JPH0618363A - Lens meter - Google Patents

Abstract

PURPOSE:To reduce aberration in which the position of a contact lens is moved than that of the case of an glasses lens at the time of measurement of the contact lens. CONSTITUTION:A lens 2, lens contact members 3, 5 for adjusting a position of another lens to be tested L in the direction of a light axis, a hole opening diaphragm 4, a photographing element 5 are arranged on an optical path O1 transmitted from a light source 1. The positions of the lens contact members 3, 5 and the hole opening diaphragm 4 at the time of measurement of a contact lens are moved farther from the light source 1 than those in the case of the measurement of an glasses lens and the influence of aberration is removed for the purpose of exact measurement of a refraction value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens meter used in eye clinics and eyeglass stores.

[0002]

2. Description of the Related Art (1) In general, a contact lens has a large curvature of a surface curve and a large aberration as compared with a spectacle lens. Therefore, when measuring the refractive index of a contact lens with a lens meter, the contact lens has the same condition as that of the spectacle lens. If you do, the measured values will shift. For this reason, when measuring the refractive index of the contact lens, it is necessary to reduce the diameter of the measured light beam to such an extent that aberration is not a problem, or to correct it when calculating the measured value.

(2) In a lens meter such as a spectacle lens or a contact lens that measures refraction with transmitted light, the optical axis of the measuring light is generally in the vertical direction. This is for consideration so that the refraction can be measured only by mounting the lens on the contact member from above.

(3) In the auto lens meter, the refractive power of the spectacle lens, the amount of astigmatism, and the refraction information such as the direction are digital values.
It is very convenient because it is displayed with an accuracy of up to about 01 diopter, but from the viewpoint of precision and digital value display, even a slight mechanical change causes the change to be displayed. Causes thereof include subtle displacement and deformation of components due to shocks and vibrations caused by transportation, and distortion and optical characteristic changes due to contraction and expansion of components due to changes in ambient temperature. As a method of correcting the variation based on such a factor, for example, it is known to set an initial value without a lens to be inspected each time measurement is started, as disclosed in JP-A-58-212622. ing.

[0005]

However, in the above-mentioned conventional example (1), when measuring the refractive index of a contact lens with a lens meter, the lens contact member is changed from that for spectacle lenses to that for contact lenses. Moreover, it is necessary to switch the mode with a switch or the like, and there is a drawback that accurate measurement cannot be made if the operation is mistaken.

In the conventional example (2), since the optical axis for measurement is in the vertical direction, the height of the device becomes high, and the device becomes large when manufacturing a complex machine with an autorefractometer, for example. The result is against miniaturization.

Further, in the above-mentioned conventional example (3), an initial value is set each time measurement is started, and therefore preliminary measurement must be performed without a lens to be inspected.

A first object of the present invention is to solve the above-mentioned problems and to provide a lens meter having a simple structure and capable of highly accurate measurement.

A second object of the present invention is to provide a lens meter which is thin and in which an optical mechanism can be freely arranged.

A third object of the present invention is to provide a lens meter which performs calibration under a predetermined condition in order to correct fluctuations such as temperature changes.

[0011]

A first lens meter for achieving the above object comprises a projection means for projecting a light beam on a lens to be inspected, a lens contact member for setting the position of the lens to be inspected, A luminous flux selecting means for selecting a part of the luminous flux projected on the lens to be inspected, a luminous flux detecting means for detecting the luminous flux selected by the luminous flux selecting means, and a position of the luminous flux detected by the luminous flux detecting means. In the lens meter, which comprises a refraction index calculating means for calculating the refraction index of the lens to be inspected, the lens contact member and the light flux selecting means are used to measure the refraction index of the contact lens as the inspected lens. As an example, it has moving means for moving in the optical axis direction from the position when measuring the refractive index of the spectacle lens.

The second lens meter is a lens meter for projecting a light beam on a lens to be inspected and measuring refraction of the lens to be inspected by the transmitted light, and a spectacle lens contact member for positioning the spectacle lens on a horizontal optical path. , A contact lens contact member for positioning the contact lens on the vertical optical path.

The third lens meter comprises a projection means for projecting a light beam on the lens to be inspected, a lens contact member for setting the position of the lens to be inspected, a light beam selecting means for selecting a part of the projected light beam, and A lens meter having a light flux detecting means for detecting the light flux selected by the light flux selecting means, a refraction degree calculating means for calculating refraction information of the lens to be inspected from the position of the light flux detected by the light flux detecting means, and a timer. ,
It has a calibration means for performing automatic calibration after a lapse of a predetermined time by the timer after the power switch is turned on.

