JPH0213727B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for automatically measuring various characteristics of an optical system, such as spherical refractive power, cylindrical refractive power, and its axial direction, prismatic refractive power, and its base direction. The principles and embodiments of the present invention described below mainly relate to a method and apparatus for measuring the above-mentioned characteristics of eyeglass lenses. This does not mean that it is applied only to the invention, but it can also be used to measure various optical characteristics of lens optical systems widely used in optical instruments.

In recent years, various measurement principles and devices have been proposed for so-called automatic lens meters that automatically measure various optical properties of eyeglass lenses, such as their spherical refractive power, cylindrical refractive power, and their axial directions. . One of them is US Pat. No. 3,880,525. This U.S. patented device aims to determine the optical characteristics of the test lens from the polarization of the emitted light by making parallel light incident on the test lens parallel to the measurement optical axis. , a mask having a point aperture is arranged so that the point aperture is located off the optical axis of the lens to be tested, a detection surface is provided a predetermined distance away from the mask in the optical axis direction, and the detection surface passes through the aperture of the mask. The coordinates of the point where the light flux reaches the detection surface are detected, and the direction and amount of deflection of the light emitted from the test lens are calculated by comparing the detected coordinates with the coordinates of the aperture on the mask. It is configured to know the optical characteristics of the detection lens. In this case, in order to obtain the necessary information, the mask must have at least three openings.

In the device according to this US patent, it is necessary to accurately detect the point-to-point correspondence between the apertures on the mask and the arrival points on the detection surface, and each aperture must be arranged in a planar manner so that the emitted light beam must be made to be a non-coplanar luminous flux. For this purpose, a two-dimensional plane must be scanned, and the apparatus as a whole inevitably becomes expensive. Furthermore, it is necessary to solve five-dimensional simultaneous equations using coordinate information of at least three points, and the calculation mechanism becomes complicated and expensive.

There is an apparatus described in US Pat. No. 4,180,325 that can solve the enormous information processing problem associated with such two-dimensional plane detection.

This device focuses light from a point light source near the lens to be tested, selects a ray of light that is parallel to the optical axis out of this beam using a rotating disk with a special pattern, and rotates the rotating disk at that time. This method measures the refractive characteristics of the lens to be tested from the corner. However, in this device, the pattern on the rotating disk is very complex, and detection of its rotational position is very important. There are major problems in terms of construction and production.

The present applicant has already proposed a new optical characteristic measuring device that solves the above-mentioned drawbacks of conventional devices and can perform detection and subsequent calculations relatively easily in Japanese Patent Application No. 55-56581 (Japanese Patent Publication No. 41017) and Japanese Patent Application No. 1971-71736 (see Japanese Patent Publication No. 1-17093). These inventions are based on the physics that even if a plane light beam formed by a linear aperture with an inclination angle θ and a length l is passed through an optical system, the linearity itself does not change even if the inclination angle θ and length l change. A collimator means for converting a light beam from a light source into a parallel light beam, and a mask means having at least two straight apertures intersecting at least one point are disposed behind the collimator lens, and the collimator A test optical system whose refractive properties are to be measured is arranged between the mask means, and a part of the light beam deflected by the refractive properties of the test optical system is transmitted to the mask means so that linearity is preserved. A planar sensor or a rotating It is detected by a linear sensor or two intersecting linear sensors, and the equation of the linear projection image is calculated from the coordinates of the detected two points, and the equation of the linear image is combined with the equation of the linear aperture on the mask means. The refractive properties of the optical system under test were measured from the changes.

An object of the present invention is to provide a different type of optical characteristic measuring device for an optical system that utilizes this principle.

The structural features of the present invention include a holding means for holding a test optical system, and a large number of light emitting units that project a light beam onto the test optical system, substantially or virtually within a two-dimensional plane; A linear pattern is formed by a light source that selectively emits light from one of the light emitting units, and at least two lines that select the luminous flux from this light source, and that has at least one substantially or virtually intersection point. and a mask means disposed between the light source and the test optical system, and an aperture that allows only the light rays selected by the mask means to pass through the test optical system and be made into parallel rays by the test optical system. A light collecting means for guiding the light to the means, a detecting means for detecting the light beam passing through the aperture means, and light emitting position information of the light emitting unit of the light source when the detecting means detects the light beam passing through the aperture means. The present invention provides an optical characteristic measuring device for an optical system, which includes a calculating means for calculating the refractive characteristics of the optical system to be tested.

A second feature of the structure of the present invention is that at least three linear patterns intersecting at least three points are formed on the mask means, and the light source is a linear light emitting element array in which a large number of light emitting units are linearly arranged. so that at least two lines virtually intersect,
The present invention is an optical characteristic measuring device for an optical system that requires less detection and calculation time and is more cost-effective.

The principle and embodiments of the present invention will be explained below with reference to the drawings.

