JP2019074332A - Marker - Google Patents

Abstract

To provide a marker which allows an image from a detection object part to clearly appear and be detected by preventing aberrations from occurring in each lens part due to tilt of an optical axis.SOLUTION: The marker of this invention includes a lens body, and the lens body has, on one surface side, a plurality of lens parts continuously arranged in a plane direction and has, on the other surface side, a plurality of detection object parts which can be detected from the one surface side and correspond to the lens parts respectively. The pitch of the plurality of lens parts and that of the plurality of detection object parts are different from each other. An overall surface of each of the plurality of lens parts which has a tilt larger than 0° with respect to a direction of a center axis is an optical function part, and the plurality of lens parts include a group of lens parts on the upstream side and a group of lens parts on the downstream side with an arbitrary lens part as a reference lens part, and each of lens parts in the group of lens parts on the upstream side and the group of lens parts on the downstream side has an aspherical shape laterally asymmetric with respect to the center axis, and each of the lens parts focuses light on a corresponding detection object part by its sectional shape.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a marker.

  In the fields of Augmented Reality (hereinafter, also referred to as “AR”) and robotics, so-called visual recognition markers are used to recognize the position, posture, and the like of an object. As the marker, for example, a marker in which a lenticular lens is disposed on a black stripe pattern is reported (Patent Document 1).

  The lenticular lens is generally a lens body in which cylindrical lenses obtained by dividing a cylinder in the axial direction are continuously arranged such that the axial direction is parallel. In the marker, a cylindrical lens (also referred to as a lens portion) having a convex portion extending in the axial direction is parallel to the axial direction and the black line direction of the stripe pattern, and the pitch is the lens portion And are arranged and formed on the striped pattern so as to be different from the pitch of. With such a structure, when the marker is viewed by a camera or the like from the convex portion side of the lenticular lens, an image of the pattern projected on the lenticular lens is detected by movement or deformation depending on the visual direction. . For this reason, the visual direction can be known from the detected image, and it is possible to recognize the position, posture, etc. of the object as described above.

  However, in each lens unit of the marker, the tilt of the optical axis may cause an aberration, and the image of the detected unit may not appear clear.

JP, 2012-145559, A

  Therefore, an object of the present invention is to provide a marker capable of suppressing the occurrence of aberration in each lens unit due to the inclination of the optical axis, making the image from the detected unit appear clearly, and detecting it.

In order to achieve the above object, the marker of the present invention is
Including the lens body,
The lens body is
On one surface side, it has a plurality of lens parts arranged continuously in the plane direction,
In the other surface side, it has a plurality of detected parts which can be detected from the one surface side and correspond to the respective lens parts,
The pitches of the plurality of lens portions and the pitches of the plurality of detected portions are different,
The plurality of lens portions are
Each of the entire surface having an inclination of more than 0 ° with respect to the central axis direction is an optical function unit,
An optional lens unit as a reference lens unit, including an upstream lens unit group and a downstream lens unit group;
The upstream lens unit group and the downstream lens unit group are
Each lens portion has an aspheric shape that is asymmetrical with respect to the central axis,
Each lens unit is
It is characterized in that the light is condensed on each corresponding detection target according to each cross-sectional shape.

  In the marker of the present invention, as described above, the light is collected by focusing the light on the corresponding detected portions according to the cross-sectional shapes of the reference lens portion, the upstream lens portion group, and the downstream lens portion group. It is possible to suppress the occurrence of aberration in each lens unit due to the inclination of the axis, make the image from the detected unit appear clearly, and improve the detection accuracy of the marker.

1 (A) is a top view showing an example of a lens body in the marker of Embodiment 1, and FIG. 1 (B) is a cross-sectional view of the marker seen from the II direction of FIG. 1 (A). . FIG. 2 is a cross-sectional view of the lens body in the marker of the first embodiment. FIG. 3 is a cross-sectional view of the lens body in the marker of the first embodiment, and shows an outline of light collection. FIG. 4 is a cross-sectional view of the marker of the reference example, showing an outline of light collection. FIG. 5 is a view schematically showing an optical path of light at an optical axis of 20 ° in the marker of the first embodiment and the marker of the reference example. FIG. 6A is a graph showing the shape of each lens portion in the marker of Embodiment 1, and FIG. 6B is a graph showing the shape of the central portion of each lens portion.

