JPS5837504A - Method and device for centering lens - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to aligning the centers of each of the refractive systems formed by the refractive system on the same axis.

The lens may be mounted on some optical instrument or may be a spectacle lens for vision correction.

In the case of a lens mounted on an optical instrument, the optical axis of the lens must be aligned with the optical axis of its mount, and slight eccentricity with respect to the mount may result in geometric aberrations and/or! It evokes the same kind of jealous changes as those based on rhythmic effects.

These lenses are actually spherical lenses or aspheric lenses of revolution, and plano-concave or plano-convex lenses can be viewed as lenses whose plane is a spherical surface with an infinite radius.

Various methods have been proposed for centering these lenses.

The simplest method is for the holding push or holding sleeve to rest against the lens to be centered by its/its surface. The retaining sleeve has a circular edge or edge which lies in a plane perpendicular to the axis of the retaining sleeve and whose center lies on the axis.

Since the surface on which the lens to be centered rests on the holding sleeve is spherical, its center is automatically located on the axis of the holding sleeve.

In that case, the other surface (the surface opposite the retaining sleeve)
The lens need only be moved while remaining in contact with the retaining sleeve until it is also positioned on the axis of the retaining sleeve.

This operation is generally done approximately and the results are inaccurate.

Multiple retaining sleeves, each with an edge on each side of the lens to be centered, may be used, but moving the lens in contact risks altering its surface.

Other methods have been proposed that are more complex and accurate, but
It takes a long time to operate and requires expensive equipment to carry out.

The lens is rotated about itself about its estimated axis.

This rotation is difficult to coordinate with the in-plane omnidirectional movement required for desired centering.

This makes the corresponding equipment complex and expensive.

Even in the case of eyeglass lenses that are attached to eyeglass frames, it is necessary to accurately know the optical axis to ensure proper attachment to the eyeglass frame.

Also, after determining the optical axis of the spectacle lens, a mark to represent the optical axis is marked on one surface of the lens in order to facilitate its installation.

In any case, the actual operation for determining the optical axis of a spectacle lens is performed visually, requires the use of a front focometer, and often depends on the operator's ability, visual acuity, and attentiveness.

Therefore, with these visual inspection methods, large installations may cause errors.

The general object of the invention is to avoid these drawbacks.

The present invention provides a method for centering a lens with one surface of the lens supported by a holding sleeve, in which a plurality of points on the lens, which are appropriately distributed circularly around the axis of the holding sleeve, are identified by light points. , directing the light flux from the light point toward the analyzer using a plane mirror with a reflective surface inclined with respect to the axis, and arranging the plane mirror around the axis that forms an angle with the perpendicular line drawn to the reflective surface. rotating and recording the transit time of the beam through a fixed reference point of the analyzer and moving the lens in contact with the retaining sleeve as a function of the transit time until the desired centering of the lens is obtained; Provided is a centering method characterized in that the centering method comprises:

In the most preferred practical case, in which the light spots formed according to the invention are distributed along the same circumference about the axis of the holding sleeve and the plane mirror is rotated at a constant speed, the light spots formed according to the invention are The lens is centered when the light fluxes from a point have equal transit times through a fixed reference point of the analyzer.

According to the invention, what is rotated about the axis in order to center the lens in this way is not the lens to be centered, but a separate member, namely a plane mirror.

Therefore, the flooding/draining device according to the invention is very simple.

The fixing device according to the invention has a retaining sleeve for supporting the lens by one surface thereof.
illumination means on one side of the retaining sleeve for forming a plurality of light spots at the support sleeve circularly distributed about the axis of the retaining sleeve; and on the other side of the retaining sleeve. a plane mirror on the axis of the retaining sleeve and an analysis device transverse to the axis of the retaining sleeve, the plane mirror being inclined with respect to said axis and forming an angle between the plane mirror and the normal to the reflective surface of the plane mirror; The analyzer is mounted so as to rotate around an axis containing the light point, and the analyzer is adapted to receive a beam of light emitted from the light point and changed in direction by being reflected by a plane mirror, and is characterized in that it is provided with a fixed reference point. .

