JP2007281791A - Image reading apparatus and image reading method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure the security of originals such as confidential documents. <P>SOLUTION: In the case of reading an image of the original in a fixed reading mode, infrared rays are emitted to a read side of an original, then infrared ray data are acquired on the basis of a result of receiving the infrared ray reflected on the original. Thereafter, identification information is acquired from the obtained infrared ray data, confirmation information, wherein the obtained identification information and personal authentication information of a user are made correspond to each other, is outputted to an external server, and copyright information is obtained from the external server. When the obtained copyright information indicates "presence of copyright", the image reading apparatus emits white light to the read side of the original to acquire visible data on the basis of a result of reception of the white light reflected in the original, and outputs image information obtained resulting from applying prescribed processing to the visible data. On the other hand, when the obtained copyright information indicates "absence of copyright", the image reading apparatus inhibits itself from an acquisition operation of the visible data. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image reading apparatus and an image reading method for reading an image of a document.

2. Description of the Related Art Image reading devices that automatically read image information of a document are used as reading devices such as copying machines and facsimile machines, and scanners for computer input. In this type of image reading apparatus, an image of an original is read by irradiating the original with light using a light source and receiving reflected light reflected from the original with an image sensor.
Recently, in order to distinguish special manuscripts such as banknotes and securities from general manuscripts in response to the heightened security awareness and the trend of digitization, image shapes that absorb or reflect infrared rays on special manuscripts, for example. A technique for forming an invisible image that is difficult to see visually by using a material (ink, toner, etc.) has begun to be adopted. In addition to the special manuscript, a technique for forming an invisible image in which code information such as ID is embedded in the manuscript on which confidential information or the like is formed as a visible image by using the image forming material is also considered. ing.

  For this reason, image reading apparatuses are also required to read infrared images in addition to reading visible images. In response to such a request, an infrared light reflecting mirror that transmits visible light and reflects infrared light is provided in an optical path that guides reflected light from a document to a sensor for reading a visible image. A technique for providing an infrared image reading sensor that receives reflected light (infrared light) from a reflecting mirror has been proposed (see, for example, Patent Document 1). In the image reading device described in Patent Document 1, visible light and infrared light irradiated from a halogen lamp and reflected from an original are separated using an infrared light reflecting mirror, and the visible light is read by a visible image reading sensor. The infrared light is received by an infrared image reading sensor.

Japanese Patent Laid-Open No. 7-23176 (5th page, FIG. 1)

  However, in the method described in Patent Document 1, a visible image and an invisible image (an infrared image formed with infrared absorbing ink) on a document are read simultaneously. Therefore, the visible image is also read until it is determined whether or not the original is a copy-inhibited object based on the obtained infrared image data, and the visible image data is stored in the image reader. Will be captured.

In order to deal with such a problem, in Patent Document 1, when it is determined from the analysis result of the infrared image data that the manuscript is a copy-prohibited object, a measure is taken to prohibit the output of the visible image data acquired so far. I'm taking it.
However, even if such measures are taken, since visible image data is captured to some extent, for example, when the captured visible image data is sucked out, the outflow of visible image data can be suppressed. There was a risk of disappearing.

  The present invention has been made to solve such technical problems, and an object of the present invention is to ensure the security of an original such as a confidential document.

  For this purpose, the image reading apparatus to which the present invention is applied uses the first reading means to irradiate the original with light in the first wavelength region and receive the reflected light from the original, thereby to the original. By reading the first image to be formed, using the second reading means, irradiating the original with light in the second wavelength region different from the first wavelength region, and receiving the reflected light from the original, The formed second image is read. Here, in the image reading apparatus of the present invention, based on the reading result of the first image executed by the first reading means, it is determined whether or not the second reading means is to execute the reading of the second image.

  In such an image reading apparatus, the first reading unit irradiates light in the infrared region as the first wavelength region, thereby reading an invisible image as the first image, and the second reading unit as the second wavelength region. By irradiating light in the visible region, a visible image can be read as the second image. In this case, the image processing apparatus further includes an acquisition unit that acquires identification information included in the invisible image read by the first reading unit, and the determination unit performs determination based on the identification information acquired by the acquisition unit. Can be a feature. Further, it may further include a moving means for moving the document relative to the first reading means and the second reading means.

  From another viewpoint, the image reading method to which the present invention is applied includes a step of reading an invisible image formed on a document by irradiating the document with infrared light and receiving reflected light from the document. And a step of acquiring identification information included in the invisible image from the reading result of the invisible image, and a step of reading the visible image formed on the document after acquiring the identification information in the step.

  Here, between the step of acquiring the identification information and the step of reading the visible image, a step of determining whether reading of the visible image formed on the document is permitted based on the acquired identification information. Further can be included. Then, when it is determined in the determining step that reading of a visible image is permitted, in the step of reading the visible image, the document is formed by irradiating the document with visible light and receiving reflected light from the document. Visible image can be read. Further, it may further include a step of prohibiting the reading of the visible image when it is determined that the reading of the visible image is not permitted in the determining step.

  According to the present invention, it is possible to ensure the security of a document such as a confidential document.

The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a diagram illustrating a configuration example of an image reading apparatus to which the exemplary embodiment is applied. In this image reading apparatus, it is possible to read an image of a fixed original and also to read an image of a conveyed original. The image reading apparatus includes a document feeding device 10 that sequentially conveys documents from a stack of stacked documents, and a reading device 50 that reads an image by scanning. Further, a CIS (Contact Image Sensor) unit 60 is provided inside the document feeder 10.

  The document feeder 10 includes a document tray 11 on which a bundle of documents composed of a plurality of documents is stacked, and a paper discharge tray 12 that is provided below the document tray 11 and stacks documents that have been read. In addition, the document feeder 10 includes a nudger roll 13 that takes out and conveys documents from the document tray 11. Further, on the downstream side of the nudger roll 13 in the document conveying direction, there is provided a mechanism 14 for separating sheets one by one by a feed roll and a retard roll. A pre-registration roll 15, a registration roll 16, a platen roll 17, and an out-roll 18 are provided in order from the upstream side in the document conveyance direction in the first conveyance path 31 through which the document is conveyed. The pre-registration roll 15 conveys the originals that have been rolled up one by one toward the downstream roll and forms a loop of the originals. The registration roll 16 rotates and temporarily stops, then restarts at the same timing, and supplies a document while performing registration adjustment on a document reading unit to be described later. The platen roll 17 assists document conveyance during reading by the reading device 50. The out roll 18 conveys the document read by the reading device 50 further downstream. A second transport path 32 for guiding the document to the paper discharge tray 12 is provided downstream of the out-roll 18 in the document transport direction. A discharge roll 19 is disposed in the second transport path 32.

Further, in this image reading apparatus, a third transport path 33 is provided between the outlet side of the out roll 18 and the inlet side of the pre-registration roll 15 so that the images formed on both sides of the document can be read in one process. It has been. The discharge roll 19 described above also has a function of reversing and transporting the document to the third transport path 33.
Furthermore, this image reading apparatus is provided with a fourth transport path 34 for reversing the original and discharging it to the paper discharge tray 12 when the original is read on both sides. The fourth transport path 34 is provided on the upper side of the second transport path 32. The discharge roll 19 described above also has a function of reversing and transporting the document to the fourth transport path 34.

  On the other hand, the reading device 50 supports the document feeding device 10 described above so as to be openable and closable, supports the document feeding device 10 by the device frame 51, and reads an image of a document conveyed by the document feeding device 10. Yes. The reading device 50 includes an apparatus frame 51 that forms a casing, a first platen glass 52A on which an original to be read is placed in a stationary state, and a light beam for reading an original conveyed by the original feeding device 10. A second platen glass 52B having an opening is provided.

