JP3846882B2 - Auto lens meter - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a lens meter for measuring optical characteristics such as refractive power in an optical system, and further to a lens meter having an observation function for observing the outer surface and / or inner surface of a lens to be examined.
[0002]
[Prior art]
Conventionally, there are auto lens meters that automatically measure the optical characteristics of the test lens by processing the electrical signal obtained by the light receiving means, but sometimes problems with the test lens (for example, dirt, scratches, In some cases, accurate measurement was difficult due to peeling of the coat, lens dripping, and the like. In order to solve this problem, most of the auto lens meters that do not have a function for grasping the state of the lens have an electrical signal from the light receiving means that is substantially obtained for the measurement of the lens.
[0003]
On the other hand, manual lens meters that have been used in the past have the advantage of being able to observe the state of such lenses because they are directly measured while observing the lens under test. It is used for.
[0004]
However, this observation function of the manual lens meter allows the examiner to see the target image directly by looking at the target image during lens measurement. It is difficult to grasp the cause, and the grasp is largely at the discretion of the examiner.
[0005]
In Japanese Patent Laid-Open No. 7-16203, the ratio of the light amount and the light beam width of the measurement light beam obtained on the detection means is calculated, and the degree of the optical state of the test lens is determined and displayed by comparison with a normal lens. However, even if the presence of scratches and dirt on the lens can be recognized, it is difficult to determine how much it is and whether it is scratched or dirty. The existence of factors (for example, coat peeling and lens dripping) cannot be grasped. Further, since the actual lens surface is not displayed on the monitor, the detailed optical state cannot be grasped.
[0006]
[Problems to be solved by the invention]
Accordingly, the present invention is the conventional optical properties optical system for measuring the observed ability to grasp the surface condition of the lens by incorporating an observation optical system you observe the outer surface and the inner surface of such a subject lens It aims at providing the provided auto lens meter.
[0007]
[Means for Solving the Problems]
The feature of the present invention made to solve such a problem is that the measurement light beam projected from the light emitting means and transmitted through the test lens placed on the lens receiver is photoelectrically converted. In an auto lens meter that is detected by a light receiving means of a mold and measures the optical characteristics of the test lens based on the detected value, the measurement lens of the test lens is included in a measurement optical system that measures the optical characteristics of the test lens. When an observation optical system capable of observing the outer surface or / and the inner surface is incorporated, and the outer surface or / and the inner surface of the test lens is observed as an illumination system for irradiating the test lens The diffusing plate is placed in the lens receiver or in place of the lens receiver or between the lens receiver and the test lens, and the illumination light is directed from above the test lens toward the test lens. It is provided with a light emitting means for emitting.
[0008]
[Action]
Since the auto lens meter according to the present invention incorporates an observation optical system for observing the outer surface and / or inner surface of the test lens in a conventional optical characteristic measurement optical system, the surface of the test lens It is possible to observe the state of the lens, and to measure the abnormality of the lens under test (scratches, dirt, peeling off of the coat or lens dripping) quickly and confirming the surface condition of the lens under test. Measurement performance can be improved. Further, the display may be enlarged and displayed on the monitor , whereby the grasp of the surface condition of the lens to be examined is less dependent on the discretion of the examiner.
[0009]
According to a third aspect of the present invention, there is provided an auto lens meter having light emitting means for emitting diffused light toward the upper test lens at a lower portion of the lens receiver . For example, it also improves the measurement performance of possible to be progressive power lenses from Rukoto be displayed on the monitor hidden mark of the progressive addition lens.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.
[0011]
First, FIG. 1 shows a schematic configuration of a measurement optical system as one embodiment of the present invention. In such a measurement optical system, measurement light is emitted by the light source 10 and is condensed and projected in approximately one direction. A collimating lens 16 as a projection optical system of the light source 10 is arranged coaxially with respect to the optical axis 14 of the measurement light beam 12, and the measurement light from the light source 10 passes through the collimating lens 16. The measurement light beam 12 is a substantially parallel light beam. Further, a lens 18 to be tested is supported by the lens receiver 5 at the tip of the collimating lens 16 and can be arranged substantially coaxially with the optical axis 14 of the measurement light beam 12. The measurement light beam 12 is made to be a substantially parallel light beam and then transmitted to the lens 18 to be measured. Further, a condensing lens 20 and an imaging lens 22 are arranged on the optical axis of the measurement light beam 12 that has passed through the lens 18 to be measured, and are further spaced apart from each other. A light receiving element 24 is disposed apart from the imaging lens 22 on the optical path of the light beam 12. Then, the measurement light beam 12 that has passed through the test lens 18 is condensed by the condenser lens 20 and then guided to the light receiving element 24 by the imaging lens 22. Further, the light receiving surface of the light receiving element 24 is conjugated with the test lens 18 by the condenser lens 20 and the imaging lens 22, and the measurement light incident on a fixed position of the test lens is detected by the test lens. Regardless of the refractive power of 18 or the like, the light is guided to a certain position on the light receiving surface of the light receiving element 24.
