JP3590508B2 - Optical system assembly adjustment device and assembly adjustment method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an assembly adjustment device and an assembly adjustment method for a general optical system such as a photographic lens.
[0002]
[Prior art]
Generally, strict tolerances are required for optical systems that require high imaging performance, such as photographic lenses. However, in the case of a photographic lens composed of a plurality of single lenses, even if the tolerance of the shape and refractive index of each lens is small, the influence of the tolerance of each lens is synergistic, and the focal length and the rear end of the lens on the optical axis. The distance from the focal plane (hereinafter, referred to as back focus) may greatly change.
[0003]
[Problems to be solved by the invention]
As described above, in a conventional optical system using a combination of a plurality of lenses, the focal length and the back focus deviate from their nominal values, sometimes exceeding the allowable range of the use conditions. For example, there is a case where the actual focal length becomes 2500 mm in spite of the fact that the nominal value of the focal length is 3000 mm.
[0004]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and easily and accurately assembles and adjusts an optical system so that deviations from a nominal value of a focal length and a back focus are reduced. It is an object of the present invention to obtain an assembly adjustment device and an assembly adjustment method for an optical system that can perform the adjustment.
[0005]
[Means for Solving the Problems]
An apparatus for adjusting and assembling an optical system according to the present invention is provided between a light source and an optical system for irradiating the optical system having a plurality of lenses with a light beam, and irradiating the optical system with the light beam. Shielding means for changing the area, and detection means provided at a design nominal position of the back focus of the optical system and detecting the back focus of the optical system by detecting the position of the center of gravity of the intensity distribution of light passing through the optical system It is provided with.
[0006]
According to a second aspect of the present invention, there is provided an apparatus for adjusting and assembling an optical system, wherein a detecting means having a CCD for receiving light passing through the optical system and an arithmetic unit connected to the CCD is used.
[0007]
An assembly adjustment device for an optical system according to a third aspect of the present invention includes a light source for irradiating a light beam to an optical system having a plurality of lenses, and a reflector provided at a design nominal position of a back focus of the optical system. And a detecting means for detecting a back focus of the optical system by calculating a wavefront aberration from interference fringes between light incident on the optical system and light reflected from the reflector.
[0008]
According to a fourth aspect of the present invention, there is provided an apparatus for adjusting and assembling an optical system, wherein a Fizeau type phase measuring interferometer is used as a detecting means.
[0010]
Claim 5 An apparatus for adjusting and assembling an optical system according to the present invention is provided with a light source for irradiating an optical system having a plurality of lenses with light, and a reciprocally movable parallel to the optical axis of the optical system. And a detecting means for detecting.
[0011]
Claim 6 An apparatus for adjusting and assembling an optical system according to the invention includes a point light source arranged at a back focus position on the image space side when an optical system having a plurality of lenses is used, and a light beam incident on the optical system from the point light source. It comprises a stop means for reducing the diameter to a predetermined size, and a detection means arranged on the object space side when the optical system is used and detecting the diameter of a light beam passing through the optical system.
[0012]
Claim 7 A light source for irradiating an optical system having a plurality of lenses with a light beam inclined with respect to an optical axis and rotating a light beam incident on the optical system around the optical axis. And a detecting means disposed at the back focus position of the optical system and detecting the focal length of the optical system from the diameter of the trajectory of the light beam passing through the optical system.
[0014]
Claim 8 The assembly adjustment method of the optical system according to the invention of Irradiating light to the optical system having a plurality of lenses, and detecting the back focus of the optical system, so that the back focus is a design nominal value, adjust the interval between the plurality of lenses, The back focus of the optical system is detected by detecting a change in the position of the center of gravity of the intensity distribution of the light passing through the optical system while changing the irradiation area of the light beam to the optical system.
[0015]
Claim 9 The assembly adjustment method of the optical system according to the invention of Irradiating light to the optical system having a plurality of lenses, and detecting the back focus of the optical system, so that the back focus is a design nominal value, adjust the interval between the plurality of lenses, Detecting the back focus of the optical system by calculating wavefront aberration from interference fringes between the light incident on the optical system and the reflected light from the reflector placed at the nominal position of the back focus of the optical system It is.
[0016]
Claim 10 According to the method of adjusting and assembling an optical system according to the present invention, an interval between a plurality of lenses is adjusted so that a spherical aberration amount calculated from interference fringes becomes a design nominal value.
[0018]
Claim 11 The method for assembling and adjusting an optical system according to the invention includes irradiating an optical system having a plurality of lenses with light, detecting an F-number of the optical system, and setting a plurality of lenses so that the F-number becomes a design nominal value. This is to adjust the interval.
