JPH09243513A - Lens evaluating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to discriminate the non-defect/defect of a lens system to be detected including an aspheric lens without using a special purpose null lens and to discriminate the non-defect/defect of a lens system of the different type by one lens evaluating apparatus. SOLUTION: The luminous flux output from a light source 101 is once transmitted to a reference lens system 102 having approximately equal optical performance to that of the same constitution and designing value of a lens system 105 to be detected, the sign of the spatial phase distribution is inverted by a reflecting member 104, reflected, the luminous flux is separated to two by a luminous flux dividing member 103, and they are transmitted through the systems 105 and 102. If the characteristics of the system 105 are different from those of the system 102, the characteristics of the flux transmitted through the both are different, and hence the non-defect/defect of the lens-to-detected route can be easily discriminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens group formed by assembling a single lens or a plurality of lenses as a component constituting an optical system (finished product) such as a zoom lens (hereinafter, both are collectively referred to as a lens system). ) Is compared with a reference lens system having the same configuration as that of the lens system to be inspected (lens system to be inspected) and having optical characteristics equal to or very close to design values, thereby determining the quality of the lens system to be inspected. The present invention relates to a lens evaluation device.

[0002]

2. Description of the Related Art Generally, in an optical system such as a zoom lens, the individual characteristics of each lens system forming the optical system have a great influence on the characteristics of the entire optical system. One of a lens system as a component of an optical system or a lens system 1
If even one lens has a defect in the shape or the glass material (lens medium), the characteristics of the entire optical system may deteriorate, and the expected characteristics may not be obtained. Therefore, conventionally, regarding each lens system that constitutes an optical system, the characteristics of each lens system are measured and evaluated in advance before the entire optical system is configured, and each characteristic has a value sufficiently close to the design value. The optical system is configured by using the one that has been confirmed to be within the allowable range.

In recent years, not only spherical lenses but also aspherical lenses have been used as lenses constituting an optical system or a lens system. The characteristics of the spherical lens can be evaluated relatively easily by a focal length measurement method and a shape measurement method using an interferometer. However, the characteristics of the aspherical lens are not determined only by the focal length, and it is difficult to obtain sufficiently high measurement accuracy in the shape by a simple method using an interferometer. Therefore, when the lens system to be inspected includes an aspherical lens, a null lens system is prepared in advance, and when the lens system to be inspected is as designed, from the light flux transmitted through the null lens system and the lens system to be inspected, ideally, A method is used in which a device that can obtain a diffraction-limited point image is configured and the quality of the lens system to be inspected is determined based on the degree of deterioration of the image obtained through the lens system to be inspected.

Regarding the above-mentioned conventional lens evaluation method, FIG.
This will be briefly described with reference to FIG. In FIG. 18, reference numeral 1801 is a light source, 1802 is a null lens system, 1803 is a lens system to be evaluated, and 1804 is a detector. Light source 18
A laser is generally used as 01. Light source 18
The light flux output from 01 enters the null lens system 1802. The null lens system 1802 processes the wavefront of the incident light flux so that a diffraction-limited point image can be obtained at the imaging position of the lens system to be inspected when the lens system to be inspected has characteristics as designed. The light flux that has passed through the null lens system 1802 enters the lens system 1803 to be inspected, and the lens system 18 to be inspected
The light flux emitted from 03 is imaged on the detector 1804. The detector 1804 measures the state of the image obtained by the lens system 1803 to be inspected, and discriminates a good product and a defective product from the characteristics of the lens system 1803 to be inspected based on the measurement result.

[0005]

However, in the above-mentioned conventional lens evaluation method, when the lens system to be inspected includes an aspherical lens, a dedicated null lens system must be prepared for each lens system to be inspected. The cost required for lens evaluation for designing, manufacturing, and inspecting the null lens system is increased, and it takes time to manufacture the null lens system. Further, since the null lens system is not compatible, when evaluating a plurality of types of lens systems to be inspected, there is a problem that a lens evaluation device must be prepared for each of the lens systems to be inspected.

The present invention has been made in order to solve the problems of the above-mentioned conventional example, and does not require a dedicated null lens system or the like adapted to the lens system to be inspected, and a plurality of different types can be obtained by one device. It is an object of the present invention to provide a lens evaluation device that can evaluate a lens to be inspected, has high versatility, and can reduce inspection cost.

[0007]

In order to achieve the above object, a lens evaluation apparatus of the present invention comprises a reference lens system having substantially the same structure as the lens system to be tested and a predetermined optical performance, and the reference lens system. A light source that outputs a luminous flux to
The light output from the light source, the reflection means for inverting the sign of the spatial phase distribution of the light flux transmitted through the reference lens system and reflecting the light flux, and splitting the light flux reflected by the reflection means,
And a light beam splitting means for allowing one of the split light beams to enter the lens system to be inspected.

In the above structure, it is preferable that a parallel light beam conversion means is provided between the light source and the reference lens system to convert the light beam output from the light source into a parallel light beam and make it enter the reference lens system.

Alternatively, it is preferable to provide a point light source conversion means between the light source and the reference lens system to convert the light flux output from the light source into a point light source and make it enter the reference lens system.

In each of the above structures, it is preferable that the light beam splitting means is provided between the reference lens system and the reflecting means, and the other split light beam is made incident on the reference lens system.

Further, in each of the above-mentioned constitutions, there is a compensating means for making the optical path from the light source to the reflecting means and the optical path from the reflecting means to the lens system to be inspected through the luminous flux splitting means in aberrations. It is preferable.

Further, in each of the above-mentioned configurations, the respective light fluxes reflected by the reflecting means, split by the light flux splitting means, and transmitted through the reference lens system and the lens system under test are reflected from the reflecting means. It is preferable to provide an interfering means for interfering the respective light fluxes under the condition that the optical path lengths are substantially equal.

Further, it is preferable to include a detection means for detecting the interference fringes obtained by the interference means. Also,
The interference means is provided on the opposite side of the light beam splitting means with respect to the reference lens system, and divides the light flux transmitted through the reference lens system to the light source side,
A position which is provided on the opposite side of the light beam splitting means with respect to the lens system to be inspected, is divided by the second light beam splitting means, and travels in a different direction from the light source, and the optical path length from the reflecting means is equal. Second reflection means for reflecting the light flux that has passed through the lens system to be intersected, and light flux integration means provided at a position where the light flux intersects and integrating the respective light fluxes in the same direction. Is preferred.

Alternatively, in each of the above-mentioned constitutions, it is preferable to include a detection means for detecting at least one of the wavefront and the spatial intensity distribution state of the light beam split by the light beam splitting means and transmitted through the lens system to be tested. .

Further, another lens evaluation apparatus of the present invention comprises a reference lens system having substantially the same structure as the lens system to be inspected and a predetermined optical performance, and a light source for outputting a light beam to the reference lens system. A reflecting means provided between the reference lens system and the reflecting means, the reflecting means outputting light from the light source and transmitting the reference lens system by inverting the sign of the spatial phase distribution of the light flux and reflecting the light; First light beam splitting means for splitting the light flux reflected by the means, and causing one of the split light fluxes to enter the lens system to be tested and the other light flux to enter the reference lens system; the light source and the reference. A light which is provided between the lens system and transmits the light beam output from the light source to enter the reference lens system, is reflected by the reflecting means, and is transmitted through the reference lens system to the light source side. A second light beam splitting means for splitting the light into two, and a second light flux splitting means for detecting at least one of a wavefront and a spatial intensity distribution state of the light flux split by the first light flux splitting means and transmitted through the lens system under test. 1 detection means,
Second detecting means for detecting the wavefront and spatial intensity distribution of one of the light fluxes transmitted through the reference lens system to the light source side and split by the second light flux splitting means, and from the light source to the reflecting means. And the first compensating means set so that the optical path from the reflecting means to the lens system under test through the first light beam splitting means becomes equal in aberration, and from the light source, An optical path that reaches the reflecting means via the second light beam splitting means, the reference lens system, the first light beam splitting means, and the first light beam splitting means from the reflecting means, the lens system to be tested, the A second compensating means which is set so that the optical paths reaching the first detecting means via the first compensating means are aberrationally equivalent.

In the above structure, it is preferable that a parallel light beam conversion means is provided between the light source and the reference lens system to convert the light beam output from the light source into a parallel light beam and make it enter the reference lens system.

Alternatively, it is preferable to provide point light source conversion means between the light source and the reference lens system for converting the light flux output from the light source into a point light source and making the light source enter the reference lens system.

In each of the above-mentioned configurations, it is preferable to provide a light amount adjusting means for adjusting the intensity of a light beam incident on the reference lens system from the light source between the light source and the reference lens system.

Alternatively, it is preferable to provide a light amount adjusting means between the reflecting means and any one of the light beam splitting means. Alternatively, it is preferable to provide a light amount adjusting means immediately before any of the detecting means.

Further, in each of the above-mentioned constitutions, a positive beam including at least one lens is provided between the light beam splitting means located on the reflection means side of the reference lens system of the light beam splitting means and the reflecting means. It is preferable to provide a lens system having a refractive power of.

Alternatively, it has a negative refracting power including at least one lens between the beam splitting means and the reflecting means, which are located closer to the reflecting means than the reference lens system, among the beam splitting means. It is preferable to provide a lens system.

In each of the above structures, it is preferable that the reflecting means is any one selected from a phase conjugate element and a quasi-phase conjugate element. Further, it is preferable that the reflecting means is a nonlinear optical crystal.

Further, it is preferable that any one of the light beam splitting means is selected from a half mirror that does not depend on polarization and a polarization beam splitter that has polarization dependency.

The compensating means is preferably a glass plate having a thickness equivalent to the optical path length.

Further, in each of the above constitutions, it is preferable that the light quantity adjusting means is an ND filter. Further, it is preferable that the light amount adjusting means is selected from a plurality of ND filters which are provided exchangeably and have different densities and an ND filter in which the densities are spatially changed stepwise or continuously.

Further, at least one of the light source, the reference lens system, the reflecting means, the luminous flux splitting means, the lens system to be inspected, and the detecting means has a function of adjusting its position and posture. It is preferable.

The light source is preferably a laser. Further, it is preferable to provide return light removing means immediately before the light source.

Further, in each of the above-mentioned configurations, the output from each of the detecting means is fetched, and the deviation amount of the characteristic of the light flux transmitted through the reference lens system and the lens system under test is compared with a value inputted in advance. It is preferable to have a function of determining the quality of the lens system to be inspected.

