JP2017055197A - Image reader and image reading system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for identifying the fluorescent region of a medium marked by means of a fluorescent pen or a fluorescent marker, by a simple configuration.SOLUTION: An image processing apparatus includes a light source irradiating three kinds of light having different wavelengths, a first image reading sensor for reading the first image of the medium from the reflection light when the medium is irradiated with light from the light source, a second image reading sensor for reading the second image of the medium by receiving only the light of a predetermined wavelength region, transmitting an optical filter placed between the medium, out of the reflection light when the medium is irradiated with light from the light source, and identification means for identifying the fluorescent region included in the medium, based on the spectral characteristics of the second image.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an image reading apparatus and an image reading system that can specify a fluorescent region assigned to a medium such as a document.

  Conventionally, a part of an original to be read is marked with a fluorescent pen or a fluorescent marker, and scanning is performed using an image reading device such as a scanner. There is an image reading apparatus that performs image processing different from an unmarked area on a marked area of a read image, and a technique for discriminating a fluorescent area included in a read image of a document is known.

  When light having a specific wavelength (excitation light) is irradiated onto a fluorescent region such as a fluorescent pen or a fluorescent marker, the fluorescent region absorbs the irradiated light having a specific wavelength, so that electrons are excited. It is known that an electron in an excited state emits light having a longer wavelength than the irradiated light having a specific wavelength (excitation light) when returning to a more stable ground state.

  For example, a fluorescent region in which a white document is marked with a yellow fluorescent marker is irradiated with blue monochromatic light of about 440 [nm] as excitation light, the wavelength is 520 [nm] along with the reflected light of blue light. A certain amount of light emission is confirmed.

  Similarly, when a fluorescent region in which a white original is marked with a green fluorescent marker is irradiated with blue monochromatic light of about 440 [nm] as excitation light, the wavelength is 500 [nm] together with the reflected light of blue light. A certain amount of light emission is confirmed. In addition, a fluorescent region in which a white original is marked with a pink fluorescent marker is irradiated with green monochromatic light of about 540 [nm] as excitation light, the reflected light of green light and the wavelength are 580 [nm]. Emission of a certain degree is confirmed.

  In Patent Document 1, an image reading apparatus has a two-line sensor for detecting a fluorescent region separately from an image reading monoline sensor in an image reading unit. The two-line sensor for detecting the fluorescent region uses a G filter that transmits only green light and an R filter that transmits only red light.

  When the original has a fluorescent region where the excitation light is blue light, the fluorescent region is confirmed to emit light having a wavelength longer than that of the blue light when irradiated with the blue light as excitation light. Further, when the original has a fluorescent region fluorescent region where the excitation light is green light, the fluorescent region is confirmed to emit light having a wavelength longer than that of the green light when irradiated with the green light that is the excitation light.

  Therefore, the fluorescent region is detected using a two-line sensor including a G filter that transmits only green light and an R filter that transmits only red light. The image reading apparatus sequentially turns on the light sources (R (red), G (green), and B (blue)), and uses the monochromatic light R (red), the monochromatic light G (green), and the monochromatic light B (blue) as a document. Irradiate.

  The image reading device acquires reflected light from the original and light emission from the fluorescent region by a monoline sensor, and generates a read image of the original. At the same time, the image reading apparatus acquires the reflected light from the original and the light emission from the fluorescent region with a two-line sensor. Since the two-line sensor includes a G filter that transmits only green light and an R filter that transmits only red light, the reflected light from the original and light emitted from the fluorescent region are transmitted through the G filter and the R filter. Things are acquired with a two-line sensor. Based on the data acquired by the two-line sensor, the fluorescent region in the document is detected.

  In Patent Document 2, ultraviolet light having a shorter wavelength and higher energy than visible light is used as a light source. When the fluorescent region is irradiated with ultraviolet light which is invisible light, the energy obtained by absorbing the ultraviolet light is emitted as visible light. Since the reflected light when the ultraviolet light is irradiated to the fluorescent region is significantly larger than the reflected light when the ultraviolet light is irradiated outside the fluorescent region, the reflected light when the ultraviolet light is irradiated is accumulated by the image sensor. By using the image data, the fluorescent region in the document is detected.

