JPH10197397A - Method and equipment for measuring nonspherical shape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the three-dimensional shape of an optical element having a nonspherical shape, e.g. a nonspherical lens, easily and quickly. SOLUTION: A parallel luminous flux is converged through an illumination lens 35 and projected to the surface of a nonspherical object 10. While varying the interval between the illumination lens 35 and the nonspherical object 10, the luminous flux impinging vertically on each zone of the object 10 is detected and variation in the interval between the illumination lens 35 and the nonspherical object 10 is determined from the moving distance of the illumination lens 35. Subsequently, the height from the optical axis and the radius of curvature are operated for each zone based on the variation of interval, the setting of a variable diaphragm 34 and the focal length of the illumination lens 35. Finally, the shape data of the object 10, i.e., the displacement from the vertex, is operated based on the height, from the optical axis and the radius of curvature operated for each zone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aspherical shape measuring device for measuring the shape of an optical element having an aspherical shape such as an aspherical lens used for a zoom lens or an optical disk.

[0002]

2. Description of the Related Art In order to measure the shape of an aspheric lens,
For example, a scanning type shape measuring device as disclosed in Japanese Patent Publication No. 6-29715 is used. A scanning type shape measuring device is to measure an aspherical shape by scanning an arbitrary cross section with an optical probe or a contact type probe using laser light. Can be measured.

[0003]

Although the above-mentioned scanning type shape measuring apparatus can measure an aspherical shape with high accuracy, it is difficult to adjust and measure the device, but it is not easy to measure and a lot of time is required for the measuring time. There was a problem of cost. In particular, when trying to measure the entire surface of the aspherical shape, there is a disadvantage that the measurement requires a very long time.

The present invention has been made in order to improve such disadvantages, and has an aspherical shape capable of easily and quickly measuring a three-dimensional shape of an optical element having an aspherical shape such as an aspherical lens. It is intended to obtain a measuring device.

[0005]

An aspherical shape measuring apparatus according to the present invention comprises: an object holding means; an irradiation optical system; an imaging optical system; a display means; a diaphragm amount detecting means; a moving distance detecting means; The object holding means is arranged so that the central axis coincides with the optical axis of the irradiation optical system, holds the aspherical optical element as the object to be tested, and the irradiation optical system emits light from the light source. A collimator for converting the luminous flux into a parallel luminous flux, a variable diaphragm for converging the parallel luminous flux from the collimator, and an irradiation of the parallel luminous flux converged by the variable diaphragm as a convergent or divergent luminous flux to be incident on the object. A lens for irradiating the object and an irradiating lens and a distance varying means for varying the distance between the object and the imaging optical system for separating a light beam incident on the object and a light beam reflected from the object. The reflected parallel light beams from the test object separated by the splitter and the beam splitter are collected. Collimator to - and Tarenzu, collimator -
Light detection means for detecting the spot light collected by the lens, the display means displays an image of the spot light by the reflected light beam from the test object by the image signal from the light detection means,
The diaphragm amount detecting means detects the diaphragm amount of the variable diaphragm, the moving distance detecting means detects the moving distance of the irradiation lens moved by the variable distance means, and the arithmetic processing means displays on the display means from each orbicular zone of the test object. When an image of a spot light is formed by the reflected light beam, the moving distance of the irradiation lens detected by the moving distance detecting means and the diaphragm amount of the variable diaphragm detected by the diaphragm amount detecting means are used to detect each annular zone of the test object. It is characterized in that the height from the optical axis and the radius of curvature are calculated.

The distance varying means may move the object holding means holding the aspherical optical element as the object along the optical axis.

[0007] It is also desirable that the irradiation lens be detachable so that different irradiation lenses having different focal lengths are used.

Further, it is preferable that a magnifying optical system is provided between the beam splitter of the image forming optical system and the light detecting means.