[0012]
In short, in the measurement optical system of this embodiment, so as to face the position in the optical axis direction both sides across the target lens 18, the light source 10 and the light receiving element 24 is disposed, emitted by the light source 10 The measured measurement light beam 12 is projected onto the test lens 18 through the collimator lens 16, passes through the test lens 18, is guided to the light receiving element 24 through the condenser lens 20 and the imaging lens 22, and is supplied to the photoelectric conversion element 26 a. It is detected as an electrical signal by ~ d (light receiving point).
[0013]
In the present embodiment, as shown in FIG. 7, on the light receiving surface of the light receiving element 24, the photoelectric conversion elements (light receiving points) 26a, 26b, 26c, and 26d are positioned at the four corners of the square, respectively. A total of four photoelectric conversion elements are provided. The light receiving element 24 is arranged so that the center of the square formed by the four photoelectric conversion elements 26a to 26d is positioned on the optical axis 14 of the measurement light beam 12, and the light receiving surface is arranged perpendicular to the optical axis 14. The positions of the photoelectric conversion elements 26a, 26b, 26c, and 26d are light detection points on the light receiving surface.
[0014]
Further, on the optical path of the measurement light beam 12, a rotary plate 32 having a circular flat plate shape as a rotary chopper located between the condenser lens 20 and the imaging lens 22 is arranged in a direction perpendicular to the optical path. It is installed. The rotary plate 32 is rotationally driven by a drive motor 28 about a rotary shaft 30 that is biased parallel to the optical axis 14 of the measurement light beam 12. Further, the rotating plate 32 has an edge portion that can block the measurement light beam 12 in accordance with the rotational movement around the rotation shaft 30, and the measurement light beam 12 and thus the light receiving element by rotation around the rotation shaft 30. The incident light to 24 is interrupted.
[0015]
In particular, in the present embodiment, as shown in FIG. 8, the substantially fan-shaped window portions 34 are 90 ° apart from each other in the circumferential direction at positions intersecting the optical path with respect to the disk-shaped rotating plate 32. It is formed apart. Further, both edge portions 36 and 38 in the circumferential direction of the window portion 34 have mathematically known shapes. In particular, in the present embodiment, any of the edge portions 36 and 38 is light of the measurement light beam 12. The intersection angles α and β with respect to one circumference 40 as the locus of the intersection with the axis 14 are designed to be 45 °. Furthermore, slits 42 a and 42 b for providing a reference position in the circumferential direction of the edge portions 36 and 38 are formed on the outer peripheral portion of the rotating plate 32. In the present embodiment, the rotating plate 32 is disposed on the light receiving element 24 side from the condenser lens 20 at a position separated by the focal length of the condenser lens 20.
[0016]
In the auto lens meter having such a structure, when the test lens is disposed on the optical path, each of the test lenses 18 corresponding to the light receiving points 26a to 26d of the light receiving element 24 that is conjugate with the test lens 18 is provided. The light transmitted through the point is refracted according to the refractive power characteristics (optical characteristics such as spherical power and cylindrical power) of the lens 18 to be detected, so that the position of the rotating plate 32 on the mounting surface is displaced. It will be. Therefore, by measuring the displacement amount and the displacement direction of the light transmitted through each point of the test lens 18 on the arrangement surface of the rotating plate 32, the optical characteristics of the test lens 18 are determined from these values. It can be sought. The displacement amount and displacement direction of the transmitted light on the arrangement surface of the rotating plate 32 are determined by using the intermittent position by the edge portions 36 and 38 of the rotating plate 32 as the displacement amount of the rotation angle from the reference position. Since it can be known by detecting each of the 24 photoelectric conversion elements 26a to 26d, it can be obtained by the output signal of the photoelectric conversion elements 26a to 26d and the reference position sensor 44 such as a photoelectric switch using the slits 42a and 42b. The reference position signal of the rotating plate 32 is input to an arithmetic processing unit 46 constituted by a microcomputer or the like, and is subjected to arithmetic processing according to a preset program, whereby the target lens 18 has a spherical power and a cylindrical power. Such optical characteristics can be obtained. Note that a calculation method for obtaining optical characteristics such as spherical power and cylindrical power of the test lens 18 based on the output signals of the photoelectric conversion elements 26a to 26d is described in JP-A-5-231985. , Avoid detailed description here.