  In the marker according to the present invention, for example, in the cross section in the direction perpendicular to the continuous arrangement direction, each lens portion of the upstream side lens portion group has a different aspheric shape, and the downstream side lens portion group Each lens portion has a different aspheric shape.

  In the marker of the present invention, for example, the pitch of the lens units is equal.

  In the marker of the present invention, for example, the pitch of the lens unit is larger than the pitch of the detection target.

In the marker according to the present invention, for example, in each of the upstream lens unit group and the downstream lens unit group, each lens unit has a curvature radius R _n of a surface close to the reference lens unit and the reference lens unit And the radius of curvature R _f of the surface of the far half satisfy the relationship of R _n > R _f .

  In the marker of the present invention, for example, the pitch of the lens unit is smaller than the pitch of the detection target.

In the marker according to the present invention, for example, in each of the upstream lens unit group and the downstream lens unit group, each lens unit has a curvature radius R _n of a surface close to the reference lens unit and the reference lens unit And the radius of curvature R _f of the surface far from the point satisfy the relationship of R _n <R _f .

The marker according to the present invention is, for example, a difference between a curvature radius R _u of each lens portion and a curvature radius R _s of the reference lens portion in the upstream lens portion group and the downstream lens portion group (R _u −R The absolute value of _s ) increases with distance from the reference lens.

  In the marker of the present invention, for example, the lens unit is a cylindrical lens.

  Next, an embodiment of the present invention will be described using the drawings. The present invention is not limited or limited at all by the following embodiments. In each figure, the same reference numerals are given to the same parts. In the drawings, for convenience of explanation, the structure of each part may be appropriately simplified and shown, and the dimensional ratio etc. of each part is not limited to the conditions of the drawing.

Embodiment 1
Embodiment 1 is an example of the marker of the present invention. FIG. 1 shows an example of the lens body in the marker of this embodiment. FIG. 1A is a plan view of the marker 1, and FIG. 1B is a cross-sectional view of the marker 1 viewed from the I-I direction of FIG. In FIG. 1 (B), hatches representing cross sections are omitted in consideration of legibility. The same applies to the other cross-sectional views below. In FIG. 1, for convenience, the arrow X is referred to as a width direction, the arrow Y is referred to as a length direction, and the arrow Z is referred to as a thickness direction. In the direction X, the X1 direction toward the left is referred to as the upstream, and the X2 direction toward the right is referred to as the downstream. In FIG. 1B, a dotted line C in the Z direction indicates the central axis of each lens unit. The central axis is an axis in the thickness direction passing through the center in the width direction X in each lens portion.

  As shown in FIGS. 1A and 1B, the marker 1 includes a lens body 10. The lens body 10 has a plurality of lens portions arranged continuously in the planar direction on one surface side, that is, the upper surface side in FIG. 1B, and the other surface side, that is, FIG. And a plurality of detection target portions that can be detected from the one surface side and correspond to the respective lens portions. In the marker of the present invention, it is a point that the light is condensed on each corresponding detected portion by making the plurality of lens portions have the following cross-sectional shapes, and the other configuration etc. It is not restricted.