[0019]
Claim 12 The method for assembling and adjusting an optical system according to the invention includes irradiating the optical system with a light beam coaxial with the optical axis and a light beam parallel to the optical axis, and detecting an interval between the two light beams at two places at a predetermined interval. By doing so, the F number is detected.
[0020]
Claim Thirteen The method for assembling and adjusting an optical system according to the invention includes irradiating an optical system having a plurality of lenses with a light beam parallel to the optical axis, and measuring the diameter of the light beam at two places at a predetermined interval to obtain an F-number. Is to be detected.
[0021]
Claim 14 The method for assembling and adjusting an optical system according to the invention is directed to irradiating an optical system having a plurality of lenses with light from a point light source located at a back focus position on the image space side at the time of use, and entering the optical system. The diameter of the light beam is reduced to a predetermined size, and the distance between the plurality of lenses is adjusted so that the diameter of the light beam that has passed through the optical system has a design nominal value.
[0022]
Claim Fifteen The method for assembling and adjusting the optical system according to the invention, irradiates an optical system having a plurality of lenses with a light beam inclined with respect to the optical axis, and rotates the light beam incident on the optical system around the optical axis, The focal length of the optical system is detected from the diameter of the trajectory of the light beam at the back focus position of the optical system, and the distance between the plurality of lenses is adjusted so that the focal length becomes a design nominal value.
[0023]
Claim 16 The method for assembling and adjusting an optical system according to the invention is characterized in that a relationship between a focal length when the optical system is used in the atmosphere and a focal length when the optical system is used in a vacuum is determined, and the focal length in a vacuum is designed. The lens spacing is adjusted in the atmosphere so as to have a nominal value.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is an explanatory diagram showing a method for assembling and adjusting an optical system according to Embodiment 1 of the present invention. In the figure, reference numeral 1 denotes a lens having a refractive power (reciprocal of the focal length) φ1 for imaging a light beam from a point light source at infinity at the focal position, and 2 denotes a lens such that its optical axis coincides with the optical axis of the lens 1. 1 is a lens having a refractive power of φ2 disposed at an interval d behind, 3 is a marginal ray passing through the lens 1 at a height h1 from the optical axis, and h2 is a marginal ray from the optical axis of the marginal ray 3 in the lens 2. Height.
[0025]
Reference numeral 21 denotes a knife edge as an opaque plate made of an opaque flat plate whose end surface is formed at an acute angle. The knife edge 21 has an area for shielding approximately half of the light beam incident on the lens 1. Reference numeral 22 denotes a slide table for supporting the knife edge 21. The slide table 22 is positioned between a position at which approximately half of the light beam incident on the lens 1 is blocked (the position in FIG. 1) and a position at which the light beam is not blocked. The knife edge 21 is reciprocated.
[0026]
Reference numeral 23 denotes a CCD (imaging detector) whose detection surface is arranged perpendicular to the optical axis and at a nominal design position of the back focus, and 24 denotes an arithmetic unit which performs a numerical operation on the output of the CCD 23. The means 20 has a CCD 23 and an arithmetic unit 24. In addition, as a light source (not shown) in this example, a combination of a laser oscillator and a beam expander is used.
[0027]
Next, an assembly adjustment method will be described. As shown in FIG. 1, the combined focal length f of the optical system _net Can be considered as the distance between the intersection of the straight line (dashed line in the figure) extending the peripheral ray 3 behind the lens 2 and the peripheral ray 3 before the lens 1 and the focal position. Therefore, by adjusting the back focus bfl of the lens 2 and the height h2 of the peripheral ray 3 from the optical axis of the lens 2 to the design value, the focal length can be set to a desired value without directly measuring the focal length. Can be a value.
[0028]
That is, the composite focal length f of the lens 1 and the lens 2 _net Is f _net = 1 / (φ1 + h2 · φ2) (Expression 1) When the refractive powers of the lenses 1 and 2 are different from each other by Δφ1 and Δφ2 due to processing tolerance, respectively, the combined focal length f _net Change Δf _net Is Δf _net / F _net = -F _net (Δφ1 + h2Δφ2 + Δh2φ2) (Expression 2). Here, Δh2 is a change in height of the marginal ray 3 from the optical axis 5 in the lens 2. From equation 2, it can be seen that in a lens in which a lens having a processing tolerance is combined, the focal length change Δf due to the processing tolerance _net Is f _net It can be seen that it increases in proportion to.
