JP5650579B2 - Image scanner device - Google Patents

Description

  The present invention relates to an image scanner device, and more particularly, to a stand-type image scanner device used at a financial institution or the like.

  Currently, at a counter of a financial institution such as a bank, a stand-type image scanner device is widely used as a device that can read a medium that cannot be read by a passbook printer, such as a form or a license. Such a stand-type image scanner device is disclosed in, for example, Patent Document 1, Patent Document 2, and Patent Document 3.

  The image acquired by the stand-type image scanner device is also used for purposes such as character recognition and authentication. For this reason, the stand-type image scanner device is required to generate an image that is accurately reflected on the brightness of the medium and is free from positional deviation and distortion. Therefore, it is necessary to perform appropriate adjustment in consideration of individual differences for each device.

  On the other hand, the stand type image scanner device uses external light as illumination light, unlike a flat bed type image scanner device that illuminates a medium with illumination light emitted from a light source provided inside the device. The illuminance distribution on the medium surface strongly depends on the installation environment. For example, as illustrated in FIG. 1, depending on the installation position of the image scanner device 100, the amount of light emitted from the light source 105 such as a fluorescent lamp and applied to the pedestal 103, or the shadow 104 such as the camera head unit 101 or the column 102. The position and strength that can be changed vary. Therefore, it is difficult to perform sufficient adjustment in the adjustment work before shipment of the apparatus in which the installation environment cannot be specified.

  For this reason, in a stand-type image scanner apparatus, after a product is shipped, when a user installs the apparatus, an adjustment operation called calibration is performed. Calibration is a reference adjustment operation for correcting a deviation from the reference. Mainly, correction relating to brightness (for example, pixel gradation correction for uneven illumination distribution due to shadows, etc.) and white balance correction. And correction related to the position (for example, correction of positional deviation, distortion, and magnification).

  By performing the calibration, the stand-type image scanner device can generate an image free from positional deviation and distortion in which the brightness of the medium is correctly reflected regardless of the installation environment and individual differences.

JP 2005-78007 A JP-A-11-103371 JP 2008-61170 A

  Incidentally, as described above, the calibration is a reference adjustment operation for correcting a deviation from the reference. For this reason, the standards for brightness, color balance, position, etc. are necessary for the implementation. In the conventional stand-type image scanner device, in order to specify the standards for brightness, color balance, position, etc. As illustrated in FIG. 1, a reference medium called a calibration sheet 106 is arranged at a predetermined position on the pedestal 103.

  However, the calibration sheet is a sheet specialized for calibration purposes, and needs to be removed from the pedestal when an image is generated by scanning a form or a license, that is, in normal use. Therefore, when performing calibration, it is necessary to place a calibration sheet on the pedestal and remove it after completion.

  In addition, since the calibration sheet determines a reference such as a position, it is necessary to accurately place the calibration sheet at a predetermined position when it is placed on the pedestal of the image scanner apparatus. For this reason, the user is required to perform an accurate operation every time calibration is performed.

  Further, since the calibration sheet is arranged on the pedestal only when performing calibration, it is necessary to manage it separately from the image scanner device. Furthermore, the management is required to be appropriate management that does not deteriorate the calibration sheet.

Thus, when using a calibration sheet, the user is forced to bear various work.
On the other hand, Patent Document 3 discloses a stand-type image scanner device that can perform calibration without using a calibration sheet.

  However, the image scanner device disclosed in Patent Document 3 requires a display unit such as a reflective liquid crystal display instead of the calibration sheet. This complicates the configuration of the apparatus as compared with a conventional stand-type image scanner apparatus that performs calibration using a calibration sheet, and has other technical problems such as an increase in the size of the apparatus and an increase in manufacturing cost. It will occur.

  Therefore, an image scanner device having a configuration different from the configuration disclosed in Patent Document 3 that can perform calibration without using a calibration sheet is required.

  In view of the above circumstances, an object of the present invention is to provide an image scanner device that can perform calibration without using a calibration sheet.

