Detection device and detection method

Abstract

The present invention provides a detection device and a detection method that are capable of improving the accuracy of detection of a marking. Provided is a detection device for detecting a marking provided to a target, said detection device comprising: an illumination means that is provided with a light emitting unit for emitting light for irradiating a marking portion, which is a portion of the target at which the marking is provided, and a gap provided inward of the light emitting unit for allowing light reflected by the marking portion to pass therethrough; an imaging means that receives light which has been reflected by the marking portion and which has passed through the gap, and that images the marking portion; and a detection means that detects the marking on the basis of an image of the marking portion that has been obtained by imaging via the imaging means.

Description

Detection device and detection method

[0001] The present invention relates to a detection device and a detection method.

[0002] Conventionally, markings on the bottom of containers have been read by image processing. For example, Patent Document 1 describes an imaging system for the bottom of a glass bottle, which includes an illumination device for illuminating the bottom of the glass bottle from below, and a CCD camera for capturing an image of the light transmitted through the bottle bottom from above the bottle, thereby generating an image including the markings on the bottle bottom.

[0003] Japanese Patent Application Laid-Open No. 2000-28323

[0004] However, when the entire bottom is illuminated by surface lighting in which the light-emitting surface emits light uniformly, as in the technology described in Patent Document 1, it is sometimes difficult to detect small markings with irregularities, such as those on thin-walled resin containers, because the contrast between the irregularities is not sufficient.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a detection device and a detection method that can improve the accuracy of marking detection.

[0006] A detection device according to one aspect of the present invention is a detection device for detecting an engraving on an object, and comprises an illumination means having a light-emitting unit that emits light to irradiate the engraving portion, which is the portion of the object where the engraving is provided, and a gap provided inside the light-emitting unit through which the light reflected by the engraving portion passes, an imaging means that receives the light reflected by the engraving portion and passes through the gap to image the engraving portion, and a detection means that detects the engraving based on an image of the engraving portion obtained by imaging by the imaging means.

[0007] According to this aspect, illumination light is not irradiated onto the target object through the gap, which allows the intensity of light irradiated onto the marking portion to be relatively higher than the intensity of light irradiated onto other portions, thereby improving the accuracy of marking detection.

[0008] According to the present invention, it is possible to provide a detection device and a detection method that can improve the accuracy of marking detection.

[0009] FIG. 1 is a schematic diagram showing an example of the configuration of the detection device 1. FIG. 2 is a diagram for explaining an engraved portion 2M. FIG. 3 is a diagram for explaining the optical path of illumination light from the first illumination device 11. FIG. 4 is a diagram of the first illumination device 11 viewed from above. FIG. 5 is a schematic diagram showing an example of the hardware configuration of the control device 20. FIG. 6 is a schematic diagram showing an example of the functional configuration of the control device. FIG. 7 is a schematic diagram showing an example of the data structure of a focal length table 211. FIG. 8 is a schematic diagram showing an example of the operation processing of the detection device 1.

[0010] A preferred embodiment of the present invention will be described with reference to the accompanying drawings (in each drawing, the same reference numerals denote the same or similar configurations).

[0011] The detection device 1 according to this embodiment will be described with reference to Figures 1 to 4. Figure 1 is a schematic diagram showing an example of the configuration of the detection device 1. Figure 2 is a schematic diagram showing an example of the bottom 2d of the bottle 2 as viewed from below. Figure 3 is a diagram for explaining the optical path of the illumination light from the first illumination device 11. Figure 4 is a schematic diagram showing an example of the first illumination device 11 as viewed from above.

[0012] The bottle 2 is an example of an object, such as a resin-molded container. Specifically, the bottle 2 is a thin-walled container made of PET resin and is generally hollow and cylindrical, formed by blow molding a preform (preliminary molded body) in a predetermined mold (molding die). The axis of the hollow cylinder is referred to as axis AX. The bottle 2 has a body 2a, a neck 2b, a shoulder 2c, and a bottom 2d. The body 2a of the bottle 2 is generally cylindrical, and the shoulder 2c between the neck 2b and the body 2a is generally truncated cone-shaped. Note that this shape is merely an example, and the bottle 2 may have other shapes.