Alternatively, the detection result of the interference fringes obtained by interfering the light flux reflected by the reflecting means and transmitted through the reference lens system with the light flux reflected by the reflecting means and transmitted through the lens system under test, It is preferable to have a function of comparing the input data of the allowable range of the interference fringes and determining the quality of the lens system to be inspected.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment, which is the basic form of the lens evaluation apparatus of the present invention, will be described with reference to FIG. The first embodiment of the lens evaluation apparatus of the present invention shown in FIG.
01, the reference lens system 102 on which the light beam from the light source 101 is incident, and the reflection member 10 which reflects the light beam transmitted through the reference lens system 102 by reversing the sign of the spatial phase distribution.
4 and a light beam splitting member 103 that splits the light beam reflected by the reflecting member 104 into two. The light beam splitting member 103 is provided between the reference lens system 102 and the reflecting member 104. The test lens system 105 includes the light beam splitting member 1
Inner reference lens system 10 of two light beams divided by 03
It is arranged at a position where a light beam traveling in a direction different from 2 is incident. The reference lens system 102 is the lens system 105 to be tested.
Is a lens group that has substantially the same configuration as the above and is configured by a single lens or a plurality of lenses.

As the light source 101, it is generally preferable to use a light source having a long coherence length such as a laser.
The light beam splitting member 103 has a polarization-independent half mirror in which a semi-transparent mirror or the like is vapor-deposited on the surface of a thin plate made of an optical material such as glass or transparent resin, a beam splitter using a prism, or the like. A polarization beam splitter or the like can be used. Further, as the reflecting member 104 that reflects the sign of the spatial phase distribution of the incident light flux by reversing it, an inorganic material such as a nonlinear optical crystal (eg, BaTiO ₃ , SBN, BSO, etc.) generally called a phase conjugate element is used. A material-based material or an organic material-based material using a hologram is used. Further, a device called a quasi-phase conjugating element (quasi-phase conjugating mirror) in which prism-shaped or spherical micro-reflectors are arranged, although slightly less precise, may be used.

The light beam output from the light source 101 passes through the reference lens system 102 and the light beam splitting member 103, and is reflected by the reflecting member 104 with the sign of the phase distribution reversed.
The light flux reflected by the reflecting member 104 is split by the light flux splitting member 103 into a light flux traveling toward the reference lens system 102 side and a light flux traveling toward the test lens system 105 side. The light beam traveling toward the reference lens system 102 side returns to the light source 101 after passing through the reference lens system 102. On the other hand, the lens system 105 to be tested
The light flux traveling to the side passes through the lens system 105 to be inspected, and the light source 1
01 image is formed. Here, when the lens system 105 to be inspected has a characteristic equal to or very close to the characteristic of the reference lens system 102, the intensity distribution and wavefront state of the image of the light source 101 are equal to or almost equal to the characteristic at the time of emission of the light source 101. Will be equal. By providing screens at the focal positions of the reference lens system 102 and the lens system 105 to be inspected, the images of the light source 101 are observed. By comparing the image of the light source 101 formed on the reference lens system 102 side with the image of the light source 101 formed on the test lens system 105 side, the test lens system 1
It is possible to evaluate the characteristics of No. 05 and judge the quality.

(Second Embodiment) Next, a second embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation apparatus of the present invention shown in FIG. 2 is obtained by converting the light flux from the light source into a parallel light flux in the first embodiment, and converts the light flux from the light source 201 into a parallel light flux, for example, collimate. Parallel light flux conversion unit 202 such as a lens
And the reference lens system 203 on which the collimated light beam is incident.
And a reflection member 205 for reflecting the light beam transmitted through the reference lens system 203 by reversing the sign of the spatial phase distribution, and a light beam dividing member 204 for dividing the light beam reflected by the reflection member 205 into two. .

The light beam splitting member 204 is a reference lens system 203.
And the reflecting member 205. The lens system 206 to be inspected is arranged at a position where a light flux of the two light fluxes split by the light flux splitting member 204 and traveling in a direction different from the reference lens system 203 is incident. The reference lens system 2
03 has substantially the same configuration as the lens system 206 to be tested,
It is a lens group composed of a single lens or a plurality of lenses.

The light flux output from the light source 201 is converted into a parallel light flux by the parallel light flux converter 202, passes through the reference lens system 203 and the light flux splitting member 204, and is reflected by the reflecting member 2.
At 05, the sign of the phase distribution is reversed and reflected. The light beam reflected by the reflecting member 205 is reflected by the light beam dividing member 204.
Which is incident on the reference lens system 203 side and is divided into a light beam traveling to the test lens system side 206 side. The light flux traveling to the reference lens system 203 side is equal to the wavefront of the light flux emitted from the parallel light flux conversion unit 202.

The subject lens system 206 is the reference lens system 203.
If it has a characteristic equal to or very close to the characteristic of,
It becomes equal to the wavefront of the light beam reflected from the reference numeral 5 and transmitted through the reference lens system 203. If the characteristic of the lens system 206 to be tested is different from that of the reference lens system 203, the reflecting member 205
The light beam reflected from the light beam and transmitted through the reference lens system 203 is deviated from the parallel light beam. By detecting and comparing the wavefront and intensity distribution of the light flux on the side of the reference lens system 203 and the wavefront and intensity distribution of the light flux on the side of the lens system 206 to be tested, it is possible to determine the quality of the lens system 206 to be tested.

(Third Embodiment) Next, a third embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation apparatus of the present invention shown in FIG. 3 is the one in which the light flux from the light source is made into a point light source in the first embodiment, and the light source 3
01, a point light source conversion unit 302 for converting the light flux from the light source 301 into a point light source, a reference lens system 303 on which the light flux converted into the point light source is incident, and a spatial phase of the light flux transmitted through the reference lens system 303. A reflection member 305 that reverses the sign of the distribution and reflects the light, and a light beam dividing member 304 that divides the light beam reflected by the reflection member 305 into two.

The light beam splitting member 304 is a reference lens system 303.
And the reflecting member 305. The test lens system 306 is arranged at a position where a light flux of the two light fluxes split by the light flux splitting member 304 and traveling in a direction different from the reference lens system 303 is incident. The reference lens system 3
03 has substantially the same configuration as the lens system 306 to be tested,
It is a lens group composed of a single lens or a plurality of lenses. As the point light source conversion unit 302, an optical system, a pinhole, or the like that condenses light to the diffraction limit in consideration of the light emission characteristics from the light source 301 can be used.

The light beam output from the light source 301 is converted into a point light source by the point light source conversion unit 302, and the reference lens system 3
03 and the beam splitting member 304, and the reflecting member 305.
To reach. The light flux whose sign of the phase distribution is reversed by the reflection member 305 and is reflected is reflected by the light flux splitting member 304.
Light flux traveling to the reference lens system 303 side and the lens system 306 to be tested
It is divided into light beams that travel to the side. The light flux traveling toward the reference lens system 303 side is converted by the reference lens system 303 into the point light source conversion unit 302.
Converge to return to.

On the other hand, when the lens system to be inspected 306 has characteristics equal to or very close to those of the reference lens system 303, the image formed on the side of the lens system to be inspected 306 is the reference lens system 3.
The wavefront and intensity distribution are similar to those of the point image formed on the 03 side. If the characteristic of the lens system under test 306 is the reference lens system 3
If it is different from 03, the image formed on the test lens system 306 side has a different wavefront and intensity distribution than the point image formed on the reference lens system 303 side. By comparing the point image formed on the reference lens system 303 and the image formed on the test lens system 306 side, the quality of the test lens system 306 can be determined.

(Fourth Embodiment) Next, a fourth embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation apparatus of the present invention shown in FIG. 4 is the one in which the detector for detecting the wavefront, spatial intensity distribution, etc. of the light flux transmitted through the lens system to be inspected is provided in the first embodiment. The lens evaluation device shown in FIG. 4 includes a light source 401 and a light source 401.
From the reference lens system 402, a reflection member 404 that reflects the light beam transmitted through the reference lens system 402 by reversing the sign of the spatial phase distribution, and a reflection member 40.
A light beam splitting member 403 that splits the light beam reflected by the beam splitter 4 into two, and a detector 406 provided at the image forming position of the light beam that has passed through the lens system 405 to be tested.

The light beam splitting member 403 is a reference lens system 402.
And the reflection member 404. The lens system 405 to be inspected is arranged at a position where a light flux of the two light fluxes split by the light flux splitting member 403 and traveling in a direction different from the reference lens system 402 is incident. The reference lens system 4
02 has substantially the same configuration as the lens system 405 to be tested,
It is a lens group composed of a single lens or a plurality of lenses. Further, the detector 406 detects the wavefront or the spatial intensity distribution of the light flux transmitted through the lens system 405 to be inspected, or both the wavefront and the spatial intensity distribution.

The light beam output from the light source 401 passes through the reference lens system 402 and the light beam splitting member 403 and reaches the reflecting member 404. The light beam whose sign of the phase distribution is reversed by the reflecting member 404 and reflected is reflected by the light beam splitting member 403.
Thus, it is divided into a light beam traveling to the reference lens system 402 side and a light beam traveling to the test lens system 405 side. Reference lens system 4
The light flux traveling to the 02 side passes through the reference lens system 402 and returns to the light source 401. On the other hand, the light beam split by the light beam splitting member 403 to the side of the lens system 405 to be tested is the lens system 4 to be tested.
It passes through 05 and reaches the detector 406. Detector 406
Detects at least one of the wavefront and the spatial intensity distribution of the light beam transmitted through the lens system 405 to be tested.

The test lens system 405 is the reference lens system 402.
Detector 4 if it has characteristics equal to or very close to
The characteristics detected by 06 are similar to the light emission characteristics of the light source 401. On the other hand, when the characteristic of the lens system 405 to be tested is different from the characteristic of the reference lens system 402, the characteristic detected by the detector 406 is different from the light emission characteristic of the light source 401. By evaluating this difference in light emission characteristics,
The quality of the lens system 405 to be tested can be determined.