The reading device 50 is stationary under the second platen glass 52B or scans the entire first platen glass 52A to read an image, and the light obtained from the full rate carriage 53 is input to the imaging unit. A half-rate carriage 54 is provided. The full rate carriage 53 is provided with a first LED (Light Emitting Diode) light source 55 that irradiates light on the document and a first mirror 57A that receives reflected light obtained from the document. Further, the half-rate carriage 54 is provided with a second mirror 57B and a third mirror 57C that provide the light obtained from the first mirror 57A to the imaging unit. Furthermore, the reading device 50 includes an imaging lens 58 and a first image sensor 59. Among these, the imaging lens 58 optically reduces the optical image obtained from the third mirror 57C. The first image sensor 59 photoelectrically converts the optical image formed by the imaging lens 58. That is, in the reading device 50, an image is formed on the first image sensor 59 using a so-called reduction optical system.
Further, a guide 56A for guiding a document conveyed by the document feeder 10 described later is formed between the first platen glass 52A and the second platen glass 52B. A white reference plate 56 extending along the scanning direction is mounted.

  The reading device 50 further includes a control / image processing unit 70. The control / image processing unit 70 performs predetermined processing on document image data input from the first image sensor 59 and a second image sensor 65 (see FIG. 2 described later) provided in the CIS unit 60. The control / image processing unit 70 controls the operation of each unit in the reading operation of the image reading device (the document feeder 10, the reading device 50, and the CIS unit 60).

FIG. 2 is a diagram for explaining the configuration of the CIS unit 60. As shown in FIG. 1, the CIS unit 60 is disposed between the platen roll 17 and the out-roll 18 of the document feeder 10 and at a position facing the guide 56 </ b> A provided in the reading device 50. . The CIS unit 60 is mounted so as to read the document surface on the opposite side (back side) from the document surface read by the reading device 50.
The CIS unit 60 includes a housing 61, a glass 62, a second LED light source 63, a rod lens array 64, and a second image sensor 65. Among these, the glass 62 is attached to an opening formed on the first conveyance path 31 side of the housing 61. The second LED light source 63 irradiates the document with light through the glass 62. The rod lens array 64 collects the reflected light of the irradiation light from the second LED light source 63. The second image sensor 65 receives the light collected by the rod lens array 64. The second image sensor 65 can read an image having an actual width (for example, A4 longitudinal width 297 mm). That is, in the CIS unit 60, an image is captured by the contact optical system using the rod lens array 64 and the second image sensor 65 without using the reduction optical system. Therefore, the structure can be simplified, the housing can be downsized, and power consumption can be reduced.

Now, details of each unit constituting the image reading apparatus will be described.
FIG. 3A is a diagram illustrating an example of the configuration of the first LED light source 55 provided in the reading device 50. As shown in FIG. 1, the first LED light source 55 irradiates the document with light from both sides of the first mirror 57A. The first LED light source 55 includes a rectangular base 91 having an opening at the center, a plurality of white LEDs 92, and a plurality of infrared LEDs 93. These white LEDs 92 and infrared LEDs 93 are alternately arranged along the longitudinal direction, that is, the main scanning direction of the document. As will be described later, the white LED 92 emits white light including red (R), green (G), and blue (B). The infrared LED 93 emits infrared light including infrared (IR).

  FIG. 3B is a diagram illustrating an example of the configuration of the second LED light source 63 provided in the CIS unit 60. As shown in FIG. 2, the second LED light source 63 irradiates the document with light from both sides of the rod lens array 64. The second LED light source 63 includes a rectangular base 95 having an opening at the center and a plurality of white LEDs 96. That is, unlike the first LED light source 55, the second LED light source 63 does not have an infrared LED. The white LED 96 has the same light emission characteristics as the white LED 92 provided in the reading device 50, and emits white light including red (R), green (G), and blue (B).

  FIG. 4 is a diagram showing the wavelength-emission characteristics of the white LED 92 (white LED 96) and the infrared LED 93. As shown in FIG. The white LED 92 (white LED 96) is configured to include a blue-violet light emitting diode having an emission wavelength in the blue region (for example, 405 nm) and a phosphor material of red, green, and blue, and from the blue region (around 400 nm) to green. Light having a wavelength that continues to the red region (near 800 nm) across the region (near 550 nm) is output. However, the white LED 92 (white LED 96) emits little light in the near infrared region (800 nm to 1000 nm) as shown in the figure. On the other hand, the infrared LED 93 is composed of an infrared light emitting diode having a light emission wavelength in the infrared region (center wavelength 850 nm). However, the infrared LED 93 emits little light in the visible region (400 nm to 800 nm) as shown in the figure. Therefore, in this embodiment, the white LED 92 outputs light in the visible region as the first wavelength region, and the infrared LED 93 outputs light in the infrared region as the second wavelength region.

  In this embodiment, the white LED 92 (white LED 96) having the above-described configuration is used. However, the present invention is not limited to this. FIG. 4 also shows the light emission characteristics of a white LED 92 (white LED 96) manufactured by combining a blue LED, a green LED, and a red LED. Thus, it is also possible to generate white light by combining three of the blue LED, the green LED, and the red LED. Even when white light is obtained in this way, there is no emission spectrum in the near infrared region.

  FIG. 5A is a diagram illustrating a schematic configuration of the first image sensor 59 provided in the reading device 50. The first image sensor 59 includes a rectangular sensor board 59a and four line sensors 59B, 59G, 59R, and 59I attached on the sensor board 59a. In the following description, these four line sensors 59B, 59G, 59R, and 59I are referred to as a first blue sensor 59B, a first green sensor 59G, a first red sensor 59R, and an infrared sensor 59I, respectively. The first blue sensor 59B, the first green sensor 59G, the first red sensor 59R, and the infrared sensor 59I are configured by, for example, a CCD (Charge Coupled Device) image sensor or the like. The first blue sensor 59B, the first green sensor 59G, the first red sensor 59R, and the infrared sensor 59I each extend in a direction (main scanning direction) orthogonal to the document transport direction, and They are arranged in parallel in the document transport direction (sub-scanning direction). The first blue sensor 59B, the first green sensor 59G, the first red sensor 59R, and the infrared sensor 59I are each configured by arranging m phototransistors PT in a straight line (main scanning direction). Then, the distance between the first blue sensor 59B and the first green sensor 59G, the distance between the first green sensor 59G and the first red sensor 59R, and the first red sensor 59R and the infrared sensor 59I are respectively in the sub-scanning direction. There are two lines.

  Here, the first blue sensor 59B, the first green sensor 59G, the first red sensor 59R, and the infrared sensor 59I are each equipped with a color filter for transmitting different wavelength components. As a result, the first blue sensor 59B, the first green sensor 59G, the first red sensor 59R, and the infrared sensor 59I are respectively a blue line sensor, a green line sensor, and a red (red) It functions as a line sensor for Red) and a line sensor for infrared (InfraRed: IR).

  FIG. 5B is a diagram illustrating a schematic configuration of the second image sensor 65 provided in the CIS unit 60. The second image sensor 65 includes a rectangular sensor board 65a and three line sensors 65B, 65G, and 65R attached on the sensor board 65a. In the following description, these three line sensors 65B, 65G, and 65R are referred to as a second blue sensor 65B, a second green sensor 65G, and a second red sensor 65R, respectively. The second blue sensor 65B, the second green sensor 65G, and the second red sensor 59R are constituted by, for example, a CCD (Charge Coupled Device) image sensor or the like. Each of the second blue sensor 65B, the second green sensor 65G, and the second red sensor 59R extends in a direction (main scanning direction) orthogonal to the document transport direction, and the document transport direction ( Are arranged in parallel in the sub-scanning direction). The second blue sensor 65B, the second green sensor 65G, and the second red sensor 65R are each configured by arranging n phototransistors PT on a straight line (main scanning direction). The distance between the second blue sensor 65B and the second green sensor 65G, and the distance between the second green sensor 65G and the second red sensor 65R are each two lines in the sub-scanning direction.

