opened.
The image forming apparatus described.