(Fifth Embodiment) Next, a fifth embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation apparatus of the present invention shown in FIG. 5 is the second embodiment provided with a detector for detecting the wavefront of the light beam transmitted through the lens system to be inspected, the spatial intensity distribution, and the like. The lens evaluation device shown in FIG. 5 includes a light source 501 and a light source 501.
Parallel light flux conversion unit 502 that converts the light flux from
And a reference lens system 503 on which the collimated light flux is incident.
A reflecting member 505 that reflects the light flux transmitted through the reference lens system 503 by reversing the sign of the spatial phase distribution; a light flux splitting member 504 that splits the light flux reflected by the reflecting member 505 into two; The detector 507 is provided so that the light flux transmitted through the inspection lens system 506 is incident.

The beam splitting member 504 is a reference lens system 503.
And the reflecting member 505. The lens system to be tested 506 is arranged at a position where a light flux of two light fluxes split by the light flux splitting member 504 and traveling in a direction different from the reference lens system 503 is incident. The reference lens system 5
03 has substantially the same configuration as the lens system 506 to be tested,
It is a lens group composed of a single lens or a plurality of lenses. Further, the detector 507 detects the wavefront or the spatial intensity distribution of the light flux transmitted through the lens system 506 to be inspected, or both the wavefront and the spatial intensity distribution.

The light beam output from the light source 501 is converted into a parallel light beam by the parallel light beam conversion unit 502, passes through the reference lens system 503 and the light beam splitting member 504, and is reflected by the reflecting member 5.
The light beam is reflected by 05 and is split by the light beam splitting member 504 into a light beam that travels toward the reference lens system 503 side and a light beam that travels toward the test lens system 506 side. The light passes through the reference lens system 503 and travels toward the light source 501 side as parallel light. On the other hand, the light flux traveling to the test lens system 506 side passes through the test lens system 506 and enters the detector 507. The detector 507 detects at least one of the wavefront and the intensity distribution of the light beam that has passed through the lens system 506 to be tested.

The subject lens system 506 is the reference lens system 503.
If it has a characteristic equal to or very close to, the information of the wavefront characteristic as a parallel light flux is detected by the detector 507. If the characteristic of the lens system 506 to be tested is the reference lens system 5
If it is different from 03, the light flux reflected from the reflecting member 505 and transmitted through the lens system 506 to be tested deviates from the parallel light flux, and is detected by the detector 507 as a wavefront different from the parallel light flux. When the output of the detector 507 indicates a parallel light flux, it is a non-defective product, and the quality can be determined by the amount deviated from the characteristic of the parallel light flux.

(Sixth Embodiment) Next, a sixth embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation apparatus of the present invention shown in FIG. 6 is the third embodiment provided with a detector for detecting the wavefront of the light beam transmitted through the lens system to be inspected, the spatial intensity distribution, and the like. The lens evaluation device shown in FIG. 6 includes a light source 601 and a light source 601.
A point light source conversion unit 602 for converting the light flux from the light source into a point light source,
Reference lens system 603 on which the light flux converted into a point light source is incident
A reflection member 605 that reflects the light flux transmitted through the reference lens system 603 by reversing the sign of the spatial phase distribution, a light flux splitting member 604 that splits the light flux reflected by the reflection member 605 into two, and The detector 607 is provided so that the light flux transmitted through the inspection lens system 606 is incident.

The light beam splitting member 604 is a reference lens system 603.
And the reflection member 605. The test lens system 606 is arranged at a position where a light flux of two light fluxes split by the light flux splitting member 604 and traveling in a direction different from the reference lens system 603 is incident. The reference lens system 6
03 has substantially the same configuration as the lens system 606 to be tested,
It is a lens group composed of a single lens or a plurality of lenses. Further, the detector 607 detects the wavefront or the spatial intensity distribution of the light flux transmitted through the lens system 606 to be tested, or both the wavefront and the spatial intensity distribution.

The luminous flux output from the light source 601 is converted into a point light source by the point light source conversion unit 602, and the reference lens system 6
03 and the beam splitting member 604, and a reflecting member 605.
To reach. The light flux whose sign of the phase distribution is reversed by the reflection member 605 and is reflected is reflected by the light flux splitting member 604.
The light flux traveling to the reference lens system 603 side and the lens system 606 to be tested
It is divided into light beams that travel to the side. The light flux traveling to the reference lens system 603 side is converted by the reference lens system 603 into the point light source conversion unit 602.
Converge to return to. On the other hand, the light flux that has passed through the lens system to be tested 606 is incident on the detector 607, and at least one of the wavefront and the spatial intensity distribution is detected.

The test lens system 606 is the reference lens system 603.
Detector 6 if it has characteristics equal to or very close to
The detection result of 07 is the same wavefront and intensity distribution as the point light source obtained by the point light source conversion unit 602. If the characteristic of the lens system to be inspected 606 is different from that of the reference lens system 603, the detection result by the detector 607 has a different wavefront and intensity distribution from the point light source obtained by the point light source conversion unit 602. Therefore, by comparing the detection result of the detector 607 with the reference characteristic corresponding to the point light source, the quality of the lens system 606 to be tested can be determined.

(Seventh Embodiment) Next, a seventh embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation apparatus of the present invention shown in FIG. 7 is the same as the fourth embodiment except that a detector is also provided on the reference lens system side. The lens evaluation device shown in FIG. 7 includes a light source 701 and a light source 701.
From the reference lens system 703, a reflection member 705 that reflects the light beam transmitted through the reference lens system 703 by reversing the sign of the spatial phase distribution, and a reflection member 70.
The first light beam splitting member 704 is provided for splitting the light beam reflected by the beam splitter 5.

The first light beam splitting member 704 is provided between the reference lens system 703 and the reflecting member 705. The lens system to be inspected 706 is arranged at a position where a light flux of the two light fluxes split by the first light flux splitting member 704 and traveling in a direction different from the reference lens system 703 is incident. A first detector 709 is provided at the image forming position of the light beam that has been split by the first light beam splitting member 704 and transmitted through the lens 706 to be tested. A second light flux dividing member 702 is provided between the reference lens system 703 and the light source 701. Second
The light beam splitting member 702 is reflected by the reflecting member 705, and the first light beam splitting member 704 and the reference lens system 703.
The light beam transmitted to the light source 701 side is divided into two. Second
A second detector 707 is provided at a position where the traveling light flux converges to a side different from the light source 701, of the two light fluxes split by the light flux splitting member 702. Further, a compensating member 708 for compensating for the optical path length, aberration, etc. is provided between the lens system to be tested 706 and the first detector 709.

The reference lens system 703 is a lens group having substantially the same structure as the lens system 706 to be tested and composed of a single lens or a plurality of lenses. Further, the first detector 709 detects the wavefront or the spatial intensity distribution of the light flux transmitted through the lens system 706 to be detected, or both the wavefront and the spatial intensity distribution, and the second detector 707 is the reference lens. System 7
The wavefront or spatial intensity distribution of the light flux transmitted through 03 is detected, or both the wavefront and the spatial intensity distribution are detected.

The luminous flux output from the light source 701 reaches the reflecting member 705 through the second luminous flux splitting member 702, the reference lens system 703, and the first luminous flux splitting member 704. The light flux whose sign of the phase distribution is reversed by the reflecting member 705 and is reflected is split by the first light flux splitting member 704 into a light flux that proceeds to the reference lens system 703 side and a light flux that proceeds to the test lens system 706 side. The luminous flux traveling to the reference lens system 703 side is
After passing through the reference lens system 703, it is split into two by the second light beam splitting member 702, and one light beam is incident on the second detector 707. The second detector 707 detects at least one of the wavefront and the spatial intensity distribution of the light flux transmitted through the reference lens system 703. On the other hand, it is split by the first light beam splitting member 704, and the test lens system 706 is
The light flux traveling to the side passes through the compensating member 708 and enters the first detector 709. The first detector 709 detects at least one of the wavefront and the spatial intensity distribution of the light flux transmitted through the lens system 706 to be tested.

The light beam reflected by the reflecting member 705, transmitted through the first light beam splitting member 704, and returned to the reference lens system 703 has the same light emission characteristic as that of the light source 701. The characteristics detected by the detector 707 are substantially equivalent to the emission characteristics of the light source 701. That is, the second detector 707 can be regarded as detecting the light emission characteristic of the light source 701.

The subject lens system 706 is the reference lens system 703.
When the light flux has a characteristic equal to or very close to, the light flux reflected by the reflecting member 705, split by the first light flux splitting member 704 and traveling to the lens system under test 706 side is the same as the light flux returning to the reference lens system 703 side. Therefore, the output result of the first detector 709 is equal to that of the second detector 70.
It is almost the same as the output result of 7. If the lens system under test 7
When the characteristic of 06 is different from that of the reference lens system 703,
The luminous flux traveling to the side of the lens system 706 to be inspected is the reference lens system 703.
The detection result of the first detector 709 is different from the detection result of the second detector 707 because it has a characteristic different from that of the light beam returning to the side. By comparing the output result of the first detector 709 and the output result of the second detector 707 and evaluating the deviation amount, it is possible to determine the quality of the lens system 706 to be tested.

(Eighth Embodiment) Next, an eighth embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation apparatus of the present invention shown in FIG. 8 is the same as the fifth embodiment except that a detector is also provided on the reference lens system side. The lens evaluation device shown in FIG. 8 includes a light source 801 and a light source 801.
Parallel light beam conversion unit 802 for converting the light beam from the light beam into a parallel light beam
And a reference lens system 804 on which the collimated light beam is incident.
A reflection member 806 that reflects the light flux that has passed through the reference lens system 804 by reversing the sign of the spatial phase distribution, and a first light flux splitting member 805 that splits the light flux reflected by the reflection member 806 into two. It is equipped with.

The first light beam splitting member 805 is provided between the reference lens system 804 and the reflecting member 806. The lens system to be tested 807 is arranged at a position where a light flux of the two light fluxes split by the first light flux splitting member 805 and traveling in a direction different from the reference lens system 804 is incident. It is split by the first light beam splitting member 805, and the lens system 807 to be tested is
The first detector 81 is located at the position where the light flux transmitted through
0 is provided. A second light flux dividing member 803 is provided between the reference lens system 804 and the parallel light flux conversion unit 802. The second light beam splitting member 803 includes the reflecting member 8
The light flux that is reflected by 06 and transmitted through the first light flux splitting member 805 and the reference lens system 804 to the light source 801 side is split into two light fluxes. A second detector 808 is provided at a position of the two light beams split by the second light beam splitting member 803, in which a progressive light beam is incident on a side different from the light source 801. A compensating member 8 for compensating for the optical path length, aberration, etc. is provided between the lens system to be tested 807 and the first detector 810.
09 is provided.