  FIG. 6 is a block diagram of the control / image processing unit 70 shown in FIG. The control / image processing unit 70 includes a signal processing unit 71 and a control unit 72. Here, the signal processing unit 71 outputs image data input from the first image sensor 59 (specifically, the first blue sensor 59B, the first green sensor 59G, the first red sensor 59R, and the infrared sensor 59I). Apply processing. The signal processing unit 71 processes image data input from the second image sensor 65 (specifically, the second blue sensor 65B, the second green sensor 65G, and the second red sensor 65R). On the other hand, the control unit 72 controls the operations of the document feeder 10, the reading device 50, and the CIS unit 60.

The signal processing unit 71 includes a first preprocessing unit 100, an infrared postprocessing unit 200, and a first postprocessing unit 300. The signal processing unit 71 further includes a second preprocessing unit 400 and a second postprocessing unit 500.
The first preprocessing unit 100 receives each image data (analog data) input from the first blue sensor 59B, the first green sensor 59G, the first red sensor 59R, and the infrared sensor 59I of the first image sensor 59. Convert to digital data. Further, from the first pre-processing unit 100, image data for invisible images converted into digital data is output to the infrared post-processing unit 200, and image data for visible images is output to the first post-processing unit 300. The
The infrared post-processing unit 200 performs image analysis on the input image data for an invisible image, and extracts and outputs identification information included in the invisible image.
The first post-processing unit 300 performs predetermined image processing on the input image data for visible image, and outputs it as image information.
The second preprocessing unit 400 converts each image data (analog data) input from the second blue sensor 65B, the second green sensor 65G, and the second red sensor 65R of the second image sensor 65 into digital data. . In addition, the second preprocessing unit 400 outputs image data (in this case, all data for visible images) to the second postprocessing unit 500.
The second post-processing unit 500 performs predetermined image processing on the input image data for visible image and outputs it as image information.

On the other hand, the control unit 72 includes a reading controller 81, an image sensor driver 82, an LED driver 83, a scan driver 84, and a transport mechanism driver 85.
A reading controller 81 that functions as a determination unit or an acquisition unit controls the entire document feeding device 10, the reading device 50, and the CIS unit 60 shown in FIG.
The image sensor driver 82 controls the image data capturing operation by the first image sensor 59 (first blue sensor 59B, first green sensor 59G, first red sensor 59R, infrared sensor 59I: see FIG. 5A). To do. Further, the image sensor driver 82 controls the image data capturing operation by the second image sensor 65 (second blue sensor 65B, second green sensor 65G, second red sensor 65R: see FIG. 5B).
The LED driver 83 outputs a lighting switching signal to the first LED light source 55, and controls lighting / extinguishing of the white LED 92 and the infrared LED 93 (see FIG. 3A) in accordance with the document reading timing. Further, the LED driver 83 outputs a lighting signal to the second LED light source 63, and controls lighting / extinguishing of the white LED 96 (see FIG. 3B) in accordance with the document reading timing.
The scan driver 84 controls the scanning operation by the full rate carriage 53 and the half rate carriage 54 by turning on / off the motor in the reading device 50.
The transport mechanism driver 85 controls motor control, various rolls, clutches, and gate switching operations in the document feeder 10.

  These various drivers output control signals to the document feeder 10, the reading device 50, and the CIS unit 60, and based on these control signals, these operation controls are possible. The reading controller 81 sets a reading mode based on a control signal from the host system, a sensor output detected in the automatic selection reading function, a selection from the user via a UI (User Interface), etc. The device 10, the reading device 50, and the CIS unit 60 are controlled. Examples of the reading mode include a fixed reading mode for reading a document placed on the first platen glass 52A, and a conveyance reading mode for reading a document conveyed on the second platen glass 52B by the document feeder 10. . Further, in the conveyance reading mode, there are a single-side mode for reading an image on one side of a document, a double-side mode for reading images on both sides of a document, and the like.

The control unit 72 further includes an authentication unit 86 and a transmission / reception unit 87.
The authentication unit 86 receives an authentication card 90 made of, for example, an IC card, and acquires personal authentication data recorded on the received authentication card 90.
In addition, the transmission / reception unit 87 transmits confirmation information that associates the personal authentication data acquired by the authentication unit 86 with the identification information acquired by the infrared post-processing unit 200 to an external server. Note that this reading information is generated by the reading controller 81. Then, the transmission / reception unit 87 receives the copy right information returned from the external server based on the confirmation information, and passes it to the reading controller 81.

FIG. 7 is a block diagram illustrating configurations of the first preprocessing unit 100, the infrared postprocessing unit 200, and the first postprocessing unit 300 illustrated in FIG.
The first preprocessing unit 100 includes a first analog processing unit 110 and a first A / D conversion unit 120. The first analog processing unit 110 includes the first blue detection data BA0 from the first blue sensor 59B constituting the first image sensor 59, the first green detection data GA0 from the first green sensor 59G, and the first red. The first red detection data RA0 from the sensor 59R and the infrared detection data I0 from the first infrared sensor 59I are independently input. The first blue detection data BA0, the first green detection data GA0, the first red detection data RA0, and the infrared detection data I0 input from the first image sensor 59 are analog data.
The first analog processing unit 110 performs analog correction such as offset gain adjustment on each of the first blue detection data BA0, the first green detection data GA0, the first red detection data RA0, and the infrared detection data I0.
The first A / D converter 120 converts the first blue detection data BA0, the first green detection data GA0, the first red detection data RA0, and the infrared detection data I0 that have been subjected to analog correction into digital data.

The infrared post-processing unit 200 includes an infrared shading correction unit 210 and an identification information analysis unit 220. The infrared post-processing unit 200 receives infrared detection data I0 converted into digital data.
The infrared shading correction unit 210 performs infrared shading correction on the input infrared detection data I0 using the infrared shading data. In the present embodiment, the white reference plate 56B is read by the infrared sensor 59I in a state where the infrared LED 93 is turned on before the reading operation is started. Infrared shading data is acquired in advance based on the reading result.
In the infrared shading correction, the sensitivity variation of the phototransistor PT in the corresponding infrared sensor 59I and the light quantity distribution characteristic of the first LED light source 55 (in this case, the infrared LED 93) with respect to the input infrared detection data I0. Make corrections according to.

  The identification information analysis unit 220 analyzes the identification information from the code image included in the input infrared data IR. Then, the identification information analysis unit 220 outputs the identification information obtained as the analysis result of the code image to the reading controller 81 (see FIG. 6).

On the other hand, the first post-processing unit 300 includes a first visible shading correction unit 310, a first delay processing unit 320, and a first image processing unit 330.
The first visible shading correction unit 310 performs visible shading correction on the input first blue detection data BA0, first green detection data GA0, and first red detection data RA0 using the first visible shading data. Apply. In the present embodiment, the white reference plate 56B is read by the first blue sensor 59B, the first green sensor 59G, and the first red sensor 59R in a state where the white LED 92 is lit before the start of the reading operation. . And based on this reading result, the 1st visible shading data corresponding to each is acquired beforehand.
In the first visible shading correction, corresponding first blue sensor 59B, first green sensor 59G, and first green detection data BA0, first green detection data GA0, and first red detection data RA0 are input. Correction is performed in accordance with the variation in sensitivity of the phototransistor PT in the first red sensor 59R and the light quantity distribution characteristic of the LED light source 55 (in this case, the white LED 92).