[0029]
On the other hand, when it is not possible to reduce the change in the focal length by making the processing tolerance strict, the lens distance can be adjusted while measuring the focal length, and the focal length can be set to the target value. The principle is that by adjusting the lens interval, h2 on the right side of the above equation 1 is made arbitrary, and as a result, f2 _net Is optional.
[0030]
Hereinafter, a case will be described in which the changes Δφ1 and Δφ2 due to the tolerance of the refractive powers φ1 and φ2 of the lenses 1 and 2 are sufficiently smaller than the allowable error of the focal length. Here, bfl of the lens 2 is bfl = (h2 / h1) f _net = H2f _net It is represented by (Equation 3). From Equation 3, the variation Δbfl due to the tolerance of bfl when the lens interval d is the design nominal position is Δbfl = Δh2 (∂bfl / ∂h2) + Δf _net (∂bfl / ∂f _net ) = Δh2f _net + Δf _net h2 (Equation 4).
[0031]
Here, if the lens group interval is adjusted so that Δbfl = 0, then Δf _net / F _net = −Δh2 / h2 (Equation 5) is established. That is, by adjusting the lens interval d so that the back focus bfl becomes a design nominal value, the focal length f _net Can be said to be suppressed to about the fluctuation of h2.
[0032]
On the other hand, if the distance between the image point of the lens 1 and the lens 1 is x1, and the distance between the object point of the lens 2 and the lens 2 is x2, the relationship of h1: h2 = x1: x2 (formula 6) holds. Further, x2 = h2 (1 / φ1) (Expression 8) is obtained from x1 = φ1 (Expression 7). Here, in the image forming relationship of the lens 2, by adjusting bfl, that is, the image point to the design nominal value, the object point which is the conjugate point inevitably has almost the design nominal value. Therefore, the change Δx2 of x2 is expressed as Δx2 = Δh2 (∂x2 / ∂h2) + Δφ1 (∂x2 / ∂φ2) ≒ 0 (Equation 9). Further, from Expressions 8 and 9, Δh2 / h2 ≒ Δφ1 / φ1 (Expression 10) is obtained.
[0033]
From Equations 5 and 10, Δf _net / F _net ≒ −Δφ1 / φ1 (Equation 11) is obtained. That is, by adjusting the lens interval d so that the back focus bfl becomes a design nominal value, Δfnet can be set to about Δφ1.
[0034]
Therefore, a method of setting the back focus bfl to a design nominal value will be described. By placing the CCD 23 at the back focus position of the design nominal, the light intensity distribution at the converging point can be obtained. The light intensity distribution detected by the CCD 23 changes depending on whether or not the light beam is blocked by the knife edge 21. Here, when bfl deviates from the design nominal position, the position of the center of gravity of the light intensity distribution changes depending on the presence / absence of the light flux, but when bfl is at the design nominal position, depending on the presence / absence of the light flux, The position of the center of gravity of the light intensity distribution does not change.
[0035]
Therefore, while maintaining the distance between the lens 2 and the CCD 23 at the design nominal value of bfl, the actual focal length is set by setting the lens distance d such that the position of the center of gravity of the light intensity distribution does not change depending on the presence or absence of light flux. Can also be a design nominal value. Note that the center of gravity of the light intensity distribution is calculated by processing the output of the CCD 23 with the arithmetic unit 24.
[0036]
As described above, the light intensity distribution is detected by the CCD 23 and the arithmetic unit 24 while the light beam is shielded / released by the knife edge 21 and the lens interval is adjusted, so that the focal length and the back focus are easily set to the design nominal values. Therefore, the assembly adjustment of the optical system can be performed more accurately. For example, when the nominal value of the focal length is 3000 mm, the actual focal length may be 2500 mm in the past, but by performing the adjustment of the present invention, the deviation of the focal length can be reduced to about ± 1 mm. Could be reduced.
[0037]
As a method of measuring the focal length, a nodal slide method described in, for example, Japanese Industrial Standard B7094-1978 "Method of measuring the focal length of a photographic lens" is also known, but in this method, It was necessary to use a device whose overall length was larger than the focal length, and the measurement operation was also troublesome. On the other hand, according to the method of the present invention, the size of the device can be sufficiently reduced, and the operation can be facilitated.
[0038]
In the above example, the knife edge 21 is moved between the position where the light flux is not blocked and the position where the light beam is blocked, but it is sufficient that the change in the center of gravity of the light intensity distribution can be detected. However, the present invention is not limited to this.
[0039]
Embodiment 2 FIG.