One aspect of the present invention is an image scanner device that images a medium illuminated by external light, and includes an achromatic gray pedestal sheet on which the medium is disposed, and the pedestal sheet is a reference of the pedestal sheet. for indicating the location, it has a reference mark color different achromatic said base sheet, the tone value of the reference mark provides a lower image scanner than the tone value of the pedestal seat.
Another aspect of the present invention is an image scanner device that captures an image of a medium illuminated by external light, including an achromatic gray pedestal sheet on which the medium is arranged, and the pedestal sheet includes the pedestal sheet. A reference mark of an achromatic color different from the color of the pedestal sheet for indicating a reference position, a reference mark showing a gradation value lower than the gradation value of the pedestal sheet, and a reference position of the pedestal sheet Therefore, there is provided an image scanner device including a reference mark of an achromatic color different from the color of the pedestal sheet and having a gradation value higher than the gradation value of the pedestal sheet.

  According to the present invention, it is possible to provide an image scanner device capable of performing calibration without using a calibration sheet.

It is a schematic block diagram of the stand-type image scanner apparatus which concerns on a prior art. It is a figure for demonstrating the characteristic of the stand-type image scanner apparatus and calibration sheet | seat based on a prior art. It is a figure for demonstrating the characteristic of the calibration sheet | seat which concerns on a prior art. It is another figure for demonstrating the characteristic of the calibration sheet | seat based on a prior art. 1 is a schematic configuration diagram of a stand-type image scanner device according to an embodiment of the present invention. It is the figure which illustrated the base sheet of the image scanner apparatus shown by FIG. It is the figure which illustrated the modification of the base sheet of the image scanner apparatus shown by FIG. It is a figure for demonstrating the shadow correction by the calibration sheet | seat which concerns on a prior art. It is a figure for demonstrating the shadow correction by the base sheet of the image scanner apparatus shown by FIG. It is a figure which compares the shadow correction demonstrated in FIG. 8, and the shadow correction demonstrated in FIG. FIG. 6 is a diagram showing a state in which a reading medium is arranged in the image scanner device shown in FIG. 5. It is the figure which showed the relationship between the light quantity from the base sheet of the image scanner apparatus shown by FIG. 5, and the light quantity from the reading medium arrange | positioned on a base sheet.

  First, in order to facilitate understanding of the features of the present invention, features of a stand-type image scanner device and a calibration sheet according to the related art will be described with reference to FIG. FIG. 2 is a diagram for explaining the features of a stand-type image scanner device and a calibration sheet according to the related art.

  The image scanner device 200 according to the related art and the calibration sheets (calibration sheet 204, calibration sheet 205) used for the calibration have the following characteristics.

  The first feature is that the material of the calibration sheet is paper. The main reason for using paper without using a special material for the calibration sheet is that the reading medium 206 targeted by the image scanner device 200 is mainly a paper form. The use of a paper calibration sheet is desirable in that adjustment by calibration can be performed under conditions close to the conditions for acquiring the image of the reading medium 206.

  On the other hand, as illustrated in FIG. 3A, the paper calibration sheet 204 is likely to be bent 204a, bent, or curled 204b. When the calibration sheet 204 having the bent 204a, bending, or curl 204b is abutted against a predetermined structure of the image scanner device 200, the calibration sheet 204 is predetermined as illustrated in FIG. It will deviate from the position. For this reason, the reference position is set incorrectly by calibration. If the reference position is set incorrectly, as shown in FIG. 3C, the recognition / authentication area A1 on the reading medium used for character recognition and authentication and the recognition / authentication on the acquired image are used. Since the area A2 is shifted, the accuracy of character recognition and authentication deteriorates. Further, as illustrated in FIG. 3D, distortion is likely to occur in the paper calibration sheet 204, but when the calibration sheet 204 is very large, the calibration cannot completely correct the distortion. The image will also be distorted.

  The second feature is that the color of the calibration sheet is white. The main reason for using a white calibration sheet is that a white system is suitable as a basic color for white balance correction performed in order to accurately reproduce the hue of the reading medium 206, and a shadow generated in the reading area. Information can be captured more accurately.