First, in FIG. 1, the test lens T is arranged on a plane having orthogonal coordinates X-Y, and the first principal axis r ₁
and a second principal radial line r ₂ , whose optical center O is on the coordinate origin O ₀ of the orthogonal coordinates X-Y, and a first principal radial line r ₁
is inclined by θr ₁ with respect to the X axis.
Cartesian coordinates X ₀ with the origin placed on the measurement optical axis O _A at a position △d away from the test lens T in the optical axis direction
There is an X ₀ -Y ₀ plane having -Y ₀ , and the mask M is placed on this X ₀ -Y ₀ plane. A pattern consisting of two straight lines A and B that intersect with each other is formed on the mask M. The intersection of the straight lines A and B is defined as i, and the respective end points of the straight lines A and B are defined as j and k. The angle between straight line A and the _X0 axis is θ ₁ , and the angle between straight line B and the _X0 axis is _θ2 ,
Let the length of a line segment, ie, straight line A, be l _A , and the length of the line segment, ie, the length of straight line B, be l _B .

X ₀ −Y At a distance d along the optical axis from _{the 0} plane, orthogonal coordinates X′− with the origin on the optical axis
Assume a light source surface S having Y'. On the other hand, a condenser lens CL is placed behind the test lens T.
A pinhole PH is arranged at the focal point position, and a photodetector element D is further arranged behind it.

Now, when a light beam L is irradiated toward the mask M from an arbitrary position on the light source surface S, a certain light beam in the light beam L, for example, a light beam LB, passes through the straight line pattern of the mask B and enters the test lens T. Some of these can also pass through the condenser lens CL.
Then, a more limited light ray irradiated from the light source surface S, that is, a light emitting unit located at a limited position on the straight line A' and the straight line B' that intersect at the intersection angle θ' on the light source surface S, is emitted from the light emitting unit of the mask M. For example, only the light ray LB ₀ shown in the figure passes through the straight line patterns A and B. After passing through the test lens T, it becomes a ray parallel to the optical axis O _A and passes through the pinhole PH placed at the focal point of the condenser lens CL. Can be done. In other words, this is the linear pattern A, B on the mask M from the focal point or focal line F ₁ , F ₂ of the lens T to be tested.
This means that only rays that pass through the pinhole PH can pass through the pinhole PH.

From this principle, among the light emitting units on the light source surface S,
The emitted light passes through the pinhole PH and is a set of light emitting units that can be detected by the detection element D, that is, the straight line A',
If B' can be determined, the optical characteristics of the lens T to be tested, that is, the spherical refractive power, the cylindrical refractive power and its axial direction, or the prismatic refractive power can be determined.

Let i', j', k' be the light emitting units corresponding to intersection i, end points j, k on mask M, and let θ ₁ ', θ ₂ ' be the angles that straight lines A', B' make with the X' axis, respectively. , the length of line segment '', that is, the length of straight line A', is l _A ′, and the length of line segment ′′, that is, the length of straight line B' is l _B ′. Also, tanθ ₁ = m _A ,
Let tanθ ₂ = m _B , tan θ ₁ ′ = m _A ′, tan θ ₂ ′ = m _B ′, and the distances of the focal lines F ₁ and F ₂ from the mask M are Z ₁ and
The refractive power of the test lens T, which is _Z2 , is obtained as the following quadratic equation. _A・_B (m _A −m _B ) (d/z+1) ² − [ _A (m _A −m _B ′)+ _B (m _A ′+m _B )](d/z+1) +(m _A ′−m _B ′)=0 ……(1) However, Therefore, the two roots 1/z ₁ and 1/z ₂ of equation (1) are obtained, and from these, the vertex refractive power 1/fr ₁ of the test lens T,
1/fr ₂ is the distance between the test lens T and the mask M △
Using d, the following equation 1/fr ₁ = 1/z ₁ /△d/z ₁ -1 ...(2) 1/fr ₂ = 1/z ₂ /△d/z ₂ -1 ...(3 ) But I'll stop.

Further, the angles θr ₁ and θr ² of the cylinder axis are expressed by the following equations.

θr ₂ = θr ₁ +90° ...(4) θr ₁ = tan ^-1 [m _A・_A・(1+d/Z ₁ )−m _A ′/ _A (
1+d/z ₁ )−1] …(5) θr ₁ =θr ₂ +90° …(6) θr ₂ = tan ⁻¹ [m _A・_A (1+d/z ₂ )−m _A ′/ _A (1
+d/z ₂ )-1] ...(7) In the present invention, as a light source, as shown in FIG. 1, a large number of light emitting units, for example light emitting elements S ₁ , S ₂ , ... _A planar light emitting element array may be used in which the light emitting elements are arranged in two dimensions, that is, in a plane, and the light emitting elements are sequentially scanned to emit light, or the light emitting elements may be arranged in a straight line as shown in Figure 2. It is optically equivalent to arranging linear light emitting element arrays 10 and 11 formed of A structure in which the mask M' is placed in front of the mask M' may be used.

At this time, at least three straight line patterns A, B, and C that intersect at at least three intersection points i, j, and k are formed on the mask M', and the straight line A is at an angle θ with the X ₀ axis as in FIG. ₁ , and straight line B forms an angle θ ₂ with the Y ₀ axis.

