JP2013054021A - Method and device for detecting transparent body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for surely detecting presence/absence of a colorless contact lens and a transparent body sealed in a transparent plastic film.SOLUTION: Since many contact lenses contain ultraviolet absorber in order to protect eyes from harmful ultraviolet, an illumination unit 2 illuminates a package 1 of the contact lens for emitting ultraviolet, the package 1 is photographed with a camera 3 that detects the ultraviolet, and the image is image-processed with a personal computer 4. Because the contact lens absorbs the ultraviolet, an image of a package storing a contact lens is apparently different from an image of a package not storing a contact lens. Consequently presence/absence of the contact lens can be detected.

Description

  The present invention relates to a transparent body detection method represented by a contact lens and a detection device used therefor, and more particularly to a contact lens detection method and a detection device in a form encapsulated in a transparent film made of a polymer material together with a storage solution. It is about.

  In the correction of visual acuity such as myopia, hyperopia, and astigmatism, eyeglasses are used, while contact lenses are also frequently used. Compared with eyeglasses, contact lenses are directly mounted on the cornea of an eyeball, and thus have a feature that image distortion and change in size are small.

  Also, when the left and right eyesights are extremely different, correction with glasses may not be used for a long time due to headaches and eye strain, although there are individual differences, but in such cases, contact lenses should be used. Is effective. Furthermore, since the contact lens is directly attached to the cornea as described above, a field of view that is the same as that of the naked eye can be obtained, and the lens itself is small. It does not fall or become cloudy due to condensation.

  In addition, there is no change in appearance as when wearing eyeglasses, and especially for women, it may be used from the viewpoint of beauty and aesthetics. In addition, color contact lenses are also used because of aesthetic effects.

  Contact lenses can be broadly classified into hard lenses and soft lenses. Soft lenses use polyhydroxyethyl methacrylate and polyvinylpyrrolidone as materials, and are soft and flexible as they are literally. Less than a lens. On the other hand, since bacteria are easy to propagate, regular cleaning and disinfection are necessary.

  For this reason, disposable contact lenses that are used and discarded for one day to one week are frequently used. Such a packaging form in the circulation of the lens is generally formed of a film of a transparent polymer material such as polyolefin, and is enclosed in a package filled with a protective solution such as physiological saline.

  The problem here is how to confirm that the contact lens is securely enclosed in the package. In general, when there is a transparent object in a transparent liquid and there is no large difference in the refractive index between the liquid and the object, it is difficult for light to be reflected or scattered at the interface. This is one of the reasons.

As a method for detecting the presence / absence of a contact lens housed in a case, the number of existing contact lenses, and the type of lens, Patent Document 1 discloses data prepared in advance by calculating the chromaticity coordinates of reflected light by irradiating visible light. And a method for detecting the presence or absence of a lens or the like is disclosed.
According to this method, it is possible to detect the matter with high accuracy, but the target contact lens is limited to a colored one and cannot be applied to a normal colorless contact lens.

  Japanese Patent No. 4091778

  Accordingly, an object of the present invention is to provide a method and apparatus for reliably detecting the presence or absence of a colorless contact lens encapsulated in a transparent plastic film.

  In recent years, lenses for correcting vision have been used for both normal eyeglasses and contact lenses, and lenses made of materials containing UV absorbers have been used to protect the eyes from harmful UV rays. In many cases, the surface is coated with an ultraviolet absorber. The present inventors have paid attention to this point, and as a result of studying an optimal arrangement of an irradiation lamp using an ultraviolet lamp and an ultraviolet camera, the present invention has been made.

  That is, the present invention provides a detection method for detecting the presence or absence of the transparent body by irradiating illumination light onto a transparent body housed in a package made of a transparent film of a polymer material and detecting reflected light. In the detection method, the illumination light is ultraviolet light.

  Further, the present invention is the detection method described above, wherein the wavelength band of the illumination light is 380 nm or less.

  Moreover, the present invention is the detection method described above, wherein the peak wavelength of the illumination light is 320 to 380 nm.

  Further, the present invention is the detection method described above, wherein the illumination light is irradiated onto the transparent body from a plurality of light sources from different directions.

  Moreover, this invention is the said detection method characterized by the said transparent body being a contact lens.

  According to another aspect of the present invention, there is provided a lighting device having at least one light source that emits ultraviolet light, and a camera capable of detecting ultraviolet light, and detecting a transparent body contained in a package made of a transparent film made of a polymer material. Device.

  The present invention also provides the detection device for a transparent body housed in a package made of a transparent film of the above-described polymer material, wherein the wavelength band of illumination light of the light source emitting ultraviolet light is 380 nm or less.

  The present invention also provides a detection device for a transparent body housed in a package made of a transparent film of the above-mentioned polymer material, wherein the peak wavelength of illumination light of the light source emitting ultraviolet light is 320 to 380 nm. is there.