  The first delay processing unit 320 corrects a gap due to a difference in attachment positions of the first blue sensor 59B, the first green sensor 59G, and the first red sensor 59R. That is, as shown in FIG. 5 (a), the first green sensor 59G is shifted by two lines in the sub-scanning direction with respect to the first blue sensor 59B, and the first red sensor is shifted with respect to the first green sensor 59G. 59R is shifted by two lines in the sub-scanning direction. Therefore, in the image reading apparatus according to the present embodiment, when a document reading operation is performed, a specific part (main scanning direction line) of the original is first read by the first blue sensor 59B, and then this specific part. Is read by the first green sensor 59G, and finally this specific part is read by the first red sensor 59R. In other words, at the same timing, the first blue sensor 59B, the first green sensor 59G, and the first red sensor 59R each read an image of a portion shifted by two lines in the sub-scanning direction. Become. Therefore, the first delay processing unit 320 uses the first red detection data RA0 from the first red sensor 59R that is read last as a reference, and uses the first green detection data GA0 from the first green sensor 59G as the reference. The first red detection data RA0 is delayed by two lines in the sub-scanning direction, and the first blue detection data BA0 by the first blue sensor 59B is delayed by four lines in the sub-scanning direction with respect to the first red detection data RA0 ( The first green detection data GA0 is delayed by two lines in the sub-scanning direction). Thereby, the first delay processing unit 320 outputs the first blue detection data BA0, the first green detection data GA0, and the first red detection data obtained by reading the same part (the same main scanning direction line) of the document. RA0 is output synchronously.

  The first image processing unit 330 performs various types of image processing on the input first blue detection data BA0, first green detection data GA0, and first red detection data RA0, and outputs first blue image data as image information. BA, first green image data GA, and first red image data RA are output. Examples of processing performed by the image processing unit 330 include γ / gray balance correction, color space conversion, enlargement / reduction, filtering processing, contrast adjustment, and background removal.

FIG. 8 is a block diagram showing the configuration of the second pre-processing unit 400 and the second post-processing unit 500 shown in FIG.
The second preprocessing unit 400 includes a second analog processing unit 410 and a second A / D conversion unit 420. In the second analog processing unit 410, the second blue detection data BB0 from the second blue sensor 65B constituting the second image sensor 65, the second green detection data GB0 from the second green sensor 65G, and the second The second red detection data RB0 from the red sensor 65R is input independently. The second blue detection data BB0, the second green detection data GB0, and the second red detection data RB0 input from the second image sensor 65 are analog data.
The second analog processing unit 410 performs analog correction such as offset gain adjustment on the second blue detection data BB0, the second green detection data GB0, and the second red detection data RB0.
The second A / D conversion unit 420 converts the second blue detection data BB0, the second green detection data GB0, and the second red detection data RB0 that have been subjected to analog correction into digital data.

On the other hand, the second post-processing unit 500 includes a second visible shading correction unit 510, a second delay processing unit 520, and a second image processing unit 530.
The second visible shading correction unit 510 performs visible shading correction on the input second blue detection data BB0, second green detection data GB0, and second red detection data RB0 using the second visible shading data, respectively. Apply. In the present embodiment, a white reference tape (not shown) is affixed to the upper surface of the guide 56 </ b> A arranged to face the CIS unit 60. Then, before starting the reading operation, the white reference tape (not shown) is read by the second blue sensor 65B, the second green sensor 65G, and the second red sensor 65R with the white LED 96 turned on. . And based on this reading result, the 2nd visible shading data corresponding to each is acquired beforehand.
In the second visible shading correction, corresponding second blue sensor 65B, second green sensor 65G, and second blue detection data BB0, second green detection data GB0, and second red detection data RB0 are input. Correction is performed according to variations in the sensitivity of the phototransistor PT in the second red sensor 65R and the light quantity distribution characteristics of the LED light source 63 (in this case, the white LED 96).

  The second delay processing unit 520 corrects a gap due to a difference in attachment positions of the second blue sensor 65B, the second green sensor 65G, and the second red sensor 65R. That is, as shown in FIG. 5B, the first green sensor 59G is arranged to be shifted by two lines in the sub-scanning direction with respect to the first blue sensor 59B, and the first red sensor 59G is shifted from the first green sensor 59G. 59R is shifted by two lines in the sub-scanning direction. Therefore, in the second delay processing unit 520, as in the first delay processing unit 320, the second green sensor is based on the second red detection data RB0 by the second red sensor 65R that is read last. The second green detection data GB0 by 65G is delayed by two lines in the sub-scanning direction with respect to the second red detection data RB0, and the second blue detection data BB0 by the second blue sensor 65B is changed to the second red detection data RB0. On the other hand, it is delayed by 4 lines in the sub-scanning direction (by 2 lines in the sub-scanning direction with respect to the second green detection data GB0). Thereby, the second delay processing unit 520 reads the second blue detection data BB0, the second green detection data GB0, and the second red detection data obtained by reading the same part (the same main scanning direction line) of the document. RB0 is output synchronously.

  The second image processing unit 530 performs various image processing on the input second blue detection data BB0, second green detection data GB0, and second red detection data RB0, and outputs second blue image data as image information. BB, second green image data GB, and second red image data RB are output. The processing performed by the second image processing unit 530 includes, for example, γ / gray balance correction, color space conversion, enlargement / reduction, filtering processing, contrast adjustment, and background removal, similar to the first image processing unit 330 described above. Etc.

  Next, the original image read by the image reading apparatus will be described in detail. In this image reading apparatus, for example, in addition to a document having only a general visible image formed with normal colors such as yellow, magenta, cyan, and black, it is formed with a visible image and a code image including the identification information described above. It is also possible to read a document having an invisible image. Here, “visible” and “invisible” are not related to whether they can be recognized visually. In other words, it distinguishes between “visible” and “invisible” depending on whether an image printed (formed) on a medium (paper) can be recognized by the presence or absence of color development due to absorption of a specific wavelength in the visible light region. It is.

  FIGS. 9A to 9C are diagrams for explaining a two-dimensional code image constituting an invisible image. FIG. 9A is a diagram expressed in a lattice shape to schematically show units of a two-dimensional code image formed and arranged by an invisible image. FIG. 9B is a diagram showing one unit of the two-dimensional code image. Further, FIG. 9C is a diagram for explaining a diagonal line pattern of backslash “\” and slash “/”.

  These two-dimensional code images shown in FIGS. 9 (a) to 9 (c) are formed as invisible images that can be stably read over a long period by machine reading by infrared irradiation and information can be recorded at high density. Is done. Moreover, it is preferable that it is an invisible image which can be provided in arbitrary areas irrespective of the area | region in which the visible image of the medium surface which outputs an image was formed. In the present embodiment, an invisible image is formed on the entire surface of the medium (paper surface) in accordance with the size of the medium to be printed. Further, it is more preferable that the image is an invisible image that can be recognized by a difference in gloss when visually observed. However, “entire surface” does not mean to include all four corners of the paper. In an electrophotographic apparatus such as a laser printer, the end of the paper surface is usually a part that cannot be printed, and therefore it is not necessary to print an invisible image on such part. In this embodiment, it is assumed that the two-dimensional code image is made of a material having an absorption peak at a wavelength near 850 nm that is a near infrared region.

  The two-dimensional code pattern shown in FIG. 9B includes an area in which a position code indicating a coordinate position on a medium is stored and an area in which an identification code for uniquely identifying an electronic document or a print medium is stored. Contains. It also includes an area for storing the synchronization code. Then, as shown in FIG. 9A, a plurality of two-dimensional code patterns are arranged, and two-dimensional information in which different position information is stored on the entire surface of the medium (paper surface) according to the size of the medium to be printed. Cords are arranged in a grid. That is, a plurality of two-dimensional code patterns as shown in FIG. 9B are arranged on one surface of the medium, each of which includes a position code, an identification code, and a synchronization code. In the plurality of position code areas, different position information is stored depending on the place where each area is arranged. On the other hand, the same identification information is stored in the areas of the plurality of identification codes regardless of the place where they are arranged.