[0017]
Here, as shown in FIG. 1, a half mirror 52 is disposed between the collimating lens 16 and the test lens 18, and the surface of the test lens is observed in a direction of approximately 90 degrees with respect to the test lens optical characteristic measurement system. An observation optical system (imaging lens 50 and area CCD camera 51) is arranged.
[0018]
Since the imaging lens 50 can be adjusted so that the image of the surface of the lens 18 to be examined is formed on the CCD element of the area CCD camera 51, the imaging lens 50 can be moved back and forth with respect to the optical axis 53 of the observation optical system. It has a simple structure. The image signal obtained from the area CCD camera 51 is displayed on the monitor 57 via the arithmetic processing unit 46.
[0019]
Here, when the surface of the test lens 18 is observed, the light source 10 for measuring optical characteristics of the test lens is turned off.
[0020]
Although the half mirror 52 is disposed between the collimating lens 16 and the test lens 18 in FIG. 1, it may be disposed between the light source 10 and the collimating lens 16 as shown in FIG. In this case, the collimating lens 16 functions as an imaging lens in the observation optical system. Therefore, there is an advantage that the number of lenses can be reduced compared to the example of FIG. In this case, the area CCD camera 51 is structured to be movable in the front-rear direction with respect to the optical axis 53, and the area CCD camera 51 is adjusted so that the image of the surface of the lens 18 to be examined is formed on the CCD sensor.
[0021]
The examples in FIGS. 1 and 2 use indoor natural light as the light source of the optical system for observation. However, there are cases where the room is dark and a sufficient amount of light cannot be obtained for observation. In some cases, the surface state of the lens cannot be sufficiently observed.
[0022]
As countermeasures, FIGS. 3, 4, and 5 show examples in which an illumination system for observation is arranged.
[0023]
FIG. 3 shows an example in which a diffusing plate 54 such as ground glass and a light source 55 are arranged below the lens receiver 5 and the diffused light is irradiated from below the lens receiver 5 toward the lens 18 to be examined. Thereby, it is possible to improve the surface observation performance of the test lens 18.
[0024]
FIG. 4 shows an example in which a diffusing plate 54 such as ground glass is disposed on the lens receiver 5 and a light source 55 is disposed obliquely above the lens 18 to be examined. In this example, light is irradiated from above the test lens 18 and irradiated to the diffuser plate 54 to irradiate the test lens 18 with diffused light from below the test lens 18.
[0025]
In either of the methods shown in FIGS. 3 and 4, when the surface of the lens 18 to be examined is observed, the lens receiver 5 needs to be replaced. FIG. 5 shows an example in which the lens receiver 5 does not need to be replaced. A diffusing plate 54 such as frosted glass is placed between the lens to be examined and the lens receiver 5, and light is irradiated from the obliquely upper light source 55 and irradiated to the diffusing plate 54 as in the example of FIG. The diffused light is applied to the lens 18 from below.
[0026]
Further, FIG. 6 shows the measurement light source 10 used as an observation light source. By irradiating measurement light with a diffusion plate 54 such as ground glass on the lower side of the test lens, the test lens 18 is irradiated with diffused light from below. Since an observation light source is not provided, it is advantageous in terms of cost.
[0027]
In addition, although not enumerated one by one, the present invention can be implemented in a mode with various changes, modifications, improvements, and the like based on the knowledge of those skilled in the art, and such embodiments are not limited to the present invention. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.
[0028]
【The invention's effect】
As apparent from the above description, according to the present invention, those in the conventional optical system for measuring the optical characteristics were input set an observation optical system for observing the outer surface or / and the inner surface of the lens Therefore, it is possible to observe the surface state of the lens to be examined, and it is possible to promptly cope with the abnormality (scratches, dirt, peeling off of the coat, lens dripping) of the lens to be examined at the time of measurement.
