JP4973473B2 - Non-contact scanner - Google Patents

Description

  The present invention relates to a non-contact scanner.

  In order to save the contents described in the form as image data, a mat part for placing the form etc. with the imaging surface facing upward, a digital camera installed at a certain height above the mat part, etc. A non-contact scanner having an imaging unit is used (see, for example, Patent Document 1). In such a non-contact scanner, the image data of the form is acquired by using the reflected light from the form surface derived from normal indoor illumination light or the like.

  When this non-contact scanner is used to image a glossy imaging surface such as a license, a part of the imaging surface causes so-called whitening due to reflected light from the imaging surface, and a part of the image is There may be a problem in visibility due to faint or missing white. As a method for solving such a problem, there can be considered a method of performing imaging by placing an imaging medium directly under an imaging unit in which reflection from the imaging surface is unlikely to occur.

However, even when the imaging medium is placed directly under the imaging unit, whiteout may occur partially due to warpage of the imaging medium. Also, if the image pickup unit is enlarged by making the shadow of the image pickup unit larger and the image pickup surface of the image pickup medium fits in the shadow, whiteout can be suppressed, but the image pickup unit becomes larger. It becomes difficult to ensure the illuminance of the imaging surface, and a new problem arises that it becomes difficult to obtain a clear image.
JP 2002-344739

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a non-contact scanner capable of reducing reflected light from an imaging medium incident on an imaging unit.

A non-contact scanner according to the present invention includes a holding member having a concave curved surface for holding an image pickup medium, an image pickup unit for picking up the image pickup medium held by the holding member, and the image pickup unit and the holding member. comprising a space holding portion which are spaced from each other by a constant interval between the concave curved surface of the holding member has an arcuate cross-section, drawn from the optical focal point of the imaging unit vertically against the concave curved surface normal Is equal to the radius of curvature of the concave curved surface.

  ADVANTAGE OF THE INVENTION According to this invention, the reflected light from the to-be-imaged medium which injects into an imaging part can be reduced. Therefore, it is possible to obtain a clear image without whiteout when the imaged medium is imaged. In addition, when the concave curved surface of the holding member is a cylindrical concave curved surface, wrinkles are unlikely to occur on the imaged medium.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view showing the schematic structure of the non-contact scanner, and FIG. 2 is a plan view showing the schematic structure of the non-contact scanner. The non-contact scanner 10 includes a holding jig 14 that is a holding member having a cylindrical concave curved surface for holding an imaged document 21 as an image pickup medium, and a mat portion (stage) 13 for mounting the holding jig 14. As an interval holder that holds the imaging unit 11 by separating the imaging unit 11 that captures the imaging document 21 held by the holding jig 14, and the imaging unit 11 and the holding jig 14 at a predetermined interval. A support column 12 is provided.

  Here, the imaged document 21 refers to a card having a license or a laminate process, glossy paper on which a predetermined image or photo is printed, and the like having a glossy surface.

  FIG. 3 is a perspective view showing a schematic structure of the holding jig. The shape and installation direction of the holding jig 14 are closely related to the shape, installation height, and installation direction of the imaging unit 11. Therefore, in order to simply and clearly describe the configuration of the non-contact scanner 10 in consideration of these relationships, the upper surface (horizontal plane) of the mat portion 13 is an XY plane as shown in FIGS. A three-dimensional orthogonal coordinate system is defined in which the direction (vertical direction) orthogonal to the XY plane is the Z direction.

  The holding jig 14 has a cylindrical concave curved surface with a radius of curvature R facing the imaging unit 11 side (Z direction) and an arc-shaped side surface (hereinafter referred to as “arc-shaped side surface”) parallel to the X direction. The mat portion 13 is mounted such that the side surface on the straight line (hereinafter referred to as “straight side surface”) is parallel to the Y direction. A circle S shown in FIG. 1 is a circle having a radius R with the inner periphery of the holding jig 14 as a part of an arc, and the center thereof coincides with the optical focus P of the imaging unit 11 as described later. To do.

  The holding jig 14 is detachable from the mat portion 13. As this attachment / detachment mechanism, projections 16 are formed at two locations separated in the Y direction at the center in the X direction on the back surface of the holding jig 14, and a hole 17 for fitting the projection 16 into the mat portion 13. Is formed. This attachment / detachment mechanism also serves to position the holding jig 14 with respect to the mat portion 13.