Now, each of straight lines A, B, and C is part of mask M′.
Coordinate points on the axis that intersect the X ₀ axis and Y ₀ axis X ₁ , X ₂ , X ₃
and points X _{′ 1} , X _{′ 2} , X′ 3 and Y′ ₁ on the X′ axis and Y′ axis of the virtual light source surface S′ corresponding to Y ₁ , Y ₂ , and Y ₃ respectively
,
Considering Y′ ₂ and Y′ ₃ , as can be seen from the principle of FIG. ₁ , the light emitting units _{11 3 and} 11 2 on the linear light emitting element array ₁₁ corresponding to X′ ₁ , ，
Only _the light rays emitted by 11 ₁ pass through _{the axial points X 1 ,} It can be detected by the detection element D. Similarly _, light emitting units _{10 3 ,}
10 ₂ , 10 ₁ emit light and only the emitted light rays are masked
It passes through the axial points Y ₁ , Y ₂ , Y ₃ of M′ and becomes a parallel ray under the refraction action of the test lens T,
The light can enter the pinhole PH and be detected by the detection element D. Then, a straight line is drawn from _{the 2} points of X′ and _{the 2} points of Y′.
From A′, ₁ point of X′ and ₃ points of Y′ to ₁ point of Y′ of straight line B′
From the _point
j′, k′ can be determined, and then the length of line segment i′, j′ is l _A ′, and the line segment
The length l _B ′ of i′k′ can be determined. Also, from the equations of straight lines A' and B', the intersection angles θ ₁ ' and θ ₂ ' with the X' axis can be determined, and as in Figure 1, using equations (1) to (7), Thus, the refractive characteristics of the lens T to be tested can be determined.

This means that the condenser lens passing through the pinhole PH
This means that the refractive characteristics of the lens T to be tested can be measured by knowing the light emitting positions of the light emitting units on the linear light emitting element arrays 10 and 11 when the light beam from CL can be detected by the detection element D.

Further, the present invention provides a linear light emitting element array 10,
11 is not limited to the arrangement shown in FIG. 2, and as shown in FIG.
1 in parallel to the plane S at an interval ε, and the Y ₁ ' axis and
They may be placed on the Y ₂ ' axis. Similarly to the above-mentioned principle, when the detection element D detects the light beam from the condenser lens CL, the light emitting element array 10,1
1 luminescent units Y ₁₁ ′, Y ₁₂ ′, Y ₁₃ ′ and Y ₂₁ ′, Y ₂₂ ′,
The refractive characteristics of the lens T to be tested can be measured from the light emitting position of Y ₂₃ '. In other words, from Y′ ₁₂ and Y′ ₂₁ , the equation of straight line A′ is obtained, from Y′ ₁₃ and Y′ ₂₃ , the equation of straight line B′ is obtained from Y′ ₁₁ ,
The equation of the straight line C' is determined from _Y'22 , and the following is the procedure explained in Figures 1 and 2 above.
By determining l' _A , l' _B , m _A ', and m _B ', the refractive characteristics of the lens T to be tested can be determined using equations (1) to (7).

To calculate the prism refractive power, in a mask pattern consisting of three straight lines, Xi + Xj + Xk
=0, Yi+Yj+Yk=0, and find the light emission positions and coordinates on the light source surface corresponding to these intersections.

4 and 5 are virtual light source planes shown in FIG. 2.
Oblique coordinate system X′− intersecting at angle γ at S′
Considering Y', an example where linear light emitting element arrays 10 and 11 are virtually arranged on the X' axis and Y' axis via the relay lens 13 and half mirror 12 shown in FIG. It is a diagram showing the principle with arrays 10 and 11 omitted. In this case, as shown in FIG. 5, the equation of straight line A' is obtained from the points _x3 ' and _y2 ' on the X' and Y' axes corresponding to the light emitting unit positions of the light emitting element arrays 10 and 11. , from the x ₁ ′ and y ₁ ′ points, we can obtain the equation of the straight line B′, and from the x ₂ ′ and y ₃ ′ points, we can obtain the equation of the straight line C′. Here, the oblique coordinate system X′−Y′ on the virtual light source surface S′ and the coordinate system X′−Y _′ on the mask surface
When there is a relationship with Y ₀ as shown in Figure 6,
From the oblique coordinate system X'-Y' to the orthogonal coordinate system X-Y,
It can be converted using the following equation: Can calculate refractive properties.

Alternatively, in calculating the refractive power and astigmatism axis at the first principal meridian γ ₁ and the second principal meridian γ ₂ , if the test lens T is not inserted into the measurement optical path in advance, it passes through the straight line pattern of the mask M' and is detected. Detect the light emitting unit position of the light emitting element array in the oblique coordinate system X'-Y' that emits the light beam detected by element D, and
Calculate A', B', and C', set these values as initial values, and then insert the lens T to be measured into the measurement optical path.
By detecting and calculating in the same manner and taking the difference from the initial value, the refractive characteristics of the lens to be tested can be measured. In this way, the present invention is a device that is independent of the coordinate system, and the light-emitting element array is aligned with the X ₀ - Y ₀ coordinate system of the mask M', and is independent of the arbitrary coordinate system X' - Y'. Since it can be placed anywhere, it is an extremely advantageous feature in terms of device manufacturing and maintenance management.

In addition, in the present invention, the straight line patterns A, B, and C on the mask M' are masked as shown in FIG.
Virtual intersections, without requiring any real intersections on M′,
j. This means that the principle of the present invention is to calculate the equation of the straight line from the straight line patterns A, B, C on the mask surface and the light emitting position of the light emitting element array corresponding to each axis of the X'-Y' coordinate system on the light source surface. Motome,
The positions of the intersections i', j', k' are calculated based on this equation, so the intersections i, j, k
This is because there is no need for it to actually exist as a pattern. Moreover, the straight line patterns A, B, and C are the ninth
As shown in the figure, there is no need to form triangles on the mask M'; it is sufficient to virtually form triangles i, j, k by extending the straight line patterns A, B, C, respectively.

