JP2010266405A - Spectral characteristic acquisition device array and image evaluation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spectral characteristic acquisition device array capable of measuring data at the same point on an image carrier medium even if the conveyance speed of the image carrier medium varies and the image carrier medium is conveyed slantly with respect to a predetermined conveyance direction in measuring spectral characteristics of an image formed on the image carrier medium over a full width, and an image evaluation device using the same. <P>SOLUTION: The spectral characteristic acquisition device array comprises a plurality of spectral characteristic acquisition devices arranged side by side. Each spectral characteristic acquisition device includes a first light irradiating means and a second light irradiating means for irradiating a target to be read with light and a light receiving means having a plurality of photoelectric conversion regions arranged in a line for acquiring diffused reflected light of the light from the first light irradiating means and the second light irradiating means to irradiate the target. The respective first light irradiating means of the respective spectral characteristic acquisition devices have light sources with spectral distribution different from one another. The respective second light irradiating means of the respective spectral characteristic acquisition devices have light sources with the same spectral distribution. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a spectral characteristic acquisition device array that acquires spectral characteristics of an image formed on an image bearing medium, and an image evaluation apparatus using the spectral characteristic acquisition device array.

  There are many image products in the market, such as printers, copiers, multi-function printers that are high value-added products such as printers and communication functions, and commercial printers. Electrophotographic methods, ink jet methods, and heat sensitive image forming methods are also available. There are various methods. In the field of production printing, digitization of both sheet-fed machines and continuous book machines has progressed, and many products such as electrophotographic systems and ink jet systems have been put on the market. As user needs shift from monochrome printing to color printing, multi-dimensional images and high-definition and high-density printing are promoted, high-quality photo printing, catalog printing, and advertisements that respond to individual preferences for invoices, etc. With the diversification of service forms that can be delivered to customers, demands for high image quality, guarantee of personal information, and color reproduction are also increasing.

  As a technology that supports high image quality, the electrophotographic system is equipped with a density sensor that detects the toner density before fixing on the intermediate transfer member and photoconductor to stabilize the toner supply amount. Regardless of the method, the output image is captured by a camera or the like and inspected by character recognition or difference detection based on the difference between images. For color reproduction, a color patch is output, and one or more color measurements are performed with a spectrometer. Things to do have been put on the market. These techniques are preferably executed over the entire image in order to cope with image variations between pages and within pages.

  As a technique for measuring the spectral characteristics of an image formed on an image carrying medium in full width, for example, an image carrying medium that scans at high speed while maintaining a 45/0 arrangement geometry used in a general spectral characteristic obtaining apparatus. A technique for measuring the color of an image formed in the above is disclosed. More specifically, a line scanner including an irradiation system including a light source and a collimator lens and a photoelectric light receiving unit including a selfoc lens array, a color filter, and a CIS element is different from each other only in the spectral characteristics of the color filter ( For example, a multi-channel line scanner configuration in which six line scanners are arranged in parallel to each other is disclosed (see, for example, Patent Document 1) where two line scanners share one light source.

  However, in the conventional technology, a plurality of line scanners are installed at a certain distance, so that the image carrying medium fluctuates or the image carrying medium is conveyed obliquely with respect to a predetermined conveying direction. In this case, there is a problem that the measurement data of each point output from each line scanner is not the data of the same point on the image bearing medium, and an accurate color cannot be measured.

  In view of the above points, when measuring the spectral characteristics of the image formed on the image carrying medium in full width, when the carrying speed of the image carrying medium fluctuates, or when the image carrying medium is oblique with respect to the predetermined carrying direction It is an object of the present invention to provide a spectral characteristic acquisition device array capable of measuring data at the same point on an image bearing medium and an image evaluation device using the same even when being conveyed.

  The spectral characteristic acquisition apparatus array is a spectral characteristic acquisition apparatus array in which a plurality of spectral characteristic acquisition apparatuses are arranged in parallel, and each spectral characteristic acquisition apparatus includes a first light irradiation unit that irradiates light to a reading object, and A plurality of photoelectric elements arranged in a row for obtaining diffuse reflected light of the light irradiated to the reading object from the second light irradiation means, the first light irradiation means and the second light irradiation means; Light receiving means having a conversion region, and each first light irradiating means of each of the spectral characteristic acquisition devices has a light source having a different spectral distribution from each other, and each second of the spectral characteristic acquisition devices. The light irradiating means is required to have light sources having the same spectral distribution.

