JPH07154595A - Image forming device - Google Patents

Abstract

PURPOSE:To perform decision processing to a special source document without preliminary scanning by reading infrared ray information, at the time of return scanning after reciprocating scanning of source document reading and deciding whether the source document is a special source document based on the received infrared ray information. CONSTITUTION:A read filter 104 is used to implement 1st read scanning. Then an infrared ray filter 105 is used, scanning is implemented at the time of a 1st return and a special source document decision section 111 detects a characteristic 1. After the end of the scanning, the filter 104 is selected and 2nd and 3rd read scannings are made similarly to detect characteristics 2, 3. Then the decision section 111 makes 1st decision as to whether or not the source document 101 is the special source document based on the characteristics 1-3 and when the source document is decided to be the special source document, a printer section 113 performs output inhibit processing. When the result of decision indicates a negative result, a characteristic 4 is detected similarly to the characteristics 1-3, 2nd decision is made and when the source document is decided to be a special one, copy inhibit processing is implemented and when the result indicates a negative result, copying is processed. Thus, the decision is made with high accuracy by plural number of times of read scanning.

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 bills and securities. The present invention relates to an image forming apparatus that executes optical information reading and performs special document determination processing.

[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 Unexamined Patent Publication No. 4-367082, since prescan is performed to determine a special document by infrared light, extra time is required for prescan. However, there is a problem that the copying efficiency is lowered because of the necessity.

[0006] In addition, one prescan and CC
Since the D image sensor detects the infrared wavelength at the same time to determine the special document, it is necessary to increase the infrared sensitivity of the CCD image sensor in order to increase the determination accuracy of the special document. When the determination accuracy is improved by increasing the infrared sensitivity, there is a problem that reading of a normal document is hindered.

The present invention has been made in view of the above, and it is a first object of the present invention to reduce the time required for prescanning and to avoid a decrease in copy efficiency.

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

[0009]

In order to achieve the first object, the present invention provides a light source for irradiating a document with light including infrared light, an image sensor sensitive to infrared light, and visible light. An optical filter for blocking infrared rays and transmitting infrared light; a filter switching means for retracting the optical filter from the optical path during normal document reading; and inserting the optical filter in the optical path during infrared light information reading; and the light source. Infrared light input control means for controlling the image sensor and the filter switching means to execute infrared light information reading during the backward scanning after the document scanning forward scanning and the infrared light input by the image sensor An image forming apparatus provided with a special document determining means for determining whether or not a document is a special document based on information.

In order to achieve the first and second objects, the present invention provides a light source for irradiating a document with light including infrared light, an image sensor sensitive to infrared light, and visible light. An optical filter for blocking and transmitting infrared light; a filter switching means for retracting the optical filter from the optical path during normal document reading; and inserting the optical filter in the optical path for reading infrared light information; Infrared light information reading control means for controlling the image sensor and the filter switching means to execute infrared light information reading at the time of backward scanning after the original scanning forward scanning of each color of R, G, B and BK, There is provided an image forming apparatus provided with a special document determining unit that determines whether or not a document is a special document based on infrared light information input by the image sensor.

The special manuscript judgment means is the R.
For each infrared light information read in the backward scan corresponding to each of G, B, and BK colors, different characteristic parts are used to determine whether the document is a special document.

Further, the special manuscript judgment means is the R.
For each infrared light information read in the backward scanning corresponding to each color of G, B, and BK, it is determined whether or not a special document is a different target region as a determination target region.

In order to achieve the first and second objects, the present invention provides a light source for irradiating a document with light including infrared light, an image sensor sensitive to infrared light, and at least visible light. A plurality of optical filters including an optical filter that blocks infrared rays and transmits infrared light, and when reading a normal document, the optical filters are retracted from the optical path, and when reading judgment information,
Filter switching means for selectively inserting the optical filter into the optical path, the light source, the image sensor, and the filter switching means are controlled to perform original scanning of the R, G, B, and BK colors during the backward scanning after the forward scanning. , It is determined whether or not the original is a special original based on the determination information read control means for selectively reading the determination information by switching the optical filter and the determination information input by the image sensor. The present invention provides an image forming apparatus including a special document determining unit for performing the above.

[0014]

According to the image forming apparatus (Claim 1) of the present invention, the infrared light information is read during the backward scan after the original scan forward scan, and the original is special based on the input infrared light information. By determining whether the document is a document, the special document determination process is performed without performing the prescan.