JP-A-10-107970 JP 2010-273302 A

  Here, as in Patent Document 1, adding a two-line sensor for detecting a fluorescent region separately from an image reading monoline sensor to the image reading unit leads to an increase in product cost. Further, as in Patent Document 2, adding an ultraviolet light source as a light source leads to an increase in product cost and an increase in the number of parts of the product, resulting in a complicated configuration of the image reading unit. It was.

  The present invention provides a technique for specifying a fluorescent region of a medium marked with a fluorescent pen or a fluorescent marker with a simple configuration.

  The image reading apparatus of the present invention includes a light source that emits three types of light having different wavelengths, a first image reading sensor that reads a first image of a medium from reflected light when the medium is irradiated with light from the light source, and the light source. A second image reading sensor that receives light in a predetermined wavelength range that passes through an optical filter disposed between the medium and reflected light when the medium is irradiated with light from the medium, and reads a second image of the medium; And a specifying unit that specifies a fluorescent region of the medium based on the second image.

According to another aspect of the present invention, there is provided an image reading system including: an image reading apparatus that reads an image on a medium; and an information processing apparatus that is connected to the image reading apparatus and receives an image from the image reading apparatus. The apparatus includes a light source that irradiates three types of light having different wavelengths, a first image reading sensor that reads a first image of the medium from reflected light when the medium is irradiated with light from the light source, and light irradiation from the light source to the medium. A second image reading sensor that receives the transmitted light that passes through the optical filter out of the reflected light and reads the second image of the medium,
The information processing apparatus includes a specifying unit that specifies a fluorescent region of a medium based on the second image among the first image and the second image received from the image reading apparatus.

  According to the present invention, it is possible to realize an image reading apparatus and an image reading system capable of specifying a fluorescent region of a medium marked with a fluorescent pen or a fluorescent marker with a simple configuration.

1 is a diagram illustrating a configuration example of an image reading system according to an embodiment of the present invention. 1 is a diagram illustrating a functional configuration of an image reading apparatus and a host computer according to an embodiment of the present invention. The figure which shows the structural example of the image sensor which concerns on one Embodiment of this invention. FIG. 3 is a schematic diagram illustrating spectral sensitivity characteristics of an image sensor when a white document is irradiated with R, G, and B. Schematic showing the filter characteristic of an image sensor. Schematic showing the spectral sensitivity characteristic of the yellow fluorescent pen in a document at the time of B light irradiation. Schematic showing the spectral sensitivity characteristic of the pink highlighter pen in the original at the time of G light irradiation.

Hereinafter, the present invention will be described in detail based on embodiments.
First, the configuration of an image reading system to which the present invention is applied will be described with reference to FIG. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus that feeds a plurality of documents placed on a document placement table and reads the fed documents as image data. The present invention relates to an image reading apparatus for determining whether or not.

  As shown in FIG. 1, the image reading system according to the present embodiment includes an image reading device 300 and a host computer 800 that is an information processing device. The image reading device 300 and the host computer 800 include an image reading system ( Or an image processing apparatus).

  The host computer 800 is connected to the image reading apparatus 300 and controls the image reading apparatus 300 in an integrated manner. Therefore, the host computer 800 includes a scanner application and a scanner device driver for controlling the image reading operation of the image reading apparatus 300.

  The image reading apparatus 300 and the host computer 800 are connected to each other via, for example, a USB cable or a LAN cable, but may be connected via radio. An image sensor is attached to the optical unit 202 in the image reading apparatus, and the image data of the document 201 placed on the document table is read by moving the optical unit 202 by the belt 203.