The reference lens system 804 is a lens group having substantially the same structure as the lens system to be tested 807 and composed of a single lens or a plurality of lenses. Further, the first detector 810 detects the wavefront or the spatial intensity distribution of the light flux transmitted through the lens system 807 to be detected, or both the wavefront and the spatial intensity distribution, and the second detector 808 is the reference lens. System 8
The wavefront or spatial intensity distribution of the light flux transmitted through 04 is detected, or both the wavefront and the spatial intensity distribution are detected.

The luminous flux emitted from the light source 801 is converted into a parallel luminous flux by the parallel luminous flux converter 802, and is transmitted through the second luminous flux splitting member 803, the reference lens system 804 and the first luminous flux splitting member 805. The reflection member 806 is reached. The light beam reflected by the reflecting member 806 so that the sign of the spatial phase distribution is reversed is the first light beam splitting member 8
By 05, it is divided into a light beam traveling to the reference lens system 804 side and a light beam traveling to the test lens system 807 side. The light flux traveling to the reference lens system 804 side is transmitted through the reference lens system 804 and then split into two by the second light flux splitting member 803, and one light flux reaches the second detector 808. Second
The detector 808 of 1 detects at least one of the wavefront and the spatial intensity distribution of the light flux transmitted through the reference lens system 804. On the other hand, the light flux that travels to the test lens system 807 side passes through the test lens system 807 and the compensation member 809,
The first detection member 810 is reached. First detector 810
Detects at least one of the wavefront and the spatial intensity distribution of the light flux transmitted through the lens system 807 to be tested.

The light beam reflected by the reflecting member 806 and incident on the reference lens system 804 is detected by the second detector 808 as to the image formation state after passing through the reference lens system 804. The image formation characteristic detected by the second detector 808 is substantially equal to the wavefront characteristic of the parallel light flux converted by the parallel light flux converter 802. When the lens system under test 807 has characteristics equal to or very close to those of the reference lens system 804, the light flux reflected by the reflecting member 806, split by the first light flux splitting member 805, and traveling to the lens system under test 807 side is analyzed. The output result of the first detector 810 is substantially the same as the output result of the second detector 808 because it has the same image forming characteristics as the light flux returning to the reference lens system 804 side.
If the characteristic of the lens system to be tested 807 is the reference lens system 804
Is different from that of the reference lens system 804, the output of the first detector 810 is the second output. It differs from the output result of the detector 808. First detector 8
By comparing the output result of 10 and the output result of the second detector 808 and evaluating the amount of deviation,
The quality of 07 can be determined.

(Ninth Embodiment) Next, a ninth embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation apparatus of the present invention shown in FIG. 9 is the same as the sixth embodiment except that a detector is also provided on the reference lens system side. The lens evaluation device shown in FIG. 9 includes a light source 901 and a light source 901.
A point light source conversion unit 902 for converting the light flux from the light source into a point light source,
Reference lens system 904 on which the light flux converted into a point light source is incident
A reflection member 906 that reflects the light beam that has passed through the reference lens system 904 by reversing the sign of the spatial phase distribution, and a first light beam splitting member 905 that splits the light beam reflected by the reflection member 906 into two. And.

The first light beam splitting member 905 is provided between the reference lens system 904 and the reflecting member 906. The lens system to be tested 907 is arranged at a position where a light flux of the two light fluxes split by the first light flux splitting member 905 and traveling in a direction different from the reference lens system 904 is incident. The first detector 910 is provided at a position where the light beam split by the first light beam splitting member 905 and transmitted through the lens 907 to be tested is incident.
Is provided. A second light beam splitting member 903 is provided between the reference lens system 904 and the point light source conversion unit 902. The second light beam splitting member 903 includes a reflecting member 906.
The light flux that is reflected by the first light flux splitting member 905 and the reference lens system 904 and is transmitted to the light source 901 side is split into two.

A second detector 908 is provided at a position of the two light beams split by the second light beam splitting member 903, in which a progressive light beam is incident on a side different from the light source 901. In addition, a compensating member 9 for compensating the optical path length, aberration, etc. is provided between the lens system to be tested 907 and the first detector 910.
09 is provided. The reference lens system 904 is a lens group that has substantially the same configuration as the lens system 907 to be tested and is configured by a single lens or a plurality of lenses. Also,
The first detector 910 detects the wavefront or the spatial intensity distribution of the light flux transmitted through the lens system 907 to be tested, or both the wavefront and the spatial intensity distribution, and the second detector 908 detects the reference lens system 904. The wavefront or the spatial intensity distribution of the light flux transmitted through the light flux, or both the wavefront and the spatial intensity distribution are detected.

The light beam emitted from the light source 901 is converted into a point light source by the point light source conversion unit 902, and is transmitted through the second light beam splitting member 903, the reference lens system 904 and the first light beam splitting member 905, The reflection member 906 is reached. The light flux reflected by the reflecting member 906 so that the sign of the spatial phase distribution is inverted, the first light flux splitting member 905 advances the light flux to the reference lens system 904 side and the light flux to the test lens system 907 side. Is divided into Reference lens system 90
After passing through the reference lens system 904, the light flux that proceeds to the 4 side is
The second beam splitting member 903 splits the beam into two beams, and one beam reaches the second detector 908. The second detector 908 detects at least one of the wavefront and the spatial intensity distribution of the light flux transmitted through the reference lens system 904. On the other hand, the light flux traveling toward the lens system to be tested 907 passes through the lens system to be tested 907 and the compensating member 909, and reaches the first detecting member 910. The first detector 910 detects at least one of the wavefront and the spatial intensity distribution of the light flux transmitted through the lens system 907 to be tested.

The light beam reflected by the reflection member 906 and transmitted through the reference lens system 904 has substantially the same wavefront and intensity distribution as the point light source output from the point light source conversion unit 902. Therefore, the characteristic of the light flux detected by the second detector 908 is substantially equal to the characteristic of the point light source converted by the point light source conversion unit 902. On the other hand, when the lens system to be inspected 907 has a characteristic equal to or very close to that of the reference lens system 904, it is reflected by the reflecting member 906, is divided by the first light beam splitting member 905, and proceeds to the side of the lens system to be inspected 907. Since the light flux has the same characteristics as the light flux returning to the reference lens system 904 side, the output result of the first detector 910 is almost the same as the output result of the second detector 908. If the characteristic of the lens system to be tested 907 is the reference lens system 9
If it is different from 04, since the light flux traveling to the test lens system 907 side has different imaging characteristics from the light flux returning to the reference lens system 904 side, the output result of the first detector 910 is the second The output result of the detector 908 is different. By comparing the output result of the first detector 910 and the output result of the second detector 908 and evaluating the amount of deviation, the quality of the lens system 907 to be tested can be determined.

(Tenth Embodiment) Next, a tenth embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation apparatus of the present invention shown in FIG. 10 is provided with an interference optical system for interfering the two light beams split by the light beam splitting member in the first or fourth embodiment, which is the basic mode of the present invention. It is a thing. The lens evaluation apparatus shown in FIG. 10 reflects a light source 1001, a reference lens system 1003 on which a light beam from the light source 1001 is incident, and a light beam transmitted through the reference lens system 1003 by reversing the sign of the spatial phase distribution. First reflecting member 1005 and first reflecting member 10
The first light beam splitting member 1004 is provided for splitting the light beam reflected by 05 into two.

The first light beam splitting member 1004 is provided between the reference lens system 1003 and the first reflecting member 1005. The lens system 1006 to be inspected is the first light beam splitting member 1
Inner reference lens system 1 of two light beams divided by 004
It is arranged at a position where a light beam traveling in a direction different from 003 is incident. On the side opposite to the first light beam splitting member 1004 with respect to the lens system 1006 to be inspected, the second reflecting member 100 for changing the direction of the light beam transmitted through the lens system 1006 to be inspected.
8 and a compensating member 1007 that is configured integrally with the second reflecting member 1008 and that compensates for the optical path length, aberration, and the like. In addition, between the light source 1001 and the reference lens system 1003, there are two light beams reflected by the first reflecting member 1005 and transmitted through the reference lens system 1003 to the light source 1001 side.
A second light beam splitting member 1002 for splitting into two is provided.

A light beam which has passed through the lens system 1006 to be tested and which has been reflected in a predetermined direction by the second reflecting member 1008 and a reference lens system 1003 which has passed through the second light beam splitting member 10
A light flux integrating member 1009 is provided at a position where a light flux split by 02 and traveling in a direction different from the light source 1001 intersects. The light flux integrating member 1009 changes the direction of the light flux transmitted through the lens system 1006 to be tested, and
Light flux transmitted through the lens system 1006 to be tested and reference lens system 1
The light flux transmitted through 003 is integrated. Luminous flux integrating member 10
At the image forming position of the light fluxes integrated by the detector 09.
10 are provided. The reference lens system 1003 is a lens group that has substantially the same configuration as the lens system 1006 to be tested and is configured by a single lens or a plurality of lenses. Further, the detector 1010 detects an interference fringe due to the two integrated light fluxes.

The luminous flux output from the light source 1001 is
Of the first luminous flux splitting member 1002, the reference lens system 1003, and the first luminous flux splitting member 1004, and the first reflecting member 1
Reach 005. The light flux whose sign of the phase distribution is reversed by the first reflecting member 1005 and is reflected is split by the first splitting member 1004 into a light flux that travels toward the reference lens system 1003 side and a light flux that travels toward the test lens system 1006 side. The light flux that travels toward the reference lens system 1003 side and the light flux that travels toward the light source 1001 side by the second light flux splitting member 1002 and the light source 10
It is divided into light beams that travel in a direction different from 01.

On the other hand, the light flux traveling to the side of the lens system 1006 under test passes through the lens system 1006 under test and the compensating member 1007, is reflected by the second reflecting member 1008, and intersects the light beam passing through the reference lens system 1003. To proceed. The light flux that has passed through the lens system 1006 to be tested is a light flux integrating member 1
The moving direction is changed by 009, and the reference lens system 100
It is integrated with the luminous flux transmitted through 3. The integrated light flux reaches the detector 1010, and the detector 1010 detects the interference fringes of the two light fluxes. By evaluating the interference fringes detected by the detector 1010, the difference between the lens system under test 1006 and the reference lens system 1003 is derived, and the lens system under test 10 is tested.
The quality of 06 can be determined.

