JPH04305144A - Outer circumference chipping inspector for contact lens - Google Patents

Abstract

PURPOSE:To achieve automatic inspection of a chipping as generated in the outer circumference of a contact lens at a high speed and accurately. CONSTITUTION:This inspector is made up of a contact lens detection means A to convert an image of contact lens 1 into an electrical signal, an image processing means B which coverts the electrical signal into a video signal to extract an outer circumference part alone of the contact lens, an arithmetic processing/judging means C which performs an arithmetic processing of the extracted part to judge an outer circumferential chipping detect of the contact lens searching an outer circumferential chipping and a moving means D to move the contact lens to a position which allows the detection of a part to be detected of the contact lens.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting chips on the outer periphery of contact lenses.

0002

BACKGROUND OF THE INVENTION In conventional contact lens peripheral chipping inspection, a person holds the contact lens with tweezers or the like and visually detects peripheral chipping using a magnifying glass or the like.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, since the inspection was performed visually by a human, it took a long time to conduct the inspection, and there was a large difference in detection ability between individuals.
Small chips on the order of microns were sometimes overlooked. Additionally, when holding a contact lens with tweezers, the contact lens could be accidentally dropped and lost. SUMMARY OF THE INVENTION The present invention is intended to solve these problems, and its purpose is to provide a contact lens outer periphery chipping inspection device that can automatically inspect chips occurring on the outer periphery of a contact lens at high speed and reliably. be.

0004

[Means for Solving the Problems] The contact lens outer periphery chipping inspection device of the present invention, as shown in the functional block diagram of FIG. Image processing means B that converts a signal into a video signal and extracts only the outer circumferential portion of the contact lens, and arithmetic processing determining means that performs arithmetic processing on the extracted portion to search for outer circumferential chipping and determine whether the outer circumferential chipping of the contact lens is defective. C, and a moving means D for moving the contact lens to a position where the contact lens detection unit can detect the contact lens.
It is characterized by being composed of.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below with reference to the drawings. FIG. 2 is a schematic diagram showing an embodiment of the present invention. Reference numeral 1 in the figure indicates a contact lens, which has been moved to an inspection position by an inspection moving device 6. The enlarged image of the contact lens 1 illuminated by the illumination device 7 is formed into an image within the ITV camera 3 by the camera lens 2 and converted into an electrical signal. Here, the camera lens uses a microscope objective lens with a magnification of 5 to 10 times, and the ITV camera uses a solid-state image sensor with about 360,000 pixels, so that even a chip of about 20 μm can be identified.

[0006] Reference numeral 4 in the figure is an image processing device, and the ITV
An electrical signal from the camera 3 is input and converted into a video signal, and the edge portion of the contact lens 1 is extracted and converted into coordinate data. Reference numeral 5 in the figure is a personal computer, which receives the coordinate data from the image processing device 4, performs arithmetic processing, and searches for peripheral defects. Next, a rotation signal is sent from the personal computer to the inspection moving device 6, and the contact lens 1 is rotated so that an image of the unsearched portion can be captured by the ITV camera, thereby detecting the outer periphery chipping over the entire circumference. By inputting the outer diameter of the contact lens, the magnification of the camera lens, and the field of view of the ITV camera into the personal computer in advance, the personal computer can determine the optimal rotation angle of the contact lens and the necessary information to capture images of the entire circumference. Inspection time is reduced because the number of repetitions is calculated and signals are sent to the inspection mobile device accordingly. In addition, if the center of the outer diameter of the contact lens does not match the center of the rotation axis of the inspection moving device, rotating the contact lens will cause the edge position to shift from the center of the ITV camera's field of view, and in the worst case, repeated rotations will cause the edge to shift. It becomes undetectable. Therefore, the image processing device also detects the position of the edge of the contact lens and sends a signal to the inspection moving device so that the edge is always near the center of the field of view of the ITV camera.

[0007] After the detection is completed over the entire circumference, the personal computer determines whether the outer circumference is chipped or not from the data on the entire circumference of the contact lens.

FIG. 3 shows an embodiment in which a plurality of detection means are provided. By connecting multiple ITV cameras 3 and camera lenses 2 so that they are equally distributed on the outer circumference of the contact lens, and switching the input ITV camera using an image processing device, the number of repetitions required to capture images of the entire circumference can be reduced. The time required for inspection can be shortened.