  Next, functional configurations of the image reading apparatus 300 and the host computer 800 will be described with reference to FIG. FIG. 2 is a block diagram illustrating functional configurations of the image reading apparatus 300 and the host computer 800 according to the present embodiment.

  The image reading apparatus 300 includes a CPU 111, an image memory 112, an I / F control unit 113, a motor control unit 114, and an image reading unit 115. The CPU 111 controls the image reading apparatus 300 in an integrated manner.

  As shown in FIG. 2, the CPU 111 and each functional block are connected by an internal bus. The motor control unit 114 controls the drive of each motor such as a scanner motor, and controls the movement of the optical unit 202.

  The image reading unit 115 controls the image sensor installed in the optical unit 202 and reads the image data of the document 201 placed on the document table. The image memory 112 stores the image data read by the image reading unit 115. The I / F control unit 113 controls exchanges with the host computer 800 connected via a USB cable, a LAN cable, or the like.

  On the other hand, the host computer 800 includes a CPU 411, a temporary storage unit 412, an information storage unit 413, an I / F control unit 414, and an image processing unit 415. The CPU 411 controls the host computer 800 in an integrated manner.

  The I / F control unit 414 controls exchanges with the image processing apparatus 300 connected via a USB cable, a LAN cable, or the like.

  In response to an image data transfer request from the host computer 800, the image data read by the image reading device 300 is transmitted to the host computer 800 via a USB cable, a LAN cable, or the like.

  The temporary storage unit 412 temporarily stores image data received via a USB cable, a LAN cable, or the like.

  The image processing unit 415 performs image processing on the image data stored in the temporary storage unit 412.

  The information storage unit 413 stores and saves image data that has been subjected to image processing by the image processing unit 415.

  FIG. 3 is a configuration diagram of the optical unit 202. The optical unit 202 includes an image sensor 401 (401a, 401b), a light guide 402, a lens 403, a filter 404, an LED light source R for R light (not shown), an LED light source G for G light, and an LED light source B for B light. Composed. Each of these light sources can be switched sequentially to irradiate light.

  The image sensor 401 is a CIS (Contact Image Sensor). For example, in this embodiment, the image sensor 401 is a two-line sensor including a 401a that does not include a filter and a 401b that includes a filter 404 that transmits only G-color light. That is, the image sensor 401a is an example of a first image reading sensor that is sensitive to three types of light (R, G, B) having different wavelengths, and the image sensor 401b passes through a filter to determine a fluorescent region. This is an example of a second image reading sensor having sensitivity to light in a predetermined wavelength range (G color in the present embodiment). That is, it is possible to identify the presence of the fluorescent region by receiving reflected light having a wavelength different from the wavelength of the light emitted from the light source from the image region 401b from the fluorescent region.

  When an LED light source (not shown) is turned on, the light passes through the light guide 402 and is applied to the document 201. The reflected light from the original 201 is imaged on the image sensor 401 by the lens 403.

  When the image sensor 401 is irradiated with light for a certain period of time, charges are accumulated. The electric charge accumulated in the image sensor 401 is converted into a voltage, and the voltage is converted into digital data by an A / D converter (not shown). The read image of the document 201 converted into digital data is stored in the image memory 112.

  FIG. 4 shows spectral sensitivity characteristics of the sensor 401a when a white original is irradiated with a light source R for R color light, a light source G for G color light, and a light source B for B color light.

  The vertical axis represents relative sensitivity [%], and the horizontal axis represents wavelength [nm]. The spectrum (501) when a white original is irradiated with a light source R of R color light substantially matches the wavelength 630 [nm] of the R color light that is the light source.

  Similarly, the spectrum (502) when a white color original is irradiated with the light source G of G color light substantially matches the wavelength 530 [nm] of the G color light as the light source. Similarly, the spectrum (503) when the white original is irradiated with the light source B of B-color light substantially matches the wavelength 460 [nm] of the B-color light that is the light source.