Another aspherical surface shape measuring apparatus according to the present invention has an object holding means, an irradiation optical system, an imaging optical system, a display means, a diaphragm amount detecting means, a moving distance detecting means, and an arithmetic processing means. The object holding means is arranged so that the central axis coincides with the optical axis of the irradiation optical system, holds the aspherical optical element as the object to be tested, and the irradiation optical system emits a light beam emitted from the light source. A collimator for converting the collimator into a collimated light beam, a variable diaphragm for converging the collimated light beam from the collimator, an irradiation lens and an irradiation lens for projecting the parallel light beam converged by the variable diaphragm as a convergent or divergent light beam A beam splitter for separating a light beam incident on the object and a light beam reflected from the object, the image forming optical system comprising:
A collimator lens for condensing the reflected parallel light beam from the test object separated by the beam splitter; and a light detecting means for detecting spot light condensed by the collimator lens, and the display means is a light detecting means. An image of a spot light by a reflected light beam from the test object is displayed by an image signal from the object, an aperture amount detecting means detects an aperture amount of a variable aperture, and a moving distance detecting means of the irradiation lens moved by the interval variable means. The moving distance is detected, and the arithmetic processing unit detects the moving distance of the irradiating lens detected by the moving distance detecting means when the image of the spot light by the reflected light flux from each orbicular zone of the test object is formed on the display means. The height and radius of curvature of each orb of the test object from the optical axis and the radius of curvature are calculated from the stop amount of the variable stop and the focal length of the irradiation lens detected by the stop amount detecting means and the respective orb of the test object. Height from the optical axis and the song Shape data of the test object from a radius - characterized by calculating the data.

According to the method of measuring an aspherical shape according to the present invention, a collimated parallel light beam emitted from a light source passes through a variable stop and a beam splitter, and is then converted into a convergent or divergent light beam by an irradiation lens. Incident on the test object which is an optical element, the distance between the irradiation lens and the test object is changed,
When an image of a spot light is formed by a parallel light flux reflected from each orbicular zone of the test object, the distance between the irradiation lens and the test object, the stop amount of the variable stop, and the focal length of the irradiation lens are determined. It is characterized in that the height and the radius of curvature of the orbicular zone from the optical axis are calculated.

In another aspherical shape measuring method according to the present invention, a collimated collimated light beam emitted from a light source passes through a variable stop and a beam splitter, and is then converted into a convergent or divergent light beam by an irradiation lens. When the light is incident on the test object, which is a spherical optical element, the distance between the irradiation lens and the test object is changed, and the image of the spot light is formed by the reflected parallel light flux from each annular zone of the test object. Then, the height from the optical axis and the radius of curvature of each ring zone are calculated from the change in the distance between the irradiation lens and the test object, the stop amount of the variable stop, and the focal length of the irradiation lens, and the calculated ring of the test object is calculated. It is characterized in that the shape data of the test object is calculated from the height of the band from the optical axis and the radius of curvature.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An aspherical shape measuring apparatus according to the present invention is a test apparatus for holding an irradiation optical system and an aspherical optical element, the center axis of which is aligned with the optical axis of the irradiation optical system. It has an object holding means, an imaging optical system, a display means, a diaphragm amount detecting means, a moving distance detecting means, and an arithmetic processing means.

The irradiating optical system has a light source, a collimator lens, a variable aperture, an irradiating lens and an interval varying means. The light emitted from the light source is converted into a parallel light, and the amount of the parallel light is varied by the variable aperture to irradiate the light. The luminous flux is converged on the test object by the lens for use, and the reflected light beam from the surface of the orbicular zone of the test object is converted into a parallel light beam. The interval varying means changes the distance between the irradiation lens and the test object by moving the irradiation lens. The imaging optical system has a beam splitter composed of a half mirror provided between an irradiation lens and a variable stop, and a light detecting means composed of a collimator lens and a CCD. A spot light in which the reflected parallel light flux from the specimen is collected is detected and converted into an image signal. The display means displays an image of a spot light based on a light beam reflected from the test object based on an image signal from the light detection means. The stop amount detecting means detects the stop amount of the variable stop, and the moving distance detecting means detects the moving distance of the irradiation lens changed by the interval changing means.