  In the vicinity of one linear side surface on the cylindrical concave surface of the holding jig 14, a clip portion 15 having a function of pressing the imaging paper 21 against the cylindrical concave curved surface of the holding jig 14 extends in the Y direction. Is provided. When a blank portion of the imaged document 21 that does not require imaging is sandwiched between the clip portions 15, the position of the imaged document 21 is fixed and the imaged document 21 is held in close contact with the cylindrical concave surface of the holding jig 14. The By fixing the imaged document 21 to the holding jig 14 in this way, it is possible to suppress wrinkling of the imaged document 21.

  The imaging unit 11 includes a so-called digital camera 26 that captures a captured image using an optical system composed of a plurality of lenses in a light receiving element such as a CCD or CMOS inside a housing 25 having a spheroid shape. Are preferably used. The digital camera 26 is housed inside the housing 25 so that the optical system focal point P is located directly below the center of the housing 25.

The imaging unit 11 is configured so that the major axis of the housing 25 is parallel to the Y direction, and the optical focus P of the digital camera 26 is positioned directly above the center of the cylindrical concave surface of the holding jig 14. as the length of the normal line drawn perpendicular against the cylindrical concave surface of the holding jig 14 from the optical focal point P is equal to the radius of curvature R of the cylindrical concave surface, is positioned by struts 12, it is retained ing. In other words, the holding jig 14 needs to be attached to the mat portion 13 so that the above condition is satisfied when the imaging unit 11 is installed at a certain position.

Although the imaging document 21 has a certain thickness, so long as the imaging document 21 is in close contact along the cylindrical concave surface, the law line from the optical focal point P of the digital camera 26 to the surface of the imaging document 21 The length and the radius of curvature of the surface of the imaged document 21 are equal. Further, even when a plurality of imaging originals 21 are bundled in a booklet shape and a page necessary for imaging needs to be opened and imaged, the bundled imaging originals 21 are held in close contact with each other along the cylindrical concave curved surface. lever, is equal to the length of the legal line from the optical focal point P of the digital camera 26 to the uppermost surface of the imaging document 21 and the radius of curvature of the surface of the imaging document 21.

  Next, the shapes of the holding jig 14 and the imaging unit 11 and the installation conditions thereof will be described. As shown in FIGS. 1 and 2, the length between the linear side surfaces of the holding jig 14 (the length in the X direction, not the length along the cylindrical concave curved surface of the holding jig 14) is set to “D”. And the length between the arc-shaped side surfaces (the length in the Y direction) is “L”. In addition, the minor axis of the imaging unit 11 is “X1”, and the major axis is “Y1”. The short diameter and long diameter of the imaging unit 11 are equal to the short diameter and long diameter of the housing 25, respectively.

  In the X direction, the cylindrical concave surface of the holding jig 14 always faces the optical focal point P of the digital camera 26, so that the illumination light is directly reflected at a certain point on the imaged document 21 and enters the digital camera 26. For this purpose, the light source must be on a line connecting a certain point on the imaged document 21 and the lens of the digital camera 26. For this reason, when illumination light such as room illumination light is emitted from above the imaging unit 11 toward the mat unit 13, the illumination light is blocked by the housing 25 regardless of the illumination angle of the illumination light. In the X direction of the cylindrical concave curved surface of the holding jig 14, reflection on the glossy surface of the imaged document 21 held on the cylindrical concave curved surface of the holding jig 14 hardly occurs. That is, in the X direction, the reflected light (directly reflected light) from the glossy surface of the imaging document 21 held on the cylindrical concave curved surface of the holding jig 14 is difficult to enter the optical focus P of the digital camera 26.

  Therefore, in the X direction, the imaging document 21 held on the cylindrical concave curved surface of the holding jig 14 can be imaged without causing whiteout, that is, the length D between the straight side surfaces of the holding jig 14. Is not limited to the shadow range in the X direction of the imaging unit 11. Therefore, theoretically, D <2R (R: radius of curvature of the cylindrical concave curved surface in the holding jig 14) may be used without being limited by the minor axis X1 of the imaging unit 11. However, when the entire imaged document 21 is imaged, distortion of information such as characters and figures drawn on the imaged document 21 increases near the linear side surface of the holding jig 14, and the entire imaged document 21 is focused. It becomes difficult to match. Therefore, practically, it is preferable to set the length D between the linear side surfaces of the holding jig 14 to a value that allows an acceptable image to be captured.