  Each of the plurality of lens portions has an optical function portion over the entire surface area having an inclination of more than 0 ° with respect to the central axis C direction. The term “optical function part” means to transmit or refract and collect light arriving from the outside. The lens portion whose entire surface is an optical function portion may be, for example, an aspheric convex shape having a curvature, and the curvature may be appropriately determined. The lens main body 10 of FIG. 1 (B) which is a specific example is a form which has a level | step difference between lens parts. For example, the lens portion 112 b has a surface at 0 ° with respect to the central axis C direction at the boundary with the lens portion 112 a on the lens portion 112 a side. In this case, in the lens portion 112b, the entire surface having curvature is the optical function portion, and the surface at 0 ° (that is, the surface having no curvature) is not the optical function portion. In the plane at 0 ° with respect to the central axis C direction, for example, due to a manufacturing error or the like, a shape exceeding 0 ° (for example, the angle D with respect to the central axis C direction is 0 ° <D ≦ 3 ° In the case of a surface of a certain degree, that is, a surface having an angle D of not 0 ° but having no curvature is also included. And each lens is designed so that light may condense on each corresponding to-be-detected part by each cross-sectional shape.

  In FIG. 1, the plurality of lens units are continuously arranged in the X direction, that is, in the width direction. Hereinafter, the arrangement direction of the plurality of lens portions will be described as the width direction X, and the perpendicular direction to the continuous arrangement direction will be described as the thickness direction Z.

  Specifically, the plurality of lens units have a lens unit at an arbitrary position as a reference lens unit 111, and further, an upstream side lens unit group 112 continuously disposed on the upstream side of the reference lens unit 111 And a downstream lens unit group 113 continuously disposed downstream. A lens surface 11 is formed on one surface side of the lens body 10 by the reference lens portion 111, the upstream lens portion group 112, and the downstream lens portion group 113.

  Although the number of the lens portions in the lens body 10 is nine in FIG. 1, this is an example, and the present invention is not limited thereto. For example, when the number of lens units is an even number, the number of reference lenses may be two. Further, the number of lens portions in the upstream side lens portion group 112 and the number of lens portions in the downstream side lens portion group 113 may be, for example, the same or different. The number of lens portions in the lens body 10 is not particularly limited, and is, for example, 221, 101, or 51.

  In the lens body 10, for example, the lens unit is a cylindrical lens. The lens unit is also called, for example, a lenticular lens. In the lens main body 10, the size of each lens portion is not particularly limited, and can be appropriately determined according to, for example, the number of the lens portions, the use of the marker 1, and the like. In each lens portion, the length W1 in the width direction X is, for example, 1 mm, 0.5 mm, 0.37 mm, the length in the length direction Y is, for example, 25 mm, 5 mm, and the center in the thickness direction Z The length (thickness) passing through the axis C is, for example, 1.7 mm, 1 mm, 0.6 mm.

  In the cross section in the thickness direction Z, the reference lens portion 111 preferably has, for example, an aspheric shape which is symmetrical with respect to the central axis C, and in that case, the vertex thereof is on the central axis C. For example, the radius of curvature of the reference lens portion 111 increases from the vertex toward the adjacent lens portion, and the radius of curvature (R) may increase continuously or intermittently, for example. May be The radius of curvature of the reference lens portion 111 can be represented, for example, by the radius of curvature of the apex, and as a specific example, it is in the range of 0.25 to 1 mm. In the present invention, “symmetry” includes, for example, substantially the same meaning as long as the same function is exhibited, in addition to being completely identical in shape.

  On the other hand, in the cross section in the thickness direction Z, the respective lens portions 112a, 112b, 112c, 112d of the upstream side lens portion group 112 and the respective lens portions 113a, 113b, 113c, 113d of the downstream side lens portion group 113 are Each has an aspheric shape that is asymmetrical with respect to the central axis C. The upstream side lens unit group 112 has, for example, different aspheric shapes for each lens unit, and the shape changes as the lens unit is separated from the reference lens unit 111. Specifically, for example, as the lens portions of the upstream side lens portion group 112 move away from the reference lens portion 111, the apexes thereof change so as to be positioned farther on the surface than the point of intersection with the central axis C. The same applies to the downstream side lens unit group 113. For example, each lens unit has a different aspheric shape, and the shape changes as it is separated from the reference lens unit 111. Specifically, for example, as the lens portions of the downstream side lens portion group 113 move away from the reference lens portion 111, the apexes thereof change so as to be positioned farther on the surface than the intersection with the central axis C.