  FIG. 5 shows the filter characteristics of the filter 404 of the optical unit. The vertical axis represents the filter transmittance [%], and the horizontal axis represents the wavelength [nm]. The filter 404 transmits G color light and does not transmit R color light or B color light. It transmits a wavelength near the wavelength 530 [nm] of the G light.

  When the image reading apparatus 300 receives an image reading start instruction from the host computer 800, the motor control unit 114 rotates a motor (not shown) in the forward direction to move the optical unit 202 and place it on the document table. The image reading process of the original 201 being started is started.

  The image reading apparatus 300 controls the image reading unit 115 and turns on an LED light source R of R color light (not shown) of the optical unit 202. The LED light source R of R color light passes through the light guide 402 of the optical unit 202 and is irradiated onto the document 201.

  The reflected light of the LED light source R of R color light from the document 201 is imaged on the image sensor 401 by the lens 403. In the image sensor 401a, the reflected light of the LED light source R, which is R color light from the document 201, is accumulated.

  The image sensor 401b accumulates light that has passed through the filter 404 out of the reflected light of the LED light source R that is R color light from the document 201.

  When the LED light source R for R color light is turned on for a certain period of time, the image reading apparatus 300 turns off the LED light source R and turns on the LED light source G for G color light. The LED light source G of G color light passes through the light guide 402 of the optical unit 202 and is irradiated onto the document 201.

  The reflected light of the LED light source G of G color light from the original 201 is imaged on the image sensor 401 by the lens 403.

  In the image sensor 401a, the reflected light of the LED light source G, which is G color light from the original 201, is accumulated. In the image sensor 401b, the light transmitted through the filter 404 out of the reflected light of the LED light source G, which is G color light from the document 201, is accumulated.

  When the LED light source G for G color light is turned on for a certain period of time, the image reading apparatus 300 turns off the LED light source G and turns on the LED light source B for B color light. The LED light source B of B color light passes through the light guide 402 of the optical unit 202 and is irradiated onto the document 201.

  The reflected light of the LED light source B of B color light from the original 201 is imaged on the image sensor 401 by the lens 403.

  In the image sensor 401a, the reflected light of the LED light source B which is B color light from the document 201 is accumulated. In the image sensor 401b, the light transmitted through the filter 404 among the reflected light of the LED light source B, which is B color light from the document 201, is accumulated.

  In this way, the image reading device 300 reads image data for one line by sequentially turning on the LED light source R for R color light, the LED light source G for G color light, and the LED light source B for B color light.

  When the image reading apparatus 300 acquires image data for one line of the document 201 placed on the document table, the motor control unit 114 drives a motor (not shown) to advance the optical unit 202 to the next line.

  The image reading apparatus 300 reads the original 201 by repeatedly reading one line of the image from end to end.

  When the reading of the document 201 is completed, the image reading apparatus 300 transmits the read image data to the host computer 800 via a USB cable or a LAN cable in response to an image data transfer request from the host computer 800.

  When receiving image data from the image reading apparatus 300, the host computer 800 stores the image data in the temporary storage unit 412. The image processing unit 415 performs fluorescent region detection processing for determining whether or not a fluorescent region marked with a fluorescent pen or a fluorescent marker exists in the document 201. That is, the image processing unit 415 serves as a specifying unit that specifies the fluorescent region included in the document (medium). Since the image processing unit 415 can determine (determine) whether or not the document includes a fluorescent region, if the document includes a fluorescent region, the fluorescent region is different from the image processing for a region other than the fluorescent region. It is possible to perform image processing according to the above.

  When a fluorescent region is present in the original 201, when the fluorescent region is irradiated with light having a specific wavelength, the fluorescent region absorbs the irradiated light, and the electrons are in an excited state.

  The electrons in the excited state emit light having a longer wavelength than the light irradiated when returning to a stable ground state.

  That is, when the fluorescent region is present in the original 201, when the LED light source B, which is B color light, is irradiated, G light having a wavelength longer than that of the irradiated B light is emitted. When the LED light source B which is B color light is irradiated, the filter 404 that transmits only the G color light is attached to the image sensor 401b, and therefore the B color light is not transmitted.