[0013] The engraved portion 2M will be described with reference to FIG. 2. FIG. 2 shows a schematic diagram of the bottom 2d of the bottle 2 as viewed from below. The bottom 2d has a generally circular shape concentric with a center 2e. The center 2e may coincide with the axis AX of the bottle 2. At least a portion of the bottom 2d may be recessed inward. The engraved portion 2M is provided at a position on the bottom 2d spaced a predetermined distance r from the center 2e. The engraved portion 2M includes an engraving provided on the bottom 2d of the bottle 2. The engraving is formed, for example, as an uneven surface with a height of approximately 0.5 mm or less. The engraving may be identification information composed of numbers, symbols, or the like for identifying the mold used to mold the bottle 2. However, the content of the engraving is not limited to this and may include any information related to the bottle 2 or its molding.

[0014] The detection device 1 is a device for detecting an inscription on a bottle 2. As shown in Fig. 1, the detection device 1 includes a first lighting device 11 as an example of lighting means that illuminates the bottle 2 from below, a first moving device 11D as an example of moving means for moving the first lighting device 11, an imaging device 12 as an example of imaging means that images the bottle 2, a second lighting device 13 as an example of second lighting means that illuminates the bottle 2 from above, a second moving device 13D as an example of second moving means for moving the second lighting device 13, and a control device 20 as an example of detection means.

[0015] The first lighting device 11 illuminates a portion of the bottle 2, including at least the engraved portion 2M, from below the bottle 2 with a predetermined illumination light. The first lighting device 11 has an annular shape with a first illumination optical axis La as its axis. Note that the first lighting device 11 does not have to have a closed annular shape in the circumferential direction, and may have a shape that is partially open in the circumferential direction. The first lighting device 11 is arranged, for example, so that the first illumination optical axis La of the first lighting device 11 coincides with the axis AX of the bottle 2. Note that the first illumination optical axis La does not have to coincide with the axis AX. For example, the first illumination optical axis La may be arranged in the same direction (parallel) as the axis AX but offset by a predetermined distance, or may be oriented so as to form an angle with respect to the axis AX that is less than a predetermined threshold value.

[0016] FIG. 3 is a schematic diagram showing the vicinity of the bottom 2d of the bottle 2, the first lighting device 11, and the imaging device 12. In FIG. 3, the first lighting device 11 is shown as a cross-sectional view of a plane passing through the first lighting optical axis La and parallel to the paper. A first light-emitting portion 11a having a predetermined R-shape is formed on the inner side of the first lighting device 11 facing the first lighting optical axis La. The R-shape of the first light-emitting portion 11a is not particularly limited, but may be formed as a parabola, for example. The first light-emitting portion 11a may include, for example, an LED as a light source and a diffusion plate (an example of a diffusion portion) that diffuses the light emitted by the LED. As a result, the first light-emitting portion 11a emits diffused light as illumination light. Note that the first light-emitting portions 11a of the first lighting device 11 do not have to be provided over the entire circumferential direction, but may be provided discretely.

[0017] 3 and 4 , the first lighting device 11 includes a gap 11b provided inside the first light-emitting portion 11a. The gap 11b may have a substantially cylindrical shape with a predetermined radius and a center on the first lighting optical axis La of the first lighting device 11. Note that the center of the gap 11b does not necessarily have to be the first lighting optical axis La, and the gap 11b may have a substantially cylindrical shape with a center at a position shifted a predetermined distance from the first lighting optical axis La.

[0018] Fig. 3 shows a portion of the optical path of the illumination light from the first illumination device 11. As shown in Fig. 3, a portion of the illumination light emitted by the first light-emitting unit 11a reaches the engraved portion 2M provided on the bottom 2d of the bottle 2. Then, a portion of the illumination light that reaches the engraved portion 2M is reflected by the engraved portion 2M, and the reflected illumination light passes through the inside of the gap 11b and reaches the imaging device 12.