  On the other hand, as illustrated in FIG. 4A, in the white calibration sheet 204, dirt 204c and fading are easily noticeable. Further, since the paper calibration sheet 204 has low wear resistance, local color change is likely to occur. When calibration is performed using the calibration sheet 204 in which a local color change has occurred due to dirt or fading, as shown in FIG. 4B, the brightness of the area A3 corresponding to dirt or the like is illustrated. Is not corrected correctly, and as a result, gradation correction and white balance correction that make the brightness uniform are not performed correctly. For this reason, the brightness and color reproducibility of the acquired image are reduced.

  The third feature is that calibration is performed using a plurality of calibration sheets (calibration sheet 204, calibration sheet 205). For example, as illustrated in FIG. 2, a calibration sheet 204 is used for gradation correction and white balance correction for uniform brightness, and a calibration having a reference mark 205a for correction related to position. The action sheet 205 is used. Thus, by sharing the role among a plurality of calibration sheets, the manufacturing cost of each calibration sheet can be suppressed.

  A fourth feature is that the color of the pedestal sheet 203 of the image scanner device 200 is black. Note that the pedestal sheet 203 is a sheet provided in the pedestal portion to indicate an area where the reading medium 206 is to be arranged, and is different from the calibration sheet and is always installed in the image scanner device 200. The main reason for using the black pedestal sheet 203 is that most of the background colors of the reading medium 206 are white, so that it is suitable for detecting the boundary with the reading medium 206 (that is, the four sides of the reading medium 206). It is. It is also desirable that the reflectance of light from a light source such as a fluorescent lamp is lower than that of a white light source.

  Next, a stand-type image scanner device according to this embodiment will be described. FIG. 5 is a schematic configuration diagram of a stand-type image scanner device according to the present embodiment. FIG. 6 is a diagram illustrating a pedestal sheet of the image scanner device shown in FIG. FIG. 7 is a diagram illustrating a modification of the base sheet of the image scanner device shown in FIG.

  An image scanner device 10 illustrated in FIG. 5 is a stand-type image scanner device that captures an image of a medium illuminated by external light. As illustrated in FIG. 5, a camera head unit 11 and a camera head unit 11 are illustrated. And a gray pedestal sheet 13 which is an achromatic color on which a reading medium is arranged.

  As illustrated in FIG. 6, the pedestal sheet 13 has an achromatic reference mark different from the color of the pedestal sheet 13 for indicating the reference position of the pedestal sheet 13. More specifically, the pedestal sheet 13 has a rectangular shape and has four reference marks (reference mark 13a, reference mark 13b, reference mark 13c, reference mark 13d) in the vicinity of at least four corners of the pedestal sheet 13. The gradation values of these four reference marks are lower than the gradation values of the pedestal sheet.

  The material of the pedestal sheet 13 is a polycarbonate resin sheet that has been subjected to a surface antireflection treatment (unevenness by molding). The material of the pedestal sheet 13 may be polyester. However, when the material of the base sheet 13 is polyester, it is desirable that the base sheet 13 is coated with a coating agent for suppressing surface gloss and unevenness.

  In the image scanner device 10 according to the present embodiment, the pedestal sheet 13 indicating the area where the reading medium is to be arranged functions as a calibration sheet when performing calibration. For this reason, the image scanner apparatus 10 can perform calibration without using a calibration sheet.

  Note that the image scanner device 10 may include a pedestal sheet 14 illustrated in FIG. 7 instead of the pedestal sheet 13 illustrated in FIG. 6. The pedestal sheet 14 has a rectangular shape and has four reference marks (reference mark 14a, reference mark 14b, reference mark 14c, reference mark 14d) in the vicinity of at least four corners of the pedestal sheet 13. The same as the sheet 13. However, the pedestal sheet 14 is not only a reference mark (reference mark 14a, reference mark 14b, reference mark 14c) showing a gradation value lower than the gradation value of the pedestal sheet 14, but higher than the gradation value of the pedestal sheet. The difference from the pedestal sheet 13 is that it includes a reference mark 14d indicating a gradation value.

