JP2003057611A - Contact lens inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact lens inspection device by which defects such as a scratch, a stain, etc., caused on a lens to be inspected are inspected more sharply than before, and the defects are vividly and reliably inspected even in the state where the lens to be inspected is dipped in a liquid, the inspection device comprising an almost horizontal placement plate for placing the contact lens to be inspected thereon and a video camera for photographing the optical image of the lens to be inspected from an upper part. SOLUTION: The contact lens inspection device is provide with a ring-shaped illuminating part 4 for irradiating the contact lens 3' to be inspected with light from its circumferences almost annularly in a horizontal direction.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a contact lens inspection device,
In particular, it relates to an apparatus for detecting and inspecting the outer shape of contact lenses, surface scratches, dust, stains, and damage to contact lenses.

In a contact lens, as shown in FIG. 1, an inner surface 21 of the contact lens 20 that comes into contact with the cornea of the eyeball is usually formed into a shape corresponding to the outer shape of the cornea, and the inner surface 2
1 The central portion is a substantially concave spherical surface, but the peripheral edge portion 22 of the inner surface 21
Is formed into a spherical curved surface having a larger radius of curvature than the central portion of the inner surface 21. The inner peripheral edge portion 22 is called a "bevel". By the way, when the contact lens 20 is worn on the eye, if the radius of curvature of the bevel 22 at the peripheral portion of the inner surface 21 is too small, the peripheral edge of the inner surface 21 strongly hits the cornea, causing pain to the eye, and the radius of curvature of the bevel 22 is large. If it is too much, the contact lens 20 is likely to be displaced on the cornea. Therefore, it is necessary to inspect the degree of bevel of the inner peripheral edge of the contact lens before it is attached to the eye or after the contact lens is processed.

Further, since the contact lens is used by being directly attached to the eye, it may seriously affect the eye if it has scratches, stains, tears, etc. Therefore, it is always clean and free from scratches. Is required. For this reason,
It is necessary to grasp the condition of contact lenses frequently.
Generally, as a means for detecting and observing scratches, dust, stains, etc. on the surface of a contact lens, a so-called aerial observation method of observing a lens to be inspected in the air has been conventionally used.

However, because of the nature of soft contact lenses, they must be stored in a state in which they are always immersed in a clean liquid except when they are worn. In addition to the need to take out, the soft contact lens itself may be contracted when the inspection in the air takes a long time.

Further, in the conventional contact lens inspecting means, it is difficult to determine whether the surface of the lens to be inspected has scratches, dust, stains or the like on the inner surface or the outer surface of the lens to be inspected, and fine scratches or dust. , Stains, etc. could not be detected sharply, and the accuracy and detection sensitivity of the inspection device were not yet sufficient.

[0006]

DISCLOSURE OF THE INVENTION The present invention is a further development of the above-mentioned conventional contact lens inspection device, which is clear and clear even when the lens to be inspected is immersed in the liquid.
An object of the present invention is to provide a contact lens inspection device capable of surely detecting scratches, dust or stains on the surface of a contact lens and damage to the lens.

A further object of the present invention is to make it possible to inspect and display scratches, dust, stains, etc. formed on the surface of a contact lens more sharply than before and display the inspection data such as a bevel image as it is, Moreover, it is to provide a contact lens inspection device that does not require maintenance.

In order to solve the above problems, the present invention provides a substantially horizontal mounting plate on which a contact lens to be inspected is mounted, and an optical lens for taking an optical image of the contact lens on the above-mentioned mounting plate from above. And a video camera, the ring having a plurality of light sources arranged in an annular shape around the opening and having an opening at the center for accommodating a container holding a contact lens to be inspected. A contact lens inspection device is provided, in which a circular illumination unit is provided, and illumination light is emitted from the periphery of the aperture toward the center of the aperture.

Further, according to the present invention, there is provided a light projecting device for projecting an elongated slit beam having a length which is at least twice the diameter of the test lens in an oblique direction with respect to the test contact lens on the mounting plate. , A reflected light detection optical system including a second optical lens for receiving the reflected light from the lens to be inspected of the irradiation light from the light projecting device and a second video camera is provided together with the above-mentioned ring-shaped illumination unit, (EN) Provided is an inspection device capable of performing an inspection by switching between illumination systems of both depending on the condition of contamination of a lens to be inspected or by using both in combination.

Further, by using a color light source of red, green and blue as a light source of the ring-shaped illuminating section or the reflected light detecting optical system in the above-mentioned structure and by providing a device for controlling the emission intensity of each color light source, (EN) Provided is an inspection device capable of illuminating a test lens with white light or monochromatic light and capable of more clearly detecting scratches and stains on the lens surface by a simple operation.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. In the drawings, the same numbers are given to the same components.

