JP3417972B2 - Lens inspection apparatus and inspection method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens inspection device and method for inspecting the surface of a lens, and more particularly to a device suitable for inspecting hidden marks and scratches on a progressive multifocal lens. Regarding the method.

[0002]

2. Description of the Related Art A spectacle lens before being framed has its refraction characteristics marked on the surface of the lens so that it can be easily seen. Only a small hidden mark is left on the lens surface. The optical design of progressive multifocal lenses varies greatly from one company to another, and it is difficult to measure the addition power accurately, so when adjusting a new progressive multifocal lens, the type of lens manufacturer and the addition power of the lens currently worn. It is important to know. Since this hidden mark is formed by minute depressions so as not to interfere with the wearer's eyes,
It is only to barely observe by holding the lens over the light of a fluorescent lamp or the like. Some hidden marks are formed by loose dents, which are extremely difficult to read. Also, as a method for inspecting minute surface scratches on an object such as glass or a lens, a Foucault test in which a pinhole is arranged on the light source side and a knife edge is arranged in the vicinity of the image forming position of the pinhole is known. Has been. Further, the Schlieren method is also known as one application of the Foucault test. In the Schlieren method, the pinhole is arranged on the light source side, the pinhole is provided at the image forming position of the pinhole, and the scattered light is cut by the pinhole of the eyepiece section (camera section). , Makes surface scratches black.

[0003]

A method of observing a hidden mark by holding a lens over the light of a fluorescent lamp or the like is as follows.
It has the drawback of requiring sufficient visual acuity and skill for the observer. Further, the Foucault test and the Schlieren method have not yet been proposed as a method for observing hidden marks.
In particular, in the case of a progressive multifocal lens, the light from the pinhole is not focused at one point, so there is a problem that the entire body cannot be observed. Further, when the pupil is used as a pinhole for the eyepiece section (camera section), there is a problem in that its alignment is difficult. A first object of the present invention is to provide an inspection apparatus in which a hidden mark can be easily visually recognized by an observer in view of the above-mentioned drawbacks of the prior art. A second object of the present invention is to provide an inspection device for detecting hidden marks and scratches that can be easily aligned.

[0004]

In order to solve the above problems, the present invention is characterized by having the following configuration. (1) In a lens inspection device for detecting hidden marks and scratches on a lens to be inspected, a support means for supporting the lens at a predetermined position of the inspection device, a first illumination light source, and the first illumination light source are used. A pinhole plate on which a large number of illuminated pinholes are arranged; and a pinhole image forming optical system for forming a pinhole image by an illumination light beam passing through the pinhole plate and passing through a lens to be inspected. A second illumination light source and the second illumination light source
The light flux of
Grazing incidence illumination optical system, and illumination by the first illumination light source
Selection means for selecting illumination by the second illumination light source
When the first illumination light source is selected , the pupil of the inspector is placed at a position where the pinhole image is formed by the pinhole image forming optical system. It is characterized by detecting hidden marks and scratches on the lens.

(2) First and second illumination light sources of (1)
Is common, and the shutter can be selectively inserted in the optical path.
The features.

(3) Detect hidden marks and scratches on the lens to be inspected.
In the lens inspection device that comes out, place the lens at the inspection device.
Support means for supporting the fixed position, a first illumination light source,
A large number of pinholes illuminated by the first illumination light source are arranged.
The first pinhole plate arranged in a row and the pinhole plate passing through
A pinhole image is formed by the luminous flux that passes through the lens.
Pinhole image forming optical system and the pinhole image forming optical system
The first position provided at the position where the pinhole image is formed by the system.
Two-pin hole plate and luminous flux passing through the second pin hole plate
Optical system for projecting a hidden mark onto a specified image plane by
And a second illumination light source and a light flux of the second illumination light source
Oblique incidence illumination that is obliquely incident from the back of the lens to be viewed by the operator.
Bright optical system, illumination by the first illumination light source, and second illumination light
Selection means for selecting the illumination by the source .

(4) First and second illumination light sources of (3)
Is common, and the shutter can be selectively inserted in the optical path.
The features.