FIG. 4 is an enlarged end view of a cross-sectional view of a contact lens. FIG. 5 is an enlarged end view of a plan view seen from above the apex of the contact lens. Since the end points of the two types of curves with different curvatures are different, two edge curves are visible when viewed from above the apex. 6 and 9 are output examples of the image processing device 4, and are images before processing of a contact lens without a chip on the outer periphery and a contact lens with a chip on the outer periphery, respectively. Further, FIGS. 7 and 10 are images after image processing of a contact lens without a chip on the outer periphery and a contact lens with a chip on the outer periphery, respectively, and only the edge portions are extracted. FIGS. 8 and 11 show the calculation results of a contact lens without a chip on the outer periphery and a contact lens with a chip on the outer periphery using a personal computer, respectively. FIG. 6 is a diagram in which quadratic curve approximation of the edge position coordinates is performed using the least squares method, and the difference between the obtained curve and the edge position coordinates is plotted. In FIG. 11, since there is a chip on the outer periphery, only the part with the chip on the outer periphery shows different characteristics. Therefore, by appropriately setting the inspection reference value 8 on the personal computer, the personal computer can reliably determine the outer periphery chipping defect. Also, as a matter of course, if there is a chip in even one place, the contact lens is defective. Therefore, instead of making a judgment after taking in data from the entire circumference, a personal computer makes a judgment of failure when it detects the chipped part of the outer periphery, and by omitting detection of the remaining part, the inspection time can be shortened. It will be planned.

FIG. 12 is a schematic diagram of a contact lens stage 9 provided in an inspection moving device. When a camera lens has a high magnification, the height from the edge to the apex varies depending on the type of contact lens, making it difficult to focus and causing small defects to be overlooked. Therefore, by providing the inspection moving device with a vertical movement function and a contact lens stage, the position of the edge in the height direction is constant regardless of the type of contact lens, and no out-of-focus occurs.

[0011]

Effects of the Invention As explained above, the present invention is a medical device that comes into direct contact with the eye, and is capable of detecting chipping on the outer periphery of a contact lens. Inspecting with a lens peripheral chipping inspection device enables automatic inspection that is reliable and faster than visual inspection, without the oversights that humans sometimes make, and has the effect of providing contact lenses that are highly safe and can be used with peace of mind. be.

[Brief explanation of drawings]

FIG. 1 is a block diagram for clearly showing the configuration of a contact lens peripheral chipping inspection apparatus according to the present invention.

FIG. 2 is a schematic diagram showing an embodiment of the contact lens peripheral chipping inspection apparatus of the present invention.

FIG. 3 is a schematic diagram showing an embodiment of the contact lens outer periphery chipping inspection apparatus of the present invention in which a plurality of detection means are provided.

FIG. 4 is an enlarged end view of a cross-sectional view of a contact lens.

FIG. 5 is an enlarged end view of a plan view seen from above the apex of the contact lens.

FIG. 6 is an image output diagram of a contact lens without peripheral chipping before image processing.

FIG. 7 is an image output diagram after image processing of a contact lens without peripheral chipping.

FIG. 8 is an output diagram of a calculation result by a personal computer of a contact lens with no peripheral chipping.

FIG. 9 is an image output diagram before image processing of a contact lens with a chipped outer periphery.

FIG. 10 is an image output diagram after image processing of a contact lens with a chipped outer periphery.

FIG. 11 is an output diagram of calculation results obtained by a personal computer for a contact lens with a chipped outer periphery.

[Figure 12] Schematic diagram of a contact lens stage installed in the inspection moving device

[Explanation of symbols]

1 Contact lenses 2 Camera lens 3 ITV camera 4 Image processing device 5 Personal computer 6　Transfer device for inspection 7. Lighting device 8 Inspection standard values 9 Contact lens stage

Claims (1)

[Claims] Claim 1: contact lens detection means for converting an image of a contact lens into an electrical signal; image processing means for converting the electrical signal into a video signal and extracting only the outer peripheral portion of the contact lens; The present invention is characterized by comprising: arithmetic processing determining means for performing processing to search for outer periphery chipping and determining whether the outer periphery chipping of the contact lens is defective; and a moving means for moving the contact lens to a position where the contact lens detecting section can detect the contact lens. Contact lens peripheral chipping inspection device.