(Eleventh Embodiment) Next, an eleventh embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation device of the present invention shown in FIG.
Alternatively, the fifth embodiment is provided with an interference optical system that causes the light beams split by the light beam splitting member to interfere with each other. The lens evaluation device shown in FIG. 11 includes a light source 1101 and
A parallel light flux conversion unit 1102 that converts a light flux from the light source 1101 into a parallel light flux, a reference lens system 1104 on which the collimated light flux is incident, and a light flux transmitted through the reference lens system 1104 are denoted by a spatial phase distribution code. It includes a first reflecting member 1106 which reverses and reflects, and a first luminous flux dividing member 1105 which divides the luminous flux reflected by the first reflecting member 1106 into two.

The first light beam splitting member 1105 is provided between the reference lens system 1104 and the first reflecting member 1106. The lens system to be tested 1107 includes the first light beam splitting member 1
Inner reference lens system 1 of two light beams divided by 105
It is arranged at a position where a light beam traveling in a direction different from 104 is incident. On the side opposite to the first light beam splitting member 1105 with respect to the lens system to be inspected 1107, the second reflecting member 110 for changing the direction of the light beam transmitted through the lens system to be inspected 1107.
9 and a compensating member 1108 that is configured integrally with the second reflecting member 1109 and that compensates for optical path length, aberration, and the like. Parallel light flux converter 1102 and reference lens system 110
4 is reflected by the first reflecting member 1106,
A second light beam splitting member 1103 that splits a light beam that passes through the reference lens system 1104 toward the light source 1101 side into two is provided.

A light beam which has passed through the lens system 1107 to be tested and which has been reflected by the second reflecting member 1110 in a predetermined direction and a reference lens system 1104 which has passed through the second light beam splitting member 11
A light flux integrating member 1110 is provided at a position where a light flux split by 03 and traveling in a direction different from the light source 1101 intersects. The light flux integrating member 1110 changes the direction of the light flux transmitted through the lens system 1107 to be tested, and
Light flux transmitted through the lens system 1107 to be tested and the reference lens system 1
The light flux transmitted through 104 is integrated. Luminous flux integrating member 11
A detector 1111 is provided at a position where the light fluxes integrated by 10 are incident. The reference lens system 110
4 has substantially the same configuration as the lens system 1107 to be tested,
It is a lens group composed of a single lens or a plurality of lenses. Further, the detector 1111 detects an interference fringe due to the two integrated light fluxes.

The light beam output from the light source 1101 is converted into a parallel light beam by the parallel light beam conversion unit 1102, passes through the second light beam splitting member 1103, the reference lens system 1104, and the first light beam splitting member 1105, and then becomes the first light beam splitting member. Reflection member 110
Reach 6. The light flux whose sign of the phase distribution is reversed by the first reflecting member 1106 and reflected is reflected by the first dividing member 1
The light beam 105 is split into a light beam traveling to the reference lens system 1104 side and a light beam traveling to the test lens system 1107 side. The light flux traveling toward the reference lens system 1104 side is the second light flux splitting member 11
Light flux traveling toward the light source 1101 side by 03, and the light source 1101
Is divided into light beams that travel in a different direction from.

On the other hand, the light flux traveling to the side of the lens system to be inspected 1107 passes through the lens 1107 to be inspected and the compensating member 1108, is reflected by the second reflecting member 1109, and intersects with the light beam passing through the reference lens system 1104. Proceed to. The light flux that has passed through the lens system 1107 to be tested is the light flux integrating member 1
The moving direction is changed by 110, and the reference lens system 110
It is integrated with the light flux that has passed through 4. The integrated light flux reaches the detector 1111 and the detector 1111 detects the interference fringes of the two light fluxes. By evaluating the interference fringes detected by the detector 1111, the difference between the lens system under test 1104 and the reference lens system 1107 is derived, and the lens system under test 11
It is possible to judge pass / fail of 07.

(Twelfth Embodiment) Next, a twelfth embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation device of the present invention shown in FIG.
Alternatively, the sixth embodiment is provided with an interference optical system that interferes the two light beams split by the light beam splitting member. The lens evaluation device shown in FIG. 12 includes a light source 1201 and
A point light source conversion unit 1202 that converts a light flux from the light source 1201 into a point light source, a reference lens system 1204 on which the light flux converted into the point light source is incident, and a light flux transmitted through the reference lens system 1204 has a spatial phase distribution code. First to reverse and reflect
Reflection member 1206 and a first light beam splitting member 1205 that splits the light beam reflected by the reflection member 1206 into two.
And

The first light beam splitting member 1205 is provided between the reference lens system 1204 and the first reflecting member 1206. The lens system 1207 to be tested includes the first light beam splitting member 1
Inner reference lens system 1 of two light beams divided by 205
It is arranged at a position where a light beam traveling in a direction different from 204 is incident. On the side opposite to the first light beam splitting member 1205 with respect to the lens system to be inspected 1207, the second reflecting member 120 for changing the direction of the light beam transmitted through the lens system to be inspected 1207.
9 and a compensating member 1208 that is configured integrally with the second reflecting member 1209 and that compensates for optical path length, aberration, and the like. In addition, the point light source conversion unit 1202 and the reference lens system 1
A second light beam splitting member 1203 that splits a light beam that is reflected by the first reflecting member 1206 and that is transmitted through the reference lens system 1204 toward the light source 1201 side into two is provided between 204.

A light beam that has passed through the lens system 1207 to be tested and has been reflected by the second reflecting member 1209 in a predetermined direction, and a light beam that has passed through the reference lens system 1204 and has passed through the second light beam splitting member 12
A light flux integrating member 1210 is provided at a position where a light flux split by 03 and traveling in a direction different from the light source 1201 intersects. The light flux integrating member 1210 changes the direction of the light flux transmitted through the lens system 1207 to be tested, and
Light flux transmitted through the lens system 1207 to be tested and the reference lens system 1
The light flux transmitted through 204 is integrated. Luminous flux integrating member 12
A detector 1211 is provided at a position where the light fluxes integrated by 10 are incident. The reference lens system 120
4 has substantially the same configuration as the lens system 1207 to be inspected,
It is a lens group composed of a single lens or a plurality of lenses. Further, the detector 1211 detects an interference fringe formed by the two integrated light fluxes.

The light beam output from the light source 1201 is converted into a point light source by the point light source conversion unit 1202, passes through the second light beam splitting member 1203, the reference lens system 1204, and the first light beam splitting member 1205, and then the first light beam splitting member 1205. The reflection member 1206 is reached. The light flux whose sign of the phase distribution is reversed by the first reflecting member 1206 and reflected is reflected by the first dividing member 120.
5, the light beam is divided into a light beam traveling to the reference lens system 1204 side and a light beam traveling to the test lens system 1207 side. The light flux that travels toward the reference lens system 1204 is second light flux splitting member 1203.
Is split into a light flux that travels toward the light source 1201 side and a light flux that travels in a direction different from that of the light source 1201.

On the other hand, the light flux traveling toward the lens system to be tested 1207 passes through the lens system to be tested 1207 and the compensating member 1208, is reflected by the second reflecting member 1209, and intersects with the light flux which has passed through the reference lens system 1204. To proceed. The light flux that has passed through the lens system 1207 to be tested is the light flux integrating member 1
The traveling direction is changed by 210, and the reference lens system 120
It is integrated with the light flux that has passed through 4. The integrated light flux reaches the detector 1211, and the detector 1211 detects the interference fringes of the two light fluxes. By evaluating the interference fringes detected by the detector 1211, the difference between the lens system 1204 to be tested and the reference lens system 1207 is derived, and the lens system 12 to be tested is evaluated.
It is possible to judge pass / fail of 07.

(Thirteenth Embodiment) Next, a thirteenth embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation device of the present invention shown in FIG.
Alternatively, the fourth embodiment is provided with a return light removing member (optical isolator) for attenuating or blocking the return light returning to the light source and a light amount adjusting member for adjusting the intensity of the light incident on the reference lens system. is there. The lens evaluation device shown in FIG. 13 reflects a light source 1301, a reference lens system 1304 on which output light from the light source is incident, and a light flux transmitted through the reference lens system 1304 by reversing the sign of the spatial phase distribution. It includes a reflection member 1306 and a light beam splitting member 1305 that splits the light beam reflected by the reflection member 1306 into two.

The beam splitting member 1305 is the reference lens system 13
04 and the reflecting member 1306. The lens system to be inspected 1307 is arranged at a position where a light flux of the two light fluxes split by the light flux splitting member 1305 and traveling in a different direction from the reference lens system 1304 is incident. Further, a detector 1309 is provided at the image forming position of the light flux transmitted through the lens system 1307 to be inspected, and a lens system 1307 to be inspected and a detector 1309 are provided.
Between the compensating member 13 and the compensating member 13 for compensating the optical path length and the aberration.
08 are provided respectively.

Immediately before the light source 1301, the return light removing member 130 that attenuates or blocks the light flux returning to the light source 1301.
2 are provided. Between the return light removing member 1302 and the reference lens system 1304, a light amount adjusting member 130 such as an ND filter for adjusting the intensity of the light beam output from the light source 1301 and entering the reference lens system 1304.
3 are provided.

The reference lens system 1304 is a lens group having a single lens or a plurality of lenses, which has substantially the same structure as the lens system to be tested 1307. Detector 130
Reference numeral 9 detects the wavefront or the spatial intensity distribution of the light flux transmitted through the lens system 1307 to be inspected, or both the wavefront and the spatial intensity distribution.

Generally, when a laser is used as the light source 1301, the output and the wavelength may not be stable due to the returning light depending on the type of the laser. In that case, the return light removing member 1302 needs to attenuate or block the return light. Further, when the intensity of the output light of the light source 1301 is too strong, the detection value of the detector 1309 may be saturated. In that case, in order to adjust the output intensity of the light source 1301, a light amount adjusting member 1303 such as an ND filter is used.
Is valid.

(Fourteenth Embodiment) Next, a fourteenth embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. In the lens evaluation device of the present invention shown in FIG. 14, the reference lens system and the lens system under test have a negative refractive power, or the reference lens system and the lens system under test have a relatively high refractive power, and the luminous flux is a reflecting member. This is a modification of the first embodiment, which is the basic form of the present invention, in order to be adapted to the case where the light beam converges once before reaching the point 1 and the light beam diverges again.