  In FIG. 9B, the position code is arranged in a 6-bit × 6-bit rectangular area. Each bit value is formed by a plurality of minute line bitmaps having different rotation angles, and the bit value 0 and the bit value 1 are expressed by the hatched pattern (pattern 0 and pattern 1) shown in FIG. 9C. . More specifically, the bit value 0 and the bit value 1 are expressed using backslash “\” and slash “/” having different slopes. The diagonal line pattern is composed of 8 pixels x 8 pixels at 600 dpi (dot per inch). The diagonal line pattern (pattern 0) that rises to the left has a bit value of 0, and the diagonal line pattern (pattern 1) that rises to the right has bits. The value 1 is expressed. Accordingly, one bit (0 or 1) can be expressed by one oblique line pattern. By using such a minute line bitmap consisting of two types of inclination, the noise given to the visible image is extremely small, and a two-dimensional code pattern that can embed a large amount of information in high density is provided. It becomes possible to do.

That is, a total of 36-bit position information is stored in the position code area shown in FIG. Of these 36 bits, 18 bits can be used for encoding the X coordinate, and the other 18 bits can be used for encoding the Y coordinate. If all 18 bits are used for position encoding, 2 ¹⁸ (about 260,000) positions can be encoded. When each hatched pattern is composed of 8 pixels × 8 pixels (600 dpi) as shown in FIG. 9C, one dot of 600 dpi is 0.0423 mm. The size of the dimension code (including the synchronization code) is about 3 mm (8 pixels × 9 bits × 0.0423 mm) both vertically and horizontally. When 260,000 positions are encoded at intervals of 3 mm, a length of about 786 m can be encoded. In this way, all 18 bits may be used for position encoding, or redundant bits for error detection and error correction may be included when a detection error of a hatched pattern occurs.

The identification code is arranged in a rectangular area of 2 bits × 8 bits and 6 bits × 2 bits, and can store identification information of a total of 28 bits. When using the 28-bit all the identification information can be represented the identity of two ways ²⁸ (about 270 million). Similarly to the position code, the identification code can include redundant bits for error detection and error correction in 28 bits.

In the example shown in FIG. 9C, the two hatched patterns differ in angle by 90 ° from each other. For example, if the angle difference is 45 °, four types of hatched patterns can be configured. When configured in this way, 2-bit information (0 to 3) can be expressed by one oblique line pattern. That is, the number of bits that can be expressed can be increased by increasing the angle types of the hatched pattern.
In the example shown in FIG. 9C, encoding of bit values is described using a hatched pattern, but the selectable pattern is not limited to the hatched pattern. For example, it is also possible to employ a method of encoding by ON / OFF of dots or a direction in which the dot position is shifted from the reference position.

  Now, an original reading operation using the original reading apparatus according to the present embodiment will be described in detail. As described above, this image reading apparatus can execute a fixed reading mode for reading an image of a fixed original and a conveyance reading mode for reading an image of a conveyed original.

(1) Fixed Reading Mode First, the fixed reading mode will be described in detail with reference to the flowcharts shown in FIGS. 1 to 9 and FIG. In the fixed reading mode, the infrared LED 93 and the infrared sensor 59I function as the first reading unit, and the white LED 92, the first blue sensor 59B, the first green sensor 59G, and the first red sensor 59R are the second. It functions as a reading means. In the fixed reading mode, the full rate carriage 53 and the half rate carriage 54 function as moving means.

In the fixed reading mode, first, personal authentication information is acquired (step 101). Specifically, the authentication unit 86 acquires personal authentication information from the authentication card 90 received from the user. Then, the authentication unit 86 reads the acquired personal authentication information and outputs it to the controller 81.
Next, the setting of the original on the first platen glass 52A is detected (step 102). Specifically, for example, an opening / closing operation of the document feeder 10 that is performed when a document is set in the fixed reading mode is detected by a sensor. This detection result is output to the reading controller 81.

Then, the reading controller 81 outputs a control signal to each unit constituting the image reading apparatus to execute infrared prescan (step 103). The infrared prescan is performed as follows, for example.
The reading controller 81 outputs a control signal to the scan driver 84 in response to the detection of the setting of the original on the first platen glass 52 </ b> A. In response to the control signal, the scan driver 84 moves the full rate carriage 53 and the half rate carriage 54 from the home position indicated by the solid line in FIG. 1 to the right end position indicated by the two-dot chain line in FIG. Next, the reading controller 81 outputs a control signal to the LED driver 83. In response to the control signal, the LED driver 83 turns on the infrared LED 93 of the first LED light source 55. At this time, the white LED 92 remains off. Then, the reading controller 81 outputs a control signal to the image sensor driver 82 and the scan driver 84. In response to the control signal, the scan driver 84 moves the full rate carriage 53 and the half rate carriage 54 to the left in FIG. 1 at a constant speed. At this time, the full rate carriage 53 and the half rate carriage 54 move in the scan direction (in this case, the direction opposite to the arrow direction) at a ratio of 2: 1. On the other hand, the image sensor driver 82 receives such a control signal, and starts to receive light reception data by the infrared sensor 59I of the first image sensor 59. The scan driver 84 stops the full rate carriage 53 and the half rate carriage 54 at a position where the reading of the entire surface of the original on the first platen glass 52A is completed. As the full-rate carriage 53 and the half-rate carriage 54 are stopped, the reading controller 81 outputs a control signal to the LED driver 83 to turn off the infrared LED 93, and sends a control signal to the image sensor driver 82. Then, the reception of the received light data by the infrared sensor 59I is terminated.

  During this time, infrared light from the infrared LED 93 is sequentially applied to the lower surface of the document placed on the first platen glass 52A, and reflected light from the document is reflected on the first mirror 57A, the second mirror 57B, and The light is reflected in the order of the third mirror 57C and guided to the imaging lens 58. The light guided to the imaging lens 58 is imaged on the light receiving surface of the infrared sensor 59I. The infrared sensor 59I is a one-dimensional sensor and processes one line at the same time. Then, the full-rate carriage 53 and the half-rate carriage 54 are moved in a direction orthogonal to the line direction (scanning sub-scanning direction) to read the next line of the document. By executing this over the entire document, reading of one page of the document is completed. Further, the infrared detection data I0 for each line obtained by the infrared sensor 59I is sequentially output to the signal processing unit 71 of the control / image processing unit 70.

Next, processing for the infrared detection data I0 thus obtained and analysis for the infrared data IR obtained by processing the infrared detection data I0 are performed (step 104).
Specifically, the infrared detection data I0 input to the first preprocessing unit 100 of the signal processing unit 71 is offset gain adjustment by the first analog processing unit 110 and A by the first A / D conversion unit 120. The signal is output to the infrared post-processing unit 200 via / D conversion. The infrared detection data I0 input to the infrared post-processing unit 200 is subjected to infrared shading correction by the infrared shading correction unit 210 and output to the identification information analysis unit 220 as infrared data IR. Then, the identification information analysis unit 220 performs analysis of identification information using the input infrared data IR. Details of the analysis processing in the identification information analysis unit 220 will be described later.

  Then, the reading controller 81 determines whether or not there is identification information in the infrared data IR, that is, whether or not identification information is input from the identification information analysis unit 220 (step 105). If it is determined that there is no identification information, the process proceeds to step 110 described later. On the other hand, if it is determined that there is identification information, the reading controller 81 acquires this identification information (step 106), and creates confirmation information in which the acquired identification information is associated with the personal authentication information acquired in step 101 above. To do. Then, the reading controller 81 outputs this confirmation information via the transmission / reception unit 87 (step 107). Note that the confirmation information output via the transmission / reception unit 87 is output to an external server. Here, the external server is provided with a database (DB) in which identification information and personal authentication information are stored in association with duplication right information described later. The external server determines whether or not the user having the personal authentication information included in the confirmation information has the right to obtain a copy, that is, the right to copy the document having the identification information included in the confirmation information. The determination result is returned as copy right information (“copy right” or “no copy right”). Then, the reading controller 81 acquires the copy right information returned from the external server via the transmission / reception unit 87 (step 108).