  According to the disclosed technique, when the spectral characteristics of an image formed on an image bearing medium are measured at full width, the image bearing medium is moved obliquely with respect to a predetermined conveying direction when the conveying speed of the image bearing medium fluctuates. The spectral characteristic acquisition device array capable of measuring the data of the same point on the image bearing medium and the image evaluation device using the same can be provided.

It is a figure which illustrates the spectral characteristic acquisition apparatus which comprises the spectral characteristic acquisition apparatus array which concerns on 1st Embodiment. It is a figure which illustrates the spectral characteristic acquisition device array which concerns on 1st Embodiment. 1 is a block diagram illustrating an image evaluation apparatus according to a first embodiment. It is a figure which illustrates the spectral characteristic acquisition apparatus array which concerns on 2nd Embodiment. It is a figure which illustrates the spectral characteristic acquisition apparatus array which concerns on 3rd Embodiment. It is a figure which illustrates the spectral characteristic acquisition device array which concerns on 4th Embodiment.

  Hereinafter, embodiments will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is a diagram illustrating a spectral characteristic acquisition device that constitutes the spectral characteristic acquisition device array according to the first embodiment. Referring to FIG. 1, the spectral characteristic acquisition device 40 a includes a first light irradiation unit 10 a, a second light irradiation unit 20, and a photoelectric light receiving unit 30. Reference numeral 90 denotes an image bearing medium (paper or the like). The image carrying medium 90 is conveyed in the arrow direction (Y direction).

  In the optical system of the spectral characteristic acquisition device 40a, the illumination light emitted from the first light irradiation unit 10a or the second light irradiation unit 20 is incident on the image bearing medium 90 at an angle of approximately 45 degrees, and photoelectric reception is performed. The unit 30 is a so-called 45/0 optical system that receives light diffusely reflected from the image bearing medium 90 in a substantially vertical direction.

  The first light irradiation unit 10 a includes a line illumination light source 11 a and a collimating lens 12. The line illumination light source 11a has a function of irradiating light. As the line illumination light source 11a, for example, an LED (Light Emitting Diode) array having a predetermined spectral distribution can be used. The LED array has a plurality of LEDs arranged in the direction perpendicular to the paper surface (X direction) in FIG. The collimating lens 12 has a function of collimating the light emitted from the line illumination light source 11a onto the image carrying medium 90 (as parallel light). As the line illumination light source 11a and the collimating lens 12, a unit in which a light source and a collimating lens are integrated like a so-called bullet-type LED may be used. The line illumination light source 11a and the collimating lens 12 constitute a typical example of the first light irradiation means according to the present invention. However, the collimating lens 12 can be omitted.

  The second light irradiation unit 20 includes a line illumination light source 21 and a collimating lens 22. The line illumination light source 21 has a function of irradiating light. As the line illumination light source 21, an LED (Light Emitting Diode) array or the like having a spectral distribution different from that of the line illumination light source 11a can be used. More specifically, as the line illumination light source 21, a white LED array having intensity over almost the entire visible light region can be used. The LED array has a plurality of LEDs arranged in the direction perpendicular to the paper surface (X direction) in FIG. The collimator lens 22 has a function of collimating the light emitted from the line illumination light source 21 onto the image bearing medium 90 (as parallel light). As the line illumination light source 21 and the collimating lens 22, a unit in which a light source and a collimating lens are integrated like a so-called bullet-type LED may be used. The line illumination light source 21 and the collimating lens 22 constitute a typical example of the second light irradiation means according to the present invention. However, the collimating lens 22 can be omitted.

  The photoelectric light receiving unit 30 includes an imaging optical system 31 and a line sensor 32. The image forming optical system 31 functions as an image forming unit that forms an image on the line sensor 32 of the diffuse reflection light of the light applied to the image carrier medium 90 from the first light irradiation unit 10a or the second light irradiation unit 20. Have As the imaging optical system 31, for example, an element in which equal-magnification erect imaging elements such as a SELFOC lens array manufactured by Nippon Sheet Glass Co., Ltd. are arranged in the direction perpendicular to the plane of the paper (X direction) in FIG. 1 can be used.