The light emitted from the light source and passing through the collimator lens, the variable aperture, and the beam splitter is condensed by the irradiation lens and irradiated on the surface of the test object, and condensed on the surface of the test object. While observing the situation, the position of the irradiating lens is changed by the interval varying means so that the light beam from the irradiating lens is focused on the vertex of the test object, and the distance between the irradiating lens and the test object is determined by the focal length f. To match. In this state, the light incident on the surface of the test object and reflected is received by a light detecting means such as a CCD via an irradiation lens and a beam splitter, and an image based on the received light reflected from the test object is displayed. While observing by means, open the aperture of the variable aperture to the maximum and then move the irradiation lens so that the outer edge of the light beam from the irradiation lens is perpendicularly incident on the annular zone N at the outer peripheral end of the test object. Move the irradiation lens up to. The light incident on and reflected by the annular zone N is incident on the light detecting means as spot light via the irradiation lens, the beam splitter and the collimator lens, and an image of the spot light by the annular zone N is formed on the display means. I do. By confirming that the image of the spot light of the annular zone N has been formed, it is possible to detect that the outer edge of the light beam from the irradiation lens is perpendicularly incident on the annular zone N at the outer peripheral end of the test object. it can.

At this time, the arithmetic processing unit calculates a change in the position of the irradiation lens from the time when the distance between the irradiation lens and the test object matches the focal length f based on the movement distance of the irradiation lens detected by the movement distance detecting means. Is calculated from the change in the interval, the stop amount of the variable stop detected by the stop amount detecting means, and the focal length of the irradiation lens. Further, the displacement from the vertex, which is the shape data of the test object, is calculated from the calculated height of the orbicular zone N from the optical axis and the radius of curvature.

This process is repeated successively while moving the irradiation lens while changing the stop amount of the variable stop to obtain the height, radius of curvature, and shape data of the test object from the optical axis of each orbicular zone.

[0017]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. As shown in FIG.
Has an object holding means 2, an irradiation optical system 3, an imaging optical system 4, a display means 5, a diaphragm amount detecting means 6, a moving distance detecting means 7, an input means 8, and an arithmetic processing means 9. The test object holding means 2 is arranged so that its central axis coincides with the optical axis of the irradiation optical system 3, and holds the test object 10, which is an aspheric optical element.

The irradiation optical system 3 has a light source 31, collimator lenses 32 and 33, a variable stop 34, an irradiation lens 35, and a variable distance means 36. The light source 31 emits a light beam for irradiating the test object 10. The collimator lenses 32 and 33 convert the light beam emitted from the light source 31 into a parallel light beam. The variable diaphragm 34 has a diaphragm 341 and a diaphragm varying unit 342, and the aperture varying unit 342 varies the size of the aperture of the diaphragm 341 to vary the amount of parallel light beams from the collimator lenses 32 and 33. The irradiation lens 35 enters the test object 10 with the parallel light beam converged by the variable stop 34 as a convergent light beam or a divergent light beam, and converts the reflected light beam from the surface of the test object 10 into a parallel light beam. The interval varying means 36 moves the irradiation lens 35 to change the distance between the irradiation lens 35 and the test object 10. The imaging optical system 4 has an irradiation lens 35, a beam splitter 41 composed of, for example, a half mirror, a collimator lens 42, and light detecting means 43 composed of, for example, a CCD. The beam splitter 41 detects the light beam incident on the test object 10 and the test object 1.
The light flux reflected from zero is separated. Collimator lens 4
Reference numeral 2 condenses the reflected parallel light flux from the test object 10 separated by the beam splitter 41 and makes the spot light incident on the light detecting means 43. The light detecting means 43 converts the incident spot light into an image signal. The display unit 5 displays an image of a spot light based on a parallel light beam reflected from the test object 10 based on an image signal from the light detection unit 43.

The diaphragm amount detecting means 342 is provided with a diaphragm varying means 34.
2, the amount of aperture of the aperture 341 is detected. The moving distance detecting means 7 includes an irradiation lens 35 that is changed by an interval changing means 36.
The moving distance of is detected. The input means 8 instructs the arithmetic processing means 9 to calculate the shape data of the test object 10 by the operation of the measurer observing the presence or absence of the spot light image on the display means 5.