[0019] The first moving device 11D is connected to the control device 20 and drives the first lighting device 11 to move in a predetermined direction based on a control signal supplied from the control device 20. The first moving device 11D may, for example, raise and lower the first lighting device 11 in the vertical direction. The configuration of the first moving device 11D is not particularly limited, and may, for example, include a drive motor or be configured as a robot arm. Furthermore, the first moving device 11D may be configured to drive the first lighting device 11 in any direction, such as horizontal or diagonal, rather than just the vertical direction.

[0020] A substantially cylindrical gap 11b is provided near the center of the first light-emitting unit 11a. Therefore, illumination light is not irradiated from near the center of the first light-emitting unit 11a toward the bottom 2d of the bottle 2. This allows the intensity of light irradiated onto the engraved portion 2M to be relatively higher than the intensity of light irradiated onto other portions (radially inward or outward from the engraved portion 2M). This provides high contrast even when the height of the engraving is small, improving the accuracy of engraving detection. Furthermore, the intensity of light emitted by the first light-emitting unit 11a and reflected by the engraved portion 2M and reaching the imaging device 12 varies depending on the distance between the first lighting device 11 and the bottle 2. In particular, the light intensity peaks when the distance D (see FIG. 1) between the first lighting device 11 and the bottle 2 reaches a certain value. This specific value indicating the peak is sometimes referred to as the focal length of the first lighting device 11.

[0021] In the detection device 1, the distance between the first illumination device 11 and the bottle 2 may be set to be the focal length. In particular, as described below, in the detection device 1, the control device 20 may move the first illumination device 11 so that the distance between the first illumination device 11 and the bottle 2 is the focal length. By setting the distance D between the first illumination device 11 and the bottle 2 to be the focal length in this manner, the intensity of light emitted by the first illumination device 11, reflected by the engraved portion 2M, and reaching the imaging device 12 peaks compared to when the distance D is not the focal length. Because the light intensity peaks in this manner, sufficient contrast of the engraving can be obtained, improving the accuracy of engraving detection, as described below.

[0022] The imaging device 12 includes a solid-state imaging element such as a CCD image sensor or a CMOS image sensor, and a lens for focusing light onto the solid-state imaging element. The imaging device 12 converts the optical image generated by the solid-state imaging element based on the light focused by the lens into an electronic image and outputs an image signal corresponding to the electronic image to the control device 20. The imaging device 12 is positioned so that the imaging optical axis Lb of the imaging device 12 coincides with the axis AX of the bottle 2 and the focal point of the imaging device 12 coincides with the bottom 2d including the engraved portion 2M. Note that the imaging optical axis Lb does not have to coincide with the axis AX. For example, the imaging optical axis Lb may be positioned in the same direction (parallel) as the axis AX but offset by a predetermined distance, or may be oriented so as to form an angle with the axis AX that is less than a predetermined threshold. The imaging device 12 receives light emitted by the first light-emitting section 11a of the first lighting device 11 and reflected by the engraved portion 2M, and based on the light, generates an image signal corresponding to the image of the engraved portion 2M and outputs it to the control device 20.

[0023] The second lighting device 13 illuminates the bottle 2 from above. The second lighting device 13 is positioned opposite the first lighting device 11 with respect to the bottle 2. The second lighting device 13 emits light (second lighting light) from this position to illuminate the thin-walled bottom portion 2d. The second lighting device 13 is positioned so that its second lighting optical axis Lc coincides with the axis AX of the bottle 2. Note that the second lighting optical axis Lc does not have to coincide with the axis AX. For example, the second lighting optical axis Lc may be positioned in the same direction (parallel) as the axis AX but offset by a predetermined distance, or may be oriented so as to form an angle with the axis AX that is less than a predetermined threshold. The second lighting device 13 includes a second light-emitting unit 13a and a diffuser 13b.

[0024] The second light-emitting unit 13a has a surface shape with the second illumination optical axis Lc as its axis. The shape of the surface of the second light-emitting unit 13a viewed from the second illumination optical axis Lc is not particularly limited, and may be substantially circular, substantially polygonal, or the like. The second light-emitting unit 13a may also have a gap or an opening. The second light-emitting unit 13a emits directional light. The second light-emitting unit 13a may be configured to include, for example, an LED as a light source and a filter for limiting the traveling direction of the light emitted by the LED to a predetermined angle. The degree of directionality of the light emitted by the second light-emitting unit 13a may be defined as an angle with respect to the second illumination optical axis Lc being within a predetermined threshold.