  The line sensor 32 has a plurality of pixels (photoelectric conversion regions) arranged in a line in the vertical direction (X direction) in FIG. 1 and receives light diffused and reflected by the imaging optical system 31. As a function. As the line sensor 32, for example, a metal oxide semiconductor device (MOS), a complementary metal oxide semiconductor device (CMOS), a charge coupled device (CCD), a contact image sensor (CIS), or the like can be used.

  FIG. 2 is a diagram illustrating a spectral characteristic acquisition device array according to the first embodiment. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof may be omitted. Referring to FIG. 2, the spectral characteristic acquisition device array 40 has a configuration in which a plurality of spectral characteristic acquisition devices 40 a to 40 f are arranged in the Y direction.

  The spectral characteristic acquisition devices 40b to 40f have the same configuration as the spectral characteristic acquisition device 40a shown in FIG. 1, but have first light irradiation units 10b to 10f instead of the first light irradiation unit 10a. The line illumination light sources 11a to 11f constituting the first light irradiation units 10a to 10f have different spectral distributions. As the line illumination light sources 11a to 11f, for example, LED (Light Emitting Diode) arrays having different center wavelengths can be used. As a result, it is possible to obtain light that is relatively stable and has the same spectral distribution and is limited to a predetermined wavelength range.

  In addition, each line illumination light source 21 which comprises each 2nd light irradiation unit 20 of the spectral characteristic acquisition apparatuses 40a-40f is a light source which all have the same spectral distribution. Specifically, for example, the same white LED array can be used.

  In the spectral characteristic acquisition device array 40, six spectral characteristic acquisition devices (spectral characteristic acquisition devices 40a to 40f) are arranged in parallel, but any number of spectral characteristic acquisition devices may be arranged in parallel. For example, it can be selected in the range of about 4 to 16 according to the required accuracy.

  FIG. 3 is a block diagram illustrating an image evaluation apparatus according to the first embodiment. 3, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and the description thereof may be omitted. Referring to FIG. 3, the image evaluation device 50 includes a spectral characteristic acquisition device array 40, a clock generation unit 51, a lighting unit 52, an image data extraction unit 53, and a calculation unit 54.

  The clock generation means 51 has a function of generating a CLK signal that is a reference signal. The lighting means 52 has a function of alternately lighting the first light irradiation units 10a to 10f and the second light irradiation units 20. The image data extraction means 53 outputs the first light irradiation units 10a to 10f and the second light irradiation units 20 that are alternately lit from the output signals of the photoelectric light receiving unit 30 corresponding to the diffuse reflection light of the first light irradiation units 10a to 10f. The first image data corresponding to the irradiation of the light irradiation units 10a to 10f and the second image data corresponding to the irradiation of the second light irradiation unit 20 are separated and extracted. The computing means 54 calculates the amount of positional deviation of each first image data from each second image data, and based on the calculated amount of positional deviation, the image bearing medium that is the object to be read from each first image data 90 has a function of calculating the spectral distribution of the image formed in 90.

  In the image evaluation apparatus 50, the CLK signal generated by the clock generation unit 51 is input to each photoelectric light receiving unit 30 of the spectral characteristic acquisition apparatuses 40 a to 40 f constituting the spectral characteristic acquisition apparatus array 40. Although not shown, the CLK signal is also input to the lighting means 52, the image data extraction means 53, and the calculation means 54. The lighting means 52 alternately lights the first light irradiation units 10a to 10f and the second light irradiation units 20 of the spectral characteristic acquisition devices 40a to 40f in synchronization with the input CLK signal. Since the image bearing medium 90 is conveyed in the direction of the arrow (Y direction) in FIG. 2, the image data extracting means 53 is connected to each of the photoelectric receiving units 30 of the spectral characteristic acquisition devices 40a to 40f by the first line. The first image data illuminated by the light irradiation units 10a to 10f and the second image data illuminated by the second light irradiation units 20 can be separated and extracted. These are different image data.