  Further, the present invention is the detection device for a transparent body housed in a package made of a transparent film of the above polymer material, wherein the transparent body is a contact lens.

  For example, many patent documents such as Japanese Patent Application Laid-Open No. 06-172742 disclose that benzotriazole compounds are suitable as ultraviolet absorbers used for contact lenses. This compound absorbs almost 100% of ultraviolet rays having a wavelength of 290 to 320 nm called UVA waves and ultraviolet rays of 320 to 380 nm called UVB waves, so that the heat energy is less harmful than ultraviolet rays. It has the property to convert.

  Therefore, by using these lamps that radiate ultraviolet rays to detect the presence or absence of contact lenses in the package, a greater improvement in detection accuracy can be expected than in the case of using visible light.

  Moreover, according to the examination result which the present inventors performed using LED as a lamp | ramp which radiates | emits an ultraviolet-ray, although a single lens can detect a contact lens, the commercially available general purpose LED is used. In order to obtain a sufficient amount of light for detection, a plurality of LEDs are required. In the case of a single contact lens package, the plurality of LEDs are arranged in a circular shape with the highest detection accuracy. In the case of a plurality of contact lens packages, the plurality of LEDs are arranged almost linearly. It was found that the use of a plurality of illuminated units is necessary for reliable detection. In other words, it is important to appropriately examine the optimal arrangement depending on the shape of the detection target.

  Schematic which shows an example of the detection apparatus which concerns on this invention.   The figure which shows the example of the contact lens enclosed with the package of the transparent film.   The figure which shows the difference in the frequency characteristic of the reflectance by the presence or absence of a contact lens.   The figure which shows an example of the frequency characteristic of LED which emits the ultraviolet-ray which can be used for this invention.   FIG. 4A is an example in which a plurality of light sources are arranged in an annular shape, and FIG. 4B is an example in which a plurality of light sources are arranged in a straight line.   The perspective view which shows the example of a test | inspection of the contact lens package piece using the detection apparatus which concerns on this invention.   The perspective view which shows the example of a test | inspection of the continuous body which the some contact lens package using the detection apparatus which concerns on this invention connected.   The perspective view which shows an example of the test | inspection and defective product exclusion method using the detection apparatus which concerns on this invention.   The figure which shows the relationship between the number of light sources, and the frequency | count of an error.

  Next, embodiments of the present invention will be described with reference to specific drawings.

  FIG. 1 is a schematic view showing an example of a detection apparatus according to the present invention. In FIG. 1, reference numeral 1 denotes a contact lens package, 2 denotes an illumination unit, 3 denotes a camera, 4 denotes a personal computer for image processing and apparatus control, and 5 denotes a work mounting base.

  Here, as will be described later, the illumination unit 2 has a configuration in which LEDs that emit ultraviolet rays at regular intervals are arranged on an annular substrate. The camera 3 is a so-called UV camera that can detect ultraviolet rays. As the personal computer 4, a commercially available general-purpose computer can be used as long as it has a processing capability of a certain level or more. As the work mounting base 5, a conveying means such as a belt conveyor is usually used.

  FIG. 2 is a diagram illustrating an example of a contact lens sealed in a transparent film package. In FIG. 2, 6 is a contact lens, 7a and 7b are package materials made of a polymer film, and 8 is a protective liquid. As the material of the package materials 7a and 7b used here, polyolefin such as polypropylene can be used, and as the lower package material 7b in the figure, a laminate of aluminum foil or the like can be used.

  FIG. 3 is a diagram showing the difference in the frequency characteristics of the reflectance, which was performed to verify the suitability of the frequency of the light source used in the present invention. Here, the frequency at the time of irradiating illumination to the package enclosing the protective liquid and the contact lens and the package filled only with the protective liquid was swept, and the change in reflectance was measured. The solid line shows the package containing the contact lens, and the broken line shows the result of the protective liquid alone. From FIG. 3, a remarkable difference is recognized in the region where the wavelength of illumination is 380 nm or less, and it can be determined that it is useful for detection of contact lenses.

  FIG. 4 is a diagram showing an example of frequency characteristics of an LED emitting ultraviolet light used in the present invention. As is apparent from the results described in the claims and shown in FIG. 3, the present invention preferably uses a light source that emits ultraviolet light having a wavelength of 380 nm or less. In this example, the wavelength band is 320 to 380 nm, the peak The wavelength is 340 to 345 nm.

  FIG. 5 is a perspective view showing an example of an illumination unit according to the present invention. FIG. 5A is an example in which a plurality of light sources are arranged in an annular shape, and FIG. 5B is a diagram in which a plurality of light sources are arranged in a straight line. It is an example. In FIG. 5, 9a and 9b are illumination units, 10a and 10b are LEDs, and 11a and 11b are substrates.