The fourth lens meter comprises a projection means for projecting a light beam on the lens to be inspected, a lens contact member for setting the position of the lens to be inspected, a light beam selecting means for selecting a part of the projected light beam, and A lens meter having a light flux detecting means for detecting the light flux selected by the light flux selecting means, a refraction degree calculating means for calculating refraction information of the lens under test from the position of the light flux detected by the light flux detecting means, and a temperature sensor. At
It has a calibration means for performing automatic calibration when the temperature detected by the temperature sensor changes from a set value by a predetermined value or more after the power switch is turned on.

[0015]

In the first lens meter having the above structure, when measuring the refractive index of the contact lens, the measurement position of the contact lens and the position of the light beam selecting means are shifted from the position of the spectacle lens in the optical axis direction. , Correct the deviation of the measured value due to the aberration of the contact lens.

In the lens meter of the second aspect of the present invention, when measuring the refraction of the spectacle lens, the horizontal light flux passes through the spectacle lens to measure the refracting power, and when measuring the refraction of the contact lens, it is bent by the reflecting member. The vertical light flux passes through the contact lens and its refraction is measured.

The third lens meter has a built-in timer for measuring the time elapsed after the power is turned on, and when the machine becomes electrically and thermally stable after a while after the power is turned on, or every time a predetermined time elapses thereafter. Calibrate automatically.

The fourth lens meter has a built-in temperature sensor, and is automatically calibrated when the temperature detected by the temperature sensor changes by a predetermined value or more after the power switch is turned on.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiments. FIG. 1 is a block diagram of the lens meter of the first embodiment. On the optical path O1 from the light source 1, a collimator lens 2, a lens contact member 3 for adjusting the position of the lens L to be tested in the optical axis direction, and openings 4a at the center and at four symmetrical positions as shown in FIG.
A five-hole aperture stop 4 having 4e and an image sensor 5 are arranged. The output of the image pickup device 5 is connected to the image pickup device drive circuit 6, and the output of the image pickup device drive circuit 6 is connected to the television monitor 9 via the arithmetic control circuit 7 and the synthesis circuit 8. The output of the arithmetic control circuit 7 is connected to the combining circuit 8 via the light source 1 and the alignment symbol generating circuit 10.

The light beam from the light source 1 passes through the collimator lens 2 to become parallel light, and enters the lens L to be inspected. The incident light beam is bent according to the refraction degree of the lens L to be inspected, is divided into five light beams by the 5-hole aperture stop 4, and an image of five spot lights is projected on the image sensor 5. The projected light flux image is output as a video signal to the arithmetic control circuit 7 and the synthesizing circuit 8 via the image pickup element drive circuit 6. The video signal input to the arithmetic control circuit 7 is digitized and stored in an image memory (not shown) in the arithmetic control circuit 7. The arithmetic control circuit 7 also detects the position information of the light flux from the stored image data, and also calculates the refractive index of the lens L to be inspected. In the synthesizing circuit 8, the alignment mark M generated by the alignment symbol generating circuit 10 controlled by the arithmetic control circuit 7 and the images P1 to P5 by the video signal from the image pickup device driving circuit 6 are synthesized and output to the television monitor 9. .

FIG. 3 is an explanatory diagram of the measurement principle. Figure 3 (a)
Shows the case where the refractive index of the convex spectacle lens G is measured, and FIGS. 3B and 3C show the case where the refractive index of the contact lens C of the convex lens is measured. In FIG. 3 (a), the light beam incident on the spectacle lens G supported by the spectacle lens lens contact member 3 is refracted according to the refraction index of the spectacle lens G, and is divided by the five-hole aperture stop 4 to be divided. The luminous fluxes G1 and G2 are projected on the image sensor 5.

In FIGS. 3 (b) and 3 (c), the light beam supported by the contact lens lens contact member 3'and incident on the contact lens C having the same refraction index as the spectacle lens G is refracted according to the refraction index. It is divided by the 5-hole aperture stop 4. The split luminous fluxes C1 and C2 are projected onto the image sensor 5. Originally, if the refractive index is the same, the positions of the light beams C1 and C2 are the light beams G1 and G2.
Should be at the same position as, but in reality, the curvature of the surface curve of the contact lens C is large and the aberration is large, so the light beams C1 and C2 are largely bent as shown in Fig. 3 (b), and as a result, the contact lens The refractive index measurement value of the lens C is larger than the actual value.

Here, as shown in FIG. 3 (c), the luminous fluxes C1 and C2 are
If the positions of the lens abutting member 3'and the 5-hole aperture stop 4 are displaced in the direction away from the light source 1 by a distance d so that the position of is substantially the same as the positions of the light beams G1 and G2, the measured value is obtained. Can be almost corrected.