As for the light rays passing through such straight lines A, B, and C, only the light rays from the light emitting positions that form straight lines A', B', and C' on the light source surface are detected due to the refraction characteristics of the lens to be tested, similar to the principle described above. Detected by means D. That is,
As shown in Figure 8, the straight line patterns A, B, and C that make up the virtual triangles i, j, and k are X' ₁ , X' ₂ , X' ₃ , and The light emission positions are associated as Y' ₁ , Y' ₂ , and Y' ₃ , and the equations of straight lines A', B', and C' can be calculated using the same principle as in Figure 5, respectively.
Therefore, the virtual triangle i′j′k′ can be calculated from the equations of the calculated straight lines A′, B′, and C′. Then, from the virtual triangle ijk and the virtual triangle i′j′k′,
The refractive characteristics of the lens to be tested can be similarly calculated using the formula.

Calculation of prism refractive power is based on linear pattern A,
Calculate in advance _from the triangle _{ijk formed by} B _{and C} ,j′,
_{By calculating k ' and finding _} P _V can be calculated using the following formula.

P _H =A・cosθ _r1 d/z ₂ +B・sin
θ _r1 d/z ₂ + (X'-X)/3d×10 ² P _V = A・sinθ _r1 d/z ₁ −B・cos
θ _r1 d/z ₁ + (Y'-Y)/3d×10 ² ...(11) Here A=Xcosθ _r1 +Ysinθ _r1 B=Xsinθ _r1 −Ycosθ _r1 ...(12) This is as shown in Figure 6. This shows that it is possible to obtain P _H and P _V , respectively, at such coordinates by performing the conversion of equation (8) and calculating.

Hereinafter, more specific embodiments of the apparatus will be described by taking the above-mentioned principle of the present invention as an example.

FIG. 10 is an optical schematic diagram of a lens meter using the principle of FIG. 2. Linear light emitting element arrays 10 and 11 in which a large number of minute light emitting units, for example, light emitting diodes are arranged in a straight line, are arranged so that the planes containing them are orthogonal to each other and the light emitting element arrays themselves intersect within a virtual light source plane S. It is located. A prism 12 having a half mirror surface 12a serving as a light combining means is arranged between the light emitting element arrays 10 and 11. Behind this prism 12 is a relay lens 13 that reduces and projects images of the light emitting element arrays 10 and 11 onto a virtual light source surface S.
is located. A mask M is placed close to the rear of this virtual light source surface S. Behind the mask M, a test lens holding member 14 for installing the test lens T is arranged. A collimator lens 15 having its focal point at the position of the pinhole PH _{1 is arranged behind the test lens holding member 14 in order to make the parallel light beam from the test lens enter the pinhole PH 1 .} A reflecting mirror 16 is arranged behind the collimator lens 15. Behind the mask M, a light emitting element array 10,
A light-receiving element 18 is arranged to detect light rays passing through the pinhole PH 1 from the pinhole PH ₁ through the mask M. The light-receiving element 18 is preferably one with high sensitivity, such as an avalanche photodiode or a photomultiplier tube.

As shown in FIG. 11a, the mask M in FIG. 10 includes a first set of parallel straight line patterns 25, 26, a second set of parallel straight line group patterns 27, which intersect therewith,
A linear pattern consisting of 28 is formed.

Each of the straight line group patterns 27 and 28 consists of three relatively thin straight line patterns, and the straight line pattern 2
5 and 26 each consist of a relatively thick straight line. Further, at the intersections of the straight line patterns 25, 26, 27 and 28, the straight line group patterns 27 and 28 made of thin lines are cut at the intersections, as shown in FIG. 11b, so that each straight line pattern can be clearly identified. It is desirable that the pattern is configured so as not to directly overlap the straight line patterns 25 and 26 made of thick lines. In addition, the pattern on the mask M may be either transparent in the linear pattern part and opaque in the rest, or conversely, made opaque in the linear pattern part and transparent in the remaining part. I will explain it as if it were.

Furthermore, as can be seen from the principle of the present invention, the mask M and the virtual light source surface S need to be placed within the shortest focal length of the lens T to be measured.
For example, if the lens T to be tested is a (+)25 dayopter lens, it needs to be placed within 4 cm from the lens to be tested.

The light flux emitted from the light emitting element arrays 10 and 11 is
A linear pattern consisting of the transparent part of the mask M is selected, and the test lens T, the condensing lens 15, and the reflecting mirror 16 are
Head towards Pinhole PH ₁ . And for example,
As shown in Figure 12, X' ₁ , X' ₂ , X' ₃ , X' ₄ , Y' ₁ ,
Light emitting element arrays 10, 1 at positions Y′ ₂ , Y′ ₃ , Y′ ₄
Only when one light emitting unit emits light, the test lens T
The rays that passed through become parallel rays, and the condensing lens 1
6 passes through the pinhole PH ₁ and can be detected by the light receiving element 18, the position x' ₁ of this light emitting unit,
By determining x′ ₂ , x′ ₃ , x′ ₄ , and y′ ₁ , y′ ₂ , y′ ₃ , y′ ₄ and performing the necessary calculations, it is possible to obtain the refractive characteristics of the test lens T. can.