  FIG. 6 is a perspective view showing an example of inspection of a contact lens package piece using the detection apparatus according to the present invention. When the inspection is performed using the illumination unit 9a shown in FIG. 5A, the contact lens package piece 1a is arranged on the central axis of the field of view of the camera 3 as shown in FIG. It is desirable to place the central axis of the camera field of view at the center of 9a.

  FIG. 7 is a perspective view showing an inspection example of a continuous body in which a plurality of contact lens packages are connected using the detection apparatus according to the present invention. When the inspection is performed using the illumination unit 9b shown in FIG. 5B, as shown in FIG. 7, the illuminance of the portion where the contact lens package continuous body 1b is placed is changed between the two illumination units 9b. It is desirable to arrange so that the central axis of the visual field of the camera 3 substantially coincides with the central axis in the longitudinal direction of the contact lens package continuous body 1b.

  FIG. 8 is a perspective view showing an example of an inspection and defective product exclusion method using the detection apparatus according to the present invention. In this example, a contact lens package continuous body 1b is mounted on a belt conveyor 12 for transporting a workpiece, and an image processing result of a camera 3 is processed by a personal computer (not shown) so that a contact lens cannot be confirmed inside. The pusher 13 having an air cylinder or the like as a constituent element protrudes from the chute 14.

  Next, in order to confirm the relationship between the number of light sources attached to the lighting unit and the accuracy of the inspection, 1000 packages each containing a protective liquid and a contact lens and a package containing only the protective liquid were prepared. Then, with the configuration of the camera 3 and the illumination unit 9a shown in FIG. 6, the number of light sources is 1 to 10, and 1000 packages are inspected to determine the number of times that a detection error occurs. The contact lens used contains a benzotriazole-based ultraviolet absorber.

  Here, the error is determined to be that the contact lens is not present for the package in which the contact lens is sealed, and conversely, the contact lens is determined to be present for the package in which only the protective liquid is sealed. Is.

  FIG. 9 is a plot of the results. The circles show the contact lens sealed, and the triangles show only the protective liquid. From this result, it is clear that the number of light sources attached to the lighting unit is preferably plural.

  As described above, according to the present invention, it is possible to provide a detection method and a detection device that can reliably detect the presence or absence of a contact lens enclosed in a package together with a protective liquid, saving labor in an inspection process, and thus manufacturing costs. This can contribute to the reduction of quality and the improvement of quality.

  Although no specific example has been shown here, the present invention can be applied to detection of a workpiece made of a transparent body containing an ultraviolet absorber, even if it is not a contact lens. Furthermore, it is also possible to detect coating defects by applying the present invention to a normal spectacle lens or other transparent body coated with an ultraviolet absorber.

  The present invention is not limited to the above-described embodiment, and does not depart from the gist of the present invention, including various modifications and corrections that can be conceived by those having ordinary knowledge in the field of the present invention. Of course, even if there is a design change in the range, it is included in the present invention.

DESCRIPTION OF SYMBOLS 1 Contact lens package 1a Contact lens package piece 1b Contact lens package continuous body 2 Illumination unit 3 Camera 4 Personal computer 5 Work mounting base 6 Contact lens 7a, 7b Package material 8 Protective liquid 9a, 9b Illumination unit 10a, 10b LED
11a, 11b Substrate 12 Belt conveyor 13 Pusher 14 Shooter

Claims (9)

  In the detection method of detecting the presence or absence of the transparent body by irradiating illumination light to a transparent body housed in a package made of a transparent film of a polymer material and detecting reflected light, the illumination light is ultraviolet light The detection method characterized by being.   The detection method according to claim 1, wherein the illumination light has a wavelength band of 380 nm or less.   The detection method according to claim 1, wherein the illumination light has a peak wavelength of 320 to 380 nm.   The detection method according to any one of claims 1 to 3, wherein the illumination light irradiates the transparent body with a plurality of light sources from different directions.   The detection method according to claim 1, wherein the transparent body is a contact lens.   An apparatus for detecting a transparent body housed in a package made of a transparent film made of a polymer material, comprising: an illumination device having at least one light source that emits ultraviolet light; and a camera capable of detecting ultraviolet light.   The apparatus for detecting a transparent body housed in a package made of a transparent film of a polymer material according to claim 6, wherein the wavelength band of illumination light of the light source emitting ultraviolet light is 380 nm or less.   The peak wavelength of the illumination light of the light source that emits ultraviolet rays is 320 to 380 nm. The transparent body housed in a package made of a transparent film of a polymer material according to claim 6 or 7, Detection device.   9. The detection device for a transparent body housed in a package made of a transparent film made of a polymer material according to claim 6, wherein the transparent body is a contact lens.

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