JPH10160624A - Device for detection hidden mark of spectacle lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for detecting a hidden mark of spectacle lens with a simple structure that can recognize the hidden mark as a character accurately regardless of kinds of spectacle lens. SOLUTION: This detector 10 for hidden mark of spectacle lens is provided with a light source 21, a collimator lens 22, a half mirror 23 which allows a parallel light from the collimator lens 22 to reflect thereon by about 50% thereof, emits it to a first hidden mark 5 of a spectacle lens 1 and allows the remaining parallel lights to transmit therein, a total-reflection mirror 24 which allows the transmitted parallel lights to reflect totally thereon and emits them to a second hidden mark 6 of the lens 1, and first and second CCD cameras 41 and 42 which are arranged adjacent to each other on the surface 2 of the lens 1. Thanks to such a structure, hidden marks of various kinds of spectacle lens can be obtained optically in a high accuracy through character recognition. In addition, the cameras 41 and 42 need no TV lens for camera, so that the detector 10 can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a hidden mark on a spectacle lens for detecting a hidden mark imprinted on the spectacle lens.

[0002]

2. Description of the Related Art A spectacle lens 1 shown in FIG. 1 is a bifocal spectacle lens. In such a spectacle lens 1, for example, at a predetermined position on a vertical reference line passing through the center position O of the spectacle lens 1, in order to inspect whether or not the power of the bifocal lens for which the order is received is satisfied, Areas R1 (distance measuring area) and R2 for measuring frequency
(A near-use power measurement area) is formed.

In measuring the power of the spectacle lens 1, the two hidden marks 5 and 6 formed on the surface 2 of the spectacle lens 1 are checked with the naked eye, and these hidden marks 5
The center position O of the spectacle lens 1 is derived based on (6) and (6), and the positions of the frequency measurement regions R1 and R2 are found based on the center position O.

The hidden marks 5 and 6 formed on the spectacle lens 1 are used as a reference for deriving the center position O of the lens even when the outer shape of the spectacle lens 1 is adjusted. That is, in the lens forming process, the center position O of the spectacle lens 1 is derived based on the two hidden marks 5 and 6, and the spectacle lens 1 is processed into an elliptical shape or a circular shape based on the center position O. ing.

[0005]

However, the hidden marks 5 and 6 are, for example, single letters of the alphabet, simple figures such as circles and squares, and are approximately 1.6 m in length.
Since it is a very small m-square object, it is hard to find with the naked eye. For this reason, there is a problem that it takes a lot of trouble to derive the center position O of the spectacle lens 1.

For this purpose, as shown in FIG. 5, the present applicant has a point light source 21c and 21d, a transparent stage 30a which holds the spectacle lens 1 and transmits light emitted from the point light sources 21c and 21d, On the opposite side of the transparent stage 30a from the point light sources 21c and 21d, there is proposed a spectacle lens hidden mark detection device 10a having image pickup devices 41 and 42 for detecting light passing through the spectacle lens 1. (See Japanese Patent Application No. 8-225424).

[0007] According to the spectacle lens hidden mark detecting device 10a having this configuration, the light transmitted through the spectacle lens 1 can be imaged by the imaging devices 41 and 42 without checking the hidden marks 5 and 6 of the spectacle lens 1 with the naked eye. By detecting, the hidden marks 5 and 6 can be automatically detected, and the center position O of the spectacle lens can be easily derived.

However, in the spectacle lens hidden mark detecting device 10a having the above configuration, there is a problem that the hidden marks of the plus lens and the minus lens cannot both be recognized with the same accuracy.

[0009] Then, when the above-mentioned causes are investigated, light transmitted through the plus lens is refracted toward the center of the lens and light transmitted through the minus lens is refracted toward the outer peripheral edge of the lens due to the characteristics of the lens. Further, a new finding has been obtained that a mapping detected by the imaging device is distorted due to the degree of refraction.