The image forming apparatus of the present invention (claim 2)
3 and 4) perform infrared light information reading during the backward scan after the original scan forward scan for each color of R, G, B, and BK, and the original is special based on the input infrared light information. By determining whether the document is a document, the special document determination process is performed without performing the prescan. In addition, the R / G
-For each infrared light information read in the backward scanning corresponding to each color of B and BK, it is determined whether or not the document is a special document by using different characteristic portions, and the determination process of the special document is performed a plurality of different times. Alternatively, for each infrared light information read during the backward scan corresponding to each of the colors R, G, B, and BK, it is determined whether a different document on the document is a determination target region, and whether the document is a special document or not. Judgment processing of special documents is performed once.

Further, the image forming apparatus of the present invention (claim 5).
In the backward scan after the original scan forward scan for each color of R, G, B, and BK, a plurality of optical filters are selectively switched to read the determination information, and based on the input determination information. By determining whether or not the original is a special original, the special original determination processing is performed without performing the prescan, and the special original determination processing is performed a plurality of different times.

[0017]

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], [Embodiment 2] and [Embodiment 3] with reference to the drawings.

[Embodiment 1] FIG. 1 is a block diagram of an image forming apparatus according to Embodiment 1, in which light including infrared light is transmitted to an original 1
01, a halogen lamp 102 for driving the halogen lamp 102, a lamp driving unit 103 for driving the halogen lamp 102, a reading filter 104 for reading an original, and an infrared ray by cutting off visible light used when detecting a special original. The infrared light filter 105 that transmits light, the reading filter 104 and the filter driving unit 106 that performs filter switching by moving the infrared light filter 105 up and down, the reading filter 104 or the infrared light filter 105. The reflected light from the original 101 that has passed through the
A CCD image sensor 107 for generating R, G, B image data, and an A / D for converting image data (analog signal) from the CCD image sensor 107 into a digital signal.
A converter 108, a shading correction circuit 109 for performing shading correction, R after shading correction,
An image processing circuit 110 that inputs G and B image data, performs various image processing such as color conversion processing and gradation processing, and sends out as Y, M, and C image data, and an R after shading correction. A special document determination unit 111 that inputs G and B image data and determines whether the document 101 is a special document
And an output prohibition circuit 112 for prohibiting the output of the image data sent from the image processing circuit 110 based on an output prohibition signal of the special document determining section 111, which will be described later, and Y, M, C input from the image processing circuit 110. According to the image data of
A printer unit 113 that forms an image on recording paper and a system controller 114 that controls the above units are provided.

FIG. 2 shows the configuration of the optical system of the image forming apparatus of the first embodiment, and the halogen lamp 102 is arranged as shown in the drawing. The light emitted from the halogen lamp 102 is emitted from the original 101 placed on the contact glass 201.
And the reflected light is reflected by the mirrors 202, 20.
It is guided to the CCD image sensor 107 by 3, 204 and the lens 205 and input as image data.
At this time, the reflected light passes through the reading filter 104 or the infrared light filter 105 arranged between the lens 205 and the CCD image sensor 107 to read visible light or infrared light, respectively. Accordingly, light in unnecessary areas is removed.
It should be noted that the reading filter 104 or the infrared light filter 105 is moved up and down as needed by the filter driving unit 106 so that either of the reading filter 104 and the infrared light filter 105, CC
It is arranged in the optical path in front of the D image sensor 107.

The operation of the above configuration will be described with reference to the operation flowchart of FIG. In the first embodiment, every time the scanner unit (not shown) scans one reading, the printer unit 113 causes four colors of Y (yellow), C (cyan), M (magenta), and BK (black). It is assumed that the image formation is performed for each one of the colors, and the scanner unit performs a total of four scanning scans in order to form a full-color image.

First, using the reading filter 104 as an optical filter, the first reading scan is executed to execute the original 10
One surface is scanned by a carriage (not shown) (S30
1). Next, the optical filter is switched from the reading filter 104 to the infrared light filter 105 (S302), and the output of the CCD image sensor 107 when the carriage returns (that is, the first return scan) determines the special document determination unit 111. , Feature 1 (eg size,
When the carriage reaches the home position for the next reading scan, the optical filter is switched from the infrared light filter 105 to the reading filter 104 (S304).

Then, a second reading scan is executed to scan the surface of the original 101 with a carriage (not shown) (S30).
5). Next, the optical filter is switched from the reading filter 104 to the infrared light filter 105 (S306), and the output of the CCD image sensor 107 when the carriage returns (that is, the second return scan) determines the special document determination unit 111. In step 2, the feature 2 (for example, a specific mark) is detected (S307), and when the carriage reaches the home position for the next reading scan, the optical filter is switched from the infrared light filter 105 to the reading filter 104 ( S308).