  In the upstream lens unit group 112 and the downstream lens unit group 113, for example, the radius of curvature of each of the lens units increases from the vertex toward the adjacent lens unit, and the radius of curvature (R) is, for example, It may increase continuously or may increase intermittently. The asymmetry of each lens portion can be defined, for example, by the radius of curvature of the surface near the reference lens portion 111 and the radius of curvature of the surface far from the reference lens portion 111, and the radius of curvature of the one and the other The radius of curvature may be different. In each of the lens portions, the entire curvature radius is, for example, the curvature radius of a curve passing through both ends of the lens portion and the central axis, and the one curvature radius and the other curvature radius are, for example, lenses The radius of curvature of the curve from one end of the part to the central axis. The magnitude relationship between the one radius of curvature and the other radius of curvature can be determined, for example, from the shape of the lens portion.

In the cross section in the thickness direction Z, for example, the upstream-side lens unit group 112 is the difference between the curvature radius R _{u of} each of the lens portions 112 a, 112 b, 112 c, and 112 d and the curvature radius R _s of the reference lens 111 (R _u −R The absolute value of _s ) increases with distance from the reference lens 111. Further, in the upstream side lens unit group 112, for example, the lens unit 112d farthest from the reference lens 111 has a difference between the curvature radius R _u and the curvature radius R _s of the reference lens unit (R _u −R _s ) It is preferable that the absolute value of is larger than that of the other lens portions 112a, 112b and 112c.

Further, in the cross section in the thickness direction Z, for example, a difference between the curvature radius R _{u of} each of the lens portions 113 a, 113 b, 113 c and 113 d and the curvature radius R _s of the reference lens 111 (R _u The absolute value of −R _s ) increases with distance from the reference lens 111. Further, in the upstream side lens unit group 113, for example, the lens unit 113d farthest from the reference lens 111 has a difference between the curvature radius R _u and the curvature radius R _s of the reference lens unit (R _u −R _s ) It is preferable that the absolute value of is larger than that of the other lens portions 113a, 113b and 113c.

  In the cross section in the thickness direction Z, for example, the overall shape of the upstream side lens unit group 112 and the overall shape of the downstream side lens unit group 113 are symmetrical. Specifically, as shown in FIG. 1B, the upstream lens unit 112a and the downstream lens unit 113a, and the lens unit 112b and the lens unit 113b, which are at symmetrical positions with respect to the reference lens unit 111, The lens portion 112 c and the lens portion 113 c, and the lens portion 112 d and the lens portion 113 d have symmetrical shapes. Therefore, the overall shape of the upstream side lens portion group 112 and the overall shape of the downstream side lens portion group 113 are symmetrical. In the present invention, “symmetry” includes, for example, substantially the same meaning as long as the same function is exhibited, in addition to being completely identical in shape.

  The outline of the pitch of the said lens part is shown in FIG. FIG. 2 is a cross-sectional view of the marker 1 as in FIG. 1 (B). In the marker of the present invention, the pitch of the plurality of lens portions means the pitch P1 between the adjacent lens portions in the width direction X. Specifically, “the pitch P1 between adjacent lens portions” is the distance between the midpoints of the widths W1 of the lens portions in adjacent lens portions, and is, for example, the same as the width W1 of the lens portions in the width direction X . The pitches P1 of the respective lens portions of the upstream side lens portion group 112, the reference lens portions 111, and the respective lens portions of the downstream side lens portion group 113 may be the same or different, for example. By setting the pitches of the plurality of lens units equal, the movement of the image of the detection target 200 can be made more constant when the marker of the present invention is viewed.