[0008]

[0009]

[0010]

Embodiment 1 An embodiment of the present invention will be described with reference to the drawings. 1 is a side view of the optical system of the apparatus of the first embodiment, and FIG. 2 is a top view of the optical system of the apparatus. The optical system of the apparatus comprises a hidden mark reading optical system A and an oblique incidence illumination optical system B. (Hidden mark reading optical system) 1 is an illumination light source and is used as a common light source for the hidden mark reading optical system A and the oblique incidence illumination optical system B. 2 is a reflecting mirror. Reference numeral 3 is a shutter, and the inspector drives the motor by operating a switch (not shown) to selectively insert the shutter 3 into the optical path of the hidden mark reading optical system A or the oblique incidence illumination optical system B. However, the driving means is not particularly limited to manual operation or the like. 4 is a pinhole plate, the front shape of which is shown in FIG. The pinhole plate 4 has a pinhole with a diameter of 1 mm.
Are regularly arranged vertically and horizontally at a pitch of 3 mm. The pinhole diameter and the arrangement pitch of the pinholes are not limited to this. For example, the pinhole diameter is 0.3 m.
When the progressive multifocal lens was observed on a chart plate with m and pinhole pitch of 1 mm, the uneven brightness was improved compared with the pinhole plate 4, but it was a hidden marker that was visible enough with the naked eye. The contrast of the black has decreased. Generally speaking, the pinhole diameter and the pinhole pitch should be appropriately determined in consideration of various factors such as the type of the inspection object, the condition of the detection object, the magnification of the optical system, and the observation method. .
The pinhole plate 4 can be moved in the optical axis direction by operating a knob (not shown), so that the optimum position for observation can be obtained with the position of the examiner's eye fixed even if the power of the lens to be inspected changes. Reference numeral 5 denotes a light projecting lens that projects the illumination light that has passed through the pinhole plate 4 onto the subject lens 6. The lens 6 to be inspected is held in the optical path by a holding means (not shown) (only the lens is shown in the figure, but it is also possible to hold the frame in an apparatus for inspecting spectacle lenses). Reference numeral 7 is an observation lens having a diameter that covers the visual fields of the examiner's eyes 8a and 8b, and forms an image of the surface of the subject lens 6 on the fundus of the examiner's eyes 8a and 8b. In the embodiment, the observation magnification is 2 times.

(Gradient Incident Illumination Optical System) The luminous flux of the illuminating light source 1 is condensed by the condenser lens 9 into a substantially parallel luminous flux, which is then reflected by the first mirror 10 and the second mirror 11, and the lens to be inspected. Oblique incidence illumination from behind 6. 1
Reference numeral 2 denotes a light absorption plate that absorbs the illumination light that has passed through the lens 6 to be inspected. At the time of oblique incidence illumination, since the shutter 3 is inserted in the optical path of the hidden mark reading optical system, the field of view becomes dark (dark field illumination). The illumination light does not directly enter the eye to be inspected, but only the light scattered on the surface of the wound enters the eye to be inspected.

Next, the operation of the apparatus having the above structure will be described. The observation of the hidden mark of the lens to be inspected will be described. The lens to be inspected is held by the holding means and placed at a predetermined position. The examiner looks at the subject lens 6 through the observation lens 7.
An example in which one pinhole is provided when the lens to be inspected is a single focus lens will be described. As shown in FIG. 4, the light emitted from the point light source is collimated by the collimating lens and then passed through the lens to be inspected. At this time, the examiner can observe the entire lens to be inspected, but if the lens to be inspected has irregularities or internal striae, the light does not reach the eye of the inspector because the direction in which the light travels is disturbed The area of is darker than the surrounding area. Therefore, a minute mark such as a hidden mark can be observed on the examiner's eye. However, when the test lens is a progressive multifocal lens, the light from the point light source is not focused at one point and only the light in the partial area where the test lens is present reaches the examiner's eye, so the entire test lens is observed. Can not. However, by providing a plurality of point light sources and forming a set of light in the partial regions as in the embodiment, the entire lens to be inspected can be observed. Also,
As shown in FIG. 5, by arranging a large number of point light sources, it is clear that the subject's eye is a single-focus lens. Since it reaches the eyes, the limitation of the observation position can be removed unlike the case of FIG. Furthermore, this makes it possible to observe with both eyes.

As a result of such an action, the examiner's eye moves the position of the pinhole plate 4 to the most visible position according to the refractive power of the lens to be inspected, without performing a precise adjustment work of the observation position. The entire progressive power multifocal lens can be observed by simply doing. The light scattered by the hidden marks and scratches on the lens to be inspected hardly reaches the examiner's eyes, so
You can read ku and know the existence of scratches. Also, the examiner can inspect the scratch on the lens to be inspected by the oblique incidence illumination. The shutter 3 is inserted in the optical path of the hidden mark reading optical system, and oblique incidence illumination is performed from the back side of the lens to be inspected. The illumination light does not directly enter the inspector's eye, and only the light scattered on the surface of the wound or the like enters the inspector's eye. Therefore, even linear scratches can be detected with high sensitivity. In the above embodiments, direct observation by the examiner's eye is adopted as the observation method, but instead of the examiner's eye, an aperture, an imaging lens, or an imaging means may be used for indirect observation.