  When a fluorescent region exists in the original 201, the fluorescent region in the original 201 is excited by being irradiated with B light, and the emitted light is read when returning from the excited state to the ground state. Therefore, it is possible to detect whether or not there is a fluorescent region in the document by checking the image data of the image sensor 401b when the LED light source B which is B color light is irradiated.

  FIG. 6 shows the spectral sensitivity characteristics of the yellow fluorescent pen in the document when the B light is irradiated.

  Reference numeral 602 denotes the spectrum of the light source B of B color light that is irradiation light. Reference numeral 601 denotes a filter characteristic of the filter 404. Reference numeral 603 represents the spectrum of the reflected light of the yellow fluorescent pen in the white original.

  When a white fluorescent region marked with a yellow fluorescent marker is irradiated with monochromatic light of B-color light, which is excitation light, a part of the B-color light is absorbed and is in an excited state. Then, light emission having a wavelength of about 520 [nm] is confirmed when transitioning to the ground state.

  The light emitted from the yellow fluorescent marker during the B-color light irradiation passes through the filter 404 and is accumulated in the image sensor 401b. Therefore, by checking the image data of the image sensor 401b, it is possible to detect whether or not there is a fluorescent region marked with a yellow fluorescent marker in the document.

  When the LED light source G, which is G-color light, is irradiated, the image sensor 401 b is attached with a filter 404 that transmits only the G-color light. Therefore, image data read by the image sensor 401 a and the image sensor 401 b is transmitted by the filter 404. It should be almost the same with only shielding.

  When a fluorescent region is present in the original 201, the reflected light becomes weaker than the irradiated light because the fluorescent region absorbs the irradiated light. In addition, since light emitted from the fluorescent region is longer than the emitted G color light, it is shielded by the filter 404.

  For this reason, a fluorescent region is detected in the document by checking the difference between the image data read by the image sensor 401b and the image data read by the image sensor 401a when the LED light source G, which is G color light, is irradiated. Whether or not there is can be detected.

  FIG. 7 shows the spectral sensitivity characteristics of the pink highlighter pen in the document when G light is irradiated. Reference numeral 604 denotes the spectrum of the light source G of G color light that is irradiation light. Reference numeral 601 denotes a filter characteristic of the filter 404.

  Reference numeral 605 denotes a spectrum of reflected light of the pink fluorescent pen in the white original. When the white fluorescent region marked with a pink fluorescent marker is irradiated with monochromatic light of G color light, which is excitation light, a part of the G color light is absorbed and is in an excited state.

  Then, light emission with a wavelength of about 580 [nm] is confirmed when transitioning to the ground state. Since the irradiated G color light is absorbed by the fluorescent region, the reflected light transmitted through the filter 404 is greatly reduced compared to the irradiated light.

  In addition, since the light emission at the time of transition to the ground state has a wavelength longer than that of the irradiation light, the light emission in the fluorescent region at the time of the G color light irradiation is shielded by the filter 404 and is not accumulated in the image sensor 401b.

  By comparing the image data acquired by the image sensor 401a with the image data acquired by the image sensor 401b, it is possible to detect whether or not there is a fluorescent region in the document.

  In the embodiment described above, a CIS (Contact Image Sensor) is used as an image sensor. An image sensor such as a CCD (Charge Coupled Device) may be used as the image sensor. In addition, the detection process of the fluorescent region included in the document is performed by the host PC, but may be performed inside the image reading apparatus.

  The R color light, G color light, and B color light emitted from the R color light source, the G color light source, and the B color light source are irradiated onto the document, and the reflected light from the document is read by the image sensor that is the first imaging means. When the original is irradiated with the G color light and the B color light simultaneously with the reflection of the reflected light into the image sensor as the first image pickup means, it is taken into the second image pickup means through a filter that transmits only the G color light source. By comparing the image data acquired by the first imaging unit and the second imaging unit, it is possible to realize detection of a fluorescent region marked on a document with a fluorescent pen or a fluorescent marker while following a simple configuration.