  As described above, the lens body 10 can be detected from the one surface side on the other surface side, that is, the lower surface side in FIG. 1B, and a plurality of objects corresponding to the respective lens portions The detection unit 200 is included. In FIG. 1, the detection target portion 200 is a line extending along the length direction Y of the lens body 10, and a stripe pattern is formed by a plurality of lines. For example, the plurality of detection target portions 200 can be optically detected by being projected on the upper surface side of the lens main body 10 as an optically detectable image. The shape of the portion to be detected in the present invention is not limited to this, and the shape of the portion to be detected 200 may be, for example, a shape in which points (dots) are aligned in the longitudinal direction Y.

  The outline of the pitch P2 of the to-be-detected part 200 is collectively shown in FIG. The pitch of the plurality of detected parts 200 is different from the pitch P1 of the plurality of lens parts. The pitches of the plurality of detection target portions 200 mean the pitch P2 between the adjacent detection target portions 200 in the width direction X. Specifically, “a pitch between adjacent detection target portions” is, for example, a distance between the centers of the adjacent detection target portions 200 in the width direction X. The center of the detection target 200 is, for example, a middle point in the width direction X and a middle point in the length direction Y. The pitches P2 of the plurality of detection target parts 200 may be, for example, the same or different, and are preferably equal pitches.

  The width W2 in the width direction X of the detection target portion 200 is not particularly limited, and is, for example, 45 μm, 30 μm, or 10 μm. The width of the detection target portion 200 can be appropriately determined, for example, according to the pitch P1 between the adjacent lens portions. The ratio of the width W2 of the detection target portion 200 to the pitch P1 between the lens portions is, for example, 1: 200 to 1: 5. By setting the width W2 of the detection target 200 relatively large with respect to the pitch P1 between the lens units, for example, the contrast of the image to be detected can be relatively large, and is set relatively small. Thereby, for example, the sensitivity of the detection target can be further improved.

  The marker of the present embodiment has, for example, an apex of the reference lens unit 111 on the central axis C of the reference lens unit 111 and a detected unit 200 corresponding to the reference lens unit 111. Therefore, when the marker of the present embodiment is observed, for example, from the direction directly facing the marker, that is, the direction in which the central axis C of the reference lens 111 is the optical axis (0 °), the marker An image of the detection target 200 corresponding to the lens 111 is observed.

  In the marker of the present invention, the “pitch of the plurality of lens portions” and the “pitch of the plurality of detected portions” are different. Therefore, with reference to the central axis C of the reference lens 111, the other lens portions are continuously arranged on the upstream side and the downstream side at an arbitrary pitch P1, and at an arbitrary pitch P2 different from the pitch P1. The other detection target is disposed continuously on the upstream side and the downstream side. For example, the pitch P1 of the lens unit may be larger than the pitch P2 of the detection target 200, or may be smaller than the pitch P2 of the detection target 200.

When the pitch P1 of the lens units is larger than the pitch P2 of the detection units 200, for example, in the upstream lens unit group 112 and the downstream lens unit group 113, each lens unit is close to the reference lens unit 111, respectively. It is preferable that the curvature radius R _n of the half surface and the curvature radius R _f of the half surface far from the reference lens portion 111 satisfy the relationship of R _n > R _f .

On the other hand, when the pitch P1 of the lens units is smaller than the pitch P2 of the detection units 200, for example, in the upstream lens unit group 112 and the downstream lens unit group 113, each lens unit is a reference lens unit 111. It is preferable that the curvature radius R _n of the near half surface and the curvature radius R _f of the half surface far from the reference lens portion 111 satisfy the relationship of R _n <R _f .

  The lens body 10 may be formed, for example, by connecting a plurality of separately prepared lens units, that is, a lens unit having the lens unit, or may be an integrally molded article. The lens body 10 is, for example, an injection molded product, and in particular, in the case of the integrally molded product, preferably an injection molded product. In the lens body 10, it is preferable that the plurality of lens portions be connected to the adjacent lens portions without a gap.

  The lens body 10 is, for example, a translucent member. The light-transmissive member is not particularly limited, and examples thereof include resin and glass. Examples of the resin include polycarbonate, acrylic resin such as polymethyl methacrylate (PMMA), cycloolefin polymer (COP), cycloolefin copolymer (COC) and the like.