  Next, the reading controller 81 determines whether or not the obtained duplication right information is “with duplication right” (step 109). Here, when the copy right information is “with copy right” and when there is no identification information in step 105, the reading controller 81 outputs a control signal to the UI, the host system, etc. The message “Can be scanned” is displayed on the display of the system (step 110). Thereafter, the reading controller 81 determines whether or not there is a scan start instruction from the UI or the host system (step 111). If there is no scan start instruction, the process returns to step 111 to wait for a scan start instruction.

  On the other hand, when there is an instruction to start scanning, the reading controller 81 outputs a control signal to each unit constituting the image reading apparatus to execute a visible main scan (step 112). At the time when the visible main scan is started, the full-rate carriage 53 and the half-rate carriage 54 are positioned after the infrared pre-scan in step 103, that is, at the lower left side of the first platen glass 52A shown in FIG. It has stopped. This visible main scan is performed as follows, for example.

  First, the reading controller 81 outputs a control signal to the LED driver 83. The LED driver 83 receives the control signal and turns on the white LED 92 of the first LED light source 55. At this time, the infrared LED 93 remains off. Then, the reading controller 81 outputs a control signal to the image sensor driver 82 and the scan driver 84. In response to the control signal, the scan driver 84 moves the full rate carriage 53 and the half rate carriage 54 to the right in FIG. 1 at a constant speed. At this time, the full rate carriage 53 and the half rate carriage 54 move in the scanning direction (in this case, the arrow direction) at a ratio of 2: 1. On the other hand, the image sensor driver 82 receives such a control signal, and starts to receive light reception data by the first blue sensor 59B, the first green sensor 59G, and the first red sensor 59R of the first image sensor 59. It should be noted that the scan driver 84 is in a position where the reading of the entire surface of the original on the first platen glass 52A is completed (for example, the right end position indicated by a two-dot chain line in FIG. The half-rate carriage 54 is stopped. As the full-rate carriage 53 and the half-rate carriage 54 are stopped, the reading controller 81 outputs a control signal to the LED driver 83 to turn off the white LED 92 and outputs a control signal to the image sensor driver 82. Then, the reception of received light data by the first blue sensor 59B, the first green sensor 59G, and the first red sensor 59R is terminated.

  During this time, white light from the white LED 92 is sequentially applied to the lower surface of the document placed on the first platen glass 52A, and reflected light from the document is transmitted through the first mirror 57A and the like to the first image sensor. The first blue sensor 59B, the first green sensor 59G, and the first red sensor 59R receive the light. The first blue detection data BA0, the first green detection data GA0, and the first red detection data for each line of the original obtained by the first blue sensor 59B, the first green sensor 59G, and the first red sensor 59R. RA0 is sequentially output to the signal processing unit 71 of the control / image processing unit 70.

  The first blue detection data BA0, the first green detection data GA0, and the first red detection data RA0 input to the first preprocessing unit 100 of the signal processing unit 71 are used for offset gain adjustment and The signal is output to the first post-processing unit 300 through A / D conversion by the 1 A / D conversion unit 120. The first blue detection data BA0, the first green detection data GA0, and the first red detection data RA0 input to the first post-processing unit 300 are subjected to visible shading correction by the first visible shading correction unit 310, and then the first The delay processing unit 320 performs delay correction. The first blue detection data BA0, the first green detection data GA0, and the first red detection data RA0 that have been subjected to the delay correction are subjected to image processing by the first image processing unit 330, whereby the first blue image is obtained. Data BA, first green image data GA, and first red image data RA are output.

  Thereafter, in response to the output of the first blue image data BA, the first green image data GA, and the first red image data RA, the reading controller 81 creates scan history information corresponding to this scan operation. To do. Then, the reading controller 81 outputs the created scan history information via the transmission / reception unit 87 (step 113), and ends a series of processing. The created scan history information includes, for example, the personal authentication information acquired in step 101, the identification information acquired in step 106, the date and time of scanning, or the unique ID of the image reading apparatus that performed the scanning. Can be included. The output scan history information is transmitted to the above-described external server or another server, and stored in a database provided in the server. However, if it is determined in step 105 that there is no identification information, step 113 can be omitted.

  On the other hand, if the copy right information is “no copy right” in step 109, the reading controller 81 outputs a control signal to the UI or host system, and “cannot scan” on the UI or host system display. Is displayed (step 114). Further, the reading controller 81 stops outputting control signals to each unit constituting the image reading apparatus and prohibits reception of a scan start instruction from the UI, the host system, or the like (step 115), and performs a series of processing. finish.

FIG. 11 is a flowchart showing the flow of processing executed by the identification information analysis unit 220 in step 104 described above.
When infrared data IR is input from the infrared shading correction unit 210 (step 201), the identification information analysis unit 220 first shapes the input infrared data IR (step 202). The shaping of the infrared data IR includes, for example, inclination correction and noise removal. Then, the identification information analysis unit 220 detects a bit pattern (shaded pattern) such as a slash “/” or a backslash “\” from the shaped infrared data IR (step 203). Next, the identification information analysis unit 220 determines whether or not there is a bit pattern in the infrared data IR (step 204).

Here, if it is determined that there is no bit pattern in the infrared data IR, the processing is terminated as it is. On the other hand, if it is determined that there is a bit pattern in the infrared data IR, the identification information analysis unit 220 detects a synchronization code, which is a two-dimensional code positioning code, from the shaped infrared data IR (step 205). . Then, the identification information analysis unit 220 detects a two-dimensional code with reference to the synchronization code position (step 206), and extracts information such as ECC (Error Correcting Code) from the two-dimensional code. Decode (step 207). Then, the identification information analysis unit 220 restores the decoded information to the original code information (step 208).
Next, the identification information analysis unit 220 acquires identification information from the code information restored as described above (step 209), and outputs the acquired identification information to the reading controller 81 (see FIG. 6) (step 210). Then, a series of processing is completed.

(2) Transport Reading Mode Next, the transport reading mode will be described in detail with reference to the flowcharts shown in FIGS. 1 to 9 and FIG. In this description, it is assumed that a document having an image formed on only one side is read in the single-side mode. The document is set on the document tray 11 with the image forming surface facing up. Further, in the conveyance reading mode, the infrared LED 93 and the infrared sensor 59I function as a first reading unit, and the white LED 96, the second blue sensor 65B, the second green sensor 65G, and the second red sensor 65R are the second. It functions as a reading means. In the conveyance reading mode, the document feeder 10 functions as a moving unit.

Also in the transport reading mode, personal authentication information is first acquired (step 301), and the authentication unit 86 outputs the personal authentication information obtained by reading the authentication card 90 to the reading controller 81.
Next, the setting of the original (or original bundle) on the original tray 11 is detected (step 302). Specifically, for example, the presence or absence of a document on the document tray 11 is detected by a sensor. This detection result is output to the reading controller 81.
Then, the reading controller 81 determines whether or not there is a scan start instruction from the UI or the host system (step 303). If there is no scan start instruction, the process returns to step 303 and waits for a scan start instruction.

  On the other hand, when there is an instruction to start scanning, the reading controller 81 outputs a control signal to each unit constituting the image reading apparatus, and first executes infrared pre-scanning (step 304). At the start of the infrared pre-scan, the full rate carriage 53 and the half rate carriage 54 are placed at the home positions indicated by solid lines in FIG. The infrared prescan is performed as follows, for example.