As shown in the block diagram of FIG. 2, the arithmetic processing means 9 has a radius of curvature arithmetic unit 91, a measured height arithmetic unit 92, a displacement arithmetic unit 93, an output unit 94, and a memory 95. The curvature radius calculating section 91 calculates the distance between the irradiation lens 35 and the test object 10 based on the movement distance of the irradiation lens 35 detected by the movement distance detection means 7 when receiving the calculation instruction of the shape data from the input means 8. Is calculated, and the radius of curvature R (Hj) of the orbicular zone of the test object 10 forming the image at that time is calculated. The measurement height calculator 92 calculates the aperture Dj of the variable aperture 34 detected by the aperture detector 6, the radius of curvature R (Hj) of the orbicular zone of the test object 10 calculated by the radius of curvature calculator 91, and the irradiation lens 35. Is calculated from the optical axis of the annular zone of the test object 10 on which the outer edge of the light beam enters. The displacement calculator 93 calculates the displacement f () of the annular zone from the radius of curvature R (Hj) calculated by the radius of curvature calculator 91 and the height Hj from the optical axis of the zone calculated by the measured height calculator 92. Hj) is calculated. The output unit 94 outputs the curvature radius R (Hj) calculated by the curvature radius calculation unit 91, the height Hj from the optical axis of the ring calculated by the measured height calculation unit 92, and the radius of the ring calculated by the displacement amount calculation unit 93. The displacement f (Hj) is output to the memory 95 and the display unit 5.

The principle of operation when measuring the shape of the test object 10 which is an aspherical optical element with the aspherical shape measuring apparatus 1 configured as described above will be described.

The shape of a rotationally symmetric aspherical surface, such as an aspherical lens, is represented by f (H), the amount of change in the optical axis direction of the aspherical surface,
H is the height from the optical axis, R ₀ is the radius of curvature of the apex of the aspheric surface,
Assuming that C = 1 / R ₀ , K is a conical constant, and Ai is an aspheric coefficient, it can be generally expressed by the following equation (1).

[0023]

(Equation 1)

The first term of the above equation (1) represents a conic curve,
From the second term onward, the deviation from the conic curve is represented by a polynomial. The amount of change f (H) of the aspheric surface in the optical axis direction can be regarded as the amount of change of the radius of curvature R (H) in the annular zone having a height H from the optical axis. The radius of curvature R (H) in the annular zone having a height H from the optical axis can be approximated by the following equation (2).

[0025]

(Equation 2)

In the aspherical shape 12 which is a rotationally symmetric body, the center of curvature Za of the annular zones A to N having heights Ha to Hn from the optical axis.
3 to 4 exist at different positions on the optical axis as shown in FIGS. By detecting a light beam condensed on each of the centers of curvature Za to Zn, the radius of curvature R (H
a) to R (Hn) can be obtained. And each zone A ~
From the curvature radii R (Ha) to R (Hn) of N, the variation amounts f (Ha) to f (Hn) of the aspheric surface in the optical axis direction can be obtained.

Next, as shown in FIG. 3, the heights Ha to Hn from the optical axis are measured by the aspherical shape measuring apparatus 1 constructed as described above.
The operation when measuring the shape of the test object 10 which is an aspherical optical element in which the center of curvature Za to Zn of the annular zone moves away from the apex as the radius of the circle increases becomes larger, with reference to the operation process diagram of FIG. explain.

Collimator lens 3 emitted from light source 31
The light passing through the lenses 2 and 33, the variable stop 34, and the beam splitter 41 is condensed by the irradiation lens 35 and irradiated on the surface of the test object 10, and the state of light condensing on the surface of the test object 10 is observed. Meanwhile, the position of the irradiation lens 35 is changed by the interval changing means 36, and as shown in FIG.
Is focused on the vertex O of the test object 10, and the distance between the irradiation lens 35 and the vertex O of the test object 10 is made to match the focal length f of the irradiation lens 35. In this state, the test object 10
The light reflected at the vertex O passes through the same optical path as the incident light, becomes a parallel light beam at the irradiation lens 35, is reflected by the beam splitter 41, is collected by the collimator lens 42, becomes a spot light, and enters the light detecting means 43. I do. An image of the spot light is formed on the display unit 5. After confirming that the image of the spot light is formed on the display means 5, the irradiation lens 35 is checked.
Can be detected that the luminous flux from the light is focused on the vertex O of the test object 10.