  When imaging the pedestal sheet 14, since the pedestal sheet 14 includes the reference mark 14 d indicating a gradation value higher than the gradation value of the pedestal sheet 14, the width of the gradation value detected by the camera head unit 11 is large. This is wider than when the pedestal sheet 13 is imaged. For this reason, by using the pedestal sheet 14, it is possible to improve the accuracy of correction related to brightness by calibration, compared to the case where the pedestal sheet 13 is used.

  Hereinafter, it will be described more specifically that the pedestal sheet 13 of the image scanner device 10 according to the present embodiment functions as a calibration sheet and that the pedestal sheet 13 functions in the same manner as a conventional pedestal sheet.

  First, the function of the base sheet 13 as a calibration sheet will be described with reference to FIGS. FIG. 8 is a diagram for explaining shadow correction by a calibration sheet according to the related art. FIG. 9 is a diagram for explaining the shadow correction by the pedestal sheet of the image scanner device shown in FIG. FIG. 10 is a diagram comparing the shadow correction described in FIG. 8 with the shadow correction described in FIG.

  For example, as shown in FIG. 8A, in an environment where a shadow S1 having an intensity (density) of 20 and a shadow S2 having an intensity (density) of 40 are generated, a white calibration sheet. As shown in FIG. 8B, the brightness of the image 204 is 100 for the area other than the shadow, 80 (= 100-20) for the area of the shadow S1, and 60 (== for the area of the shadow S2. 100-40). Therefore, in the calibration performed using the white calibration sheet 204 as the reference medium, as shown in FIG. 8C, the brightness of the shadow S1 and shadow S2 areas is 1.25 times (= 100/80), and gradation correction to make the brightness about 1.67 times (≈100 / 60), the brightness is made uniform.

  On the other hand, for example, as shown in FIG. 9A, as in the environment shown in FIG. 8A, a shadow S3 whose strength (density) is 20 and a shadow S4 whose strength (density) is 40 are shown. 9b, the brightness of the image of the gray pedestal sheet 13 having 80% of the gradation compared to the calibration sheet 204 is as shown in FIG. Is 80, the shadow S3 region is 60 (= 80-20), and the shadow S4 region is 40 (= 80-40). For this reason, in the calibration performed using the gray pedestal sheet 13 as the reference medium, as shown in FIG. 9C, the brightness of the shadow S3 and shadow S4 regions is about 1.33 times (≈80 / 60) The brightness is made uniform by performing gradation correction to make the brightness twice (= 80/40).

  That is, as shown in FIG. 10, when the gray pedestal sheet 13 is used as the reference medium, the gain required for tone correction increases compared to the case where the white calibration sheet 204 is used. However, as in the case of the calibration sheet 204, the brightness can be made uniform.

  It should be noted that the lower the brightness of the pedestal sheet 13 (that is, darker) and the stronger the shadow, the greater the gain for correction. In general, in tone correction, noise and the like are amplified equally with other information. If the gain is too large, the absolute size of noise or the like may increase beyond an allowable range. . Further, since the dynamic range decreases as the brightness of the pedestal sheet 13 decreases, the use of the pedestal sheet 13 having an excessively low brightness may cause a significant decrease in the accuracy of gradation correction.

  However, conventionally, the accuracy of the generated image is not guaranteed for the use of the image scanner device in an environment where a strong shadow is projected onto the pedestal. For this reason, assuming that the image scanner device 10 according to the present embodiment is used in an environment similar to that of the conventional image scanner device, an extremely dark gray having an excessively low brightness is used as the color of the base sheet 13. Unless it is used, if the gray gradation value is a gradation value that does not cause saturation (saturation), appropriate gradation correction is possible. Therefore, the gray pedestal sheet 13 functions as a calibration sheet for correction related to brightness.