FIG. 2 is a diagram showing the entire structure of a contact lens inspection apparatus according to an embodiment of the present invention. Reference numeral 2 is a mounting plate on which a contact lens 3 to be inspected or the like is mounted and which is a transparent glass substrate. It is attached to the opening 31 of the machine casing 10 of the apparatus. Reference numeral 38 is an optical lens for observing the lens 3 to be inspected, and 1 is a video camera for converting an image of the optical lens 38 into an electric signal, which is a CCD color video camera. A monitor device 5 displays the output of the video camera, and is a liquid crystal display, a plasma display, a CRT display, or the like. Reference numeral 4 denotes a ring-shaped illuminating part that constitutes an essential part of the present invention, which has a circular hollow opening 6 for housing the lens 3 to be inspected in the central part thereof, and a housing which annularly houses the LED light source 7 at the periphery of this opening. It is composed of the body 4 '. This LE
16 to 20 D light sources are arranged in a circle at substantially equal intervals, and are installed so as to project light from the lateral direction toward the central portion of the opening 6, that is, the lens 3 to be inspected. In this embodiment, the LED receiving hole 45 is formed on the horizontal plane of the transparent annular block 44 having an opening substantially the same as the hollow opening 6.
Are provided along a circular line, and the LED light source 7 is vertically inserted into the LED light source 7 from above.
The lower outer peripheral edge portion 46 of the transparent annular block 44 is cut at an angle of about 45 degrees, and reflects the light emitted from the LED in the horizontal direction. In order to improve the reflection characteristics, the cut surface portion is preferably painted in silver after finishing the surface smoothly, but it may be roughened to diffusely reflect light. Transparent annular block 44
Is made of acrylic, for example, and an annular substrate 47 electrically connected to the LED light source 7 is arranged thereon.
The upper peripheral edge portion 26 of the housing forming the opening 6 serves as a light-shielding wall, which shields light transmitted obliquely upward from the light source 7 and lower peripheral edge portion 30 of the housing 4 ′ forming the opening 6. Constitutes a light-transmitting wall, but is rough or semi-transparent so that the light from the light source 7 is not directly projected onto the lens to be inspected. As a result, the light from the light source 7 is diffusely reflected inside the housing 4 ′, and the scattered light causes the lens 3 to be inspected to be illuminated from the periphery. That is, the ring-shaped illumination unit 4 including the annular light source 7 and the housing 4 ′ constitutes a dark field illumination optical system for the lens 3 to be inspected.

FIG. 3 shows a ring-shaped illumination section 4 in this embodiment.
In the perspective view of FIG. 7, the housing 4 ′ is installed on the machine housing 10 so as to be rotatable around the rotation shaft 41 in the direction of the arrow a, and as described later with reference to FIG. When dark field illumination is performed with the lens housed in a filled container, the position of this lens to be inspected can be moved and adjusted in the horizontal direction with respect to the optical axis of the video camera 1. The rotary shaft 41 is omitted in FIG. 2 and FIGS. 7 to 9 described later.

Next, the optical system including the light projecting device 11, the second optical lens 39 and the second video camera 12 arranged in the lower machine casing 10 of the mounting plate 2 is the lens 3 to be inspected.
Is an optical system that inspects the reflected light.

In the drawing, a plurality of LED light sources 16 are installed in the light projecting device 11 in a direction perpendicular to the paper surface, and the light from each light source passes through the scattering plate 42 and has a length in the direction perpendicular to the paper surface. The lens 3 to be inspected is irradiated obliquely from below as an elongated slit beam from the slit 14. The second optical lens 39 converges and receives the reflected light from the lens 3 to be inspected by the irradiation of the slit beam, and the image thereof is photoelectrically converted by the second video camera 12 and displayed as an image on the monitor device 5 described above. It

FIG. 4 is an exploded perspective view of the projector 11.
The LED light source 16 and its control element 16 'are the substrate 3
The light from each light source is projected from the elongated slit 14 toward the lens 3 to be inspected through the scattering plate 42. The light projected from the slit 14 is a kind of indirect illumination beam having a diffusive property that has passed through the scattering plate 42, so that the surface of the lens to be inspected having a concave spherical surface can be softly irradiated and one of the curved surfaces of the lens like direct light. It is possible to observe the entire lens to be inspected precisely and in a well-balanced manner by indirect illumination, without strong fear of causing strong reflection only in the part and blurring other parts. The length L of the slit 14 is preferably twice or more, preferably about 10 times, the diameter of the lens to be inspected.