  On the other hand, since no curvature is provided in the Y direction of the holding jig 14, the holding jig is used when illumination light such as room illumination light is irradiated from above the imaging unit 11 toward the mat unit 13. It is necessary to determine the length L between the arcuate side surfaces of the holding jig 14 so that the reflected light from the surface of the imaging document 21 held on the cylindrical concave curved surface 14 does not enter the optical focal point P of the imaging unit 11. Since the shape of the housing 25 is a spheroid, the length in the Y direction of the imaging unit 11 changes according to the position in the X direction. For this reason, the Y direction length of the shadow of the imaging unit 11 also changes depending on the X direction position. However, since the optical focal point P of the digital camera 26 includes the major axis of the imaging unit 11 and is located in a plane orthogonal to the X axis (see FIG. 2), only the major axis Y1 of the imaging unit 11 needs to be considered. .

FIG. 4 schematically shows the relationship between the shape of the imaging unit and the incident / reflection of illumination light in the Y direction. FIG. 4 shows a cross section in which the holding jig 14 is equally divided in the X direction. When illumination light is irradiated from the light source provided above the imaging unit 11 toward the mat unit 13, a non-reflective region of illumination light caused by a shadow caused by the major axis Y <b> 1 of the imaging unit 11 reflected on the mat unit 13 in the region, if the arcuate side surface of the holding jig 14 is seated, because the illumination light is not incident on the imaging document 21 to establish the reflection condition (reflection angle of the incident angle = light of the light), the imaging document 21 Reflected light from the surface does not enter the optical focal point P of the imaging unit 11.

Therefore, the length in the Y direction of the non-reflecting area of the illumination light caused by the shadow caused by the major axis Y1 of the imaging unit 11 is the maximum length allowed as the length L between the arcuate side surfaces of the holding jig 14. Thus, when the shape of the cylindrical concave curved surface of the holding jig 14 is determined and the imaging original 21 is held within the area of the cylindrical concave curved surface, the reflection from the imaging original 21 is reduced and the occurrence of whiteout is suppressed. A clear image is obtained.

The reason why the shape of the holding jig 14 is a cylindrical concave curved surface is that it is difficult to curve a card or paper to be imaged into a spherical shape , and it is practical to use a cylindrical shape. For this reason, as shown in FIGS. 1 and 2, for example, when the X direction is curved and the Y direction is not curved, reflection is reduced by the bending of the holding jig 14 and the curved direction is not curved. Regarding the direction, the reflection is reduced by the non-reflective area of the illumination light using the shadow of the housing 25. Thus, effective reduction of reflection can be realized by combining the shape of the holding tool 14 and the shape of the housing.

  Subsequently, an imaging procedure of the imaging document 21 by the non-contact scanner 10 will be described. FIG. 5 is a flowchart showing an imaging procedure using a non-contact scanner. First, in accordance with the curvature radius R of the cylindrical concave curved surface of the holding jig 14 to be used, the imaging unit 11 is installed at a predetermined position, and the Y direction of the shadow reflected on the mat unit 13 due to the major axis Y1 of the imaging unit 11 It is confirmed that the length is not less than the length L between the arcuate side surfaces of the holding jig 14 (ST1). The imaging document 21 is set on the holding jig 14 (ST2), this is mounted on the mat portion 13 (ST3), and imaging is performed (ST4).

  Note that the image data captured by the imaging unit 11 may be stored in a computer-readable recording medium built in the imaging unit 11, and image data from the imaging unit 11, regardless of wired or wireless, is stored in the computer system. It may be transmitted and stored in a computer-readable recording medium constituting the computer system.

  The holding jig 14 is removed from the mat portion 13 (ST5), and the imaged document 21 that has been imaged is extracted (ST6). If there is no next imaged document 21, the operation ends here. On the other hand, if there is a next imaged document 21, the process returns to ST2. Note that a method of repeatedly attaching, imaging, and removing the imaging document 21 in a state where the holding jig 14 is mounted on the mat portion 13 may be used.

  In this way, the shape of the holding jig 14 is determined in consideration of the shape and installation position of the imaging unit 11, and the imaging document 21 is held in close contact with the cylindrical concave surface of the holding jig 14. A reflected image can be suppressed and a clear image can be obtained.