  Further, since the gray pedestal sheet 13 is achromatic, it is suitable as a basic color for white balance correction, like the white calibration sheet 204. Therefore, the gray pedestal sheet 13 functions as a calibration sheet for white balance correction.

  Further, the pedestal sheet 13 has an achromatic reference mark different from the color (background color) of the pedestal sheet 13. Accordingly, the pedestal sheet 13 functions as a calibration sheet for correction relating to position in addition to correction of brightness and white balance. In the pedestal sheet 13, since the reference marks are arranged in the vicinity of the four corners of the pedestal sheet 13, it is easy to grasp a tendency as to what kind of deviation occurs in the entire reading region. In the pedestal sheet 13, the shape of the reference mark is a square that is symmetrical in the vertical and horizontal directions with respect to the center of the reference mark. For this reason, the amount of deviation and the tendency of deviation can be grasped more accurately. The shape of the reference mark is not limited to a square, and may be any shape that is vertically and horizontally symmetrical with respect to the center of the reference mark.

  Further, since the reference mark of the base sheet 13 is achromatic, the presence of the reference mark does not affect the white balance correction. Further, since the reference marks are arranged at predetermined positions such as near the four corners of the pedestal sheet 13, the brightness can be corrected in advance in consideration of the presence of the reference marks. Therefore, a common pedestal sheet can be used for correction relating to brightness, correction of white balance, and correction relating to position.

  Next, the function of the pedestal sheet 13 in the same manner as a conventional pedestal sheet will be described with reference to FIGS. 11 and 12. FIG. 11 is a diagram showing a state in which a reading medium is arranged in the image scanner device shown in FIG. FIG. 12 is a diagram illustrating a relationship between the light amount from the pedestal sheet of the image scanner device and the light amount from the reading medium arranged on the pedestal sheet.

  As shown in FIG. 11, the pedestal sheet 13 indicating the region where the reading medium 16 is to be arranged is used to detect the contour of the reading medium 16. Specifically, since the pedestal sheet 13 has a reflectance different from that of the reading medium 16 with respect to the light emitted from the light source 15, the pedestal sheet 13 is reflected and reflected by the camera head unit 11. A difference is generated between the amount of light incident on the camera head unit 11 and the amount of light reflected on the reading medium 16 and incident on the camera head unit 11. Based on this light quantity difference, the boundary between the base sheet 13 and the reading medium 16, that is, the outline of the reading medium 16 can be detected.

  Generally, the background color of a reading medium such as a form is white, and as a result, the reading medium 16 has a high reflectance. For this reason, when the reflectance of the pedestal sheet 13 is low, the difference in the amount of light increases as shown in FIG. On the other hand, when the reflectance of the pedestal sheet 13 is high, the difference in the amount of light is small as shown in FIG.

  The color of the pedestal sheet 13 of the image scanner device 10 according to the present embodiment is gray, and the gray pedestal sheet generally has a lower reflectance than a white reading medium. Moreover, as for the material of the base sheet 13, as mentioned above, the base sheet 13 made of a polycarbonate resin sheet subjected to surface antireflection treatment (unevenness by molding) can suppress reflection and gloss. Moreover, when the material of the base sheet 13 is polyester, the coating agent for suppressing the glossiness of the surface of the base sheet 13 is applied. Accordingly, the pedestal sheet 13 has a lower reflectance than the reading medium 16 and can generate a sufficient light amount difference necessary for detecting the contour of the reading medium 16, and thus functions in the same manner as a conventional pedestal sheet. To do.

Finally, the reason why the polycarbonate resin sheet is optimal as the material of the base sheet 13 will be described.
As already described above, if the reflectivity of the pedestal sheet is high, it is difficult to detect the contour of the reading medium 16, so that it is difficult to detect the contour with high accuracy. For this reason, the material of the pedestal sheet is required to have a low reflectance, but the polycarbonate resin sheet can realize a low reflectance while suppressing reflection and gloss.

  In addition, if the pedestal sheet has a lot of color unevenness, accurate brightness cannot be obtained at the time of calibration, and the accuracy of correction related to brightness deteriorates. For this reason, the material for the pedestal sheet is required to have less color unevenness, but the polycarbonate resin sheet has less color unevenness and is suitable for the pedestal sheet.