The lens evaluation apparatus shown in FIG.
01 and a reference lens system 1 having a negative refractive power or a relatively strong positive refractive power to which the output light from the light source 1401 is input.
402, a positive refracting power lens 1404 for converging the light flux that has passed through the reference lens system 1402, and a light flux that has passed through the reference lens system 1402 and the positive refraction power lens 1404 with the sign of the spatial phase distribution reversed and reflected. Reflecting member 1405, reference lens system 1402, and positive refractive power lens 1
And a light beam splitting member 1403 that splits the light beam reflected by the reflecting member 1405 into two. The lens system to be tested 1406 includes a light beam splitting member 140.
Inner reference lens system 140 of two light beams divided by 3
It is arranged at a position where a light beam traveling in a direction different from 2 is incident. The reference lens system 1402 is the lens system under test 14
The lens group has substantially the same configuration as that of 06 and is configured by a single lens or a plurality of lenses.

In this embodiment, since the positive refractive power lens 1404 is provided between the reference lens system 1402 and the reflecting member 1405, if the positive refractive power lens 1404 is not provided, the negative refraction of the reference lens system 1402 is negative. When the light flux becomes divergent light due to the force and is expected to spread wider than the surface of the reflection member 1405 when entering the reflection member 1405, or the light flux is reflected by the relatively strong positive refractive power of the reference lens system 1402. Even if the spread of the light flux when it reaches the reflection member 1405 is larger than that of the reflection surface of the reflection member 1405 by converging once before reaching the member 1405 and diverging again, the positive refracting power is increased. With the lens 1404, the light flux can be suppressed to have an appropriate spread that matches the size of the reflecting surface of the reflecting member 1405.

Further, the light beam splitting member 1403 and the reflecting member 1
Since the positive refractive power lens 1404 is provided between the reference lens system 405 and the reference lens system 1402, the same effect can be obtained when the light flux reflected by the reflecting member 1405 enters the lens system 1406 to be tested. Since the positive refracting power lens 1404 is located on the common optical path of the reflecting member 1405 and the lens system 1406 to be inspected 1405, the influence of the aberration of the positive refracting power lens 1404 is canceled out, and the light flux is spread to an appropriate size. Only the effect of In addition,
Although the present embodiment is based on the lens evaluation device of the first embodiment, the present invention is not limited to this structure and can be applied to the lens evaluation device of the second to thirteenth embodiments. It goes without saying that you can do it.

(Fifteenth Embodiment) Next, a fifteenth embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation apparatus of the present invention shown in FIG. 15 has a refracting power of a reference lens and a lens system to be inspected that are relatively strong, and is adapted to a case in which a light flux converges once before reaching a reflecting member and diverges again. It is a modification of the first embodiment, which is the basic mode of the invention.

The lens evaluation apparatus shown in FIG.
01, a reference lens system 1502 having a relatively strong positive refractive power to which the output light from the light source 1501 is input, a negative refractive power lens 1504 for diverging the light flux transmitted through the reference lens system 1502, and a reference lens. A reflecting member 1505 that reflects the light flux that has passed through the system 1502 and the negative refractive power lens 1504 by reversing the sign of the spatial phase distribution, and is provided between the reference lens system 1502 and the negative refractive power lens 1504. And a light beam splitting member 1503 that splits the light beam reflected by. The lens system to be inspected 1506 is arranged at a position where a light flux of two light fluxes split by the light flux splitting member 1503 and traveling in a direction different from the reference lens system 1502 is incident. It should be noted that the reference lens system 1502 is a lens group that has substantially the same configuration as the lens system 1506 to be tested and is configured by a single lens or a plurality of lenses.

In this embodiment, the negative refractive power lens 1504 is provided between the reference lens system 1502 and the reflecting member 1505. Therefore, if the negative refractive power lens 1504 is not provided, the light flux is reflected by the reference lens system 1502. Member 150
5 is converged once before reaching 5 and diverges again, so that when reaching the reflecting member 1505, the spread of the light flux is larger than the reflecting surface of the reflecting member 1405, etc. By means of 1504, the luminous flux can be adjusted to have an appropriate spread that matches the size of the reflecting surface of the reflecting member 1505.

Further, the light beam splitting member 1503 and the reflecting member 1
Since the negative refractive power lens 1504 is provided between 505, the same effect can be obtained when the light flux reflected by the reflecting member 1505 enters the lens system 1506 to be tested, and the reference lens system 1502 and the reflecting member are provided. Since the lens 1504 and the lens system 1506 to be inspected and the reflecting member 1505 have a common optical path on the negative refractive power lens 1504, the influence of the aberration of the negative refractive power lens 1504 is canceled and the light flux is spread to an appropriate size. Only the effect of In addition,
Although the present embodiment is based on the lens evaluation device of the first embodiment, the present invention is not limited to this structure and can be applied to the lens evaluation device of the second to thirteenth embodiments. It goes without saying that you can do it.

(Sixteenth Embodiment) Next, a sixteenth embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation device of the present invention shown in FIG.
The signal processing function and the information input / output function are added to the above embodiment. The lens evaluation device shown in FIG.
601, a reference lens system 1603 on which the light flux from the light source 1601 is incident, a reflection member 1605 that reflects the light flux transmitted through the reference lens system 1603 by reversing the sign of the spatial phase distribution, and reflected by the reflection member 1605. A first light beam splitting member 1604 that splits the split light beam into two.

The first light beam splitting member 1604 is provided between the reference lens system 1603 and the reflecting member 1605.
The lens system 1606 to be tested includes a first light beam splitting member 1604.
Reference lens system 1603 of the two light beams divided by
It is arranged at a position where a light beam traveling in a direction different from is incident. A first detector 1609 is provided at the image forming position of the light flux transmitted through the lens system 1606 to be inspected. Further, between the lens system 1606 to be tested and the first detector 1609,
A compensating member 1608 for compensating the optical path length, the aberration and the like is provided.

Between the reference lens system 1603 and the light source 1601, the first light beam splitting member 1604 and the reference lens system 1603 are reflected by the reflection member 1605 so that the light source 160
A second light flux splitting member 1602 that splits the light flux transmitted to one side into two is provided. In addition, of the two light beams split by the second light beam splitting member 1602, the light source 16
A second detector 1607 is provided at a position where the traveling light flux converges to a side different from 01. Further, the first detector 1609 and the second detector 1607 are each connected to the signal processing unit 1610. The signal processing unit 1610 includes
An input unit 1611 for inputting the characteristics of the light source 1601 on the side of the reference lens system 1603 and a display unit 1612 for displaying the determination result by the signal processing unit 1610 are connected in advance.

The reference lens system 1603 is a lens group which has substantially the same structure as the lens system 1606 to be tested and is composed of a single lens or a plurality of lenses. The first detector 1609 detects the wavefront or the spatial intensity distribution of the light flux transmitted through the lens system 1606 to be detected, or both the wavefront and the spatial intensity distribution, and the second detector 1607 is the reference lens. The wavefront or the spatial intensity distribution of the light flux transmitted through the system 1603, or both the wavefront and the spatial intensity distribution are detected.

First detector 1609 and second detector 16
The output results of 07 are input to the signal processing unit 1610. The signal processing unit 1610 processes the input data, so that the reference lens system 1603 and the test lens system 1607 are processed.
The characteristic difference is calculated and the quality is judged. Signal processing unit 16
The determination result and the evaluation value of the quality of the lens system 1606 to be tested by 10 are displayed on the display unit 1612. In addition, although the present embodiment is configured based on the lens evaluation device of the seventh embodiment, the present invention is not limited to this, and the lens evaluation device of the eighth and ninth embodiments includes a signal processing unit, You may provide an input part and a display part. Further, in the present embodiment, the outputs of the detectors on both the reference lens system side and the subject lens system side are compared. However, when the outputs on the reference lens system side are known in advance, the lens evaluations of other embodiments are performed. It is also possible to make a pass / fail judgment using only the detection result of the lens system to be inspected in the apparatus.

(Seventeenth Embodiment) Next, a seventeenth embodiment of the lens evaluation apparatus of the present invention will be described with reference to FIG. The lens evaluation apparatus of the present invention shown in FIG.
A signal processing function and an information output function (display function) are added to the first embodiment. The lens evaluation apparatus shown in FIG. 17 includes a light source 1701, a parallel light flux conversion unit 1702 that converts a light flux from the light source 1701 into a parallel light flux, a reference lens system 1704 on which the collimated light flux is incident, and a reference lens system 1704. A first reflection member 1706 that reflects the light flux that has passed through the light source by reversing the sign of the spatial phase distribution, and a first light flux splitting member 1705 that splits the light flux reflected by the reflection member 1706 into two. To do.

The first light beam splitting member 1705 is provided between the reference lens system 1704 and the reflecting member 1706.
The lens system 1707 to be tested includes a first light beam splitting member 1705.
Inner reference lens system 1704 of two light beams divided by
It is arranged at a position where a light beam traveling in a direction different from is incident. On the side opposite to the first light beam splitting member 1705 with respect to the lens system 1707 to be tested, a second reflecting member 1709 that changes the direction of the light beam transmitted through the lens system 1707 to be tested,
A compensating member 1708 that is configured integrally with the second reflecting member 1709 and that compensates for optical path length, aberration, and the like is provided. In addition, the parallel light flux converter 1702 and the reference lens system 17
Between 04, the second light beam splitting member 1 that splits the light beam that passes through the reference lens system 1704 toward the light source 1701 side into two.
703 is provided.

A light beam that has passed through the lens system 1707 to be tested and has passed through the lens system 1707 to be tested, which has been reflected in the predetermined direction by the second reflecting member 1710, and also has passed through the reference lens system 1704, and has a second light beam splitting member. A light flux integrating member 1710 is provided at a position where a light flux split by 1703 and traveling in a direction different from the light source 1701 intersects. The light flux integrating member 1710 changes the direction of the light flux transmitted through the lens system 1707 to be inspected, and at the same time, the lens system 1707 to be inspected.
The light flux that has passed through the reference lens system 1704 and the light flux that has passed through the reference lens system 1704 are integrated. A detector 1711 is provided at a position where the light fluxes integrated by the light flux integrating member 1710 are incident. The detection member 1711 is connected to a signal processing unit 1712 that determines pass / fail of the lens system 1707 to be tested from a pattern of interference fringes obtained by the detection member 1711 and a display unit 1713 that displays a determination result and an evaluation value. It should be noted that the reference lens system 1704 is a lens group that has substantially the same configuration as the lens system 1707 to be tested and is configured by a single lens or a plurality of lenses. The detector 1711 detects an interference fringe due to the two integrated light fluxes.