  The imaging document 21 can also be stored in a low-reflective and translucent folder without using the holding jig 14, and the folder can be placed on the mat unit 13 and imaged by the imaging unit 11. The reflected light from the document 21 can be reduced. However, with such a method, there is a problem that characters and images on the imaging surface become unclear, and the imaging document 21 is put in and out of a semi-transparent folder. There is a problem such as a heavy load on work. In contrast, imaging using the holding jig 14 has an advantage that such a problem does not occur.

  Next, a modified example of the holding jig 14 used in the non-contact scanner 10 will be described. FIG. 6 shows a perspective view of another holding jig used in the non-contact scanner and its peripheral portion. The upper surface of the holding jig 31 is a cylindrical concave curved surface, and the clip portion 15 is provided on the linear side surface portion. The holding jig 31 has a structure having a flat bottom so that the holding jig 31 can be stably placed on the mat portion 13.

  A marker 18 indicating the placement position is printed on the surface of the mat portion 13 so that the holding jig 31 can be easily placed at a fixed position on the mat portion 13. In the case where a plurality of holding jigs 31 having different sizes are prepared, it is preferable to print on the mat portion 13 a marker indicating a mounting position corresponding to each size. As a method of placing the holding jig 31 at a fixed position on the mat portion 13, an attaching / detaching mechanism using the projection 16 and the hole 17 can be used.

  In FIG. 6, the markers 18 for positioning the holding jig 31 at the four corners are printed on the surface of the mat portion 13. However, the present invention is not limited to this. For example, the holding jig 31 is placed on the surface of the mat portion 13. A cross line indicating the center line in the X direction and the Y direction of the power position is printed, and on the other hand, a marker indicating each center is printed on the side surface of the holding jig 31 so that these markers are aligned with each other. Also good.

  In the above embodiment, the holding jigs 14 and 31 are mounted on the mat portion 13, but it is also preferable to have a structure in which these are integrated. That is, the mat portion itself becomes a holding member. FIG. 7 is a sectional view showing a schematic structure of another mat portion. The mat portion 32 has a hollow structure, and a plurality of suction holes 33 are provided in a certain range of the central portion of the cylindrical concave curved surface formed on the upper surface. By decompressing the inside of the mat portion 32 by a decompression mechanism 34 such as a suction pump, the imaged document 21 (not shown in FIG. 7) can be reliably sucked and held along the cylindrical concave curved surface. It is preferable that a marker (not shown) for holding the imaging document 21 of various sizes in an appropriate position is printed on the cylindrical concave curved surface of the mat portion 32.

  If such a mat portion 32 is used, since the clip portion 15 is not provided on the cylindrical concave curved surface, the entire surface of the imaged document 21 can be clearly imaged even when there is no margin around the imaged document 21. There are advantages you can do. If the mat portion 32 is covered with a flat plate, it can be used as a non-contact scanner for placing an imaged document flat. Of course, the clip portion 15 may be provided on the cylindrical concave curved surface of the mat portion 32.

As mentioned above, although embodiment of this invention was described, this invention is not limited to such embodiment. For example, the holding jigs 14 and 31 having a cylindrical concave curved surface are taken up, but the shape of the holding jigs 14 and 31 is not limited to this, and the holding jigs 14 and 31 are spherical as concave curved surfaces on which the imaging document 21 is placed. What has a concave curved surface can be used. In this way, it is not necessary to use the non-reflecting area of the illumination light due to the shadow of the housing 25, so it is not necessary to secure the housing size necessary for the document size, and the housing 25 can be downsized. . However, if the flat imaging document 21 is pressed against the spherical concave surface, wrinkles are likely to occur in the imaging document 21, and therefore the radius of curvature of the spherical concave surface needs to be determined within a range where a desired image can be obtained. In such a configuration, since the surface of the imaging document 21 held on the spherical concave surface faces the optical focus P of the imaging unit 11 in all directions, it is not necessary to use a spheroid as the housing 25. For example, a spherical thing can be used.

Further, for example, it has been taken that using a housing 25 having a spheroidal shape as the imaging unit 11, the shape of the housing 25, have name limited thereto. The shape of the housing 25 can accommodate the digital camera 26, and a shadow longer than the length L between the arcuate side surfaces of the cylindrical concave curved surfaces of the holding jigs 14 and 31 is formed on the surface of the mat portion 13 in the length direction. not good if a shape that can be made. The shape of the housing 25 may be, for example, a flat ellipsoid or a cylinder. Further, the housing 25 may have a shape that covers the digital camera 26 like an umbrella.