  As described above, since the line illumination light sources 11a to 11f constituting the first light irradiation units 10a to 10f of the spectral characteristic acquisition devices 40a to 40f have different spectral distributions, the first image data has different spectral distributions. Is image data corresponding to. Therefore, the color (spectral distribution) of the image formed on the image bearing medium 90 can be calculated from the first image data.

  On the other hand, as described above, the line illumination light sources 21 constituting the second light irradiation units 20 of the spectral characteristic acquisition devices 40a to 40f are all light sources having the same spectral distribution. Therefore, the color of the image formed on the image bearing medium 90 cannot be calculated from the second image data. The second image data is used to calculate the amount of misalignment when the spectral characteristic acquisition devices 40a to 40f acquire an image formed on the image bearing medium 90.

  The calculation means 54 divides each second image data into a plurality of areas, and then prints the divided second image data on an image carrier medium 90 stored in a storage means (not shown). Compared with the printing image data used in the above, the amount of positional deviation in the transport direction of the image carrier medium 90 in each area and the direction orthogonal thereto is calculated. Then, based on the calculated amount of misalignment, the color (spectral distribution) at each point of the print image data from each first image data obtained from each photoelectric light receiving unit 30 of the spectral characteristic acquisition devices 40a to 40f. Is calculated.

  The image evaluation apparatus 50 includes, for example, a CPU, a ROM, a main memory, and the like (not shown). The functions of the lighting unit 52, the image data extraction unit 53, and the calculation unit 54 are such that a program recorded in the ROM is read into the main memory. Implemented by the CPU. At this time, an existing image processing method or the like may be used. However, some or all of the lighting unit 52, the image data extraction unit 53, and the calculation unit 54 may be realized only by hardware. Further, the lighting means 52, the image data extraction means 53, and the calculation means 54 may be physically configured by a plurality of devices.

  As described above, according to the first embodiment, the image bearing medium is conveyed in a predetermined direction. Then, by alternately lighting each first light irradiation unit having a different spectral distribution and each second light irradiation unit having the same spectral distribution of each spectral characteristic acquisition device constituting the spectral characteristic acquisition device array. Both the first image data for color measurement and the second image data for alignment are acquired. Further, by calculating the positional deviation amount from the second image data for alignment obtained from each spectral characteristic acquisition device, an image is obtained from the first image data for colorimetry based on the calculated positional deviation amount. An accurate spectral distribution of each point on the carrier medium can be obtained.

  Also, by estimating the tristimulus values from the obtained spectral distribution and calculating the color (L * a * b *, etc.), if the transport speed of the transported image bearing medium fluctuates, Even when transported obliquely with respect to a predetermined transport direction, it is possible to measure data at the same point on the image bearing medium, and accurately measure and evaluate the colors of all images on the image bearing medium. be able to.

  In addition, since spectral characteristics can be acquired without using a sensor having a two-dimensional pixel structure with a slow readout speed, high-speed data readout is possible.

<Second Embodiment>
In the second embodiment, an example of a spectral characteristic acquisition device array different from the first embodiment is shown. Hereinafter, the description of the parts common to the first embodiment will be omitted, and description will be made focusing on the parts different from the first embodiment.

  FIG. 4 is a diagram illustrating a spectral characteristic acquisition device array according to the second embodiment. 4, the same components as those in FIGS. 1 to 3 are denoted by the same reference numerals, and the description thereof may be omitted. Referring to FIG. 4, the spectral characteristic acquisition device array 60 has a configuration in which a plurality of spectral characteristic acquisition devices 60a to 60f are arranged in parallel in the Y direction.

  In the spectral characteristic acquisition devices 60a to 60f, the line illumination light source 21 is deleted from the spectral characteristic acquisition devices 40a to 40f shown in FIG. The spectral characteristic acquisition devices 60 a and 60 b have a common line illumination light source 61. The spectral characteristic acquisition devices 60 c and 60 d have a common line illumination light source 61. The spectral characteristic acquisition devices 60 e and 60 f have a common line illumination light source 61. In the spectral characteristic acquisition devices 60a to 60f, the common line illumination light source 61 and each collimator lens 22 constitute the second light irradiation unit 20 of the spectral characteristic acquisition devices 60a to 60f. As the line illumination light source 61, similarly to the line illumination light source 21, a white LED array or the like having an intensity in almost the entire visible light region can be used. Since the other points of the spectral characteristic acquisition devices 60a to 60f are the same as those of the spectral characteristic acquisition devices 40a to 40f, description thereof will be omitted.