  Upon receiving a scan start instruction, the reading controller 81 outputs a control signal to the transport mechanism driver 85. In response to the control signal, the transport mechanism driver 85 takes out the original bundle on the original tray 11 one by one from the top and conveys it. Specifically, the uppermost document from the document bundle on the document tray 11 is drawn into the first conveyance path 31 by the nudger roll 13 and is fed one by one by the separation mechanism 14, and then the pre-registration roll 15 is moved. Through the position of the registration roll 16. At this time, the registration roll 16 has stopped rotating, and the document forms a loop with its leading end in contact with the nip portion of the registration roll 16. Thereby, the posture of the document is corrected. Then, by starting the driving of the registration roll 16 at a predetermined timing, the document reaches the second platen glass 52B in a state where the posture is corrected.

  Next, the reading controller 81 sends a control signal to the image sensor driver 82 and the LED driver 83 in accordance with the timing when the leading edge of the conveyed document reaches the reading position on the second platen glass 52B by the first image sensor 59. Output. In response to the control signal, the LED driver 83 turns on the infrared LED 93 of the first LED light source 55. At this time, the white LED 92 remains off. On the other hand, the image sensor driver 82 receives such a control signal, and starts to receive light reception data by the infrared sensor 59I of the first image sensor 59. The reading controller 81 outputs a control signal to the LED driver 83 to turn off the infrared LED 93 and outputs a control signal to the image sensor driver 82 at the timing when reading of the entire surface of the conveyed document is completed. The capturing of received light data by the infrared sensor 59I is terminated.

  During this time, infrared light from the infrared LED 93 is sequentially applied to the lower surface of the document passing over the second platen glass 52B, and reflected light from the document is reflected on the first mirror 57A, the second mirror 57B, and the third mirror. The light is reflected in the order of the mirror 57C and guided to the imaging lens 58. The light guided to the imaging lens 58 is imaged on the light receiving surface of the infrared sensor 59I. As described above, the infrared sensor 59I is a one-dimensional sensor and processes one line at a time. Then, the original is moved in a direction orthogonal to the line direction (scanning sub-scanning direction), and the next line of the original is read. By executing this over the entire document, reading of one page of the document is completed. Further, the infrared detection data I0 for each line obtained by the infrared sensor 59I is sequentially output to the signal processing unit 71 of the control / image processing unit 70.

Next, processing for the infrared detection data I0 thus obtained and analysis for the infrared data IR obtained by processing the infrared detection data I0 are performed (step 305). Note that step 305 is the same as step 104 described above, that is, as shown in FIG.
Then, the reading controller 81 determines whether or not there is identification information, that is, whether or not identification information is input from the identification information analysis unit 220 (step 306). If it is determined that there is no identification information, the process proceeds to step 311 described later. On the other hand, if it is determined that there is identification information, the reading controller 81 acquires this identification information (step 307), and creates confirmation information in which the acquired identification information is associated with the personal authentication information acquired in step 301 above. Then, this confirmation information is output via the transmitter / receiver 87 (step 308). The confirmation information is sent to an external server as in the above-described fixed reading mode, and as a result, the copy right information is returned from the external server. Then, the reading controller 81 acquires the copy right information returned from the external server via the transmission / reception unit 87 (step 309).

  During this time, the document on which the infrared pre-scan has been completed is conveyed again to the first conveyance path 31 through the third conveyance path 33 with the paper roll 19 or the like being reversed. The reversely conveyed document is stopped while forming a loop at a position where the leading end of the document comes into contact with the registration roll 16.

  Next, the reading controller 81 determines whether or not the acquired copy right information is “with copy right” (step 310). Here, when the copy right information is “with copy right”, and when there is no identification information in step 306, the reading controller 81 outputs a control signal to each unit constituting the image reading apparatus, A visible main scan is executed (step 311). This visible main scan is performed as follows, for example.

  Upon receiving an instruction to execute the visible main scan, the reading controller 81 outputs a control signal to the transport mechanism driver 85. In response to the control signal, the transport mechanism driver 85 starts driving the registration roll 16 and the like, so that the document reaches the guide 56A (opposite the CIS unit 60) with the posture corrected.

  Next, the reading controller 81 outputs a control signal to the image sensor driver 82 and the LED driver 83 in accordance with the timing at which the leading edge of the reversely conveyed document reaches the reading position on the guide 56A by the second image sensor 65. . In response to the control signal, the LED driver 83 turns on the white LED 96 of the second LED light source 63. On the other hand, the image sensor driver 82 receives the control signal, and starts to receive light reception data by the second blue sensor 65B, the second green sensor 65G, and the second red sensor 65R of the second image sensor 65. The reading controller 81 outputs a control signal to the LED driver 83 to turn off the white LED 96 at the timing when reading of the entire surface of the conveyed document is completed, and outputs a control signal to the image sensor driver 82 to output the control signal. The capturing of the received light data by the 2 blue sensor 65B, the second green sensor 65G, and the second red sensor 65R is terminated.

  During this time, white light from the white LED 96 is sequentially irradiated on the upper surface of the document passing over the guide 56A (the same surface as the infrared prescan in step 304), and the reflected light from the document is reflected on the first mirror 57A, The second mirror 57B and the third mirror 57C are sequentially reflected and guided to the imaging lens 58. The light guided to the imaging lens 58 is imaged on the light receiving surfaces of the second blue sensor 65B, the second green sensor 65G, and the second red sensor 65R. The second blue sensor 65B, the second green sensor 65G, and the second red sensor 65R are one-dimensional sensors and process one line at the same time. Then, the original is moved in a direction orthogonal to the line direction (scanning sub-scanning direction), and the next line of the original is read. By executing this over the entire document, reading of one page of the document is completed. Further, the second blue detection data BB0, the second green detection data GB0, and the second red detection data RB0 for each line obtained by the second blue sensor 65B, the second green sensor 65G, and the second red sensor 65R are obtained. Are sequentially output to the signal processing unit 71 of the control / image processing unit 70.

  The second blue detection data BB0, the second green detection data GB0, and the second red detection data RB0 input to the second pre-processing unit 400 of the signal processing unit 71 are adjusted by the second analog processing unit 410 for the offset gain adjustment and the second The signal is output to the second post-processing unit 500 through A / D conversion by the 2A / D conversion unit 420. The second blue detection data BB0, the second green detection data GB0, and the second red detection data RB0 input to the second post-processing unit 500 are subjected to visible shading correction by the second visible shading correction unit 510, and then the second The delay processing unit 520 performs delay correction. The second blue detection data BB0, the second green detection data GB0, and the second red detection data RB0 that have been subjected to the delay correction are subjected to image processing by the second image processing unit 530, whereby the first blue image Data BB, first green image data GB, and first red image data RB are output.

  Thereafter, in response to the output of the second blue image data BB, the second green image data GB, and the second red image data RB, the reading controller 81 creates scan history information corresponding to this scanning operation. Then, the obtained scan history information is output via the transmission / reception unit 87 (step 312). The scan history information includes the same information as the above-described fixed reading mode. Similarly to step 105 above, if it is determined in step 306 that there is no identification information, step 312 can be omitted. The reading controller 81 determines whether there is a document to be read next (step 313). If there is a document to be read next, the process returns to step 304 and the same processing is executed. On the other hand, when there is no document to be read next, that is, when there are no more documents on the document tray 11, the series of processes is terminated.

  On the other hand, if the copy right information is “no copy right” in step 310, the reading controller 81 outputs a control signal to the UI or host system, and “cannot scan” on the UI or host system display. Is displayed (step 314). In addition, the reading controller 81 outputs a control signal to the transport mechanism driver 85. In response to the control signal, the transport mechanism driver 85 starts driving the registration roll 16 and the like. At this time, the reading controller 81 stops outputting control signals to the image sensor driver 82 and the LED driver 83, and as a result, the document is discharged as it is without performing a visible main scan (step 315). Terminate the process. In step 311, the original that has been subjected to the visible scan is further reversed on the front and back by the paper discharge roll 19 and the like, and is then transported to the fourth transport path 34 and discharged onto the paper discharge tray 12. At this time, the original is discharged onto the paper discharge tray 12 in a state where the front and back sides are reversed from when the original was placed on the original tray 11. By doing so, the arrangement order of the plurality of documents can be made the same when they are placed on the document tray 11 and when they are ejected onto the paper ejection tray 12.