  Further, as the holding jig 14, a structure having the clip portion 15 only in the vicinity of one linear side surface on the cylindrical concave curved surface has been taken up. As a modified example, the clip portion is provided in the vicinity of both linear side surfaces. 15 may be provided. By adopting such a configuration, for example, even when the imaging document 21 is hard or has a spring property, the imaging document 21 can be reliably brought into close contact with the cylindrical concave curved surface. As another modification of the holding jig 14, a clip portion 15 is provided in the vicinity of both linear side surfaces, and a curved clip portion along the curvature is also provided in the vicinity of one arcuate side surface so that the imaging document 21 is moved in three directions. It is also preferable that the structure is held by In this case, the imaging document 21 may be inserted from the arcuate side surface on which the curved clip portion is not provided.

  Note that if a transparent material is used for the clip portion 15, an image can be acquired even for a portion where the imaging document 21 is pressed. In that case, since the size of the clip portion 15 can be increased, the clip portion 15 can be more closely attached to the holding jig 14.

  The sizes of the holding jig 14, the housing 25, and the digital camera 26, and the radius of curvature and the center thereof do not have to be exactly the same, but need only be approximately the same as long as the effects of the present invention are achieved. Needless to say.

It is a front view which shows schematic structure of the non-contact scanner which concerns on one Embodiment of this invention. It is a top view which shows schematic structure of a non-contact scanner. It is a perspective view which shows schematic structure of a holding jig. It is a figure which shows typically the relationship between the shape of the imaging part in a Y direction, and the incident / reflection of illumination light. It is a flowchart which shows the imaging procedure by the non-contact scanner which concerns on one Embodiment of this invention. It is a perspective view of another holding jig used for the non-contact scanner concerning one embodiment of the present invention, and its peripheral part. It is a section showing the schematic structure of another mat part used for the non-contact scanner concerning one embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Non-contact scanner 11 Image pick-up part 12 Support | pillar part 13 Mat | matte part 14 Holding jig 15 Clip part 16 Projection part 17 Hole part 18 Marker 21 Imaging document 25 Housing 26 Digital camera 31 Holding jig 32 Mat part 33 Suction hole 34 Decompression mechanism

Claims (7)

A holding member having a concave curved surface for holding the imaging medium;
An imaging unit that images the imaged medium held by the holding member;
An interval holding unit that separates the imaging unit and the holding member at a constant interval, and
Said concave surface of said retaining member has an arcuate cross-section, the length of the normal line drawn perpendicular against the concave surface of the optical focal point of the imaging unit is equal to the radius of curvature of the concave surface A non-contact scanner characterized by that.   The non-contact scanner according to claim 1, wherein the concave curved surface is a cylindrical concave curved surface. The holding member is a holding jig;
It further comprises a mat portion on which the holding jig is placed,
In a state in which illumination light is applied to the imaging medium held by the holding jig at a predetermined angle from above the imaging unit, the length between the arc-shaped side surfaces of the cylindrical concave curved surface is in the length direction. The non-contact scanner according to claim 2, wherein the non-contact scanner has a length equal to or shorter than a length of a non-reflective area of the illumination light caused by a shadow reflected on the mat portion of the imaging unit.   The non-contact scanner according to claim 3, wherein the mat portion and the holding jig include an attaching / detaching mechanism that allows the holding jig to be attached to and detached from the mat portion.   The non-contact scanner according to claim 3, wherein a marker indicating the installation position of the holding jig is printed on the surface of the mat portion.   6. The holding jig according to claim 1, further comprising: a pressing unit that presses the imaging medium to bring the imaging medium into close contact with the concave curved surface. The non-contact scanner described. A mat portion having a concave curved surface for holding an image pickup medium;
An imaging unit for imaging the imaging medium held by the mat unit;
An interval holding unit that separates the imaging unit and the mat unit at regular intervals, and
Said concave surface of said mat portion has an arcuate cross-section, the length of the normal line drawn perpendicular against the concave surface of the optical focal point of the imaging unit is equal to the radius of curvature of the concave surface A non-contact scanner characterized by that.

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