Next, FIG. 13 is a block diagram of an electric circuit showing the drive and detection means for the light emitting element array of this embodiment.

The switching circuit 30 is driven by the measurement start signal S ₁ or the switching signal S ₂ and is used to select which of the light emitting element arrays 10 and 11 to drive.
It is connected to the drive circuit 33 and the second drive circuit 34. The first drive circuit 33 includes a light emitting element array 1
0, the second drive circuit 34 has a light emitting element array 1
1 are connected to each other. Light emitting element array 1
0 and 11 are a large number of minute light emitting diodes 10 ₁ , 10 ₂ , 10 ₃ . . . each having a size of about 10 to 20 μ, for example.
...It is constructed by arranging 1000 to 2000 10 _o-1 and 10 _o in a linear manner. The light emitting element arrays 10 and 11 are connected from the clock circuit 31 to the drive circuit 3.
The light emitting diodes 10 ₁ , 10 ₂ , 10 ₃ are sequentially activated by the clock pulse 703 inputted to 3 and 34.
...10 _o-1 and 10 _o are scanned and emitted.

Light emitted from the light emitting element array 10 or 11 passes through the optical system shown in FIG. 10 and is detected by the light receiving element 18. The output of the light receiving element 18 is amplified by the amplifier 36 and sent to the sample hold circuit 3.
7 is given. The output of the sample and hold circuit 37 is applied to a comparator 38, where it is compared with a reference value from a reference setter 39 and binarized to produce an output 701. Clock circuit 3
1 inputs a measurement start signal S ₁ or a switching signal S ₂ and outputs a scan start pulse 702 to the first or second drive circuit 33 or 34 via the switching circuit 30, and outputs a scan start pulse 702 from the clock circuit 31.
3, the drive circuits 33 and 34 are driven. FIG. 14 shows various pulses, in which a shows the scan start pulse, b shows the clock pulse, c shows the output pulse of the sample and hold circuit 37, and d shows the output of the comparator 38.

In the arrangement shown in Fig. 13, when sequentially scanning and emitting light from the light emitting diodes of the light emitting element array, the light emitted by which light emitting diode passes through which linear pattern of the mask pattern, and after passing through the test lens, it becomes a parallel beam. It is necessary to know whether the light receiving element 18 has been able to detect the light using the condensing lens. To do this, it is sufficient to know which light emitting diode on the light emitting element array is located from the center of the time series output pulse from the light receiving element corresponding to the width of the linear pattern.

For example, the purpose is achieved by counting up to the midpoint between the rise and fall of the time-series output pulses of the light-receiving element using a clock pulse that is synchronized with the light emission scanning drive of the light-emitting diode. 13th
In the figure, output 701 from comparator 38 is applied to rising edge detector 40a and falling edge detector 40b, and scan start pulse 702 and clock pulse 7
03 is given to the counter 41. Counter 41 is first cleared by scan start pulse 702 and then counts clock pulses 703. Counter 41
The output of the counter 41 is input to a latch circuit 44, which latches the output of the counter 41 at the rising edge detection output 101. At this time, the latch circuit 44
The output represents the position of the light emitting diode on the light emitting element array, which corresponds, for example, to the leading edge of pulse _L1 in FIG.

The gate circuit 42 has an output pulse 701 of “1”.
During this period, a clock pulse is supplied to the counter 43, which has been cleared in advance by the scan start pulse 702. The output of the gate circuit 42 is shown in Fig. 15g.
Indicated by Therefore, the output of the counter 43 indicates the number corresponding to the width of the linear pattern on the mask M of the plurality of light emitting diodes that emitted the light beam detected by the light receiving element 18. If the counter 43 is a binary counter, the least significant bit of the output of the counter 43 is discarded and the value shifted by 1 bit toward the lower bit and the output of the latch circuit 44 are input to the adder 47. Accordingly, the position of the light emitting diode located at the center of a certain number of light emitting diode groups corresponding to the width of the straight line pattern from which the light beam detected by the light receiving element 18 is emitted can be determined.

Reference numeral 46 denotes a delay circuit, which functions to delay the output 102 of the falling edge detector 40b by Δt. This state is shown as f in FIG. 15. The output of delay circuit 46 is provided to counter decoder 48. This counter decoder 48
is for sequentially latching the output of the adder 47 up to the latches 191, 192, . . . , 198. Incidentally, the output of the delay circuit 46 is also used to reset the counter 43.

With the circuit described above, when one scan of the light emitting element array 10 is completed, the latch 191 receives light rays from a certain group of light emitting diodes on the light emitting element array corresponding to the pattern width of any of the linear patterns on the mask M. The first one is the light receiving element 18.
The position of the light emitting diode located at the center of the light emitting diode group detected by the sensor, in other words, the position of the light emitting diode located at the center of the light emitting diode group detected by The position of the light emitting diode located at the center of the first light emitting diode group among a plurality of light emitting diode group rows that can participate in the refraction measurement of the detection lens is maintained. Similarly, latch 192 holds the position of the light emitting diode located at the center of the second group of light emitting diodes in the chronological arrangement of the groups of light emitting diodes. For example, when the light emitting element array 10 emits light and scans along the Y' axis in FIG. 16, the light receiving element 18 outputs a detection output signal corresponding to the eight straight line patterns on the mask M as shown in FIG. 14c. . That is, by scanning the light emission of the light emitting element array, detection output signals corresponding to the eight light emitting diode groups that were able to participate in the measurement of the refractive characteristics of the lens to be tested were obtained. Therefore, eight latch circuits 191 to 198 are required.