Further, the third reading scan is continuously executed to scan the surface of the original 101 with a carriage (not shown) (S309). Next, the optical filter is used as the reading filter 1.
04 to the infrared light filter 105 (S31
0), the special document determination unit 111 detects the feature 3 (for example, the mark detail) from the output of the CCD image sensor 107 (that is, the scan at the time of the third return) when the carriage returns (S311), and the carriage moves next. When the optical pickup reaches the home position for the reading scan of, the optical filter is switched from the infrared light filter 105 to the reading filter 104 (S312).

At this point, the special document determination unit 111 makes a first determination (special document determination) as to whether the document 101 is a special document by using the detected features 1 to 3 (S313). . If it is determined that the document is a special document, the process proceeds to step S319, and the copy inhibition process is executed so that the printer unit 113 does not form a correct image. Specifically, the special document determination unit 111 outputs a copy prohibition signal to the output prohibition circuit 112 and the system controller 114, and the copy prohibition circuit 112 prohibits the image processing circuit 110 from outputting image data to the printer unit 113. . In addition, the system controller 11
Reference numeral 4 instructs each unit to stop the subsequent image forming operation.

On the other hand, when it is determined that the original is not a special original, the fourth reading scan is executed and the surface of the original 101 is scanned by a carriage (not shown) (S314). Next, the optical filter is switched from the reading filter 104 to the infrared light filter 105 (S315), and the output of the CCD image sensor 107 when the carriage returns (that is,
From the fourth return scan), the special document determination unit 111 detects the feature 4 (for example, the mark detail again) (S316), and the detected feature 4 is used to detect the document 101.
The second determination (special document determination) as to whether or not is a special document is performed (S317). If it is determined that the document is a special document, the flow advances to step S319 to execute copy prohibition processing. If it is determined that the original is not a special document, the optical filter is switched from the infrared light filter 105 to the reading filter 104 when the carriage reaches the home position for the next reading scan (S
318), and the process ends.

As described above, in the first embodiment, the infrared light information is input from the output of the CCD image sensor 107 at the time of returning during a plurality of reading scans to determine the special document, so that the prescanning or the like is performed. It is possible to reduce the extra time. In addition, since the features to be determined are switched in the determination of the special document at the time of each return, it is possible to perform the determination with high accuracy by performing the determination a plurality of times using different characteristic portions.

Since the scan speed at the time of return is usually faster than the read scan speed, the image signals at the time of return have different main-scanning and sub-scanning magnifications.
It may be possible that the feature detection / judgment may be hindered, but after the main scanning scaling processing (generally one of the image processings included in the image processing circuit 110) is applied to the magnification according to the return speed It suffices to input to the special document determination unit 111.

Further, in the first embodiment, since the feature is detected at the time of return, the image is input in reverse. Therefore, in order to determine the special document, for example, an image in which the determination pattern of the special document used for the determination is reversed is stored in a memory (not shown) in the special document determination unit 111, or It is necessary to read the judgment patterns from the memory in the special manuscript judgment unit 111 in reverse and compare them.

[Embodiment 2] In the second embodiment, in the same configuration as the first embodiment, the original area is divided into a plurality of areas and the special original determination processing is executed.

FIG. 4 shows an operation flowchart of the second embodiment, which is basically the same as the operation flowchart of the first embodiment shown in FIG. 3, and the common reference numerals indicate the same processing. Only different parts will be described.

First, the original area is divided into three parts, and the feature detection in the area 1 is performed at the time of return after the first reading scan (S401). Similarly, at the time of returning after the second reading scan, the area 2 and the third reading scan are performed. Area 3 on return later
(S402, S403), and based on the result of the feature detection of all the areas (areas 1 to 3), it is determined whether the document is the first special original (special original determination). Further, the characteristic re-detection is performed at the return after the fourth scanning (S404) in the area doubted by the special document determination (S404), and it is determined whether the document is the second special document (special document determination).

As is apparent from the above operation, in the second embodiment, the CCD is returned at the time of return during a plurality of reading scans.
Infrared light information is input from the output of the image sensor 107,
Since the special document is judged, it is possible to reduce extra time such as prescan. Further, since the feature detection areas are switched at each return, the detection / recognition time spent per unit area is longer than that required to detect / recognize all areas at once, which enables highly accurate detection / judgment.

[Third Embodiment] In the third embodiment, at the time of each return, the optical filter is switched each time to detect the feature including the infrared light information.