In view of the above, it is an object of the present invention to provide an eyeglass lens hidden mark detecting apparatus having a simple configuration capable of accurately recognizing hidden marks with characters regardless of the type of eyeglass lens.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, based on the above-mentioned new knowledge, a hidden mark detecting device for a spectacle lens according to the present invention has first and second hidden marks formed on the surface. Holding means for holding the spectacle lens, optical means for irradiating the first hidden mark and the second hidden mark of the spectacle lens held by the holding means with parallel light, and the holding means First and second detecting means for detecting the first and second hidden marks based on the parallel light from the optical means transmitted through the spectacle lens and disposed close to the held spectacle lens. And an imaging device.

In the present invention, the light transmitted through the spectacle lens is refracted by the characteristics of the lens. However, since the first and second imaging devices are arranged close to the spectacle lens, the refraction of the light is performed. The transmitted light from the lens is detected by the first and second imaging devices at a stage not significantly affected by the above. In addition, the spectacle lens is irradiated with parallel light having high directivity. For this reason, the distortion of the image due to the degree of refraction of various spectacle lenses (a plus lens, a minus lens, etc.) can be reduced, and the hidden mark can be set by the imaging device on any spectacle lens regardless of the type of the spectacle lens. Can be recognized with high accuracy. As a result, it is possible to greatly improve the efficiency of operations such as power measurement and shaping of the spectacle lens that requires the operation of detecting the hidden mark, and increase the productivity of the spectacle lens.

The optical means includes a light emitting diode, a collimator lens for converting light emitted from the light emitting diode into parallel light, and a collimator lens for irradiating the parallel light from the collimator lens to the first hidden mark. A second parallel light and a second hidden mark for irradiating the second hidden mark.
And a dispersing means for dispersing the light into parallel light. Further, a configuration including first and second light-emitting diodes and first and second collimator lenses that convert light emitted from these light-emitting diodes into parallel light, respectively, may be adopted. In the case of this configuration, the first light-emitting diode and the first collimator lens form first parallel light for irradiating the first hidden mark, and the second light-emitting diode and the second parallel light are formed. The second collimating lens forms a second parallel light for irradiating the second hidden mark. However, for simplification of the apparatus, it is more advantageous to adopt a configuration in which the parallel light from the collimator lens is split by the spectral means.

As the first and second imaging devices, those each having a charge transfer device can be used.

In the present invention, it is preferable to provide a light-shielding box for preventing the first and second imaging devices from responding to disturbance light. By providing such a light-shielding box, a TV lens for a camera conventionally provided in an image pickup apparatus can be omitted, so that a hidden mark detection apparatus for a spectacle lens with a simpler configuration can be realized.

In the apparatus for detecting a hidden mark of a spectacle lens according to the present invention, it is preferable to provide a monitor for displaying the detection results of the first and second hidden marks by the first and second image pickup devices. . The hidden mark enlarged and displayed by the monitor means can be visually confirmed.

In the apparatus for detecting a hidden mark of a spectacle lens according to the present invention, the distance between the first and second hidden marks and the distance between the center of the visual field of the first and second imaging devices are set to be substantially the same. It is desirable to keep.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a spectacle lens hidden mark detection apparatus to which the present invention is applied.
As shown in this figure, the apparatus 10 for detecting the hidden mark of the spectacle lens includes the first and second hidden marks 5 of the spectacle lens 1.
Mark detection unit 20 for detecting hidden marks 5 and 6, and an image processing device 60 for processing and outputting an output signal from the hidden mark detection unit 20 as a video signal of hidden marks 5 and 6
And a monitor 70 that displays the hidden marks 5 and 6 based on the video signal from the image processing device 60.

The hidden mark detection unit 20 includes a dark box (light shielding box) 50 for shielding disturbance light. In the dark box 50, a work holding jig 30 for holding the spectacle lens (plus lens) 1 and a work holding jig. An optical system for irradiating the spectacle lens 1 held by the jig 30 with parallel light, and a first optical system provided on the opposite side of the optical system to the spectacle lens 1
And second CCD cameras 41 and 42 are housed.

The work holding jig 30 is of a chucking type which holds the outer peripheral portion of the spectacle lens with the work held therebetween. However, the work holding jig 30 may be a transparent stage made of a transparent material such as a glass plate or a plastic plate that can transmit light.