In FIG. 13, reference numeral 45 is a digital comparator, which compares the output of the reference value generator 50 and the output of the counter 43 and latches the comparison output 191 to 198.
supply to. This is to determine whether the position information of the light emitting diode corresponds to a thick linear pattern or a thin linear pattern among the linear patterns on the mask. Therefore, the output of each latch is sent to the determination circuit 51 along with the positional information of the light emitting diode at the center of each light emitting diode group and information as to whether it corresponds to a thick straight line pattern or a thin straight line pattern. sent to. The reason why the mask pattern is composed of one thick straight line pattern and three thin straight lines is because, as already mentioned, the light emitted from which light emitting diode on the light emitting element array passes through which straight line pattern on the mask. This is to easily determine whether the light has been detected by the light receiving element. This will be explained in detail using FIG. 17.

FIG. 17 is an enlarged view of the intersection of the straight lines. The code 25 indicates a thick straight line pattern, and the code 27 indicates a thick straight line pattern.
are three straight lines 27-1 and 27-2 that are thin enough to be easily distinguished from the thick straight line pattern 25.
Linear pattern groups consisting of 7-2 and 27-3 are shown, respectively. Now, if the light emitting element array performs light emitting scanning to scan a pattern at position a or e, the center of the thick straight line 25 is determined to be the position of the straight line, and the central straight line 27 of the three straight lines The center of -2 can be detected as the position of the straight line group 27. When the pattern is scanned at position b, the light receiving element 19 obtains a detection output corresponding to the light emission of the light emitting diodes corresponding to the straight lines 25, 27-2, and 27-3. Similarly, at position c, straight lines 27-1, 25, 2
7-3, at position d, straight lines 27-1, 27-
Detection outputs corresponding to numbers 2 and 25 are obtained in this order. Therefore, when the light emitting element array scans only two thin linear patterns, the position of the center light emitting diode corresponding to each straight line and group of straight lines can be detected and determined by performing the following judgment. can.

(1) The position of the straight line 25 is always the center position of the light emitting diode group corresponding to the thick straight line.

(2) When outputs corresponding to three thin straight lines are output as output signals, the position of the center of the straight line is calculated from the output corresponding to the intermediate straight line, and is taken as the position of the straight line group 27.

(3) When only two lines of output are output corresponding to a thin straight line, (a) If the order is thick, thin, thin, then the center of the first thin line, (b) Thin, thick, thin. (c) If the order is thin, thin, thick, then the center position of the second thin straight line is the position of straight line group 27. .

The above determination is performed by the determination circuit 51 shown in FIG. Although the determination circuit 51 can be constructed from random logic, a preferred configuration is to use a microprocessor to perform the subsequent data processing including the determination circuit. Making the above determination using a microprocessor would be easy for those in related industries. Although the above explanation concerns the intersection between the straight line 25 and the group of straight lines 27, it goes without saying that other intersections can also be determined using the same method.

FIG. 18 shows an example of the overall configuration of a lens meter based on the measurement principles and embodiments described above.

In FIG. 18, reference numeral 1000 is composed of the optical system shown in FIG. 10 and the circuit shown in FIG. 13, and outputs a detection output to the microprocessor 52. In FIG. The microprocessor 52 is composed of a data memory section 53, a program memory section 54, a display interface section 55, a printer interface section 57, and a group of output registers 291 to 295 that output the results of operations performed by the microprocessor. Also, for those in the field of handling microprocessors, such a configuration is easy.

When the positions of y ₁ ′, y ₂ ′, y ₃ ′, and y ₄ ′ are obtained as shown in FIG. 16 by the first light emitting scan of the light emitting element array 10, the switching signal S ₂ is inputted and the switching circuit is activated. At 30, the second drive circuit is activated to switch to light emission scanning of the light emitting element array 11. As a result, the positions of x' ₁ , x' ₂ , x' ₃ , and x' ₄ in FIG. 16 can be determined.

Based on the positional information of x' ₁ to x' ₄ and y' ₁ to y' ₄ , the optical characteristics of the lens to be tested are calculated by the following arithmetic processing.

(i) Find the equations of the straight lines 25 and 26 and the straight line groups 27 and 28, and let the slope of the straight line group 27 be m _A ', and the slope of the straight line 26 be m' _B.

(ii) Find the length of the group of straight lines 27 sandwiched between the straight lines 25 and 26 and set it as the length l' _A .

(iii) Find the length of the straight line 26 sandwiched between the straight lines 27 and 28, and let that length be l' _B.

(iv) In calculating the prism refractive power, the coordinates of i, j, k, and l in Figure 16 are expressed as (x' _i ,
y′ _i ), (x′ _j , y′ _j ), (x′ _k , y′ _k ), (x′ _l , y
′ _l ), horizontal prism refractive power P _H (X-axis direction)
and vertical prism refractive power P _V (Y-axis direction)
extends equations (1) and (10) to the case of four points, and sets X=x _i +x _j +x _k +x _l Y=y _i +y _j +y _k +y _l ……(9)′, and Find X′=x′ _i +x′ _j +x′ _k +x′ _l Y′=y′ _i +y′ _j +y′ _k +y′ _l ……(10)′ from the intersection on the light source plane, where By forming a straight line pattern on the mask in advance so that = 0,
Expression (11) Calculate as. Here, d is the distance between the mask M and the virtual light source surface S.