In addition, this invention includes the following aspects.
As one aspect of the present invention, a light source that emits three types of light having different wavelengths, a first image reading sensor that reads a first image of a medium from reflected light when the medium is irradiated with light from the light source, and the light source A second image reading sensor that receives transmitted light that passes through the optical filter among reflected light when the medium is irradiated with light from the medium and reads a second image of the medium, and a fluorescent region of the medium based on the second image And an identifying means for identifying the image reading apparatus.
According to this aspect of the present invention, the fluorescent region of the medium can be specified based on the second image obtained through the optical filter while acquiring the first image obtained from the reflected light from the medium without passing through the optical filter.

In the present invention, the specifying unit is configured to generate the fluorescent region based on the second image obtained by the second image reading sensor receiving reflected light having a wavelength different from the wavelength of light emitted from the light source. It may be characterized by specifying the presence of.
According to this aspect of the present invention, the presence of the fluorescent region can be specified on condition that the wavelength of light emission and the wavelength of light reception are different.

In the present invention described above, in an image reading system including an image reading device that reads an image on a medium and an information processing device that is connected to the image reading device and receives an image from the image reading device, the image reading device includes: A light source that emits three types of light having different wavelengths, a first image reading sensor that reads a first image of a medium from reflected light when the medium is irradiated with light from the light source, and a light that is irradiated to the medium from the light source A second image reading sensor that receives transmitted light that passes through the optical filter out of the reflected light and reads a second image of the medium, and the information processing device receives the first image received from the image reading device. An image reading system comprising: a specifying unit that specifies a fluorescent region of a medium based on the second image of the second images.
According to this aspect of the present invention, the fluorescent region of the medium can be specified on the information processing apparatus side.

In the image reading system of the present invention, the specifying means is based on the second image obtained by the second image reading sensor receiving reflected light having a wavelength different from the wavelength of the light emitted from the light source. The presence of the fluorescent region may be specified.
According to this aspect of the present invention, the presence of the fluorescent region can be specified on condition that the wavelength of light emission and the wavelength of light reception are different.

111 CPU
112 Image memory 113 I / F control unit 114 Motor control unit 115 Image reading unit 201 Document (an example of medium)
202 Optical Unit 203 Belt 300 Image Reading Device 401 Image Sensor 402 Light Guide 403 Lens 404 Filter 800 Host Computer

Claims (4)

A light source that emits three types of light with different wavelengths;
A first image reading sensor that reads a first image of a medium from reflected light when the medium is irradiated with light from the light source;
A second image reading sensor that receives transmitted light that passes through an optical filter among reflected light when the medium is irradiated with light from the light source, and reads a second image of the medium;
Specifying means for specifying a fluorescent region of the medium based on the second image;
An image reading apparatus comprising:   The specifying means specifies the presence of the fluorescent region based on the second image obtained by the second image reading sensor receiving reflected light having a wavelength different from the wavelength of the light emitted from the light source. The image reading apparatus according to claim 1, wherein: In an image reading system comprising: an image reading device that reads an image on a medium; and an information processing device that is connected to the image reading device and receives an image from the image reading device.
The image reading apparatus includes: a light source that emits three types of light having different wavelengths; a first image reading sensor that reads a first image of a medium from reflected light when the medium is irradiated with light from the light source; A second image reading sensor that receives the transmitted light that passes through the optical filter among the reflected light when irradiated with light, and reads the second image of the medium, and
The information processing apparatus includes an identification unit that identifies a fluorescent region of a medium based on the second image of the first image and the second image received from the image reading apparatus. Reading system. The specifying means specifies the presence of the fluorescent region based on the second image obtained by the second image reading sensor receiving reflected light having a wavelength different from the wavelength of the light emitted from the light source. The image reading system according to claim 3.

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