  The size of the lens body 10 is not particularly limited, and can be determined as appropriate according to, for example, the number of lens portions, the use of the marker 1, and the like. The lens body 10 has, for example, a length (width) in the width direction X of, for example, 110 mm, 20 mm, a length in the length direction Y of, for example, 25 mm, 5 mm, and a thickness direction passing through the central axis C The length (thickness) of Z is, for example, 1 mm, 0.6 mm, or 1.7 mm.

  In the marker 1, the detection target portion 200 only needs to be optically detectable from the one surface side, and examples thereof include a colored film. The color of the colored film is not particularly limited, and is, for example, black. The colored film is, for example, a coating film and can be formed by a paint. The paint is not particularly limited, and may be, for example, a liquid paint or a powder paint. The paint can form the coating film, for example, by applying or fixing after application. Examples of the application method include spray application and screen printing. Examples of the fixing method include drying of the liquid paint, curing of a curing component (for example, radical weight compound etc.) in the paint, and baking of the powder paint.

  The to-be-detected part 200 may be disposed, for example, so as to be positioned inside the lens main body 10 with reference to the exposed surface on the other surface side of the lens main body 10, It may be located at In the former case, for example, the other surface of the lens body 10 has a recess that is recessed inside, and the colored film is disposed in the recess. In the latter case, for example, the other surface of the lens body 10 is flat, and the colored film is disposed (laminated) on the flat surface. In the latter case, for example, the other surface of the lens body 10 may have a convex portion, and the colored film may be disposed (laminated) at the protruding end of the convex portion.

  In the cross-sectional view of FIG. 1B described above, the other surface (lower surface) of the lens body 10 has the concave portion, and a colored film or the like is disposed in the concave portion to form the detection portion 200. It is an example of the form which exists.

  The detected unit 200 may be, for example, optically distinguishable. The term “optically distinguishable” means, for example, that the detected portion 200 can detect an optically significant difference as compared with the other regions. An optically significant difference means, for example, having a significant difference in optical characteristics. Examples of the optical characteristics include lightness, saturation, hue such as hue, intensity of light such as luminance, and the like. The optically significant difference may be, for example, a difference that can be confirmed visually or a difference that can be confirmed by an optical detection device such as a camera. Moreover, when the to-be-detected part 200 emits fluorescence, for example, the difference which can be confirmed by operation, such as irradiation of a UV lamp, may be sufficient.

  The pattern formed by the detection target 200 is not limited at all. In the case where the pattern is, for example, the stripe pattern, the color depths forming the stripe pattern may be, for example, the same or may be shades.

  When the marker 100 is placed on a white object, for example, among the light incident from the upper surface of the lens body 10 of the marker 1, the light reaching the detection part 200 is a detection part 200 (for example, black) The light absorbed by the colored film is transmitted through the lens body 10 and reflected on the surface of the object. Therefore, an image (for example, a black line) of the detection target 200 is projected on the white background on the upper surface of the lens body 10.

  Next, an image of the detection target 200 when the marker of the first embodiment is used will be described with reference to FIGS. 3 to 6. FIG. 3 is a cross-sectional view of a region including the reference lens portion 111 and the upstream lens portion group 112 in the marker 1 of FIG. In FIG. 3, each lens unit has a detection target at the same position as that in FIG. 1, but is not shown for convenience. Further, although the downstream side lens unit 113 is omitted in FIG. 3, the downstream side lens unit 113 is symmetrical to the upstream side lens unit 112 with the reference lens unit 111 as a center, and is similar to FIG.

  In the marker 1, the reference lens portion 111 has an apex on its central axis C and has a corresponding detected portion 200, and for the optical axis (0 °) in the direction coaxial with the central axis C. The lens portion 112a, the lens portion 112b, the lens portion 112c, and the lens portion 112d are lenses for optical axes (5 °, 10 °, 15 °, 20 °) inclined at a predetermined angle from the central axis C. It is.