(v) Calculations based on the equations (1) to (8) described above are performed by a microprocessor to obtain the required optical characteristics.

The results obtained in this manner are output as spherical power, cylinder power, cylinder axis angle, and prism refractive power to the display 56, printer 58, and output registers 291 to 295 shown in FIG. 18. Note that the display 56 is equipped with a device capable of two-dimensional display (for example,
By using a CRT display device, etc.), the prism refractive power and cylinder axis angle can be displayed as a two-dimensional pattern. By doing this, there is an advantage that alignment between the lens to be examined and the lens meter can be performed easily and quickly.

FIG. 19 is a diagram showing a second embodiment of the present invention. This embodiment uses only one linear light emitting element array instead of the two linear light emitting element arrays used in the first embodiment described above. This is an example of a lens meter that can perform measurements. In the drawings, the same or equivalent components as in the first embodiment are given the same reference numerals, and their explanations will be omitted. The light emitted from the light emitting element array 10 is divided into two by a half mirror 303, and one half is split into two by a mirror 306, a relay lens 301, and a half mirror 30.
4. Form a first optical path toward the mask M, the test lens T, the collimator lens 15, the mirror 16, and the pinhole PH. The other side passes through a mirror 305, a relay lens 300, a half mirror 304, and a mask M to form a second optical path similar to the first optical path. Shutter means 308 and 309 are used to switch between the first optical path and the second optical path. An image rotator 307 is arranged between the half mirror 303 and the mirror 305 on the second optical path. This image rotator 307 is connected to the relay lens 3 of the first optical path.
The conjugate image of the light emitting element array 10 formed by the relay lens 300 of the second optical path intersects with the conjugate image of the light emitting element array 10 formed by the relay lens 300 of the second optical path. The other components of this embodiment, ie, the electric circuit for driving the light emitting element array and the detection means, and the calculation configuration for optical characteristics are the same as in the first embodiment. However, the opening and closing states of the shutter means 308 and 309 are reversed by the switching signal _S2 , and the light emitting element array is scanned for light emission again.
The only difference is that only one light receiving element is required.

FIG. 20 shows a third embodiment of the arrangement of the light emitting element array of the present invention. Note that the optical system is the same as in the first embodiment. Light emitting element array 10
The pulse motor 350 rotates the light emitting element array 10 by a predetermined angle after one light emission scan of the light emitting element array is completed. The amount of rotation of the pulse motor 350 is determined by the pulse from the pulse transmitter 351 by a predetermined angle. The rotation angle from this pulse generator is input to the calculator 352. The detection data already explained in the first embodiment is input to this calculator 352, combined with the angle information, and outputted to the microprocessor 52 as coordinate value information. Furthermore, instead of rotating the light emitting element array 10, a known image rotator may be used to rotate the light emitted from the light emitting element array.

In FIG. 21, instead of arranging two light emitting element arrays in parallel as in the embodiment shown in FIG. This shows an embodiment in which light from the light emitting element array 10 is shifted in parallel using an image shifting means.

Note that in the present invention, the light source is not limited to one in which light emitting diodes are arranged in a planar or linear manner, and as can be seen from the above-mentioned principle and numerous embodiments, essentially
Any light source, whether virtual or virtual, may be used as long as it is placed on a two-dimensional plane. As another embodiment of the light source, as shown in FIG. 22, a light beam from a laser oscillator 400 is driven by a driving circuit 401. It is also possible to use an assembly 404 of a large number of fine light beam diffusing rods 403 which are scanned by a known scanning means 402 and a condensing lens is attached to the back surface of the scanned light beams.

In addition, the mask M forms an aperture-type linear pattern that selectively transmits the light flux, but the mask M
It goes without saying that the present invention can also be applied to a reflective linear pattern that selectively reflects the light flux.

[Brief explanation of drawings]

1 to 3 are diagrams illustrating the principle of the present invention and examples of the basic arrangement of light sources, and FIGS.
The figure is a diagram showing the principle of the present invention in an oblique coordinate system, FIG. 6 is a diagram showing the relationship between an oblique coordinate system and a rectangular coordinate system, and FIG. 7 is an example of a virtual intersection of straight line patterns. 9 is a perspective view showing another example of virtual intersection, FIG. 8 is a front view thereof, and FIG. 10 is a schematic diagram of an optical system showing an embodiment of the present invention, and FIG. 11a , b are diagrams showing examples of mask patterns and their intersections. FIG. 12 is a diagram showing the relationship between the oblique coordinate system on the virtual light source plane and the straight line corresponding to the mask pattern. FIG. 13 is a block diagram showing the electric circuit of the driving and detection means of the first embodiment, and FIG. 14 shows the signal obtained from the detection output from the light receiving element.
Figure 5 shows the pulses of the signal processing process, Figure 16 is a diagram showing the relationship between the scanning of the light emitting element array and the straight line corresponding to the mask pattern, Figure 17 is a schematic diagram showing the scanning of the intersection, and Figure 18 is a block diagram showing the electric circuit following FIG. 13 of the present invention, FIG. 19 is a diagram showing the optical system of the second embodiment of the present invention, and FIG. 20 is a diagram showing the third embodiment of the present invention. FIG. 21 is a schematic diagram of a mold with some parts omitted; FIG. 21 is a schematic diagram showing a fourth embodiment of the present invention with a mold partially omitted; FIG. 22 is a diagram showing another embodiment of the light source of the present invention. . 10, 11... linear light emitting element array, 13...
...Relay lens, 14...Test lens holding means,
15...Condensing lens, PH, PH ₁ ...Pinhole,
18, 19... Light receiving element.