[0025] The diffuser 13b diffuses the light emitted by the second light-emitting unit 13a. The diffuser 13b has a surface shape with the second illumination optical axis Lc as its axis. The surface shape of the diffuser 13b viewed from the second illumination optical axis Lc may be substantially the same as or different from the surface shape of the second light-emitting unit 13a. The diffuser 13b may be fixed to a predetermined jig or a second moving device 13D (described later) or the like so that its position relative to the second light-emitting unit 13a is fixed or variable. Note that the second lighting device 13 does not necessarily need to include the diffuser 13b if the second light-emitting unit 13a has a desired directivity, for example.

[0026] The light emitted by the second lighting device 13, i.e., the light emitted by the second light-emitting unit 13a and passing through the diffuser 13b, has a predetermined directionality. The light enters the interior of the bottle 2 through an opening (not shown) provided at the top of the neck 2b of the bottle 2 and travels inside the bottle 2 toward the bottom 2d. At least a portion of the light that reaches the bottom 2d of the bottle 2 passes through the bottom 2d, including the engraved portion 2M, and then passes through the gap 11b of the first lighting device 11 to reach the imaging device 12.

[0027] In addition to the light emitted by the first illumination device 11 and reflected by the engraved portion 2M, the imaging device 12 may also receive light emitted by the second illumination device 13 and transmitted through the engraved portion 2M, as described above, and generate an image signal corresponding to an image of the engraved portion 2M based on the light and output the image signal to the control device 20. If the engraved portion 2M of the bottle 2 is processed to have a highly uneven pattern, such as a matte finish, the illumination light from the first illumination device 11 alone may not provide sufficient contrast between the shadows of the engraving in the image captured by the imaging device 12 due to diffuse reflection from the bottom 2d. In this case, by using the directional second illumination device 13 as transmitted light in addition to the first illumination device 11, the unevenness of the engraved portion 2M on the bottom 2d can be emphasized in the image generated by the imaging device 12, improving the accuracy of detecting the matte finish or other engraving.

[0028] The second moving device 13D is connected to the control device 20 and drives the second lighting device 13 to move in a predetermined direction based on a control signal supplied from the control device 20. The second moving device 13D may, for example, move the second lighting device 13 in the vertical direction. Furthermore, the second moving device 13D may be configured to drive the second lighting device 13 in any direction, such as horizontal or diagonal, rather than just vertically. The configuration of the second moving device 13D is not particularly limited, but may include, for example, a drive motor or may be configured as at least a part of an arm robot. Furthermore, the second moving device 13D may be configured to have a bottle 2 fixed thereto in addition to the second lighting device 13, so that it can move the bottle 2 together with the second lighting device 13. For example, if the second moving device 13D is configured as an arm robot, the bottle 2 may be grasped by an end effector of the arm robot, and the second lighting device 13 may be fixed to the arm robot by a predetermined jig.

[0029] 5 is a schematic diagram illustrating an example of the hardware configuration of the control device 20. As illustrated in FIG. 5 , the control device 20 includes a processor 21 such as a CPU (Central Processing Unit) or a GPU (Graphical Processing Unit), a storage device 22 such as a semiconductor memory, a hard disk drive (HD) and / or a solid state drive (SSD), a communication interface (IF) 23 for wired or wireless communication, an input device 24 for accepting input operations, and an output device 25 for outputting information. The input device 24 is, for example, a keyboard, a touch panel, a mouse, and / or a microphone. The output device 25 is, for example, a display, a touch panel, and / or a speaker.

[0030] 6 is a schematic diagram showing an example of the functional configuration of the control device 20. The control device 20 includes a storage unit 210 and a control unit 220.

[0031] The storage unit 210 can be realized using a storage unit 22 included in the control device 20. The control unit 220 can be realized by the processor 21 of the control device 20 executing a computer program stored in the storage unit 22. The computer program can be stored in a storage medium. The storage medium storing the computer program may be a non-transitory computer-readable medium. The non-transitory storage medium is not particularly limited, and may be, for example, a storage medium such as a USB memory or a CD-ROM.