  FIG. 6 is a graph showing a curved surface shape in a cross section in the thickness direction for the reference lens portion 111 and each lens portion 112 a, 112 b, 112 c, 112 d of the upstream lens portion group 112. FIG. 6A is a graph showing the overall curved surface shape of each lens unit, and FIG. 6B is a graph showing the curved surface shape around the central axis C (central portion) of each lens unit. In FIG. 6, the X axis of the graph indicates the shape in the width direction X, the zero position is the central axis C of the lens unit, and the Y axis of the graph indicates the shape in the thickness direction Z. As shown in FIGS. 6A and 6B, the reference lens unit 111 for the optical axis 0 ° has an aspheric shape (curved surface shape) symmetrical with respect to the central axis C. On the other hand, as shown in FIGS. 6A and 6B, the lens portions 112a, 112b and 112c, and the lens portion 112d are apexes as the optical axes are inclined to 5 °, 10 °, 15 ° and 20 °. However, the radius of curvature of the curved surface closer to the reference lens portion 111 is smaller than the point of intersection with the central axis C and compared to the reference lens portion 111, and the curved surface far from the reference lens portion 111 has a curvature The radius is getting bigger.

  Then, as shown in FIG. 3, when the light at the optical axis 0 ° reaches the marker 1, the reference lens unit 111 condenses the light at the corresponding detection target 200, and the light at the optical axis 5 ° reaches Then, the lens portion 112a refracts the light on its surface, condenses the light on the corresponding detected portion, and when the light having an optical axis of 10 ° reaches, the lens portion 112b refracts the light on its surface, When light is condensed on the corresponding detection target, and light with an optical axis of 15 ° arrives, the lens unit 112 c refracts the light on the surface, condenses the light on the corresponding detection target, and the optical axis 20 When the light of ° arrives, the lens unit 112 d refracts the light on the surface and condenses the light on the corresponding detection target. As described above, the marker 1 is designed to change the curved surface of each lens section in the cross section in the thickness direction according to the optical axis, and to focus light on the detected section 200 to which each lens section corresponds. ing. Therefore, as described above, in each of the lens units, occurrence of aberration can be suppressed, and an image of the detection target 200 can be developed and detected with higher accuracy.

  On the other hand, in the case of a marker in which the plurality of lens portions have the same shape as that of the reference lens portion 111 in the cross section in the thickness direction, the effect as the marker 1 of the present embodiment can not be obtained. The marker of this reference example is shown in FIG. FIG. 4 is a cross-sectional view of the marker 4 of the reference example, and all the lens portions have the same shape as the aspheric reference lens portion 111 in the marker 1 of the first embodiment. In FIG. 4, each lens unit has a detection target at the same position as the marker of FIG. 3 (that is, the same position as the marker of FIG. 1), but is not shown for convenience. In the marker 5 of the reference example, when light at an optical axis of 0 ° arrives, the lens portion 111 at the right end condenses the light at the position of the detection portion, but the other lens portions 111a, 111b, 112c, In the case of 112 d, as the distance from the reference lens unit 111 increases, the focal point shifts more (circled area in FIG. 4), and light is not sufficiently collected at the position of the detection target. For this reason, in each said lens part, an aberration generate | occur | produces by the inclination of an optical axis, and the precision of detection of the said to-be-detected part can not be improved.

  Specifically, light with an optical axis of 20 ° in FIG. 3 and light with an optical axis of 20 ° in FIG. 4 are shown again in FIG. As shown in FIG. 5A, when light at an optical axis of 20 ° reaches the marker 1 of the first embodiment, the lens unit refracts the light at the surface, and the light is transmitted to the corresponding detection target unit 200. Focus. On the other hand, as shown in FIG. 5B, when light at an optical axis of 20 ° reaches the marker 4 of the reference example, the lens unit corresponds to the same position as the marker 1 of the first embodiment. Although the detection unit 200 is provided, sufficient light collection does not occur at the position of the detection unit 200.