In the first embodiment, the distance between the lenses 1 and 2 is adjusted by detecting a change in the position of the center of gravity of the light intensity distribution. However, another method may be used as long as it can detect the back focus. For example, as shown in FIG. 2, the reflector 15 is placed at the back focus position of the design nominal, the wavefront aberration is calculated from the interference fringe between the incident light and the reflected light, and the lens distance is set so that the defocus component is minimized. d may be adjusted. As a detecting means for detecting an interference fringe and obtaining a wavefront aberration, for example, a Fizeau type phase measuring interferometer 16 is used.
[0040]
Embodiment 3 FIG.
Further, the lens distance d can be adjusted using another aberration amount instead of the defocus component. For example, among the wavefront aberrations calculated from the interference fringes, the lens interval d may be adjusted so that the third-order or higher-order spherical aberration amount becomes a design nominal value. In particular, when there are three or more lenses, since there are two or more lens intervals that can be adjusted, there is a possibility that aberrations may be shifted even if only the focal length is adjusted. On the other hand, by adjusting the lens interval d using bfl and the wavefront spherical aberration, not only the focal length but also the amount of aberration can be reduced.
[0041]
Embodiment 4 FIG.
Next, FIG. 3 is an explanatory diagram showing a method of assembling and adjusting an optical system according to Embodiment 4 of the present invention. In the drawing, reference numeral 25 denotes a laser oscillator which oscillates a laser beam coaxial with the optical axis, 26 denotes a laser oscillator which is parallel to the optical axis and oscillates a laser beam having an incident height h1 in the lens 1, and 27 denotes a laser oscillator. This is a slide table for freely moving the CCD 23 in a direction parallel to the optical axis.
[0042]
Next, the operation will be described. When the back focus is different from the design nominal value, the output of the CCD 23 has two bright spots. On the other hand, when the back focus coincides with the design nominal value, the two laser beams cross on the CCD 23, so that the number of bright spots becomes one. Therefore, by adjusting the lens interval d so that the number of bright spots becomes one, bfl can be easily set to a design nominal value, and the assembly adjustment can be easily and accurately performed without increasing the size of the apparatus. be able to.
[0043]
Specifically, it is easy to emit a laser beam alternately from the laser oscillators 25 and 26, detect the center of gravity of the intensity distribution of the transmitted light by the detection means 20, and adjust the lens interval d so that the centers of gravity overlap. is there. Further, a method is also possible in which the colors of the lasers from the laser oscillators 25 and 26 are set to different colors, and the light received by the CCD 23 is image-processed and the position of the bright spot is viewed on a monitor.
[0044]
In the above example, the laser from the laser oscillator 25 is coaxial with the optical axis. However, it is not always necessary to overlap the laser with the optical axis, and it is sufficient if a plurality of laser beams can be incident parallel to the optical axis.
[0045]
Embodiment 5 FIG.
In each of the above examples, the case where the change amounts Δφ1 and Δφ2 due to the tolerance of the refractive powers φ1 and φ2 of the lenses 1 and 2 are sufficiently smaller than the allowable error of the focal length has been described. Therefore, by adjusting bfl to the design nominal value, h2 also approached the design nominal value, and the focal length could be made almost the desired value. However, if the error in the refractive power of the lenses 1 and 2 is large, it is necessary to measure the amounts corresponding to h2 and bfl, respectively.
[0046]
In such a case, first, bfl is detected by the apparatus shown in FIG. 3 in the same manner as in the fourth embodiment. After that, the distance Δhi between the two bright spots at the position where the slide base is moved by Δz is measured. At this time, since there is a relationship of h2: bfl = Δhi: Δz (Equation 12), Δhi / Δz becomes the design nominal value h2 / bfl, that is, the F number (in this example, specifically, the F number The focal length can be adjusted to a desired length by adjusting the lens interval d so that [1/2] becomes a design nominal value.
[0047]
Specifically, the operation of placing the CCD 23 at the actual back focus position, that is, the position where the two luminescent spots overlap, moving the CCD 23 by ΔZ therefrom, and measuring Δhi is repeated while adjusting the lens interval d. Δhi / Δz is made equal to the design nominal value h2 / bfl.
[0048]
Embodiment 6 FIG.
Although the laser oscillators 25 and 26 are used in the above example, another light source may be used instead of the laser light. For example, the collimated light having the radius h1 is incident on the lens 1, the light flux diameters are measured at two places separated by Δz by the CCD 23, and the same adjustment as in the fifth embodiment can be made by converting the light flux into h2 / bfl. .