FIG. 4 is an explanatory view of the measurement principle when the concave lens is the lens L to be inspected, and FIGS. 4A and 4B show the case where the refractive index of the contact lens C of the concave lens is measured. . The light beam incident on the contact lens C supported by the contact lens lens contact member 3 ′ is refracted according to the refraction degree and is split by the five-hole aperture stop 4. The split luminous fluxes C1 and C2 are projected onto the image sensor 5. Luminous flux
The positions of C1 and C2 are deviated from the light beams G1 and G2 in the case of using the spectacle lens G having the same refractive index as the contact lens C due to the influence of the curvature of the contact lens C.
Here, as shown in FIG. 4B, the positions of the lens contact member 3 and the five-hole aperture stop 4 are set so that the positions of the light beams C1 and C2 are almost the same as the positions of the light beams G1 and G2. If the distance d is shifted in the direction away from, as a result, the measured value of the refractive index can be substantially corrected.

FIG. 5 shows a contact lens C as a spectacle lens G.
FIG. 7 is a graph showing the deviation of the measured value when the refractive index is measured at the same position as in FIG. 6, and FIG. 6 is a graph showing the deviation of the corrected refractive index measured value.

As described above, even if the contact lens C is a convex lens or a concave lens, the measured value of the refractive index can be satisfactorily corrected by displacing it in the same direction. Therefore, for example, the lens contact members 3 and 5 are used. The integrated aperture stop 4 may be prepared for a spectacle lens and a contact lens whose fixed position is corrected, and may be replaced according to the lens L to be inspected. The lens contact member 3 is arranged at a position substantially conjugate with the rear surface of the lens L to be inspected.
The conjugate position of the five-hole aperture stop 4 may be located substantially on the rear surface of the lens L to be tested in accordance with the change of the position.

Although the image sensor 5 is used as the light flux detecting means, a line sensor or a position detector (PS) is used.
D), a photo sensor or the like may be used. Further, although the 5-hole aperture stop 4 having a plurality of apertures is used as the light flux selecting means, a ring-shaped one or a shape corresponding to the light flux detecting means may be used as the light flux selecting means. Further, the lens meter of the present embodiment can obtain the same effect with a manual lens meter in addition to the automatic lens meter.

FIG. 7 is a block diagram of the second embodiment. This lens meter is an automatic measuring device, and there are several optical paths O2 having a plurality of bends from the light source 21 to the image sensor 22. Optical members are arranged. That is, the collimator lens 2 is provided on the optical path O2 extending from the light source 21 in the horizontal direction.
3, a spectacle lens contact member 24 having a supporting surface for the lens G to be inspected in the vertical direction, and a mirror 25 are arranged, and a contact lens having a supporting surface in the horizontal direction on the optical path O2 bent in the vertical direction by the mirror 25. Contact member 26, mirror 2
7 is arranged, and the optical path O2 is further bent in the horizontal direction by the mirror 27 so that the lens 28 and the contact lens abutting member 26 with respect to this lens 28 are substantially conjugate with each other. A hole aperture stop 29 and a lens 30 are arranged and reach the image sensor 22.

When measuring the spectacle lens G, the optical axis of the spectacle lens G is arranged in front of the spectacle lens abutting member 24. When measuring the contact lens C,
The contact lens C is placed on the contact lens contact member 26. In FIG. 7, the spectacle lens G and the contact lens C are drawn at the same time, but they are not measured at the same time, and either one is arranged and measured.

Now, the eyeglass lens G is brought into contact with the eyeglass lens contact member 24, and the refractive power of the eyeglass lens G is measured. The light beam emitted from the light source 21 passes through the collimator lens 23 to become parallel light, and enters the spectacle lens G. The incident light beam is bent according to the refraction degree of the spectacle lens G, is reflected by the mirror 25 and the mirror 27, is transmitted through the lens 28, and is a four-hole aperture stop 29.
Is divided into four light beams by the lens 30, and four spot lights are formed on the image pickup device 22 by the lens 30. Since the refraction index of the spectacle lens G is related to the coordinates of the four spot lights projected on the image sensor 22, the refraction index of the spectacle lens G is measured by calculating the position of the spot light by a computer (not shown). To be done.

When measuring the refraction of the contact lens C, the contact lens C is placed on the contact lens abutting member 26 without disposing the spectacle lens G, and the light source 21 emits light in the same manner to pick up the image pickup element. The refractive power is calculated from the image obtained at 22. Since the arrangement of the eyeglass lens contact member 24 and the contact lens contact member 26 is different, the coordinates of the spot light projected on the image sensor 22 change, but this can be corrected by calculation.