Further, it may be possible to perform measurement while confirming the surface condition of the lens to be examined.
Further, the image may be enlarged and confirmed on the monitor.
According to the present invention, it is less dependent on the discretion of the examiner when grasping the surface state of the lens to be examined.
Furthermore, it goes without saying that the monitor screen may be shown to the customer, which is effective as a sales promotion tool. In particular, it is effective to display the surface state of a contact lens on a monitor and use it for explanation to a customer. As a result, customer serviceability can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration in which an observation system is incorporated in a conventional measurement optical system as one embodiment of the present invention. (Example 1)
FIG. 2 is a diagram showing a schematic configuration in which an observation system is incorporated in a conventional measurement optical system as an embodiment of the present invention. (Example 2)
FIG. 3 is a diagram showing a schematic configuration for observation light irradiation as an embodiment of the present invention. (Example 3) (The measurement system is omitted.)
FIG. 4 is a diagram showing a schematic configuration for observation light irradiation as an embodiment of the present invention. (Example 4) (The measurement system is omitted.)
FIG. 5 is a diagram showing a schematic configuration for irradiation of observation light as one embodiment of the present invention. (Example 5) (The measurement system is omitted.)
FIG. 6 is a diagram showing a schematic configuration for observation light irradiation as an embodiment of the present invention. (Example 5) (The measurement system is omitted.)
7 is a front view of a light receiving element employed in the measurement optical system shown in FIG. 1. FIG.
FIG. 8 is a front view of a rotating plate employed in the measurement optical system shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Light source 12 Measurement light beam 18 Test lens 24 Light receiving element 26 Photoelectric conversion element (light receiving point)
32 Rotating plate 50 Imaging lens (observation system)
51 Area CCD camera 52 Half mirror 54 Diffuser 55 Light source (for observation)
57 Monitor

Claims (8)

Detecting the measuring beam which allowed transmits through the inspected lens is placed on only the lens platform is projected from the light emitting unit in the photoelectric conversion type light receiving means, measuring the optical properties of the subject lens on the basis of the detected value In the auto lens meter
The Rutotomoni incorporated an outer surface and / or the observation optical system capable of observing the inner surface of the test lens in the measurement optical system for measuring optical characteristics of the lens,
When observing the outer surface or / and the inner surface of the test lens as an observation illumination system for irradiating the test lens, the lens receiver is used instead of the lens receiver or in place of the lens receiver. An auto lens meter comprising: a diffusing plate placed between the test lenses; and a light emitting means for emitting illumination light in the direction of the test lens from above the test lens . As an illumination system for the observation, the time to observe the outer surface or / and the inner surface of the lens, the irradiation of irradiating diffused light toward to said sample lens from a surface opposite to the observation surface of the sample lens The auto lens meter according to claim 1 , further comprising means. A light source in the illumination system for observation is provided separately from the light source for measuring the optical characteristics of the lens to be examined, and the light source for observation and the light source for measuring optical characteristics are selectively emitted. The auto lens meter according to claim 1 or 2 . As a light source in the illumination system for the observation, the auto-lens meter according the to claim 1 or 2 using the measurement of the light source of the optical properties of the lens. Wherein with the observation optical system is adapted to obtain an image signal of the subject lens, any of claims 1 to 4 provided with a monitor for displaying images observations該被subject lens on the basis of the image signal The auto lens meter according to claim 1. 6. The auto lens meter according to claim 5 , wherein a monitor that displays a measurement result of the optical measurement of the lens to be examined is used as the monitor that displays an image of the observation result of the lens to be examined. The auto lens meter according to claim 5 or 6 , further comprising an enlarged display means for enlarging an observation result of the test lens based on an image signal of the test lens and displaying an enlarged image on the monitor. A half mirror is disposed in the measurement optical system for measuring the optical characteristics of the lens to be measured, and the optical path of the observation optical system is branched from the optical path of the measurement optical system of the optical characteristics. on the optical path of the system, according to any one of claims 1 to 7 provided with the adjustment mechanism of the imaging conditions in the optical system for the observation by adjusting the distance from the optical path of the bifurcated said measuring optical system Auto lens meter.

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