[0049]
Embodiment 7 FIG.
Further, in Embodiments 1 to 6, light is incident from the object space side during use, but the same effect can be obtained by placing a light source on the image space side during use. For example, as shown in FIG. 4, the point light source 31 is placed at the position of bfl, and the object space side in use when the light beam diameter of the lens 2 is reduced to h2 by the shielding plate (aperture means) 32 having the hole 32a. The focal length can be set to a desired value, and the light source can be easily configured, even if the light beam diameter is measured and the lens interval d is adjusted so that the light beam diameter becomes a design nominal value. The measurement of the luminous flux diameter may be performed by, for example, the detection unit 35 having the CCD 33 and the arithmetic unit 34.
[0050]
Embodiment 8 FIG.
FIG. 5 is an explanatory diagram showing an assembly adjustment method of an optical system according to Embodiment 8 of the present invention. In the figure, reference numeral 41 denotes a laser oscillator for emitting a laser beam 43 coaxial with the optical axis of the optical system, and reference numeral 42 denotes a laser beam 43 emitted from the laser oscillator 41 at an arbitrary angle on a meridional plane (a plane including the optical axis). It is a prism that refracts only by θ, and the angle θ is adjustable. 44 is a light source having a laser oscillator 41 and a prism 42, 45 is a CCD for receiving the laser beam 43 passing through the optical system, 46 is an arithmetic unit connected to the CCD 45, 47 is a detecting means having a CCD 45 and an arithmetic unit 46. is there.
[0051]
Next, the operation will be described. First, the actual back focus of the optical system including the lenses 1 and 2 is measured, and the CCD 45 is disposed there. In this state, when the laser beam 43 is emitted from the laser oscillator 41 and the prism 42 is rotated once around the optical axis, the trajectory of the laser beam 43 on the CCD 45 becomes a circle. Measure with
[0052]
At this time, the focal length f _net And hi are given by f _net = Hi · tanθ, and by measuring hi, f _net Can be measured. Therefore, from hi to f _net And the f _net The lens distance d may be adjusted so that is a design nominal value.
[0053]
The means for changing the angle of the laser beam 43 is not limited to the prism 42. For example, the angle of the laser oscillator 41 itself may be offset by θ with respect to the optical axis, or reflected by using a mirror. Is also good.
[0054]
Embodiment 9 FIG.
In the above example, the method of adjusting the change in the focal length of the optical system due to the tolerance of the lenses 1 and 2 has been described. And changes in the refractive index of the lens material. Therefore, it is necessary to perform the above adjustment work under the same conditions as the use environment. However, in the case of an optical system used in a vacuum, for example, it is very difficult to perform the adjustment work in a vacuum. Therefore, there is a great merit if the adjustment operation can be performed at normal temperature and normal pressure and the focal length when placed in a vacuum can be a design nominal value.
[0055]
The change in the focal length between the atmosphere and the vacuum can be expressed by Expression 2 in the same manner as the change due to the tolerance. Hereinafter, the tolerance dependency of Δφ1 and Δφ2 will be estimated. Assuming that the lens 1 is a thin plano-convex lens and the surface curvature is 1 / R, the refractive power φ is represented by φ1 = (n−1) 1 / R (Equation 14). Further, assuming that a change in the refractive index n due to a change in atmospheric pressure is Δn, Δφ1 = Δn · 1 / R = ｛Δn / (n−1)｝ φ1 (Equation 15). From Expression 15, it can be seen that the change in the refractive power due to the change in the refractive index from the atmosphere to the vacuum is proportional to φ1.
[0056]
Here, assuming that there is an error due to a tolerance in φ1, the order of the dependence of Δφ1 on the tolerance is, from Equation 15, the order of multiplying the error of the refractive power φ1 by Δn, and Δn is 10 ^-3 Since this is an order, it is about 1/1000 of the error of φ1 due to tolerance. Therefore, it can be said that the tolerance dependency of Δφ1 can be almost ignored. This is the same for the refractive power φ2 of the lens 2.
[0057]
Next, also regarding the optical system in which the lens 1 and the lens 2 are combined, the focal length change Δf due to the change in the refractive index between the atmosphere and the vacuum. _net Can be expressed as Expression 2 similarly to the tolerance dependency. Where f _net Is the focal length in the atmosphere. As described above, the tolerance dependence of Δφ1 and Δφ2 is negligible, and the tolerance dependence of Δh2 is also considered to be negligible due to Δφ1. _net Is f _net Is governed by Therefore, f _net Is a constant condition, Δf _net Is also considered to be almost constant.