  In addition, the pedestal sheet is basically always installed in the image scanner device. However, if the pedestal sheet has low durability, the replacement frequency increases. For this reason, high durability is required for the material of the base sheet, but the polycarbonate resin sheet has high durability.

The pedestal sheet is for placing a reading medium. Since the polycarbonate resin sheet is slippery, the reading medium can be easily installed and is suitable for a pedestal sheet.
In this way, the polycarbonate resin sheet satisfies the main requirements for the pedestal sheet, such as low reflectance, low color unevenness, high durability, and good sliding. It is the best material for the sheet.

  In addition, although the polyester material itself is not necessarily optimal as a material for the pedestal sheet, by applying a coating agent for suppressing surface gloss and unevenness, a transparent coating agent (for example, an acrylic coating agent), etc., The above-mentioned requirements can be satisfied.

  As described above, according to the image scanner device 10 of the present embodiment, calibration can be performed using the pedestal sheet 13 without using a calibration sheet. For this reason, the image scanner device 10 according to the present embodiment can eliminate the trouble of accurately arranging the calibration sheet for each calibration.

  Further, since the pedestal sheet 13 is always installed in the image scanner device 10, it is not necessary to manage the pedestal sheet 13 separately from the image scanner device 10, and the management burden can be reduced. In addition, since a pedestal sheet that has been used conventionally is used instead of the calibration sheet for calibration, it is not necessary to make a large change in the apparatus configuration. For this reason, the subject of enlargement of an apparatus or an increase in manufacturing cost does not arise.

  Further, unlike the calibration sheet, the pedestal sheet 13 does not need to be removed for each calibration, and since the material is not paper, the base sheet 13 is bent, bent, curled, etc. as compared with the conventional calibration sheet. It is hard to get dirty. That is, there are few factors that degrade the accuracy of calibration correction. For this reason, the image scanner device 10 according to the present embodiment can stably exhibit high correction performance.

10, 100, 200 Image scanner device 11, 101 Camera head part 12, 102 Post 13, 13, Pedestal sheet 13a, 13b, 13c, 13d, 14a, 14b, 14c, 14d, 205a Reference mark 16, 206 Reading medium 15, 105 Light source 103, 203 Pedestal 104, S1, S2, S3, S4 Shadow 106, 204, 205 Calibration sheet 204a Fold 204b Curl 204c Dirt A1, A2, A3 area

Claims (5)

An image scanner device for imaging a medium illuminated by external light,
A gray pedestal sheet that is achromatic to arrange the medium,
The pedestal seat, possess for indicating a reference position of the base sheet, the reference mark color is different achromatic said base sheet,
The image scanner device according to claim 1, wherein a gradation value of the reference mark is lower than a gradation value of the pedestal sheet . An image scanner device for imaging a medium illuminated by external light,
A gray pedestal sheet that is achromatic to arrange the medium,
The pedestal sheet is
An achromatic reference mark different from the color of the pedestal sheet for indicating the reference position of the pedestal sheet, and a reference mark indicating a gradation value lower than the gradation value of the pedestal sheet;
A reference mark of an achromatic color different from the color of the pedestal sheet for indicating the reference position of the pedestal sheet, the reference mark showing a gradation value higher than the gradation value of the pedestal sheet. An image scanner device characterized by the above. In the image scanner device according to claim 1 or 2 ,
The pedestal sheet is
Presents a rectangular shape, and
Image scanner, characterized in that it comprises four said reference marks in at least four corners of the pedestal seat. The image scanner device according to any one of claims 1 to 3 ,
The material of the pedestal sheet is a polycarbonate resin sheet subjected to a surface antireflection treatment. The image scanner device according to any one of claims 1 to 3 ,
The material of the pedestal sheet is polyester,
An image scanner device, wherein a coating agent for suppressing surface gloss and unevenness is applied to the pedestal sheet.