Although the present embodiment is based on the lens evaluation device of the eleventh embodiment, the present invention is not limited to this, and the lens evaluation device of the twelfth and thirteenth embodiments can be signaled. A processing unit and a display unit may be provided.

In each of the first to seventeenth embodiments described above, the light beam is split by the light beam splitting member so that it travels in two directions. However, it is not always necessary to split the light beam into two light beams, and polarization or the like is used to make a selection. The same effect can be obtained by changing the direction in which the light flux travels. Further, in the above embodiment, in order to compensate for the optical path length, the aberration, etc. and improve the evaluation accuracy, an adaptive optical system may be inserted in addition to the one specifically exemplified.

[0107]

As described above, the lens evaluation apparatus of the present invention outputs a luminous flux to a reference lens system having a configuration substantially equal to that of the lens system to be tested and a predetermined optical performance, and the reference lens system. Light source, a reflection means for reversing the sign of the spatial phase distribution of the light flux output from the light source and transmitted through the reference lens system, and the light flux reflected by the reflection means are divided, and one of the divided light fluxes is divided. And a light beam splitting means for making the light beam incident on the lens system to be inspected. Therefore, as long as a reference lens system that has substantially the same configuration as that of the lens system to be tested and is equal to or close to a predetermined design value is prepared, the lens system for the reference lens system is irrelevant regardless of the configuration of the lens system to be tested. The quality of the lens system can be determined.
Further, even if the lens system to be inspected includes an aspherical lens, a special null lens system is unnecessary.

Further, parallel light flux conversion means for converting the light flux output from the light source into a parallel light flux and making it enter the reference lens system is provided between the light source and the reference lens system, so that the light is transmitted through the lens system to be tested. The luminous flux is also ideally a parallel luminous flux. Therefore, if the characteristics of the lens system to be inspected are different from those of the reference lens system, the light flux transmitted through the lens system to be inspected will have a significant effect, and thus the quality of the lens system to be inspected can be easily judged. be able to.

Alternatively, a point light source conversion means for converting the light beam output from the light source into a point light source and making it enter the reference lens system is provided between the light source and the reference lens system so that the light beam passes through the lens system to be tested. The light flux ideally forms a point image. Therefore, if the characteristics of the lens system to be inspected are different from those of the reference lens system, the light flux transmitted through the lens system to be inspected will have a significant effect, and thus the quality of the lens system to be inspected can be easily judged. be able to.

Further, the luminous flux splitting means is provided between the reference lens system and the reflecting means, and the other split luminous flux is made incident on the reference lens system, so that the sign of the spatial phase distribution is reversed by the reflecting means. The reflected and reflected light beam passes through the lens system under test and the reference lens system. Therefore, by comparing the light fluxes that have passed through the lens system to be tested and the reference lens system, the quality of the lens system to be tested can be easily determined.

Further, by providing the compensating means so that the optical path from the light source to the reflecting means and the optical path from the reflecting means to the lens system to be inspected via the light beam splitting means are aberrationally equal, the lens system to be inspected is provided. When the characteristics are close to those of the reference lens system, since the light beams that have originally passed through the lens system to be inspected and the reference lens system are close to each other, the accuracy of the quality determination of the lens system to be inspected can be increased.

Further, under the condition that the optical path lengths from the reflecting means are substantially equal to the respective light rays reflected by the reflecting means, split by the light flux splitting means, and transmitted through the reference lens system and the lens system under test. By providing an interfering means for interfering the light fluxes of the two, the two light fluxes that have passed through the lens system to be tested and the reference lens system can be made to interfere, and by observing the interference fringes, it is easy to determine the quality of the lens system to be tested. It can be performed. Further, by providing the detection means for detecting the interference fringes obtained by the interference means, it becomes possible to automate the quality judgment of the lens system to be inspected.

Further, as the interference means, there is provided a second light beam splitting means provided on the side opposite to the light beam splitting means with respect to the reference lens system, for splitting the light beam transmitted through the reference lens system to the light source side, and the lens system under test. The lens to be inspected so that the light beam split by the second light beam splitting means and traveling in a different direction from the light source intersects at a position where the optical path length from the reflecting means is equal. An interference optical system having a simple structure is configured by including a second reflecting means for reflecting the light flux transmitted through the system and a light flux integrating means provided at a position where the light flux intersects and integrating the respective light fluxes in the same direction. be able to.

Alternatively, the quality of the lens system to be inspected can be determined by providing detection means for detecting at least one of the wavefront and the spatial intensity distribution state of the light beam split by the light beam splitting means and transmitted through the lens system to be inspected. It becomes possible to automate.

Further, another lens evaluation apparatus of the present invention comprises a reference lens system having substantially the same structure as the lens system to be inspected and a predetermined optical performance, a light source for outputting a light beam to the reference lens system, A light beam output from the light source and transmitted between the reference lens system and the reflecting means for reflecting the light by reversing the sign of the spatial phase distribution of the light flux and the light flux reflected by the reflecting means. Is provided between the light source and the reference lens system, and a first light beam splitting means for making one of the split light beams incident on the lens system to be inspected and the other light beam incident on the reference lens system. The light flux output from the is transmitted and made incident on the reference lens system,
A second luminous flux splitting means for splitting the luminous flux reflected by the reflecting means and transmitted through the reference lens system to the light source side into two;
First detecting means for detecting at least one of the wavefront and the spatial intensity distribution state of the light beam split by the light beam splitting means and transmitted through the lens system to be inspected, and the second lens which passes through the reference lens system to the light source side. Second detection means for detecting the wavefront and spatial intensity distribution of one of the light fluxes split by the light flux splitting means, an optical path from the light source to the reflecting means, and an inspection path from the reflecting means to the first light flux splitting means. The first compensating means set so that the optical paths to the lens system are equal in aberrations, the second light flux splitting means, the reference lens system, and the first compensating means in order from the light source.
The optical path that reaches the reflecting means via the beam splitting means and the optical path that reaches the first detecting means from the reflecting means via the first luminous flux splitting means, the lens system under test, and the first compensating means are aberrationally equivalent. And a second compensating means set so that Therefore, it is reflected by the first reflecting means,
The luminous flux split by the luminous flux splitting means is transmitted through the lens system under test and the reference lens system, respectively, and the respective luminous fluxes transmitted through the lens system under test and the reference lens system are first and second.
It can be monitored by the detection means. as a result,
The quality of the lens system to be inspected can be easily determined, and the quality determination can be automated.

Between the light source and the reference lens system, the light flux output from the light source is converted into a parallel light flux and is incident on the reference lens system, or the light flux output from the light source is converted into a point light source. By providing the point light source conversion means for making the light incident on the reference lens system, the light flux transmitted through the lens system under test and the reference lens system becomes a parallel light flux or a point image, and the characteristics of the light flux transmitted through the lens system under test and the reference lens system are analyzed. It becomes easy to detect.

Further, for adjusting the intensity of the light beam incident on the reference lens system from the light source between the light source and the reference lens system, between the reflecting means and any one of the light beam splitting means, or immediately before any of the detecting means. By providing the light amount adjusting means, it is possible to prevent the detection value of the detecting means from being saturated even when the output intensity of the light source is high.

Further, a lens system having a positive refracting power including at least one lens is provided between the beam splitting means and the reflecting means, which are located closer to the reflecting means than the reference lens system, among the beam splitting means. Thus, when the reference lens system and the lens system under test have negative refractive power, or the reference lens system and the lens system under test have strong refractive power, the light flux once converges and diverges again before reaching the reflecting means. Even in such a case, the spread of the light beam incident on the reflecting means can be adjusted to an appropriate size.

Alternatively, a lens system having at least one lens and having a negative refracting power is provided between the beam splitting means and the reflecting means, which are located closer to the reflecting means than the reference lens system, among the beam splitting means. As a result, even if the reference lens system and the lens system under test have strong refracting power and the light flux converges and diverges again before reaching the reflection means, the spread of the light flux incident on the reflection means is moderately increased. Can be adjusted to

By using any one selected from the phase conjugate element and the quasi-phase conjugate element as the reflecting means, the sign of the spatial phase distribution of the light beam incident on the reflecting means can be reversed. Further, by using a non-linear optical crystal as the reflecting means, it is possible to reverse the sign of the spatial phase distribution of the luminous flux incident on the reflecting means and at the same time reflect the incident luminous flux, which simplifies the structure of the reflecting means. You can

Further, as one of the light beam splitting means, any one selected from a polarization-independent half mirror and a polarization-dependent polarization beam splitter is used, and a glass having a thickness equivalent to the optical path length is used as the compensating means. By using the plate and the ND filter as the light quantity adjusting means, the configuration of the optical system of the lens evaluation device can be simplified and the manufacturing cost of the device can be reduced. Further, by using, as the light amount adjusting means, one of a plurality of ND filters which are provided interchangeably and have different densities and an ND filter which changes spatially in a stepwise or continuous manner, the light amount is adjusted. Can be facilitated.

Further, at least one of the light source, the reference lens system, the reflecting means, the respective light beam splitting means, the lens system to be inspected, and the respective detecting means has a function capable of adjusting the position and the posture thereof, so that the lens evaluation apparatus can be realized. It is possible to make fine adjustments, and it is possible to improve the quality determination accuracy of the lens system to be tested. Further, by using a laser as a light source, a coherent length can be obtained, and the optical system having each of the above configurations can be easily configured. Further, by providing the return light removing means immediately in front of the light source, it is possible to stabilize the output of the laser and improve the quality determination accuracy of the lens system under test.

Further, the output from each detecting means is fetched,
A function to determine the quality of the lens system to be compared by comparing the amount of deviation of the characteristics of the light flux that has passed through the reference lens system and the lens system to be tested with a value that has been input in advance, or The detection result of the interference fringes obtained by interfering the transmitted light flux with the light flux reflected by the reflection means and transmitted through the lens system to be inspected is compared with the data of the allowable range of the interference fringes which has been input in advance, and the lens to be inspected By providing the function of determining the quality of the system, the quality determination of the lens system to be tested can be automated.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of a lens evaluation device of the present invention.