As described above, in the present embodiment, an example of 10 to 20 LED light sources in which 16 to 20 LED light sources are arranged as the light source of the ring-shaped illuminating section and the reflective optical system light source is arranged in series has been described. The number can be increased or decreased according to the brightness and size of the light source and the purpose of inspection, and one or several pieces can be placed by using optical fibers or light guides instead of installing multiple light sources. Even if the light from the light source is distributed to a plurality of places and emitted, the effect remains the same. Further, the LED is fitted in the transparent annular block 44 from the horizontal direction, and the effect is not changed even if the LED is directly arranged on the inner peripheral surface 9 of the opening 6 without using the transparent annular block 44. . The LED light source is preferably a white light emitting diode having a wavelength close to that of a white fluorescent lamp, high luminous efficiency, and high brightness.

Further, instead of irradiating the lens to be inspected with the projection light from these light sources through a scattering plate, a milk color plate, a semi-transparent plate or the like by indirect illumination, the scattering plate is removed and a weak light is directly irradiated. It is also possible to use another optical element such as a diffusing lens.

Next, the inspection of the contact lens according to this embodiment will be described. To inspect a hard contact lens by the ring-shaped illumination unit 4, first, the light source switching unit 43 is switched to activate the light source 7, and the light source 16 is turned off. Next, as shown in 3'of FIG. 2, the lens to be inspected is placed on the object plate 2 with the inner surface facing upward, and the object plate 2 is rotated or tweezers while watching the image on the monitor device 5. The lens to be inspected is displaced by, for example, positioning the lens to be inspected. Here, since the ring-shaped illumination unit 4 is rotatable about the rotation shaft 41 and can be freely retracted from the mounting plate 2, the ring-shaped illumination unit 4 can be previously moved. If the lens 3 is retracted from above, the work of directly mounting the lens 3 to be inspected on the mounting plate 2 becomes easy. The light projected from the horizontal direction to the lens 3 ′ to be inspected is directly reflected by the lens 38 of the video camera 1.
The scattered light due to defects (scratches, dust, stains, breakage, etc.) of the lens 3'to be inspected is mainly observed. The defects of the lens 3'to be inspected are displayed on the monitor device 5 as bright spots in the dark field of view, and thus the contact lens inspection by the dark field illumination optical system is performed. By using the dark-field illumination optical system, the amount of light that directly enters the lens 38 is reduced, and the effect of sharply observing scratches, dust, stains, breakage, or the like can be obtained.

On the other hand, when the hard contact lens is inspected by using the reflection optics of the light projecting device 11 and the second video camera 12, the light source switching unit 43 is switched to change the light source 1.
6 and the second camera 12 are activated, and the light source 7 is turned off. Of course, the input to the monitor 5 is also the interlock switch 43 '.
Is connected to the output side of the second video camera. FIG. 5 is a perspective view showing a case where a contact lens is inspected using a reflected light detection optical system, and FIG. 6 is an enlarged view of a lens to be inspected displayed on the monitor device 5 when the reflected light detection optical system is used. The image is shown. Next, as shown in 3 of FIG. 2, the lens to be inspected is mounted on the mounting plate 2 with the inner surface facing downward,
The lens to be inspected is positioned while looking at the entire lens to be inspected displayed on the monitor device 5. At this time, the projector 1
A reflected image 32 of the projected light flux of 1 by the lens to be inspected is displayed on the monitor device 5. The reflection image 32 is an enlarged image corresponding to the cross-sectional shape of the central portion of the lens to be inspected. By observing the reflected image 32, the shape of the peripheral edge of the inner surface of the lens 3 to be inspected, that is, the bevel shape can be inspected. Since the reflected image 32 is a reflected image of the outlines of the inner surface and the outer surface of the lens surface to be inspected, double lines are projected on the monitor device 5. Which of the double lines represents the outline of the inner surface or the outer surface of the lens to be inspected,
Since the image of the entire test lens is displayed, it can be easily identified.

On the monitor device 5, scratches, dust or stains on the surface of the lens to be inspected and damage to the lens to be inspected are also displayed together with the double line. Here, the lens 3 to be inspected
When the mounting plate 2 on which is mounted is rotated, for example, it is observed on the monitor that the reflection image representing the outer surface of the lens under test is interrupted. At this time, it can be detected that the part where the reflected image is interrupted is a part where scratches, dust, stains, etc. are present, and these are attached or exist on the outer surface of the lens to be inspected. Similarly, if it is observed that the reflection image representing the inner surface of the lens under test is interrupted,
There are scratches, dust, stains, etc. on this broken part,
Moreover, it can be seen that these are on the inner surface of the lens to be inspected. Therefore, by using the reflected light detection optical system, the bevel shape inspection of the lens to be inspected can be performed, and the defect (scratch) of the lens to be inspected is utilized by utilizing the reflection image of the lens to be inspected by the slit beam from the light projecting device. , Dust, stains, damage, etc.), and whether scratches, dust, stains, etc. are on the inner surface or outer surface of the lens surface to be inspected can be determined.