The eyeglass lens 1 has a first and a second surface on its surface 2 in the same manner as the eyeglass lens described with reference to FIG.
The hidden marks 5 and 6 are engraved, and the center position O of the spectacle lens 1 can be found based on the two hidden marks 5 and 6.

The optical system includes one light source 21 and this light source 2
The collimator lens 22 converts the light emitted from the collimator 1 into parallel light and emits the collimated light, and reflects about 50% of the parallel light from the collimator lens 22 to irradiate the first hidden mark 5 of the spectacle lens 1 with the rest. , A total reflection mirror 24 that totally reflects parallel light transmitted through the half mirror 23 and irradiates the second hidden mark 6 of the spectacle lens 1, and a first hidden mark 5 A first CCD 41 camera for receiving parallel light from the second CCD camera 4 and a second CCD camera 4 for receiving parallel light from the second hidden mark 6
2 is provided. As the light source 21, a light emitting element capable of emitting highly directional light, such as a blue LED light emitting element, is used.

The first CCD camera 41 is arranged on the optical axis L 1 of the parallel light reflected by the half mirror 23 and close to the surface 2 of the spectacle lens 1.
On the other hand, the second CCD camera 42 is arranged on the optical axis L2 of the parallel light reflected by the total reflection mirror 24 and close to the surface 2 of the spectacle lens 1. The lower end faces of the first and second CCD cameras 41 and 42 have C
CD image pickup devices 43 and 44 are configured, and parallel light transmitted through the hidden marks 5 and 6 is projected on these image pickup devices 43 and 44. In this example, the CCD camera 4
No TV lenses for cameras are mounted on 1 and 41, and the CCD image pickup devices 43 and 44 are exposed. For this reason, for example, the CCD imaging device 43
And 44 and the surface 2 of the spectacle lens 1 can be brought to a very short distance of about 1 to 3 mm. Also,
Although the CCD imaging devices 43 and 44 are exposed, since the CCD cameras 41 and 42 are housed in a dark box 50 having a light shielding function, the CCD imaging devices 43 and 44 respond to disturbance light. There is no adverse effect.

The first and second CCD cameras 41 and 42 are electrically connected to the image processing device 60 by signal lines 8 and 9, respectively, and the hidden marks detected by the image pickup devices 43 and 44 are provided. The images 5 and 6 are taken into the image processing device 60 as electric signals.

In the spectacle lens hidden mark detecting device 10 having this configuration, the light emitted from the light source 21 is converted into parallel light by the collimator lens 22, so that the illumination area is widened and the light directivity is ensured. It is emitted as light. The parallel light emitted from the collimator lens 22 is reflected by the half mirror 23 at a light amount of about 50%,
It becomes parallel light (first parallel light) having an optical axis L1 that is bent by approximately 90 ° with respect to the optical axis of the parallel light emitted from the collimator lens 22. On the other hand, the collimator lens 22
The remaining parallel light emitted from the light passes through the half mirror 23 as it is.

The first parallel light is applied to the spectacle lens 1,
The light passes through the area including the portion where the first hidden mark 5 is imprinted. The parallel light that has passed through the half mirror 23 is reflected by the total reflection mirror 24, and the optical axis L2 bent approximately 90 ° with respect to the optical axis of the parallel light from the collimator lens 22.
Of the spectacle lens 1 as parallel light (second parallel light) having
Is transmitted through the region including the portion where the second hidden mark 6 is imprinted, like the first parallel light.