[0058]
From the above, the focal length f in the atmosphere is obtained by simulation according to the configuration of the optical system. _net Focal length f in vacuum for _net + Δf _net With the focal length f in the atmosphere by the method of the first to ninth embodiments. _net By adjusting the focal length f in a vacuum _net + Δf _net Can be a design nominal value. Also, Δf _net Varies depending on the configuration of the optical system, and f in air and in vacuum _net May not change, so it is necessary to perform the above simulation for each optical system. Further, as a simulation method, for example, ray tracing may be performed by changing the refractive index of the medium between vacuum and the atmosphere.
[0059]
【The invention's effect】
As described above, according to the first aspect of the present invention, there is provided an optical system assembling / adjusting apparatus, wherein a light irradiation area of a light beam to an optical system is changed by a light shielding unit while a back focus of the optical system is set at a design nominal position. Is used to detect the position of the center of gravity of the intensity distribution of light that has passed through the optical system, so that the back focus of the optical system can be adjusted to the design nominal value by adjusting the lens spacing, and the refractive power is affected by tolerances and other factors. Even in a test lens in which a lens having an error is combined, assembly and adjustment can be easily and accurately performed so that deviations from the nominal values of the focal length and the back focus are reduced, and the apparatus can be made compact.
[0060]
The apparatus for adjusting and assembling an optical system according to the second aspect of the present invention uses a detecting means having a CCD for receiving light passing through the optical system and an arithmetic unit connected to the CCD, thereby simplifying the structure of the apparatus. be able to.
[0061]
According to a third aspect of the present invention, there is provided an apparatus for adjusting and assembling an optical system, wherein a reflector is placed at a nominal design position of a back focus of the optical system, and a wavefront aberration is obtained from interference fringes between light incident on the optical system and light reflected from the reflector. By calculating, the back focus of the optical system is detected by the detection means, so that the back focus of the optical system can be set to a design nominal value by adjusting the lens interval, and there is an error in the refractive power due to tolerance and the like. Even in a test lens in which a lens having a certain combination is used, assembly and adjustment can be easily and accurately performed so that deviations of the focal length and the back focus from the nominal value are reduced, and the apparatus can be made compact.
[0062]
In the apparatus for adjusting and assembling an optical system according to the fourth aspect of the present invention, a Fizeau type phase measuring interferometer is used as the detecting means, so that the apparatus configuration can be simplified.
[0064]
Claim 5 In the apparatus for adjusting and assembling an optical system according to the invention, the detecting means for detecting the F-number of the optical system is provided so as to be able to reciprocate in parallel with the optical axis of the optical system. Can be set to the design nominal value.Even if the test lens is combined with a lens that has a large error in the refractive power due to the effects of tolerances, etc., the accuracy can be easily adjusted so that the deviation from the nominal value of the focal length and back focus is reduced. The assembly can be adjusted well, and the apparatus can be made compact.
[0065]
Claim 6 In the apparatus for adjusting and assembling an optical system according to the invention, a point light source is disposed at a back focus position on the image space side when the optical system is used, and the diameter of a light beam incident on the optical system from the point light source is determined by a stop means. The diameter of the luminous flux passing through the optical system is detected by the detection means arranged on the object space side when the optical system is used, so the back focus of the optical system is designed by adjusting the lens interval. Even if the test lens is combined with a lens that has an error in the refractive power due to the influence of tolerance or the like, the assembly and adjustment can be easily and accurately performed so that the deviation from the nominal value of the focal length and the back focus is reduced. And the device can be made compact.
[0066]
Claim 7 The apparatus for adjusting and adjusting the optical system according to the invention irradiates the optical system with a light beam inclined with respect to the optical axis, rotates the light beam incident on the optical system around the optical axis, and moves the light beam to the back focus position of the optical system. Since the focal length of the optical system is detected from the diameter of the trajectory of the light beam that has passed through the optical system by the arranged detecting means, the back focus of the optical system can be adjusted to the design nominal value by adjusting the lens interval, Even a test lens combining a lens with an error in refractive power due to tolerances, etc. can be easily and accurately assembled and adjusted so that the deviation from the nominal value of the focal length and the back focus is reduced, and furthermore, the apparatus can be adjusted. It can be made small.