  In the spectral characteristic acquisition device array 60, six spectral characteristic acquisition devices (spectral characteristic acquisition devices 60a to 60f) are arranged in parallel, but any number of spectral characteristic acquisition devices may be arranged in parallel. For example, it can be selected in the range of about 4 to 16 according to the required accuracy.

  An image evaluation apparatus similar to that of the first embodiment can be realized by using the spectral characteristic acquisition apparatus array 60 according to the second embodiment. At this time, the only difference is that the line illumination light source 61 is turned on at the timing of turning on the line illumination light source 21 of the spectral characteristic acquisition device array 40 according to the first embodiment. .

  As described above, according to the second embodiment, the same effects as those of the first embodiment can be obtained, but the following effects can be further obtained. That is, in the spectral characteristic acquisition apparatus array, by sharing the line illumination light source between the adjacent spectral characteristic acquisition apparatuses, it is possible to reduce the number of parts and to reduce the manufacturing cost of the spectral characteristic acquisition apparatus array. .

<Third Embodiment>
In the third embodiment, an example of a spectral characteristic acquisition device array different from the first embodiment is shown. Hereinafter, the description of the parts common to the first embodiment will be omitted, and description will be made focusing on the parts different from the first embodiment.

  FIG. 5 is a diagram illustrating a spectral characteristic acquisition device array according to the third embodiment. 5, the same components as those in FIGS. 1 to 4 are denoted by the same reference numerals, and the description thereof may be omitted. Referring to FIG. 5, the spectral characteristic acquisition device array 70 has a configuration in which a plurality of spectral characteristic acquisition devices 70a to 70f are arranged in parallel in the Y direction.

  In the spectral characteristic acquisition device 70a, the line illumination light source 21 and the collimating lens 22 are deleted from the spectral characteristic acquisition device 40a shown in FIG. 2, and the line illumination light source 11a is replaced with a line illumination light source 72a and a line illumination light source 74. . The line illumination light source 72a and the line illumination light source 74 are two-wavelength light sources installed in close proximity. As the line illumination light source 72a, for example, an LED (Light Emitting Diode) array having a predetermined spectral distribution can be used. As the line illumination light source 74, a white LED array or the like having an intensity in almost the entire visible light region can be used.

  The line illumination light source 72a and the collimating lens 12 constitute a first light irradiation unit 71a. Further, the line illumination light source 74 and the collimating lens 12 constitute a second light irradiation unit 73. Thus, the first light irradiation unit 71a and the second light irradiation unit 73 share the collimating lens 12.

  The spectral characteristic acquisition devices 70b to 70f have the same configuration as the spectral characteristic acquisition device 70a, but include first light irradiation units 71b to 71f instead of the first light irradiation unit 71a. The line illumination light sources 72a to 72f constituting the first light irradiation units 71a to 71f have different spectral distributions. As the line illumination light sources 72a to 72f, for example, LED (Light Emitting Diode) arrays having different center wavelengths can be used. As a result, it is possible to obtain light that is relatively stable and has the same spectral distribution and is limited to a predetermined wavelength range.

  In addition, each line illumination light source 74 which comprises each 2nd light irradiation unit 73 of the spectral characteristic acquisition apparatuses 70a-70f is a light source which all have the same spectral distribution. Specifically, for example, the same white LED array can be used. The other points of the spectral characteristic acquisition devices 70a to 70f are the same as those of the spectral characteristic acquisition devices 40a to 40f, and thus the description thereof is omitted.

  In the spectral characteristic acquisition device array 70, six spectral characteristic acquisition devices (spectral characteristic acquisition devices 70a to 70f) are arranged in parallel, but any number of spectral characteristic acquisition devices may be arranged in parallel. For example, it can be selected in the range of about 4 to 16 according to the required accuracy.