  Further, when reading images on both sides of a document in the duplex mode, when performing a visible scan on one side of the document in step 311, an infrared prescan of the other side of the document is performed using the reading device 10. Should be done. However, in this case, it is necessary to further reversely convey the original and perform visible scanning on the other side of the original.

  As described above, in this embodiment, when performing a document reading operation, first, scanning using infrared light (infrared pre-scan) is performed, and the result of reading an invisible image by this scanning is obtained. Based on the obtained identification information, it is determined whether or not to perform a scan (visible main scan) using visible light (white light) of the document based on the obtained identification information. Therefore, when the visible main scan is not permitted (prohibited) based on the execution result of the infrared prescan, the visible image is not read at all, and the visible image data is effectively sucked out. Can be impossible. As a result, security can be ensured for important documents such as confidential documents for which scanning of visible images is prohibited.

  In the present embodiment, confirmation information in which personal information acquired from the authentication card 90 and identification information acquired by infrared prescan are associated is transmitted to an external server, and the external server is based on the confirmation information. Based on the copy right information returned from, it is determined whether to allow visible main scan. As a result, even for a confidential document, for example, a user having a predetermined authority can be permitted to scan or copy a document. In this embodiment, scan history information is created in such a case. As a result, for example, when, where, and who has scanned or copied a document can be ascertained, and it becomes easy to manage documents.

  Furthermore, in this embodiment, since the white LED 92 and the infrared LED 93 are used as the light source on the reading device 50 side, visible light or infrared light can be selectively lit. Thus, the first blue sensor 59B, the first green sensor 59G, and the first red sensor 59R of the first image sensor 59 can selectively receive visible light, and the infrared sensor 59I can selectively receive infrared light. it can. For this reason, for example, the first blue sensor 59B, the first green sensor 59G, and the first red sensor 59R when infrared light is incident on the first blue sensor 59B, the first green sensor 59G, and the first red sensor 59R. Output error can be suppressed. On the other hand, for example, an output error of the infrared sensor 59I caused by visible light entering the infrared sensor 59I can be suppressed.

  Furthermore, in the present embodiment, in both the fixed reading mode and the conveyance reading mode used in a general image reading apparatus, first, after performing the infrared prescan, the infrared prescan is executed. Based on this, it is determined whether to allow execution of the visible main scan. As a result, scanning or copying of confidential documents and the like can be restricted in various image reading apparatuses.

  Here, in the fixed reading mode, it is detected in advance that the document is set on the first platen glass 52A, and before the start instruction of the scanning operation (visible main scan) by the user is performed, the infrared is read. The pre-scan is completed. In this embodiment, for example, the infrared pre-scan is executed after the full-rate carriage 53 and the half-rate carriage 54 are moved in conjunction with the opening / closing operation of the document feeder 10. Thereby, the increase in a user's waiting time can be suppressed. Further, by executing the infrared prescan in such a procedure, it is possible to perform the infrared prescan and, for example, detect the size of the document.

  On the other hand, in the double-sided reading mode, a CIS unit 60 that reads a surface opposite to the reading device 50 is attached to an image reading device having a reversing path (third conveyance path 33) that has been conventionally used, so that the original is once stored. Infrared pre-scanning and visible main scanning can be executed by the above-mentioned conveyance. In addition, this image reading apparatus can also perform double-sided reading.

In the present embodiment, the invisible image is formed of a material having absorption at a wavelength in the near infrared region. However, the design can be changed as appropriate if the wavelength is outside the visible region. However, in this case, it is necessary to change the infrared sensor 59I to a sensor that receives light of a corresponding wavelength.
In the present embodiment, the reading device 50 is configured by a reduction optical system and the CIS unit 60 is configured by a contact optical system. However, the present invention is not limited to this. That is, both may be constituted by a reduction optical system or a contact optical system, or may be in an inverse relationship.

It is a figure which shows the structural example of the image reading apparatus with which this Embodiment is applied. It is a figure which shows an example of a structure of the CIS unit (Contact Image Sensor) provided in an image reading apparatus. (a) is a figure which shows the 1st LED light source provided in the reader side, (b) is a figure which respectively shows the 2nd LED light source provided in the CIS unit side. It is a figure which shows an example of the wavelength-light emission characteristic of white LED and infrared LED. (a) is a figure which shows the 1st image sensor provided in the reading device side, (b) is a figure which respectively shows the 2nd image sensor provided in the CIS unit side. It is a block diagram of a control / image processing unit. It is a block diagram of a 1st pre-processing part, an infrared post-processing part, and a 1st post-processing part. It is a block diagram of a 2nd pre-processing part and a 2nd post-processing part. (a)-(c) is a figure for demonstrating the two-dimensional code image which comprises an invisible image. It is a flowchart which shows the flow of operation | movement in fixed reading mode. It is a flowchart which shows the flow of the process performed in an identification information analysis part. It is a flowchart which shows the flow of operation | movement in conveyance reading mode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Document feeder, 50 ... Reading apparatus, 55 ... 1st LED light source, 59 ... 1st image sensor, 59B ... 1st blue sensor, 59G ... 1st green sensor, 59R ... 1st red sensor, 59I ... Infrared sensor 60 ... CIS (Contact Image Sensor) unit, 63 ... second LED light source, 65 ... second image sensor, 65B ... second blue sensor, 65G ... second green sensor, 65R ... second red sensor, 70 ... control / image Processing unit 71 ... Signal processing unit 72 ... Control unit 100 ... First preprocessing unit 200 ... Infrared post-processing unit 220 ... Identification information analysis unit 300 ... First post-processing unit 400 ... Second front Processing unit, 500 ... second post-processing unit

Claims (8)

First reading means for reading a first image formed on the document by irradiating the document with light in a first wavelength region and receiving reflected light from the document;
Second reading means for reading a second image formed on the original by irradiating the original with light in a second wavelength region different from the first wavelength region and receiving reflected light from the original; ,
An image reading apparatus comprising: a determination unit configured to determine whether to execute reading of the second image by the second reading unit based on a reading result of the first image executed by the first reading unit. The first reading unit reads an invisible image as the first image by irradiating light in an infrared region as the first wavelength region,
The image reading apparatus according to claim 1, wherein the second reading unit reads a visible image as the second image by irradiating light in a visible region as the second wavelength region. An acquisition unit for acquiring identification information included in the invisible image read by the first reading unit;
The image reading apparatus according to claim 2, wherein the determination unit performs determination based on the identification information acquired by the acquisition unit.   The image reading apparatus according to claim 1, further comprising a moving unit that moves the document relative to the first reading unit and the second reading unit. Irradiating the original with infrared light and receiving reflected light from the original to read an invisible image formed on the original;
Obtaining identification information included in the invisible image from the reading result of the invisible image;
And a step of reading a visible image formed on the document after obtaining the identification information in the step. A step of determining whether reading of the visible image formed on the document is permitted based on the acquired identification information between the step of acquiring the identification information and the step of reading the visible image. The image reading method according to claim 5, further comprising:   In the step of determining, when it is determined that reading of the visible image is permitted, the step of reading the visible image irradiates the original with visible light and receives reflected light from the original, The image reading method according to claim 6, wherein a visible image formed on the document is read. The image reading method according to claim 6, further comprising a step of prohibiting reading of the visible image when it is determined in the determining step that reading of the visible image is not permitted.

Images