These parallel lights are divided into first and second CCDs.
CCD image pickup devices 43 and 44 of cameras 41 and 42
The first and second hidden marks 5 and 6 are automatically detected by the first and second CCD cameras 41 and 42. Also, in the eyeglass lens hidden mark detection device 10 of this example, a video signal is transferred from the first and second CCD cameras 41 and 42 to the image processing device 60, and the monitor 70 is transmitted through the image processing device 60.
The first and second hidden marks 5 and 6 are enlarged and displayed. Further, in the eyeglass lens hidden mark detection device 10 of the present example, by connecting the work holding jig 30 to an actuator such as a robot, a drive signal is supplied from the image processing device 60 to the actuator,
The position of the spectacle lens 1 can be corrected. For example, the distance between the first hidden mark 5 and the second hidden mark 6, the center of the visual field of the CCD image sensor 41, and the CCD image sensor 4
If the distance from the center of the visual field 2 is set to be the same, the rotation angle of the lens can be calculated from the amount of displacement and the positional relationship between the hidden marks 5 and 6 with respect to the reference position. The angle can be corrected.

Here, the work holding jig 30 in FIG.
Since the spectacle lens 1 held by the lens is a plus lens, the first and second parallel lights transmitted through the spectacle lens 1 are refracted toward the center of the spectacle lens 1 according to the lens characteristics. In the eyeglass lens hidden mark detection device 10 of the present example, the light transmitted through the eyeglass lens 1 is parallel light having high directivity, and the first and second CCD cameras 41 and 42 Close to surface 2. Therefore, the first and second CCs
The distortion recognized by the refraction of the plus lens 1 is reduced in the images recognized by the D cameras 41 and 42. Therefore, the first and second hidden marks 5 and 6 can be recognized with high accuracy.

When the spectacle lens 1 is a minus lens as shown in FIG. 2, the first and second parallel lights are refracted toward the outer peripheral edge of the spectacle lens 1 according to the lens characteristics. Nevertheless, the light transmitted through the spectacle lens 1 is parallel light having high directivity, and the first and second CCD cameras 41 and 42 are close to the surface 2 of the spectacle lens 1, so that the Image distortion due to lens refraction is reduced. Therefore, the spectacle lens 1
Is a minus lens, the first and second hidden marks 5 and 6 can be recognized with high accuracy.

As described above, in the apparatus for detecting a hidden mark of a spectacle lens according to the present embodiment, the light to be applied to the spectacle lens 1 is a parallel light having a high directivity, and the first and second CCD cameras 41 and 42 By arranging them close to the spectacle lens 1, the hidden marks 5 and 6 of the various spectacle lenses 1 (plus lens, minus lens, etc.) can be recognized with high accuracy. For this reason, the efficiency of power measurement, shaping, and the like of the spectacle lens 1 that requires the operation of recognizing the hidden marks 5 and 6 can be greatly improved. Thereby, the productivity of the spectacle lens 1 can be improved.

Also, an apparatus for detecting a hidden mark of a spectacle lens 1
At 0, the light is split by the half mirror 23 into two lights for detecting the first and second hidden marks 5 and 6. Therefore, since only one light source is required for the recognition of the hidden mark, the hidden mark detecting device 10 for the spectacle lens having a simple configuration can be realized.

In the eyeglass lens hidden mark detecting device 10, the first and second dark boxes 50 having a light shielding function are used.
Of the CCD cameras 41 and 42. Therefore, it is possible to prevent the CCD imaging devices 43 and 44 from responding to disturbance light, so that the CCD cameras 41 and 4 can be prevented.
2 without providing a camera TV lens, the distance between the spectacle lens 1 and the CCD cameras 41 and 42 can be made as close as possible. For this reason, the distortion of the mapping caused by the refraction due to the lens characteristics can be further reduced, and the hidden mark detection device 1 for the spectacle lens capable of performing more accurate recognition.
0 can be realized. In addition, the device 10 can be further simplified because no camera TV lens is provided.

In addition, in the eyeglass lens hidden mark detecting device 10 of the present embodiment, since a TV lens for a camera is not used, in order to adjust the amount of light entering the imaging devices 43 and 44, the light source is controlled by a volume or the like. Adjust it. Furthermore, if the image processing device 60 controls the software to improve the image quality so that the hidden marks 5 and 6 can be clearly recognized, the hidden mark can be detected with high reliability.

In the eyeglass lens hidden mark detecting device 10 of the present embodiment, the monitor 70 is connected via the image processing device 60.
The first and second hidden marks 5 and 6 are enlarged and displayed. Therefore, there is an advantage that the hidden marks 5 and 6 displayed on the monitor 70 can be visually confirmed.