FIG. 7 shows an example of an inspection of a soft contact lens which is particularly effective by the ring-shaped illumination unit provided by the present invention, in which a soft contact lens 3 ″ is filled in a container filled with the liquid 23. It is an example of inspecting by dark field illumination in a state of being housed in. By doing so, the ring-shaped illumination unit 4 and the video camera 1 can inspect the soft contact lens in the liquid. If the ring-shaped illumination unit 4 is rotated in advance and retracted from the optical axis of the optical lens 38 of the video camera 1, the work of installing the container 24 in the ring-shaped illumination unit 4 becomes easy.

FIG. 8 shows a case where a semitransparent plate 29 is placed in the opening 6 of the ring-shaped illumination unit 4 and the container 24 is placed directly on it to illuminate the lens 3 ″ to be inspected. FIG. 9 shows a case where a semi-transparent plate 27 is installed on the ring-shaped illumination unit 4, and the container is placed on the semi-transparent plate 27 to illuminate the lens to be inspected. By doing so, the defect of the lens to be inspected can be inspected by the video camera 1 by the indirect illumination light transmitted through the semitransparent plate, and the soft contact lens can be inspected while being immersed in the liquid as in the case of FIG. 7. In this way, when the scattered light is applied from the bottom, the video camera 1 does not catch diffuse reflection or scattering due to scratches, dust, stains, breakage, or the like on the surface of the lens to be inspected, as in dark-field illumination. Depending on how the material is stained or scratched, the appearance and visibility of these are different compared to the case of dark field illumination. That is, optimum illumination can be performed according to the defect of the lens, and the inspection accuracy is improved.

In the above embodiment, the light emission intensity of the LED is
This can be easily adjusted by using the control device 19 including, for example, a switch and a variable resistor. Further, unlike the above-described embodiment, the ring-shaped illumination unit or the light source of the light projecting device is configured by light emitting diodes of respective colors of red, green, and blue, and the light emission intensity of each is adjusted via the control device 19, and the illumination is performed. The color may be freely changed. The light source to be used is not only an LED that emits a single color of red, green or blue, but also a light source of red, green or blue.
A so-called three-element LED in which various types of light-emitting elements are enclosed in one package may be used. In addition, RGB LEDs are provided on the inner peripheral portion 9 of the ring-shaped illumination unit 4 or the light projecting device 11.
In addition to alternately arranged inside, RGB LEDs
Are respectively arranged at one location inside the ring-shaped illumination section 4 or the light projecting device 11, the illumination color is adjusted at this section, and the obtained light is transmitted through the ring-shaped illumination section 4 using, for example, an optical fiber. It is also possible to guide the light to the wall 30 or the slit 14 of the light projecting device 11 and irradiate the subject lens 3 with this light.

Here, depending on the type of defects such as scratches, dust, stains or damage existing on the lens to be inspected, it is better to change the color of the projected light and project light having a shorter wavelength than white light to the lens to be inspected. In some cases, these defects can be displayed more clearly on the monitor device 5, and according to the above configuration, without using a color filter such as a colored film,
Since the illumination color can be changed directly, continuously, and easily by electric means, it is possible to more easily carry out a precise inspection of defects existing in the lens to be inspected.

Further, by displaying the vertical and horizontal reference lines for measuring the bevel width on the screen of the monitor device by the known image synthesizing technique, the reference value of the bevel width, the allowable range, etc. can be easily checked. Bevel changes before and after adjustment of contact lenses, especially hard contact lenses, can be easily measured.

[0027]

According to the present invention, the following useful effects can be obtained. That is, it is possible to inspect by indirect illumination or dark-field illumination while the soft contact lens etc. is immersed in the liquid, and if necessary, by switching the light source while the lens to be inspected is reflected light. Inspection is possible. This makes it possible to easily grasp the location of the defect in the entire lens to be inspected. In particular, it is possible to sharply display a scratch or damage on the lens on the monitor device. Secondly, by projecting a high-brightness slit beam onto the contact lens obliquely from below using the reflected light detection optical system, in addition to the bevel of the contact lens, damage, dust, stains, damage, etc. can be observed simultaneously. In addition to being observable, it is also possible to easily determine whether the lens inner surface or outer surface is attached with scratches, dust, stains, etc., and the state of the contact lens can be grasped more sharply than in the conventional inspection device.