[0014]

Second Embodiment FIG. 6 is a side view of the optical system of the apparatus of the second embodiment. The second embodiment is a monocular observation device as compared with the first embodiment, the illumination light source is provided in each of the hidden mark reading optical system and the oblique incidence illumination optical system, and the oblique incidence illumination optical system. Are different in that they are composed of a pair of upper and lower optical systems. The same reference numerals are used for the members that are almost the same as in the first embodiment. Reference numerals 13 and 14 denote light sources of the oblique incidence illumination optical system, which are condensed by the condenser lenses 15 and 16 to illuminate the subject lens 6 with oblique incidence. In this embodiment, since two upper and lower light sources are used, it is possible to reduce the influence on the observation of the scratch mode of the lens to be inspected, as compared with the first embodiment. Further, instead of the switching operation of the shutter 3 of the first embodiment, in this embodiment, the light source 1 and the light sources 13 and 14 are switched and turned on. It is obvious that the above-described embodiment can be variously modified and can be applied to the inspection of a transparent substrate such as a glass substrate or a reflective substrate.
Therefore, the lens of the present application includes not only those having a unique lens function but also those described above.

[0015]

According to the present invention, the hidden mark can be easily visually recognized by the observer, and the hidden mark and the scratch can be easily detected.

[Brief description of drawings]

FIG. 1 is a side view of an optical system of an apparatus.

FIG. 2 is a view of an optical system of the apparatus as viewed from above.

FIG. 3 is a view showing a front shape of a pinhole plate.

FIG. 4 is a diagram showing a case where one point light source is provided.

FIG. 5 is a diagram showing a case where a large number of point light sources are arranged.

FIG. 6 is a side view of the optical system of the apparatus according to the second embodiment.

[Explanation of symbols]

1 Illumination light source 2 reflector 3 shutters 4 pinhole plate 5 Projection lens 6 Test lens 7 Observation lens 8 Inspector's eye 9 Condenser lens 10 First mirror 11 Second mirror 12 Absorber

Claims (4)

(57) [Claims] 1. A lens inspecting apparatus for detecting hidden marks and scratches on a lens to be inspected, supporting means for supporting the lens at a predetermined position of the inspecting apparatus, a first illumination light source, and the first illumination. A pinhole plate on which a large number of pinholes illuminated by a light source are arranged, and a pinhole image forming optical for forming a pinhole image by an illumination light flux passing through the pinhole plate and passing through a lens under test A system, a second illumination source, and a second illumination source.
When viewed from the inspector, the luminous flux of the bright light source is tilted from the rear surface of the lens under test.
Oblique incidence illumination optical system for incidence and the first illumination light source
Selection means for selecting illumination and illumination by the second illumination light source
And when the first illumination light source is selected,
Is a lens inspection characterized by detecting a hidden mark or a scratch on a lens to be inspected by locating a pupil of an inspector at a position where a pinhole image is formed by the pinhole image forming optical system. apparatus. 2. The first and second illumination light sources according to claim 1,
A lens inspecting device , which is common and has a feature that a shutter is selectively inserted in an optical path . 3. Detecting hidden marks and scratches on a lens to be inspected
In the lens inspection device, place the lens on the specified position of the inspection device.
Support means for supporting the table, a first illumination light source, and the first illumination light source.
A large number of pinholes illuminated by the illumination light source are arranged.
A first pinhole plate and a lens passing through the pinhole plate
Pin that forms a pinhole image by an illumination light beam that passes through
According to the hole image forming optical system and the pinhole image forming optical system,
Second pin provided at the position where the re-pin hole image is formed
Due to the light flux passing through the hole plate and the second pinhole plate
A projection optical system for projecting a hidden mark onto a predetermined image plane;
Of the second illumination light source and the second illumination light source from the inspector
Oblique incidence illumination optical system that makes an oblique incidence from the back surface of the lens under test
And illumination by the first illumination light source and by the second illumination light source
An inspection apparatus comprising: a selection unit that selects the illumination . 4. The first and second illumination light sources of claim 3 are common.
A lens inspecting device , which is common and has a feature that a shutter is selectively inserted in an optical path .