9 and 10 are partial block diagrams of the third embodiment. The third embodiment has a convolution type contact lens support 31. In the optical path O3 from the light source 21 to the sensor through the contact lens C, a mirror 33 that bends the optical path O3 vertically upward, a contact lens contact member 34, a mirror 35 that changes the optical path O3 horizontally, and a half mirror 36 are sequentially provided. It is arranged. Among these, the mirror 33, the contact lens contact member 34, and the mirror 35 constitute the contact lens support portion 31. Mirror 33
Has a supporting surface in the vertical direction at the rear of the horizontal direction, and an eyeglass lens abutting member 37 is arranged at a position conjugate with the contact lens abutting member 34 with respect to the image pickup element, and a vertical axis of the half mirror 36. A mirror 38 is arranged at a position where the horizontal axis of the eyeglass lens contact member 37 intersects.

When measuring the refraction of the contact lens C, as shown in FIG. 9, the contact lens C is placed from above the contact lens contact member 34, and a light beam is incident from the light source 21 along the optical path O3. The light flux is reflected by the mirror 33,
The light passes through the contact lens C, is refracted, is reflected by the mirror 35, is transmitted through the half mirror 36, is incident on the image pickup element, and the refracting power is measured.

FIG. 10 shows the state of the spectacle lens G at the time of measurement. The contact lens support portion 31 in FIG. 9 is rotated and is folded in front of the half mirror 36 shown in FIG. When the contact lens support 31 is folded,
The spectacle lens contact member 37 appears on the optical path from the light source 21. The examiner brings the spectacle lens G into contact with the spectacle lens contact member 37 while the optical axis thereof is oriented in the horizontal direction. The light flux passes through the spectacle lens G, is refracted, is reflected by the mirror 38 and the half mirror 36, and is detected by the image sensor. In this case, the contact lens abutting member 34 and the spectacle lens abutting member 37 are located at positions that are completely conjugate with the image pickup element, so that the detection unit does not need to be corrected.

FIG. 11 shows a fourth embodiment. A collimator lens 42, a lens abutting member 43 for supporting a lens L to be inspected, are provided on the optical path O4 of the light source 41, and at the center and at four symmetrical positions as in FIG. 5-hole aperture stop 44 having an aperture, image sensor 45
Are arranged. The light source 41 and the image sensor 45 are connected to the arithmetic processing unit 46, and the arithmetic processing unit 46 is connected to a power switch 47, a measurement switch 48, a display 49, a timer 50, a temperature sensor 51, and a speaker 52, respectively. ing.

The light beam emitted from the light source 41 and collimated by the collimator lens 42 is split by the 5-hole aperture stop 44 and projected on the image pickup element 45 as spot light. When the lens L to be inspected is brought into contact with the lens abutting member 43 and inserted into the optical path O4, the position of the spot light projected on the image pickup element 45 changes according to its refraction characteristics. When the measurement switch 48 is operated, the arithmetic processing unit 46 calculates the refraction information of the lens L to be measured from the amount of change in the light beam position of the image sensor 45,
The result is displayed on the display 49.

Prior to the measurement, the time after the power switch 47 is turned on is measured by the timer 50, and after a predetermined time (for example, 10 seconds at the beginning), the arithmetic processing unit 46 automatically lights the light source even if the measurement switch 48 is not pressed. 41 is turned on, the signal from the image sensor 45 is read and calculated, and if the result is deviated from the value set at the time of manufacturing the device, a new result is automatically stored as a new reference value without the lens L to be inspected. Make a correction. After that, the same automatic calibration is performed every other time set by the elapsed time measurement of the timer 50, for example, every 3 hours.

Further, the temperature sensor 51 is attached to a portion of the apparatus which is most sensitive to temperature changes in the apparatus or the temperature of the apparatus is measured to measure the temperature, and when the temperature changes beyond a value set at the time of manufacturing the apparatus. , And when the temperature changes to a predetermined value or more, the arithmetic processing unit 46 sequentially performs the same automatic calibration.

When it is determined that the automatic calibration is to be performed, a display indicating that the automatic calibration by music or the like is being performed is made from the speaker 52 from the start to the end. Good. Further, when it is determined to perform automatic calibration, when the lens L to be measured is being measured,
That is, during a certain period of time when the measurement switch 48 is pressed or during the operation of the arithmetic processing unit 46, it is automatically checked whether or not the measurement is being performed after a predetermined time has passed, and if it is not in use, automatic calibration is performed.