FIG. 2 is a diagram showing a configuration of a second embodiment of a lens evaluation device of the present invention.

FIG. 3 is a diagram showing a configuration of a third embodiment of a lens evaluation device of the present invention.

FIG. 4 is a diagram showing a configuration of a fourth embodiment of a lens evaluation device of the present invention.

FIG. 5 is a diagram showing a configuration of a fifth embodiment of a lens evaluation device of the present invention.

FIG. 6 is a diagram showing the configuration of a sixth embodiment of the lens evaluation device of the present invention.

FIG. 7 is a diagram showing a configuration of a seventh embodiment of a lens evaluation device of the present invention.

FIG. 8 is a diagram showing a configuration of an eighth embodiment of a lens evaluation device of the present invention.

FIG. 9 is a diagram showing the configuration of a ninth embodiment of a lens evaluation device of the present invention.

FIG. 10 is a diagram showing the configuration of a tenth embodiment of a lens evaluation device of the present invention.

FIG. 11 is a diagram showing a configuration of an eleventh embodiment of a lens evaluation device of the present invention.

FIG. 12 is a diagram showing a configuration of a twelfth embodiment of a lens evaluation device of the present invention.

FIG. 13 is a diagram showing the configuration of a thirteenth embodiment of the lens evaluation device of the present invention.

FIG. 14 is a diagram showing a configuration of a fourteenth embodiment of a lens evaluation device of the present invention.

FIG. 15 is a diagram showing the configuration of a fifteenth embodiment of the lens evaluation device of the present invention.

FIG. 16 is a diagram showing the configuration of a sixteenth embodiment of the lens evaluation device of the present invention.

FIG. 17 is a diagram showing the configuration of a seventeenth embodiment of the lens evaluation device of the present invention.

FIG. 18 is a diagram showing a configuration of a conventional lens evaluation device.

[Explanation of symbols]

101, 201, 301, 401, 501, 601, 7
01,801,901,1001,1101,120
1,1301,1401,1501,1601,170
1, 1801: light source 102, 203, 303, 402, 503, 603, 7
03,804,904,1001,1104,120
4,1304,1402,1502,1603,170
4: Reference lens 105, 206, 306, 405, 506, 606, 7
06,807,907,1006,1107,120
7,1307,1406,1506,1606,170
7, 1803: Lens to be inspected 104, 205, 305, 404, 505, 605, 7
05,806,906,1005,1106,120
6,1306,1405,1505,1605,170
6: (first) reflecting member 103, 204, 304, 403, 504, 604, 7
04,805,905,1004,1105,120
5,1305,1403,1503,1604,170
5: (First) light beam splitting member 202, 502, 802, 1102, 1702: parallel light beam conversion unit 302, 602, 902, 1202: point light source conversion unit 406, 507, 607, 707, 709, 808, 8
10,908,910,1010,1111,121
1, 1309, 1607, 1609, 1711: Detection unit 702, 803, 903, 1002, 1103, 120
3, 1602, 1703: Second luminous flux splitting members 708, 809, 909, 1007, 1108, 120
8, 1308, 1608, 1708: Compensating member 1009, 1110, 1209, 1709: Second reflecting member 1008, 1110, 1210, 1710: Luminous flux integrating member 1302: Return light removing member 1303: Light amount adjusting member 1404: Positive refracting power Lens 1504: Negative refractive power lens 1610, 1712: Signal processing unit 1611: Input unit 1612, 1713: Display unit

Claims (28)

[Claims] 1. A reference lens system having substantially the same structure and a predetermined optical performance as the lens system to be inspected, a light source for outputting a light beam to the reference lens system, and the reference lens output from the light source. Reflecting means for reversing the sign of the spatial phase distribution of the light flux transmitted through the system and reflecting the light flux reflected by the reflecting means, and splitting one light flux into the test lens system. A lens evaluation device comprising: a light beam splitting means. 2. Between the light source and the reference lens system,
The lens evaluation device according to claim 1, further comprising a parallel light beam conversion unit that converts a light beam output from the light source into a parallel light beam and makes the light beam incident on the reference lens system. 3. Between the light source and the reference lens system,
The lens evaluation device according to claim 1, further comprising point light source conversion means for converting a light beam output from the light source into a point light source and causing the light source to enter the reference lens system. 4. The light beam splitting means is provided between the reference lens system and the reflecting means, and causes the other split light beam to enter the reference lens system.
The lens evaluation device according to any one of 1. 5. An optical path from the light source to the reflecting means,
5. The lens evaluation device according to claim 1, further comprising compensating means for making the optical path from the reflecting means to the lens system under test through the light beam splitting means equal in terms of aberration. 6. An optical path length from the reflecting means is substantially equal to each of the light fluxes reflected by the reflecting means, split by the light flux splitting means, and transmitted through the reference lens system and the lens system under test. The lens evaluation apparatus according to any one of claims 1 to 5, further comprising an interference unit that causes the respective light beams to interfere with each other under the following conditions. 7. The lens evaluation apparatus according to claim 6, further comprising a detection unit that detects an interference fringe obtained by the interference unit. 8. The second beam splitting means is provided on the opposite side of the light beam splitting means with respect to the reference lens system, and divides the light beam transmitted through the reference lens system to the light source side. A light beam provided on the side opposite to the light beam splitting means with respect to the lens system to be inspected, split by the second light beam splitting means and traveling in a different direction from the light source, and an optical path length from the reflecting means are equal to each other. Second reflection means for reflecting the light flux transmitted through the lens system to be intersected so as to intersect at a position, and light flux integration means provided at a position where the light flux intersects and integrating the respective light fluxes in the same direction. The lens evaluation device according to claim 6 or 7. 9. The detecting means for detecting at least one of a wavefront and a spatial intensity distribution state of a light beam split by the light beam splitting means and transmitted through the lens system to be tested. The lens evaluation device described in 1. 10. A reference lens system having substantially the same structure as the lens system to be tested and a predetermined optical performance, a light source for outputting a light beam to the reference lens system, and a reference lens output from the light source. Reflecting means for reversing the sign of the spatial phase distribution of the light flux transmitted through the system and reflecting, provided between the reference lens system and the reflecting means, dividing the light flux reflected by the reflecting means, A first light beam splitting means for making one of the split light beams incident on the lens system to be inspected and the other light beam incident on the reference lens system; and a light beam provided between the light source and the reference lens system, A second luminous flux component that splits the luminous flux output from the light source into the reference lens system and the luminous flux reflected by the reflecting means and transmitted through the reference lens system to the light source side. Means, first detecting means for detecting at least one of a wavefront and a spatial intensity distribution state of the light beam split by the first light beam splitting means and transmitted through the lens system under test, and the reference lens system. Second detecting means for detecting a wavefront and a spatial intensity distribution of one of the light fluxes transmitted to the light source side and split by the second light flux splitting means; an optical path from the light source to the reflecting means; First compensating means set so that the optical path from the reflecting means to the lens system to be tested through the first luminous flux splitting means becomes equal in aberration, and the second luminous flux splitting in order from the light source. Means, the reference lens system, an optical path that reaches the reflecting means via the first luminous flux splitting means, and the first luminous flux splitting means from the reflecting means, the lens system under test, and the first compensating means. After the first detection hand Lens evaluation device in which the optical path is provided and a second compensation means which is set to be the aberration equivalent, the reaching the. 11. A parallel light beam conversion means for converting a light beam output from the light source into a parallel light beam and making the light beam incident on the reference lens system, between the light source and the reference lens system. Lens evaluation device. 12. The point light source conversion means for converting the light flux output from the light source into a point light source and causing the light flux to enter the reference lens system, between the light source and the reference lens system. Lens evaluation device. 13. The light amount adjusting means for adjusting the intensity of a light beam incident on the reference lens system from the light source is provided between the light source and the reference lens system. Lens evaluation device. 14. A light amount adjusting means is provided between the reflecting means and any one of the light beam splitting means.
The lens evaluation device according to any one of 1. 15. The lens evaluation device according to claim 1, further comprising a light amount adjusting unit provided immediately before any one of the detecting units. 16. A positive refracting power including at least one lens is provided between the reflecting means and the luminous flux dividing means located on the reflecting means side of the reference lens system among the luminous flux dividing means. A lens system is provided, and the lens system is provided.
The lens evaluation device according to any one of 1. 17. A negative refracting power including at least one lens is provided between the reflecting means and the luminous flux dividing means positioned on the reflecting means side of the reference lens system among the luminous flux dividing means. A lens system is provided, and the lens system is provided.
The lens evaluation device according to any one of 1. 18. The lens evaluation device according to claim 1, wherein the reflecting means is one selected from a phase conjugate element and a quasi-phase conjugate element. 19. The lens evaluation apparatus according to claim 1, wherein the reflecting means is a nonlinear optical crystal. 20. The lens evaluation according to claim 1, wherein any one of the light beam splitting means is selected from a polarization-independent half mirror and a polarization beam splitter having polarization dependency. apparatus. 21. The lens evaluation apparatus according to claim 1, wherein the compensating means is a glass plate having a thickness equivalent to an optical path length. 22. The lens evaluation device according to claim 13, wherein the light amount adjusting means is an ND filter. 23. The light amount adjusting means is one selected from a plurality of ND filters which are exchangeably provided and have different densities, and an ND filter in which the densities vary spatially stepwise or continuously. Item 23. A lens evaluation device according to item 22. 24. At least one of the light source, the reference lens system, the reflection means, each of the light beam splitting means, the lens system to be inspected, and each of the detection means has a function of adjusting its position and posture. The lens evaluation device according to claim 1. 25. The lens evaluation device according to claim 1, wherein the light source is a laser. 26. The lens evaluation apparatus according to claim 25, further comprising return light removing means immediately before the light source. 27. The output from each of the detecting means is fetched, the deviation amount of the characteristic of the light flux transmitted through the reference lens system and the lens system under test is compared with a pre-input value, and the lens under test is tested. 27. The lens evaluation apparatus according to claim 1, which has a function of determining whether the system is good or bad. 28. A detection result of an interference fringe obtained by interfering a light flux reflected by the reflecting means and transmitted through the reference lens system with a light flux reflected by the reflecting means and transmitted through the lens system under test, 13. The lens evaluation apparatus according to claim 10, which has a function of comparing input allowable range data of interference fringes and determining pass / fail of the lens system to be inspected.