Next, while observing the image by the reflected light from the test object 10 with the display means 5, the opening of the variable stop 34 is opened to the maximum Dn, and the irradiation lens 35 is moved toward the test object 10. When it moves, the spot light formed on the display means 5 once disappears. Then, as shown in FIG. 5B, when the irradiation lens 35 is moved to a position where the outer edge of the light beam from the irradiation lens 35 is perpendicularly incident on the ring N at the outer peripheral end of the test object 10, the ring N The light incident on and reflected by the light passes through the same optical path as the incident light, and becomes a parallel light beam corresponding to the shape 11n of the annular zone N as shown in FIG.
The light is reflected by the splitter 41 and condensed by the collimator lens 42 to become spot light, which is incident on the light detecting means 43, and an image of the spot light is formed on the display means 5. At this time, the reflected light of the light incident on an annular zone other than the annular zone N is scattered and does not become a parallel light beam when passing through the irradiation lens 35, and is not condensed as spot light on the light detecting means 43. Only the reflected light from the annular zone N is collected on the light detecting means 43. By confirming that the image of the spot light of the annular zone N has been formed, it is detected that the outer edge of the light beam from the irradiation lens 35 is vertically incident on the annular zone N at the outer peripheral end of the test object 10. be able to.

At this time, the diaphragm amount detecting means 342 detects the diaphragm amount Dn of the diaphragm 341 by the diaphragm varying means 342 and sends it to the arithmetic processing means 9, and the moving distance detecting means 7 changes the irradiation lens 35 varied by the distance varying means 36. Is detected and sent to the arithmetic processing means 9.

After confirming that a spot light image has been formed by the annular zone N, the input means 8 sends the arithmetic processing means 9
When an instruction to calculate the shape data of the test object 10 is input to the
The radius of curvature calculation unit 91 determines whether or not the movement distance of the irradiation lens 35 input from the movement distance detection means 7 and the focal point of the irradiation lens 35 coincide with the vertex O of the test object 10. , A change Rn in the space between the irradiation lens 35 and the test object 10 is calculated, and the calculated space change Rn is defined as the radius of curvature R (Hn) of the orbicular zone N. The measurement height calculation unit 92 calculates the stop amount Dn of the variable stop 34 detected by the stop amount detection unit 6, the radius of curvature R (Hn) of the orbicular zone N obtained by the curvature radius calculation unit 91, and the focal length f of the irradiation lens 35. Then, the height Hn from the optical axis of the annular zone N of the test object 10 on which the outer edge of the light beam enters is calculated. The displacement amount calculation unit 93 calculates the ring by the above equation (2) from the radius of curvature R (Hn) calculated by the curvature radius calculation unit 91 and the height Hn from the optical axis of the ring zone N calculated by the measured height calculation unit 92. The displacement f (Hn) of the band N is calculated. The output unit 94 stores the calculated displacement amount f (Hn) of the orbicular zone in the memory 95 together with the radius of curvature R (Hn) and the height Hn from the optical axis, and outputs the same to the display means 5 for display.

Next, when the variable stop 34 is stopped down while the change Rn in the distance between the irradiation lens 35 and the test object 10 is kept as it is, the light beam entering the annular zone N at the outer peripheral end of the test object 10 is The image of the spot light due to the annular zone N formed on the display means 5 is blocked by the display means 5 and disappears. Then, the position of the irradiation lens 35 is moved by the interval varying means 36 so that an image of the spot light due to the annular zone of the test object 10 is formed on the display means 5 again, as shown in FIG. Then, the irradiation lens 35 is moved to a position where the outer edge of the light beam from the irradiation lens 35 is perpendicularly incident on the inner annular zone M of the outer annular zone N of the test object 10. Then, as shown in FIG. 6 (b), when a spot light of a reflected parallel light beam having a shape 11m corresponding to the annular zone M is formed by the imaging optical system 4, and the image is displayed on the display means 5, the arithmetic processing means The curvature radius calculator 91 of 9 calculates the change ΔRm in the distance between the irradiation lens 35 and the test object 10 at that time from the moving distance detected by the moving distance detecting means 7, and calculates the sum of the previously detected distance change Rn. (Rn +
ΔRm) is calculated as a radius of curvature R (Hm) of the orbicular zone M. The measured height calculator 92 determines the aperture amount Dm of the variable aperture 34 detected by the aperture amount detection means 6 and the radius of curvature R (H
m) and the focal length f of the irradiation lens 35,
The height Hm of the zero zone M from the optical axis is calculated. The displacement calculator 93 calculates the radius of curvature R (H
m) and the height Hm of the orbicular zone M from the optical axis computed by the measured height computing unit 92, the displacement f (Hm) of the orbicular zone M is computed. This processing is sequentially repeated, and FIG.
As shown in (c), the reflected light 11a from the spherical surface A at the vertex on which the paraxial ray of the test object 10 is incident is detected, and the process ends when the image curvature radius R (Ha) of the spherical surface A at the vertex is obtained. I do.