  An image evaluation apparatus similar to that of the first embodiment can be realized by using the spectral characteristic acquisition apparatus array 70 according to the third embodiment. At this time, the line illumination light sources 72a to 72f are turned on at the timing of turning on the line illumination light sources 11a to 11f of the spectral characteristic acquisition device array 40 according to the first embodiment, and the line illumination is turned on at the timing of turning on the line illumination light source 21. Since only the point which lights the light source 74 differs and others are the same, the description is abbreviate | omitted.

  As described above, according to the third embodiment, the same effects as those of the first embodiment are obtained, but the following effects are further obtained. That is, in each spectral characteristic acquisition device constituting the spectral characteristic acquisition device array, it is possible to reduce the number of parts by sharing a collimating lens using a two-wavelength light source in which two line illumination light sources are arranged close to each other. Thus, the manufacturing cost of the spectral characteristic acquisition device array can be reduced.

  Further, the spectral characteristic acquisition device array can be reduced in size.

<Fourth embodiment>
In the fourth embodiment, an example of a spectral characteristic acquisition device array different from the first embodiment is shown. Hereinafter, the description of the parts common to the first embodiment will be omitted, and description will be made focusing on the parts different from the first embodiment.

  FIG. 6 is a diagram illustrating a spectral characteristic acquisition device array according to the fourth embodiment. 6, the same components as those in FIGS. 1 to 5 are denoted by the same reference numerals, and the description thereof may be omitted. Referring to FIG. 6, the spectral characteristic acquisition device array 80 has a configuration in which a plurality of spectral characteristic acquisition devices 80 a to 80 f are arranged in the Y direction.

  In the spectral characteristic acquisition apparatuses 80a to 80f, the line illumination light source 21 is deleted from the spectral characteristic acquisition apparatuses 40a to 40f illustrated in FIG. 2, and light is guided from one shared light source 81 and the shared light source 81 to the spectral characteristic acquisition apparatuses 80a to 80f. An optical fiber bundle 83 is added. The shared light source 81 is configured to be replaceable. The light emitted from the shared light source 81 is guided to the six optical fiber bundles 83 corresponding to the spectral characteristic acquisition devices 80a to 80f and is incident on the collimating lenses 22 constituting the spectral characteristic acquisition devices 80a to 80f. The image bearing medium 90 is irradiated via 22.

  The shared light source 81, the optical fiber bundle 83, and the collimating lens 22 constitute a second light irradiation unit 82 of the spectral characteristic acquisition devices 80a to 80f. As the shared light source 81, as in the case of the line illumination light source 21, a white LED array having an intensity in almost the entire visible light region can be used. The other points of the spectral characteristic acquisition devices 80a to 80f are the same as those of the spectral characteristic acquisition devices 40a to 40f, and thus the description thereof is omitted.

  By using one shared light source 81 as the light source of the second light irradiation unit 82 of the spectral characteristic acquisition devices 80a to 80f, the spectral distribution of the light source of the second light irradiation unit 82 of the spectral characteristic acquisition devices 80a to 80f can be obtained. This can be easily changed by changing the shared light source 81 or inserting a filter for limiting the spectral distribution between the shared light source 81 and the optical fiber bundle 83. As a result, it is possible to easily change the spectral distribution of the light beam used for the second image data for alignment (the light beam of the shared light source 81) according to the characteristics of the measurement target surface of the image bearing medium 90.

  For example, when there are many images such as characters made of black ink on the surface to be measured of the image bearing medium 90, near red rather than using a light source that emits white light as the shared light source 81 that is the light source of the second light irradiation unit 82. It is advantageous to use a light source that emits external light. The reason will be described below. Color inks such as cyan, magenta, and yellow are mainly used as images and background colors, so they are often used as intermediate colors for screening, etc., and the contrast of the image is low. The contrast of the captured image is high. Here, color ink hardly absorbs near infrared light, and only black ink absorbs infrared light well. Therefore, since an image of only black ink can be captured by imaging with near infrared light, the acquired image has a high contrast and can be positioned more accurately by image processing. Therefore, for a printed matter having a sufficiently large number of characters or the like using black ink, it is possible to measure with higher accuracy by using a light source that emits near infrared light as the shared light source 81.

  In the spectral characteristic acquisition device array 80, six spectral characteristic acquisition devices (spectral characteristic acquisition devices 80a to 80f) are arranged in parallel, but any number of spectral characteristic acquisition devices may be arranged in parallel. For example, it can be selected in the range of about 4 to 16 according to the required accuracy.