Thirdly, the ring-shaped illumination section and the reflected light detection optical system described above are provided together in one inspection apparatus, and the ring-shaped illumination section is configured to be rotatable on the machine casing. Therefore, the inspection means can be appropriately selected according to the type of the lens to be inspected and the type of defect, and the contact lens as a whole can be inspected quickly. Also, since the lighting color is electrically changed directly, it is possible to save the trouble of replacing the color filter,
Attenuation of light due to passing through the color filter can be prevented. In addition, the image displayed on the monitor device through the video camera can be directly recorded as image data, and can be printed and saved. In addition, since the light emitting diode with an extremely long life is used as the light source, it is not necessary to replace the lamp. Therefore, it is possible to save the maintenance of the inspection device.

Further, in the case of observing the lens to be inspected in the liquid in the above-mentioned embodiment, in addition to the above effects, impurities and the like existing in the liquid can be detected. In addition, when performing the inspection, the user can also inspect the contamination state of the storage solution used for the storage of the lens, and the user can be appropriately instructed regarding the precautions for hygiene management and storage of the lens.

[Brief description of drawings]

FIG. 1 is a side sectional view of a contact lens.

FIG. 2 is a side view showing an embodiment of the present invention.

FIG. 3 is a perspective view showing an embodiment of a ring-shaped illumination unit.

FIG. 4 is a perspective view showing an embodiment of a light projecting device.

FIG. 5 is a perspective view showing a reflected light detection optical system.

FIG. 6 is a diagram showing an example in which a lens to be inspected is displayed on a monitor device.

FIG. 7 is a diagram showing an example of inspecting a soft contact lens by dark-field illumination.

FIG. 8 is a diagram showing an example of inspecting a lens using light transmitted through a semitransparent plate.

FIG. 9 is a diagram showing another example of inspecting a lens using light transmitted through a translucent plate.

[Explanation of symbols]

1 video camera 2 Loading plate 3 Test lens 3'test lens 3 '' soft contact lens 4 Ring-shaped lighting unit 4'case 5 Monitor device 6 openings 7 light source 8 light emitting part 9 Inner surface 10 Machine case 11 Projector 12 second video camera 13 Lower part of inner surface 14 slits 16 Second light source 16 'control element 17 Light emitting part 18 Inside the slit 19 Control device 20 contact lenses 21 Inside 21 'exterior 22 Bevel 23 Contact lens preservation solution 24 containers 25 Upper part of inner peripheral surface 26 Light-shielding part 27 Semi-transparent plate 29 Semi-transparent plate 30 translucent wall 31 Opening of machine casing 32 Enlarged image according to the cross-sectional shape of the center of the lens under test 34 substrate 38 Optical lens 39 Second optical lens 41 rotation axis 42 Scatter plate 43 Light source selector 43 'interlocking switch 44 annular block 45 LED receiving hole 46 Lower edge 47 board 50 Contact lens inspection device

Claims (3)

[Claims] 1. An inspection apparatus comprising a substantially horizontal mounting plate on which a contact lens to be inspected is mounted, an optical lens for taking an optical image of the contact lens on the above-mentioned plate from above, and a video camera. A ring-shaped illumination section accommodating a plurality of annularly arranged light sources is provided around the opening, in the center of which the contact lens to be tested can be placed, and at the center of the opening. The contact lens inspection device is characterized in that the illumination light is emitted from the periphery of the contact lens. 2. An inspection apparatus comprising a substantially horizontal mounting plate on which a contact lens to be inspected is mounted, an optical lens for photographing an optical image of the contact lens on the above-mentioned plate from above, and a video camera. , A ring-shaped illumination unit for irradiating the contact lens under test on the object plate on the plate in a substantially horizontal direction from its peripheral portion, and from an oblique direction with respect to the contact lens under test on the object plate on the plate,
A light projecting device that projects an elongated slit beam having a length that is at least twice the diameter of the lens to be inspected, and a second device that receives the reflected light from the lens to be inspected by the light emitted from this light projecting device. A contact lens inspecting apparatus, characterized by comprising an optical lens and a reflected light detecting optical system comprising a second video camera, and capable of switching and using either one. 3. A red, green and blue color light source as a light source of the ring-shaped illuminating section or the reflected light detection optical system, and a device for controlling the emission intensity of this color light source. 3. The inspection lens can be illuminated with white light or monochromatic light.
The contact lens inspection device according to any one of 1.