[0032] The storage unit 210 stores, for example, a focal length table 211, which is a table showing the respective types of bottles 2. FIG. 7 is a schematic diagram showing an example of the data structure of the focal length table 211. As described above, because the first lighting device 11 has the gap 11b, the intensity of light emitted by the first light-emitting unit 11a and reflected by the engraved portion 2M to reach the imaging device 12 peaks at a certain focal length. The focal length table 211 is a table that associates such focal length values ​​with each type of bottle. For example, as shown in FIG. 7, the focal length of a bottle of type 1 whose bottle name is "Large 1.5L" is "50.0 mm." That is, for a bottle 2 of type 1 whose bottle name is "Large 1.5L," the focal length D between the first lighting device 11 and the bottle 2 reaches the focal length of "50.0 mm," indicating that the intensity of light reflected by the engraved portion 2M to reach the imaging device 12 peaks. For example, the focal length of a bottle of type 3 whose bottle name is "Multi 600 ml" is 10.0 mm. That is, for bottle 2 of type 3 whose bottle name is "Multi 600 ml," when the distance D between first lighting device 11 and bottle 2 is 10.0 mm, which is the focal length, the intensity of light reflected by engraved portion 2M and reaching imaging device 12 reaches a peak.

[0033] 6 again, the control unit 220 has a first movement control unit 221, a first illumination control unit 222, a second movement control unit 223, a second illumination control unit 224, an imaging control unit 225, and a recognition processing unit 226.

[0034] The first movement control unit 221 controls, for example, the movement of the first lighting device 11. The first lighting control unit 222 may, for example, control the first movement device 11D by supplying a control signal to the first movement device 11D to move the first lighting device 11 so as to change the distance between the first lighting device 11 and the bottle 2. The first movement control unit 221 may, for example, acquire information indicating the variety of the bottle 2, acquire a focal length corresponding to the variety from the focal length table 211 stored in the memory unit 210, and then control the first movement device 11D to move the first lighting device 11 so that the distance between the first lighting device 11 and the bottle 2 becomes the focal length. This causes the intensity of light emitted by the first light-emitting unit 11a, reflected by the engraved portion 2M, to reach the imaging device 12 to reach a peak, improving the accuracy of engraving detection.

[0035] The first illumination control unit 222 controls light emission by the first light emitter 11a of the first illumination device 11. The first illumination control unit 222 may control, for example, the ON / OFF, intensity, cycle, etc. of the light emission by the first light emitter 11a.

[0036] The second movement control unit 223, for example, controls the movement of the second lighting device 13. For example, the second movement control unit 223 may control the second moving device 13D by supplying a control signal to the second moving device 13D to move the second lighting device 13 so as to change the distance between the second lighting device 13 and the bottle 2. Note that if the second moving device 13D is configured to be able to move the bottle 2 in addition to the second lighting device 13, the second movement control unit 223 may control the second moving device 13D to move the second lighting device 13 and the bottle 2. Specifically, for example, the second movement control unit 223 may control the second moving device 13D to which the second lighting device 13 is fixed so that the second lighting device 13 is positioned at a predetermined position relative to the bottle 2, and control the second moving device 13D to grip the bottle 2 and transport it to a predetermined detection position.

[0037] The second illumination control unit 224 controls light emission by the second light emitter 13a of the second illumination device 13. The second illumination control unit 224 may control, for example, the ON / OFF, intensity, cycle, etc. of the light emission by the second light emitter 13a.

[0038] The imaging control unit 225 controls the imaging device 12 to acquire an image including the engraved portion 2M. The imaging control unit 225 may, for example, adjust various parameters of the imaging device 12. The imaging control unit 225 may acquire an image including the engraved portion 2M, for example, when the control device 20 accepts an operation by a user via the input device 24. Alternatively, the imaging control unit 225 may acquire an image including the engraved portion 2M at predetermined periodic / non-periodic timing.