  An image evaluation apparatus similar to that of the first embodiment can be realized by using the spectral characteristic acquisition apparatus array 80 according to the fourth embodiment. At this time, only the shared light source 81 is turned on at the timing of turning on the line illumination light source 21 of the spectral characteristic acquisition device array 40 according to the first embodiment, and the others are the same.

  As described above, according to the fourth embodiment, the same effects as those of the first embodiment are obtained, but the following effects are further obtained. That is, by using one shared light source as the light source of the second light irradiation unit of each spectral characteristic acquisition device, it is possible to reduce the number of parts and reduce the manufacturing cost of the spectral characteristic acquisition device array. it can.

  Further, the spectral distribution of the light source of the second light irradiation unit of each spectral characteristic acquisition device is changed by one shared light source, or a filter for limiting the spectral distribution is inserted between the shared light source and the optical fiber bundle. This makes it easy to change. As a result, the spectral distribution of the light beam (the light beam of the shared light source) used for the second image data for alignment can be easily changed according to the characteristics of the measured surface of the image bearing medium.

  The preferred embodiment has been described in detail above. However, the present invention is not limited to the above-described embodiment, and various modifications and replacements are made to the above-described embodiment without departing from the scope described in the claims. Can be added.

10a to 10f, 71a to 71f First light irradiation unit 11a, 21, 61, 72a to 72f, 74 Line illumination light source 12, 22 Collimator lens 20, 73, 82 Second light irradiation unit 30 Photoelectric light receiving unit 31 Imaging Optical system 32 Line sensor 40, 60, 70, 80 Spectral characteristic acquisition device array 40a-40f, 60a-60f, 70a-70f, 80a-80f Spectral characteristic acquisition device 50 Image evaluation device 51 Clock generation means 52 Lighting means 53 Image data Extraction means 54 Calculation means 81 Shared light source 83 Optical fiber bundle 90 Image bearing medium

Special table 2008-518218 gazette

Claims (6)

A spectral characteristic acquisition device array in which a plurality of spectral characteristic acquisition devices are arranged in parallel,
Each spectral characteristic acquisition device
A first light irradiation means and a second light irradiation means for irradiating the reading object with light;
A light receiving means having a plurality of photoelectric conversion regions arranged in a line, for obtaining diffuse reflection light of the light irradiated on the reading object from the first light irradiation means and the second light irradiation means; Comprising
Each first light irradiation unit of each spectral characteristic acquisition device has a light source having a different spectral distribution, and each second light irradiation unit of each spectral characteristic acquisition device has a light source having the same spectral distribution. A spectral characteristic acquisition device array. Each of the second light irradiation means includes:
A shared light source,
The spectral characteristic acquisition apparatus array according to claim 1, further comprising: a light branching unit that guides light emitted from the shared light source to each spectral characteristic acquisition apparatus.   The spectral characteristic acquisition device array according to claim 2, wherein the shared light source is configured to be replaceable. In each of the spectral characteristic acquisition devices, the first light irradiation unit and the second light irradiation unit are arranged close to each other,
The spectral characteristic acquisition device array according to claim 1, further comprising conversion means for converting light emitted from the first light irradiation means and the second light irradiation means into parallel light.   The spectral characteristic acquisition apparatus array according to claim 1, wherein among the plurality of spectral characteristic acquisition apparatuses, adjacent spectral characteristic acquisition apparatuses share a light source that constitutes the second light irradiation unit. The spectral characteristic acquisition device array according to any one of claims 1 to 5,
Lighting means for alternately lighting the first light irradiating means and the second light irradiating means of each spectral characteristic acquiring device constituting the spectral characteristic acquiring apparatus array;
From each output signal of each light receiving means corresponding to the diffusely reflected light from each of the first light irradiating means and each of the second light irradiating means that are alternately lit, the first light irradiating means Image data extraction means for separating and extracting each first image data corresponding to irradiation and each second image data corresponding to irradiation of each second light irradiation means;
An image evaluation apparatus comprising: an arithmetic unit that calculates a spectral distribution of the reading object from each first image data based on a positional deviation amount calculated from each second image data.

Images