In this manner, as shown in FIG. 7, the change characteristic of the radius of curvature R (Hj) of each orbicular zone at a height Hj (j = a to n) from the optical axis of the test object 10 is represented by: The displacement f (H
j) can be detected, and the aspherical shape of the test object 10 can be easily measured. Further, the height Hj of the test object 10 from the optical axis and the radius of curvature R (Hj) of each ring zone are determined by the displacement amount f.
The formula (1) indicating the aspherical shape of the test object 10 is created using (Hj), and the aspherical shape of the test object 10 can be specified.

In the above embodiment, the case where the irradiation lens 35 is moved by the interval varying means 36 to obtain the radius of curvature R (Hj) of the orbicular zone J having the height Hj from the optical axis of the test object 10 will be described. However, the object holding means 2 for holding the object 10
May be moved to detect a change in the interval between the irradiation lens 35 and the test object 10.

Further, the irradiation lens 35 is made detachable,
By properly using irradiation lenses having different focal lengths, the measurable range can be expanded for a wide variety of aspherical optical elements.

Further, as shown in FIG. 8, a collimator lens 4 is provided between the beam splitter 41 and the light detecting means 43.
By providing the magnifying optical system 45 that combines the light detecting means 4 and the light detecting means 4, the light reflected from the test object 10 is magnified.
3, the detection sensitivity of the reflected light from each annular zone of the test object 10 can be increased, and the measurement accuracy of the aspherical shape can be further improved.

[0037]

As described above, according to the present invention, a parallel light beam is incident on a surface of a test object which is an aspherical optical element as a convergent or divergent light beam by an irradiation lens. The distance between the test objects is varied to detect a light beam that is vertically incident on each orbicular zone of the test object, and a change in the distance between the irradiation lens and the test object is obtained from the moving distance of the irradiation lens at this time,
The height and radius of curvature of each ring zone from the optical axis are calculated from the change in the distance between the irradiation lens and the test object, the stop amount of the variable stop, and the focal length of the irradiation lens. The radius of curvature of each annular zone of the aspherical optical element can be obtained.

Further, since the displacement from the vertex, which is the shape data of the test object, is calculated from the calculated height of the orbicular zone from the optical axis and the radius of curvature of the test object, the aspherical shape and its characteristics are calculated. Can be easily obtained.

When the distance between the irradiation lens and the test object is changed, the distance between the irradiation lens and the test object can be easily adjusted by moving the test object holding means for holding the test object. The optical system can be varied and the optical system can be further simplified.

Further, by making the irradiation lens detachable and properly using irradiation lenses having different focal lengths, it is possible to measure the shapes of various kinds of aspherical optical elements with one measuring device. .

Further, by providing a magnifying optical system combining a collimator lens between the beam splitter and the light detecting means, the reflected light from the test object can be magnified and incident on the light detecting means. In addition, the detection sensitivity of a light beam that is perpendicularly incident on each orbicular zone of the test object can be increased, and the measurement accuracy of the aspherical shape can be further improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an arithmetic processing unit of the embodiment.

FIG. 3 is an explanatory diagram showing a center of curvature of each of the aspherical annular zones.

FIG. 4 is an explanatory diagram showing the center of curvature of each aspherical annular zone.

FIG. 5 is an operation process chart showing the operation of the embodiment.

FIG. 6 is a display diagram showing an image of reflected light of a test object according to the embodiment.

FIG. 7 is a change characteristic diagram of the height and the radius of curvature of each optical axis obtained according to the embodiment.

FIG. 8 is a configuration diagram illustrating an optical system according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Aspherical surface shape measuring apparatus 2 Object holding means 3 Irradiation optical system 4 Imaging optical system 5 Display means 6 Aperture amount detecting means 7 Moving distance detecting means 8 Input means 9 Arithmetic processing means 10 Object 31 Light source 32, 33 Collimator lens 34 Variable aperture 35 Irradiation lens 36 Interval variable means 41 Beam splitter 42 Collimator lens 43 Light detection means 91 Curvature radius calculator 92 Measured height calculator 93 Displacement calculator 94 Output unit 95 Memory

Claims (7)