[0039] The recognition processing unit 226 executes a marking detection process. For example, the recognition processing unit 226 executes a recognition process of the marking included in the image based on the image generated by the imaging device 12, thereby determining the position of the marking and recognizing the marking. The recognition process may include, for example, optical character recognition (OCR), which is a process of detecting characters in an image and converting them into digital text. In optical character recognition, for example, first, preprocessing such as noise removal and normalization of the image is performed, and then text regions are detected. Characters are extracted from the text regions and identified based on the characteristics of the extracted characters. In executing the recognition process, for example, a machine-learned learning model may be used.

[0040] The control unit 220 may output information about the marking recognized by the recognition processing unit 226 to the output device 105. For example, the control unit 220 may superimpose information indicating the content of the marking (e.g., text) on an image including the marking portion 2M generated by the imaging device 12 and output the image to the output device 105. The control unit 220 may, for example, determine the position of the marking. The position of the marking may include information such as the direction relative to the axis AX and the distance from the axis AX. Furthermore, the control unit 220 may determine the orientation of the bottle 2 on which the marking is provided based on the determined position of the marking.

[0041] An example of the operation process of the detection device 1 will be described with reference to FIG. 8 . In this example, as shown in FIG. 8 , the second moving device 13D is configured as an arm robot for moving both the second lighting device 13 and the bottle 2. That is, the second lighting device 13 is attached to the second moving device 13D in advance via a predetermined jig or the like. The second moving device 13D also includes an end effector 13E, which is configured to be able to grip the bottle 2. The second lighting device 13 is fixed at a predetermined distance from the bottle 2 gripped by the end effector 13E so that the illumination light from the second lighting device 13 can sufficiently enter the bottle 2.

[0042] (Step S1) First, the second movement control unit 223 controls the second movement device 13D to grip the bottle 2 with the end effector 13E and transport the bottle 2 to a predetermined position. The predetermined position may be a position where the bottom 2d of the bottle 2 is at the focal length of the imaging device 12. Note that, because the second illumination device 13 is attached to the second movement device 13D itself, there is no need for the second movement device 13D to move the bottle 2 while avoiding the second illumination device 13, and the degree of freedom in the dimensions of the bottle 2 that can be detected by the detection device 1 is increased.

[0043] (Step S2) Next, the first movement control unit 221 acquires information indicating the type of bottle 2, and then refers to the focal length table stored in the memory unit 210 to acquire the focal length corresponding to the type of bottle 2. Then, the first movement control unit 221 moves the first lighting device 11 using the first movement device 11D so that the distance between the first lighting device 11 and the bottle 2 becomes the acquired focal length.

[0044] (Step S3) Next, the first lighting control unit 222 controls the first lighting device 11, and the second lighting control unit 224 controls the second lighting device 13, causing each of the first lighting device 11 and the second lighting device 13 to emit light. The light emitted by the first lighting device 11 is reflected by the engraved portion 2M and other areas, passes through the gap 11b of the first lighting device 11 (see FIG. 3 ), and reaches the imaging device 12. The light emitted by the second lighting device 13 enters the bottle 2, and at least a portion of it passes through the bottle 2 at the bottom portion 2d, which includes the engraved portion 2M. The transmitted light passes through the gap 11b of the first lighting device 11 (see FIG. 3 ), and reaches the imaging device 12. The imaging control unit 225 controls the imaging device 12 to generate an image including the engraved portion 2M. The image may include only the engraved portion 2M, or may include part or all of the bottom portion 2d of the bottle 2. The recognition processing unit 226 then detects the engraving based on the generated image. Specifically, the recognition processing unit 226 determines the position of the marking and recognizes the marking by executing a recognition process on the image generated by the imaging device 12. The control unit 220 may output information related to the marking recognized by the recognition processing unit 226 to the output device 25. For example, the control unit 220 may superimpose information indicating the content of the marking (such as text) on the image including the marking portion 2M generated by the imaging device 12 and output the image to the output device 25.

[0045] (Step S4) Next, the first movement control unit 221 lowers the first lighting device 11 to a predetermined position, for example, to a position where the second movement control unit 223 can move the bottle 2 away.