Claims (1)

[Scope of Claims] 1. Holding means for holding a test optical system, and a large number of light emitting units that project light beams onto the test optical system, substantially or virtually in a two-dimensional plane, A light source that selectively emits light from one light emitting unit; and at least two lines that select a luminous flux from the light source, forming a linear pattern having at least one substantially or virtually intersection point; and a mask means disposed between the light source and the test optical system, and only the light beams selected by the mask means, passed through the test optical system, and made into parallel rays by the test optical system. a light condensing means for guiding the light beam to the aperture means; a detection means for detecting the light beam that has passed through the aperture means; and a light emission unit of the light source when the detection means detects the light beam that has passed through the aperture means. comprising a calculation means for calculating optical characteristics of the optical system to be tested from position information;
Optical property measuring device for optical systems. 2. The optical characteristic measuring device for an optical system according to claim 1, wherein the linear pattern is an aperture pattern that selectively transmits the light beam. 3. The optical characteristic measuring device for an optical system according to claim 1, wherein the mask means is formed with a linear pattern having at least three straight lines and at least three intersections. 4. The optical characteristic measuring device for an optical system according to claim 3, wherein the mask means is formed with a straight line pattern consisting of two sets of parallel straight lines that intersect with each other. 5. Claim No. 5, characterized in that the number of straight line patterns constituting one set of parallel straight line groups among the two sets of parallel straight line groups is different from the number of straight line patterns forming the other set of parallel straight line groups. 4. An optical characteristic measuring device for an optical system according to item 4. 6. Optical characteristic measurement of an optical system according to claim 1, wherein the mask means is formed of at least three straight lines, forming a straight line pattern having at least three virtual intersections. Device. 7. Claims 1 to 6, wherein the light source is a planar light emitting element array that has a large number of light emitting unit elements in a two-dimensional plane and sequentially scans the light emitting unit elements. An optical characteristic measuring device for an optical system according to any one of the above. 8. The light source is a linear light emitting element array that is formed by arranging a large number of light emitting unit elements in a linear manner, sequentially scanning the light emitting unit elements, and rotating about the optical axis of the device. An optical characteristic measuring device for an optical system according to any one of claims 1 to 6. 9. The light source is a linear light emitting element array in which a large number of light emitting unit elements are linearly arranged, the light emitting unit elements are sequentially emitted and scanned, and the light emitting element array is fixedly arranged. The optical system according to any one of claims 1 to 6, characterized in that a light flux rotation means for rotating the light flux from the linear light emitting element array is arranged between the mask means and the light emitting element array. Optical property measuring device. 10. Claims characterized in that the light source is formed by arranging at least two linear light emitting element arrays in parallel, in which a large number of light emitting unit elements are arranged in a straight line, and the light emitting unit elements are sequentially emitted and scanned. An optical characteristic measuring device for an optical system according to any one of items 3 to 6. 11 The light source is a linear light emitting element array which is formed by arranging a large number of light emitting unit elements in a linear manner, sequentially scans the light emitting unit elements, and is fixedly arranged; The optical system according to any one of claims 3 to 6, further comprising a light flux shifting means for shifting the light flux from the linear light emitting element array between the optical system and the mask means. Optical property measuring device. 12. The light source is characterized in that a large number of light emitting unit elements are arranged in a straight line, and at least two linear light emitting element arrays that sequentially scan the light emitting unit elements are substantially or virtually crossed. An apparatus for measuring optical characteristics of an optical system according to any one of claims 3 to 6. 13 Two linear light emitting element arrays are imaginary in a virtual plane using an optical means that transmits light from one linear light emitting element array of the light source and reflects light from another linear light emitting element array. 13. The apparatus for measuring optical characteristics of an optical system according to claim 12, wherein the optical characteristics are made to intersect with each other. 14. Claims 1 to 13 are characterized in that the light source has its image relayed to the vicinity of the mask means via a relay optical means.
An optical characteristic measuring device for the optical system according to any one of the items. 15 The calculation means calculates at least two equations of straight lines connecting the light emission units from the position information of the light emission units of the light source when detected by the detection means, and from the equations of the straight lines, the straight line is calculated. a second calculation unit that calculates the coordinates of both or one of the end points and the intersection point; a first calculation unit that calculates the inclination angle of the equation of the straight line from the calculation result from the first calculation unit; and the second calculation unit. a second calculation unit that calculates the length of the straight line from the coordinate values from the second calculation unit; and a third calculation unit that calculates the optical characteristics of the test lens from the calculation results of the first and second calculation units. An optical property measuring device according to any one of claims 1 to 14, characterized in that it has the following. 16. The optical property measuring device according to any one of claims 7 to 15, wherein the light emitting unit element is a light emitting diode. 17. Claims 7 to 15, characterized in that the light emitting unit element is a large number of diffusing optical unit elements that diffuse light from a laser light source.
The optical property measuring device according to any one of the items.