FIG. 5 shows a block diagram of the image forming apparatus of the third embodiment. The configuration of the third embodiment is basically the same as the configuration of the first embodiment shown in FIG. 1, and common reference numerals indicate the same configurations, and therefore only different portions will be described here.

In the third embodiment, as an optical filter, a reading filter 501 used at the time of reading an ordinary original document and a first color filter 502 which is a color filter which easily detects a characteristic (color) of a specific first special original document. And a second color filter 503, which is a color filter that is easy to detect the characteristic (color) of a specific second special document, and an infrared light filter 504, and the filter driving unit 106 includes: The four filters are moved up and down, and one of them is selectively inserted in the optical path.

FIG. 6 shows an operation flow chart of the third embodiment, which is basically the same as the operation flow chart of the first embodiment shown in FIG. 3, and common reference numerals indicate the same processing. Only different parts will be described.

First, after the first reading scan, the first color filter 501 is switched to (S601), and the characteristic of the first special original is detected at the time of returning after the first reading scan (S601).
602), similarly, after the second reading scan, the second color filter 502 is switched to (S603), and the characteristic of the second special document is detected at the return after the second reading scan (S6).
04), the infrared light filter 50 after the third reading scan
It is switched to 3 (S605), and the feature detection of infrared information is performed at the time of return after the third reading scan (S606). Next, based on the results of all of these feature detections, it is determined whether or not the document is the first special document (special document determination), and the feature detection filter that is determined to be suspicious by the special document determination. (S607), the feature re-detection is performed at the return after the fourth scanning (S60).
8), it is determined whether the document is the second special document (special document determination). In step S607,
A new filter set may be set and new feature detection may be performed in step S608.

As is apparent from the above operation, in the third embodiment, it is possible to reduce extra time such as prescan. Further, since the optical filter is switched at each return, it is possible to easily and highly accurately detect the feature by using the optical filter most suitable for the feature detection of each time.
Furthermore, it is possible to easily and accurately detect a plurality of special originals having different optical characteristics.

In the special manuscript judgment section 111 of the above-mentioned first to third embodiments, all the R, G, B output signals of the CCD image sensor 107 are input, and the special manuscript judgment process is performed for each signal. However, as shown in FIG. 7, only the R signal having the maximum sensitivity to infrared light is input to the special document determination unit 701, and the determination process of the special document is performed using only the R signal. It may be done. In this case, the circuit configuration of the special document determination unit 701 can be simplified.

[0040]

As described above, the image forming apparatus of the present invention includes a light source that irradiates a document with light including infrared light, an image sensor that is sensitive to infrared light, and blocks visible light. An optical filter that transmits infrared light, and when reading a normal document,
The optical filter is retracted from the optical path, and when the infrared light information is read, the filter switching means for inserting the optical filter into the optical path, the light source, the image sensor, and the filter switching means are controlled so that the document reading forward scan is performed. An infrared light information reading control means for reading infrared light information at the time of backward scanning, and a special manuscript for judging whether the manuscript is a special manuscript or not based on the infrared light information inputted by the image sensor. Since the determination means is provided, it is possible to reduce the time required for prescanning and avoid a decrease in copy efficiency.

Further, the image forming apparatus of the present invention, the light source for irradiating the original with light including infrared light, the image sensor sensitive to infrared light, the visible light is blocked and the infrared light is transmitted. An optical filter and a filter switching unit that retracts the optical filter from the optical path during normal document reading and inserts the optical filter into the optical path during infrared light information reading, and controls the light source, the image sensor, and the filter switching unit. Infrared light information reading control means for executing infrared light information reading at the time of the backward scanning after the original scanning forward scanning for each color of R, G, B, BK, and the infrared light input by the image sensor. Since a special document determining means for determining whether or not the document is a special document based on the information is provided,
It is possible to reduce the time required for pre-scan and avoid a decrease in copy efficiency. In addition, high-precision judgment can be performed without any problem in reading a normal document.

Further, the special manuscript judgment means is R / G /
For each infrared light information read in the backward scanning corresponding to each of B and BK colors, different characteristic parts are used to determine whether the original is a special document. It is possible to make an accurate determination.

Further, the special manuscript judgment means is R / G /
Detects and recognizes all areas at once in order to determine whether or not it is a special document by using different areas on the document as the determination target areas for each infrared light information read in the backward scan corresponding to each of B and BK colors. Detection rather than spending per unit area
Since recognition time is long, highly accurate detection / judgment is possible.