[0068]
Claim 8 The method for assembling and adjusting the optical system according to By irradiating light to the optical system having a plurality of lenses, and detecting the back focus of the optical system, so that the back focus is a design nominal value, so as to adjust the interval between the plurality of lenses, Even a test lens in which a lens having an error in refractive power due to the influence of a tolerance or the like can be easily and accurately adjusted for assembly so as to reduce the deviation of the focal length and the back focus from the nominal value. In addition, by detecting the change in the center of gravity of the intensity distribution of light passing through the optical system while changing the irradiation area of the light beam to the optical system, the back focus of the optical system can be more easily and accurately detected. Can be.
[0069]
Claim 9 The method for assembling and adjusting the optical system according to By irradiating light to the optical system having a plurality of lenses, and detecting the back focus of the optical system, so that the back focus is a design nominal value, so as to adjust the interval between the plurality of lenses, Even a test lens in which a lens having an error in refractive power due to the influence of a tolerance or the like can be easily and accurately adjusted for assembly so as to reduce the deviation of the focal length and the back focus from the nominal value. In addition, the back focus of the optical system can be more easily calculated by calculating the wavefront aberration from the interference fringes between the light incident on the optical system and the reflected light from the reflector placed at the nominal position of the back focus of the optical system. And accurately.
[0070]
Claim 10 The method of assembling and adjusting the optical system according to the invention adjusts the interval between the plurality of lenses so that the spherical aberration amount calculated from the interference fringe becomes a design nominal value. can do.
[0072]
Claim 11 The method for adjusting and assembling an optical system according to the invention includes irradiating an optical system having a plurality of lenses with light, detecting an F-number of the optical system, and setting a distance between the plurality of lenses so that the F-number becomes a design nominal value. Therefore, even when the refractive power error due to the influence of tolerance or the like is large, the assembly can be easily and accurately adjusted so that the deviation from the nominal value of the focal length and the back focus is reduced. Can be made small.
[0073]
Claim 12 In the method for adjusting and assembling an optical system according to the invention, a light beam coaxial with the optical axis and a light beam parallel to the optical axis are radiated to the optical system, and an interval between the two light beams is detected at two places at a predetermined interval. Thus, the F number can be easily detected.
[0074]
Claim Thirteen The method for assembling and adjusting an optical system according to the invention includes irradiating an optical system having a plurality of lenses with a light beam parallel to the optical axis, and measuring the diameter of the light beam at two places at a predetermined interval, thereby obtaining an F-number. It can be easily detected.
[0075]
Claim 14 The method for assembling and adjusting an optical system according to the invention is characterized in that an optical system having a plurality of lenses is irradiated with light from a point light source located at a back focus position on the image space side when the optical system is used, and a light beam incident on the optical system The diameter of the lens is adjusted to a predetermined size, and the distance between the multiple lenses is adjusted so that the diameter of the light beam passing through the optical system becomes the design nominal value. Even the test lens can be easily and accurately adjusted so as to reduce the deviation of the focal length and the back focus from the nominal value.
[0076]
Claim Fifteen The method for assembling and adjusting an optical system according to the invention includes irradiating an optical system having a plurality of lenses with a light beam inclined with respect to the optical axis, and rotating the light beam incident on the optical system around the optical axis. The focal length of the optical system is detected from the diameter of the trajectory of the light beam at the back focus position of the system, and the distance between the multiple lenses is adjusted so that the focal length becomes the design nominal value. Even in a test lens in which a lens having a certain combination is used, assembly adjustment can be easily and accurately performed so that the deviation of the focal length and the back focus from the nominal value is reduced.
[0077]
Claim 16 In the method of assembling and adjusting an optical system according to the invention, the relationship between the focal length when the optical system is used in the atmosphere and the focal length when the optical system is used in a vacuum is determined, and the focal length in a vacuum is designed nominally. Since the lens interval is adjusted in the atmosphere so as to obtain a value, even when the optical system is used in a vacuum, a shift in the focal length due to tolerance can be reduced.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a method of adjusting and assembling an optical system according to a first embodiment of the present invention;
FIG. 2 is an explanatory diagram showing a method of adjusting and assembling an optical system according to a second embodiment of the present invention;
FIG. 3 is an explanatory diagram showing a method for assembling and adjusting an optical system according to Embodiment 4 of the present invention;
FIG. 4 is an explanatory diagram showing a method of adjusting and assembling an optical system according to a seventh embodiment of the present invention;
FIG. 5 is an explanatory diagram showing a method of adjusting and assembling an optical system according to an eighth embodiment of the present invention;
[Explanation of symbols]
1, 2 lenses, 15 reflectors, 16 Fizeau type phase measurement interferometer (detection means), 20, 35, 47 detection means, 21 knife edge (light shielding means), 23 CCD, 24 arithmetic unit, 25, 26 laser oscillator ( Light sources), 31 point light sources, 32 shielding plates (aperture means), 44 light sources.