[0046] (Step S5) Next, the second movement control unit 223 controls the second movement device 13D to retract the second lighting device 13 and the bottle 2. The second movement control unit 223 may then place the bottle 2 in a predetermined location and grip the next bottle 2 for which marking detection is to be performed. This completes the operation process.

[0047] As described above, in the detection device 1 according to this embodiment, the first light-emitting unit 11a is provided with the gap 11b, and therefore illumination light is not irradiated from the gap 11b onto the bottom 2d of the bottle 2. This allows the intensity of light irradiated onto the engraved portion 2M to be relatively higher than the intensity of light irradiated onto other portions (radially inside or outside the engraved portion 2M), improving the accuracy of marking detection.

[0048] The detection device 1 may be used to detect markings on other positions on the bottle 2, not just the bottom 2d of the bottle 2. The material of the bottle 2 is not limited to PET resin, but may be other materials such as glass.

[0049] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those illustrated and can be modified as appropriate. Furthermore, configurations shown in different embodiments can be partially substituted or combined.

[0050] REFERENCE SIGNS LIST 1...detection device, 2...bottle, 2a...body portion, 2b...neck portion, 2c...shoulder portion, 2d...bottom portion, 2e...center, 2M...engraved portion, 11...first lighting device, 11a...light-emitting portion, 11b...gap, 11D...first moving device, 13...second lighting device, 13a...second light-emitting portion, 13b...diffusion plate, 13D...second moving device, 13E...end effector, 20...control device, 21...processor, 22... Storage device, 23...communication IF, 24...input device, 25...output device, 210...storage unit, 211...focal length table, 220...control unit, 221...first movement control unit, 222...first lighting control unit, 223...second movement control unit, 224...second lighting control unit, 225...imaging control unit, 226...recognition processing unit, AX...axis line, La...first lighting optical axis, Lb...imaging optical axis, Lc...second lighting optical axis

Claims

1. A detection device for detecting an inscription on an object, comprising: illumination means having a light-emitting unit that emits light to irradiate the inscription portion of the object, which is the portion where the inscription is provided, and a gap provided inside the light-emitting unit through which the light reflected by the inscription portion passes; imaging means that receives the light that has been reflected by the inscription portion and passed through the gap and images the inscription portion; and detection means that detects the inscription based on an image of the inscription portion obtained by imaging with the imaging means.

2. The detection device according to claim 1, wherein said detection means executes a recognition process for recognizing said marking based on said image.

3. The detection device according to claim 1, wherein said illumination means further comprises a diffusion section for diffusing said light emitted by said light emitting section.

4. The detection device according to claim 1, wherein the light-emitting portion has an annular shape that defines the gap.

5. The detection device according to claim 1, further comprising a moving means for moving said illumination means so that the distance between said illumination means and said object changes.

6. A detection device according to claim 5, wherein said moving means moves said lighting means so that the distance between said lighting means and said object is a distance that is set in advance depending on the type of said object.

7. The detection device according to claim 1, wherein the engraved portion is a thin portion of the object on which the engraving is provided, the detection device further comprises a second illumination means having a second light-emitting unit that emits a second light for irradiating the thin portion from a position facing the illumination means with respect to the object, and the imaging means receives the light and the second light that has passed through the thin portion to image the thin portion.

8. A detection device according to claim 7, wherein the illumination range of the second light emitted by the second light-emitting section is set to a predetermined range including the thin-walled section.

9. The detection device according to claim 7, wherein the second illumination means further comprises a second diffusion section for diffusing the second light emitted by the second light emitting section.

10. The detection device of claim 7, further comprising second moving means for moving said second illumination means so as to vary a second distance of said second light emitting portion from said object.

11. The detection device according to claim 1, wherein the object is a resin-molded container, and the engraved portion is provided on the bottom of the container.

12. A detection method for detecting an inscription on an object, comprising: a step in which an illumination means having a light-emitting unit and a gap provided inside the light-emitting unit emits light to illuminate the inscription portion, which is the portion of the object where the inscription is provided; a step in which an imaging means receives the light that has been reflected by the inscription portion and passed through the gap, and images the inscription portion; and a step in which a detection means detects the inscription based on an image of the inscription portion obtained by imaging by the imaging means.

Images