[Claims] 1. An object holding means, an irradiation optical system, an imaging optical system, a display means, a diaphragm amount detecting means, a moving distance detecting means, and an arithmetic processing means, wherein the object holding means has a central axis. A collimator for collimating a light beam emitted from a light source into a collimated light beam; A variable aperture for narrowing the parallel light beam from the projector, and an irradiation lens that enters the test object as the convergent or divergent light beam from the parallel light beam narrowed by the variable stop, and varies the distance between the irradiation lens and the test object. A beam splitter for separating a light beam incident on the test object and a reflected light beam from the test object; and an imaging optical system for separating the light beam from the test object separated by the beam splitter. A collimator lens that collects the reflected parallel light beam and a collimator lens Light detecting means for detecting the spot light that has been detected, the display means displays an image of the spot light based on the reflected light beam from the test object based on the image signal from the light detecting means, and the diaphragm amount detecting means has a diaphragm of a variable diaphragm. The moving distance detecting means detects the moving distance of the irradiation lens moved by the variable distance means, and the arithmetic processing means displays on the display means a spot light image by the reflected light flux from each orbicular zone of the test object. When formed, the height and radius of curvature of the test object from the optical axis of each annular zone are determined from the moving distance of the irradiation lens detected by the moving distance detecting means and the stop amount of the variable stop detected by the stop amount detecting means. An aspherical shape measuring device characterized by performing calculations. 2. The aspherical shape measuring apparatus according to claim 1, wherein said variable distance means moves the object holding means holding an aspherical optical element as an object along the optical axis. 3. An irradiation lens having a different focal length, wherein said irradiation lens is detachable.
Or the aspherical shape measuring device according to 2. 4. An aspherical shape measuring apparatus according to claim 3, further comprising an enlargement optical system between said beam splitter of said image forming optical system and said light detecting means. 5. An object holding means, an irradiation optical system, an imaging optical system, a display means, a diaphragm amount detecting means, a moving distance detecting means, and an arithmetic processing means, wherein the object holding means has a central axis. A collimator for collimating a light beam emitted from a light source into a collimated light beam; A variable aperture for reducing the parallel light beam from the light source, and an irradiation lens that enters the test object as a convergent or divergent light beam from the parallel light beam narrowed by the variable aperture, and an interval for moving the irradiation lens along the optical axis. A beam splitter for separating a light beam incident on the object and a light beam reflected from the object, and a reflection from the object separated by the beam splitter. A collimator lens that collects parallel light beams and a collimator lens Light detecting means for detecting the spot light; display means for displaying an image of the spot light by the reflected light beam from the test object based on the image signal from the light detecting means; The moving distance detecting means detects the moving distance of the irradiating lens moved by the variable distance means, and the arithmetic processing unit displays on the display means the spot light images by the reflected light fluxes from the respective annular zones of the test object. When formed, the optical axis of each annular zone of the test object is determined from the moving distance of the irradiation lens detected by the moving distance detecting means, the aperture amount of the variable diaphragm detected by the diaphragm amount detecting means, and the focal length of the irradiating lens. An aspherical shape measuring apparatus, which calculates a height and a radius of curvature of the object from the optical axis and calculates shape data of the object from the calculated height and a radius of curvature of each orbicular zone from the optical axis. . 6. A collimated collimated light beam emitted from a light source passes through a variable stop and a beam splitter, and is converted into a convergent or divergent light beam by an irradiation lens. The distance between the irradiation lens and the test object is changed when the distance between the irradiation lens and the test object is changed, and the image of the spot light is formed by the parallel light flux reflected from each annular zone of the test object. An aspherical shape measuring method, wherein a height from an optical axis and a radius of curvature of each orbicular zone are calculated from a change, an aperture amount of a variable aperture, and a focal length of an irradiation lens. 7. A collimated collimated light beam emitted from a light source passes through a variable stop and a beam splitter, and is converged or divergent by an irradiation lens to an object which is an aspherical optical element. The distance between the irradiation lens and the test object is changed when the distance between the irradiation lens and the test object is changed, and the image of the spot light is formed by the parallel light flux reflected from each annular zone of the test object. The height and radius of curvature of the orbicular zone from the optical axis and the radius of curvature are calculated from the change and the aperture amount of the variable aperture and the focal length of the irradiation lens. An aspherical shape measuring method comprising calculating shape data of a test object.