In the embodiment, the timer 50 and the temperature sensor 51 are provided together, but either one may be provided.

[0041]

According to the first lens meter, the positions of the lens abutting member and the light flux selecting means are set when measuring the contact lens.
The displacement due to the aberration of the contact lens can be corrected and the measurement can be accurately performed by a simple operation only by shifting from the measurement position of the spectacle lens in the optical axis direction.

Since the second lens meter bends the light beam by the reflecting member, the degree of freedom of the optical axis is increased, and the optimum configuration can be achieved in terms of the arrangement of the optical system. Further, since the measurement optical axis of the contact lens is in the vertical direction, it is only necessary to place the contact lens on the contact member, and the alignment is easy.

The third lens meter can always obtain an accurate measurement value by performing automatic calibration every time a predetermined time elapses by a timer that measures the time elapsed after the power is turned on.

The fourth lens meter can always obtain an accurate measurement value by performing automatic calibration every time the temperature sensor deviates the temperature change after the power is turned on from the set value when the device is manufactured by a predetermined value or more. .

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment.

FIG. 2 is a front view of a 5-hole aperture stop.

FIG. 3 is an explanatory diagram of a measurement principle.

FIG. 4 is an explanatory diagram of a measurement principle.

FIG. 5 is a graph showing the relationship between the refracting power and the deviation of the lens under test.

FIG. 6 is a graph showing the relationship between the refractive power of the lens to be inspected and the displacement.

FIG. 7 is a configuration diagram of a second embodiment.

FIG. 8 is a front view of a four-hole diaphragm.

FIG. 9 is a configuration diagram of a third embodiment when measuring a contact lens.

FIG. 10 is a configuration diagram of a third embodiment when measuring a spectacle lens.

FIG. 11 is a configuration diagram of a fourth embodiment.

[Explanation of symbols]

 1, 21, 41 Light source 3, 43 Lens contact member 4, 44 5 hole aperture stop 5, 22, 45 Image sensor 24, 37 Eyeglass lens contact member 26, 34 Contact lens contact member 29 4 hole aperture stop 31 Contact Lens support 47 Power switch 50 Timer 51 Temperature sensor

Claims (6)

[Claims] 1. A projection means for projecting a light beam onto a lens to be inspected, a lens contact member for setting the position of the lens to be inspected, and a light beam selecting means for selecting a part of the light beam projected onto the lens to be inspected. A lens meter comprising a light flux detecting means for detecting the light flux selected by the light flux selecting means, and a refraction index calculating means for calculating the refractivity of the lens to be inspected from the position of the light flux detected by the light flux detecting means. At, when measuring the refractive index of the contact lens as the lens to be tested,
A lens meter, comprising: a moving unit that moves in a direction of an optical axis from a position when the refractive index of a spectacle lens is measured using the lens contact member and the light flux selecting unit as a lens to be tested. 2. In a lens meter for projecting a light beam onto a lens to be inspected and measuring refraction of the lens to be inspected by the transmitted light, the eyeglass lens contact member for positioning the eyeglass lens on a horizontal optical path and the contact lens are vertically arranged. A lens meter, comprising: a contact lens contact member positioned on the optical path. 3. A projection means for projecting a light beam on a lens to be inspected, a lens contact member for setting the position of the lens to be inspected, a light beam selecting means for selecting a part of the projected light beam, and a selection by the light beam selecting means. A light flux detecting means for detecting the reflected light flux,
In a lens meter having a refractivity calculating means for calculating refraction information of a lens to be inspected from the position of the light flux detected by the light flux detecting means and a timer, automatic calibration is performed after a predetermined time has elapsed by the timer after the power switch is turned on. A lens meter having a calibrating means for performing. 4. A projection means for projecting a light beam on a lens to be inspected, a lens contact member for setting the position of the lens to be inspected, a light beam selecting means for selecting a part of the projected light beam, and a light beam selecting means for selecting the light beam. In the lens meter having a temperature sensor, a light flux detecting means for detecting the generated light flux, a refraction degree calculating means for calculating refraction information of the lens under test from the position of the light flux detected by the light flux detecting means, A lens meter, comprising a calibrating means for performing automatic calibration when the temperature detected by the temperature sensor has changed from a set value by a predetermined value or more after being charged. 5. The automatic calibration is started when the condition for performing the automatic calibration is satisfied, when the use is stopped when the automatic calibration is in use, or after a predetermined time elapses from that time. 4. The lens meter according to item 4. 6. The lens meter according to claim 3, wherein a display is made before and after the automatic calibration.