(Other Embodiments) As shown in FIG. 3, a light source 21a and a light source 21a for forming first and second parallel lights for detecting the first and second hidden marks 5 and 6 are formed. Two sets of optical systems including the collimator lens 22a may be formed. In the case of such a configuration, the light source 2
Almost all of the light emitted from 1a can be used as the first and second parallel lights for detecting the hidden marks 5 and 6, so that the light use efficiency is high. Therefore, it is suitable for inspecting colored spectacle lenses that require intense light for detection.

[0036]

As described above, according to the present invention, the first
And bringing the second imaging device close to the eyeglass lens,
Further, the light irradiated to the spectacle lens is parallel light having high directivity. Therefore, it is possible to optically recognize the hidden marks of various spectacle lenses (plus lens, minus lens, etc.) with high accuracy. For this reason, it is possible to greatly improve the efficiency of the operation for detecting the hidden mark of the spectacle lens, such as measuring the power of the spectacle lens and shaping. Thereby, the productivity of the spectacle lens can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a device for detecting a hidden mark of a spectacle lens to which the present invention is applied.

FIG. 2 is an explanatory diagram showing how parallel light is refracted when transmitted through a minus lens.

FIG. 3 is a schematic configuration diagram of another example of a hidden mark detecting device for a spectacle lens to which the present invention is applied.

4A is a plan view of an eyeglass lens, and FIG.
3 is a sectional view taken along line bb ′ of FIG.

FIG. 5 is a schematic configuration diagram of a spectacle lens hidden mark detection device proposed by the present applicant.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 spectacle lens 2 (surface of spectacle lens) 5 first hidden mark 6 second hidden mark 10 hidden mark detection device for spectacle lens 21 light source 22 collimator lens 23 half mirror (spectral unit) 24 total reflection mirror 30 work holding jig Tools (holding means) 41 First CCD camera (first imaging device) 42 Second CCD camera (second imaging device) 43, 43 CCD imaging device 50 Dark box (light-shielding box) 60 Image processing device 70 Monitor ( Monitor means)

Claims (7)

[Claims] 1. A holding means for holding an eyeglass lens having first and second hidden marks formed on a surface thereof, and the first hidden mark and the second hidden mark of the eyeglass lens held by the holding means. Optical means for irradiating the hidden mark with parallel light, and disposed close to the spectacle lens held by the holding means, to the parallel light from the optical means transmitted through the spectacle lens A first and a second image pickup device for detecting the first and second hidden marks based on the first and second hidden marks. 2. The optical system according to claim 1, wherein the optical means includes a light emitting diode, a collimator lens for converting light emitted from the light emitting diode into parallel light, and the parallel light from the collimator lens for the first hidden mark. And a spectroscopic unit for splitting the first parallel light for irradiating the second parallel light and the second parallel light for irradiating the second hidden mark. 3. The optical device according to claim 1, wherein the optical unit includes first and second light emitting diodes, and first and second collimator lenses that convert light emitted from the light emitting diodes into parallel light, respectively. The first light-emitting diode and the first collimator lens form first parallel light for irradiating the first hidden mark, and the second light-emitting diode and the second collimator lens A second parallel light beam for irradiating the second hidden mark with the second hidden mark by means of the second hidden light mark. 4. The spectacle lens according to claim 1, further comprising a light-shielding box for preventing the first and second imaging devices from responding to disturbance light. Hidden mark detection device. 5. The first and second imaging devices according to claim 1, wherein the first and second imaging devices use the first and second imaging devices.
An eyeglass lens hidden mark detecting device, comprising a monitor means for displaying a detection result of the hidden mark. 6. The apparatus according to claim 1, wherein each of the first and second imaging devices includes a CCD. 7. The apparatus according to claim 1, wherein a distance between the first and second hidden marks and a distance between the centers of the visual fields of the first and second imaging devices are set to be substantially the same. An apparatus for detecting a hidden mark of a spectacle lens.