Claims (16)

A light source for irradiating a light beam to an optical system having a plurality of lenses, a light shielding unit provided between the light source and the optical system, for changing an irradiation area of the light beam on the optical system, Detecting means for detecting the back focus of the optical system by detecting the position of the center of gravity of the intensity distribution of the light passing through the optical system, provided at a design nominal position of the back focus of the optical system. Optical system assembly adjustment device. 2. The apparatus according to claim 1, wherein the detecting means includes a CCD for receiving the light passing through the optical system, and an arithmetic unit connected to the CCD. A light source for irradiating a light beam to an optical system having a plurality of lenses, a reflector provided at a nominal position of the back focus of the optical system, light incident on the optical system, and reflected light from the reflector And a detecting means for detecting a back focus of the optical system by calculating a wavefront aberration from interference fringes of the optical system. 4. An apparatus according to claim 3, wherein said detecting means is a Fizeau type phase measuring interferometer. A light source for irradiating light to an optical system having a plurality of lenses, and a detecting means provided to be able to reciprocate in parallel with the optical axis of the optical system and detecting an F number of the optical system. An assembling / adjusting device for an optical system. A point light source arranged at a back focus position on the image space side when an optical system having a plurality of lenses is used, and a diaphragm means for reducing the diameter of a light beam incident on the optical system from the point light source to a predetermined size; A detection unit disposed on the object space side when the optical system is in use and detecting a diameter of a light beam passing through the optical system. A light source that irradiates a light beam inclined with respect to the optical axis to an optical system having a plurality of lenses, and rotates a light beam incident on the optical system around the optical axis, and is disposed at a back focus position of the optical system. And a detecting means for detecting the focal length of the optical system from the diameter of the trajectory of the light beam passing through the optical system. Irradiating light to the optical system having a plurality of lenses, and detecting the back focus of the optical system, so that the back focus is a design nominal value, adjust the interval between the plurality of lenses,
While changing the irradiation area of the light beam to the optical system, by detecting the change in the position of the center of gravity of the intensity distribution of the light passing through the optical system, you and detecting a back focus of the optical system light Academic assembly adjustment method. Irradiating light to the optical system having a plurality of lenses, and detecting the back focus of the optical system, so that the back focus is a design nominal value, adjust the interval between the plurality of lenses,
Detecting the back focus of the optical system by calculating wavefront aberration from interference fringes between the light incident on the optical system and the reflected light from the reflector placed at the nominal position of the back focus of the optical system. light Science-based assembly method of adjusting you characterized. 10. The method according to claim 9 , wherein an interval between the plurality of lenses is adjusted so that a spherical aberration amount calculated from the interference fringes becomes a design nominal value. Irradiating an optical system having a plurality of lenses with light, detecting an F number of the optical system, and adjusting an interval between the plurality of lenses such that the F number becomes a design nominal value. How to adjust the assembly of the optical system. Irradiating the optical system with a light beam that is coaxial with the optical axis and a light beam that is parallel to the optical axis, and detecting the F-number by detecting the interval between the two light beams at two places at a predetermined interval. The method for assembling and adjusting an optical system according to claim 11, wherein: Irradiated with a light beam parallel to the optical axis in an optical system having a plurality of lenses, by measuring the diameter of the light beam at two locations with a predetermined interval, claim 11, characterized in that to detect the F-number An assembling adjustment method of the optical system described in the above. An optical system having a plurality of lenses is irradiated with light from a point light source placed at a back focus position on the image space side during use, and the diameter of a light beam incident on the optical system is reduced to a predetermined size. An assembly adjustment method for an optical system, comprising: adjusting an interval between the plurality of lenses so that a diameter of a light beam passing through the optical system has a design nominal value. An optical system having a plurality of lenses is irradiated with a light beam inclined with respect to the optical axis, and the light beam incident on the optical system is rotated about the optical axis, and the light beam at the back focus position of the optical system is rotated. A method for adjusting the assembly of an optical system, comprising: detecting a focal length of the optical system from a diameter of a trajectory; and adjusting an interval between the plurality of lenses so that the focal length has a design nominal value. Find the relationship between the focal length when using the optical system in the atmosphere and the focal length when using it in a vacuum, and adjust the lens spacing in the air so that the focal length in the vacuum becomes the design nominal value. The method according to any one of claims 8 to 15 , wherein the adjustment is performed.

Images