Further, the image forming apparatus of the present invention includes a light source for irradiating a document with light including infrared light, an image sensor sensitive to infrared light, and at least blocking visible light and transmitting infrared light. A plurality of optical filters including an optical filter that
When the normal document is read, the optical filter is retracted from the optical path, and when the determination information is read, the filter switching unit that selectively inserts the optical filter into the optical path, the light source, the image sensor, and the filter switching unit are controlled, R ・ G ・
Judgment information read control means for selectively reading the judgment information by selectively switching the optical filter at the time of the backward scan after the document scanning forward scan for each of B and BK colors, and the judgment information input by the image sensor Based on the information,
Since the special document determining means for determining whether or not the document is a special document is provided, it is possible to reduce the time required for the prescan and avoid a decrease in copy efficiency. In addition, high-precision judgment can be performed without any problem in reading 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. 2 is an explanatory diagram illustrating a configuration of an optical system of the image forming apparatus according to the first exemplary embodiment.

FIG. 3 is an operation flowchart of the first embodiment.

FIG. 4 is an operation flowchart of the second embodiment.

FIG. 5 is a block diagram of an image forming apparatus according to a third exemplary embodiment.

FIG. 6 is an operation flowchart of the third embodiment.

FIG. 7 is an explanatory diagram showing an example in which only an R signal is input to a special document determination unit.

[Explanation of symbols]

 102 Halogen Lamp 103 Lamp Driving Unit 104 Reading Filter 105 Infrared Light Filter 106 Filter Driving Unit 107 CCD Image Sensor 111 Special Original Judgment Unit 114 System Controller 501 Reading Filter 502 First Color Filter 503 Second Color Filter 504 Infrared Optical filter

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G06T 1/00 G07D 7/00 E H04N 1/00 108 H 9287-5L G06F 15/62 410 Z 15 / 64 320 D 9061-5L 15/70 455 A (72) Inventor Midori Aida 1-3-6 Nakamagome, Ota-ku, Tokyo 1-chome, Ricoh Co., Ltd. (72) Takusuke Saito 1 Nakamagome, Ota-ku, Tokyo 3-6, Ricoh Co., Ltd.

Claims (5)

[Claims] 1. A light source for irradiating a document with light including infrared light, an image sensor having sensitivity to infrared light, an optical filter for blocking visible light and transmitting infrared light, and at the time of normal document reading. , The optical filter is retracted from the optical path, and when the infrared light information is read, the filter switching means for inserting the optical filter into the optical path, the light source, the image sensor, and the filter switching means are controlled so that the document reading forward scan is performed. Of the infrared light information reading control means for reading the infrared light information during the backward scanning of the document, and the special document for judging whether the document is a special document or not based on the infrared light information inputted by the image sensor. An image forming apparatus comprising: a document determining unit. 2. A light source for irradiating a document with light including infrared light, an image sensor having sensitivity to infrared light, an optical filter for blocking visible light and transmitting infrared light, and a normal document reading time. , R, G, B, by controlling the filter switching means for retracting the optical filter from the optical path and inserting the optical filter in the optical path when reading infrared light information, and the light source, the image sensor and the filter switching means. The original document is special based on the infrared light information reading control means for executing the infrared light information reading at the time of the backward scan after the original document reading forward scan of each color of BK and the infrared light information inputted by the image sensor. An image forming apparatus comprising: a special document determining unit for determining whether or not a document is a document. 3. The special manuscript determination means is the R / G /
3. The image forming apparatus according to claim 2, wherein a different original portion is used for each infrared light information read in the backward scanning corresponding to each of B and BK colors to determine whether or not the original is a special original. 4. The special manuscript determination means is the R / G /
3. The method according to claim 2, wherein it is determined whether or not the document is a special document by using a different region on the document as a determination target region for each infrared light information read in the backward scanning corresponding to each of B and BK colors. Image forming apparatus. 5. A plurality of optics including a light source for irradiating a document with light including infrared light, an image sensor sensitive to infrared light, and an optical filter for blocking at least visible light and transmitting infrared light. A filter, a filter switching unit that retracts the optical filter from the optical path during normal document reading, and selectively inserts the optical filter into the optical path during reading of determination information, and controls the light source, image sensor, and filter switching unit. Then, at the time of the backward scan after the original scan forward scan for each of the R, G, B, and BK colors, the determination information read control means for selectively switching the optical filter to execute the determination information read; An image forming apparatus comprising: a special document determining unit that determines whether or not a document is a special document based on determination information input by an image sensor.