  Therefore, the marker of the present invention suppresses the occurrence of aberration in each of the lens units by configuring each of the lens units as described above, and reveals the image of the detection target 200 with better accuracy. , Can be detected.

  It is preferable that the marker of the present invention detects the image of the detection unit in the range of the optical axis inclined at ± 30 °, for example, with the central axis C of the reference lens unit as 0 °.

Second Embodiment
Embodiment 2 is an example of the marker set of the present invention having the marker of the present invention and a two-dimensional pattern code.

  The marker set further includes, for example, a substrate, and the two-dimensional pattern code and the marker of the present invention are disposed on the substrate. In the marker set, for example, the two-dimensional pattern code is an AR marker.

  The two-dimensional pattern code is not particularly limited, and examples thereof include AR marker and QR marker. AR markers include, for example, ARToolKit, Arteaga, Cybercide, ARToolKit Plus, and the like.

  According to the marker set, by detecting the marker of the present invention together with the detection of the two-dimensional pattern code, it is possible to determine the inclination direction and the angle of the light beam (vision direction).

  Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments. The configurations and details of the present invention can be modified in various ways that can be understood by those skilled in the art within the scope of the present invention.

  As described above, according to the cross-sectional shapes of the reference lens unit, the upstream side lens unit group, and the downstream side lens unit group, the marker of the present invention focuses light on the corresponding detection target units. It is possible to suppress the occurrence of aberration in each lens unit due to the inclination of the axis, make the image from the detected unit appear clearly, and improve the detection accuracy of the marker.

1, 5 Marker 10 Lens Body 111 Reference Lens Part 112 Upstream Lens Part Group 113 Downstream Lens Part Group 200 Detected Part

Claims (8)

Including the lens body,
The lens body is
On one surface side, it has a plurality of lens parts arranged continuously in the plane direction,
In the other surface side, it has a plurality of detected parts which can be detected from the one surface side and correspond to the respective lens parts,
The pitches of the plurality of lens portions and the pitches of the plurality of detected portions are different,
The plurality of lens portions are
Each of the entire surface having an inclination of more than 0 ° with respect to the central axis direction is an optical function unit,
An optional lens unit as a reference lens unit, including an upstream lens unit group and a downstream lens unit group;
The upstream lens unit group and the downstream lens unit group are
Each lens portion has an aspheric shape that is asymmetrical with respect to the central axis,
Each lens unit is
A marker characterized in that light is condensed on each corresponding detected part according to each cross-sectional shape. In the cross section perpendicular to the continuous arrangement direction,
In the upstream lens unit group, the respective lens units have different aspheric shapes,
The marker according to claim 1, wherein each of the lens units in the downstream side lens unit group has a different aspheric shape. The marker according to claim 1, wherein a pitch of the lens unit is equal. The pitch of the lens portion is larger than the pitch of the detected portion,
In the upstream lens unit group and the downstream lens unit group,
In each lens portion, the radius of curvature R _n of the half surface near the reference lens portion and the radius of curvature R _f of the half surface far from the reference lens portion with reference to the central axis, R _n > R The marker according to any one of claims 1 to 3, which satisfies the relationship of _f . In the upstream lens unit group and the downstream lens unit group, the pitch of the lens unit is smaller than the pitch of the detection unit.
In each lens portion, the curvature radius R _n of the surface near the reference lens portion and the curvature radius R _f of the surface far from the reference lens portion satisfy the relationship of R _n <R _f The marker according to any one of claims 1 to 3. In the upstream lens unit group and the downstream lens unit group,
The absolute value of the difference (R _u −R _s ) between the radius of curvature R _u of each lens portion and the radius of curvature R _s of the reference lens portion increases as the distance from the reference lens increases. The marker according to any one of the above. The marker according to any one of claims 1 to 6, wherein the lens unit is a cylindrical lens. The marker according to any one of claims 1 to 7, wherein the lens body is an integrally molded article.

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