The analytical device may - by way of example - consist of a photovoltaic cell and a diaphragm arranged upstream of the photovoltaic cell, the slit of the diaphragm forming the fixed reference point.

The illumination means may have a point light source, for example an electroluminescent diode, and a focusing lens combined with a cover for each light spot to be formed. The cover shields half of the focusing lens according to its diameter cutting the axis of the retaining sleeve.

This creates a sharp transition from light to dark, resulting in more accurate results.

The centering device according to the invention is simple in structure and easy to use, the rotating member is always the same member independent of the lens to be centered, and the centering device is always rotationally fixed on the lens during the centering operation. is in a state.

The features and advantages of the invention will become more apparent from the following detailed description of the embodiments illustrated in the accompanying drawings.

Each figure shows an example in which the present invention is applied to the centering of a concave-convex lens 1o, that is, a lens having spherical surfaces Sl and S2 with curvatures oriented in the same direction.

To center this lens 1o, the centers R1, R21-j of the surfaces s1, S2, respectively, must lie on the axis of the stand on which the lens 1o is mounted after edging.

In FIG. 1 this axis is designated by the reference numeral l.

The centering device according to the invention for centering the lens 10 on the axis A comprises a retaining sleeve 11 known per se for supporting the lens 10 by its surface, for example by the surface s1 as shown. I am prepared to do so.

As shown better in FIG. 1, the retaining sleeve 11 is provided at its free end with an edge 12 for said support in a manner known per se.

According to another embodiment, not shown, the retaining sleeve 11 is simply concentrated at three points on the circumference centered on the axis aA.

Holding S, -+) -F Is the axis of 1 the lens 10?
Assuming that the axis A to be centered with respect to 2-+-1 is
By simply supporting the lens ]O against the edge 12 of the retaining sleeve 11, the center R1 of the surface s1 is automatically located on the axis A, which axis Aid collectively defines the optical axis of the centering device according to the invention. to form.

However, as shown in the second image, the center R2 of the spherical surface S2
11″l: May be spaced apart from axis A.

For the desired centering, therefore, the lens 10 in contact with the holding sleeve 11 must be moved laterally in such a way that the center R2 of its surface S2 is also located on the axis A.

For this purpose, the centering device according to the invention very generally comprises, on one side of the holding sleeve 11, a plurality of light spots distributed circularly around the axis A of the holding sleeve 11, as described below. an illumination device 13 for forming at the holding sleeve 11 and on the other side of the holding sleeve 11 a plane mirror 15 on the axis A of the holding sleeve 11 and transversely to the axis A of the holding sleeve 11; The plane mirror 15 is # inclined with respect to the axis A of the holding sleeve 11, and the plane mirror 150 is
The analyzer 17 is rotatably mounted around an axis R that forms an angle ia with a perpendicular line N drawn to the reflective surface 16, and the analyzer 17 is
The light beam emitted from the light point and changed direction by being reflected by the plane mirror 15 is received as described in detail below, and is received by the fixed reference point 18.
It is equipped with

In the illustrated example, lI light spots T1, T2, T3, T4 are used, which are regularly distributed on the circumference of the holding sleeve 11 about the axis A.

In other words, these light spots T1, T2, T3, and T4 are located on the same circumference, at equal distances from the axis A, and in the same plane at 90° intervals.

In FIG. 1, only λ light spots T1, T3 which lie within the plane of the drawing are actually shown.

However, light point T2 arranged in a cross shape with respect to light points T1 and T3
, T4 is shown in FIG.

The illumination device 13 used in the illustrated embodiment focuses/focuses the light point sources PI, P2, P3, P4 for each light point Tl, T2, T3, T4 to be formed in this way. It is equipped with three parts L1, L2, L3, and L4.

As with light point Tl-74, only light sources P1 and P3 are actually illustrated in FIG. 1, while light sources P2 and P4 are merely shown for their presence.

The point light sources PI, P2, P3, P4 are aligned with the light points T1, T2, T3, T4 generated thereby, two at an interval of 90° to the axis of the retaining sleeve 11 on the same circumference. regularly distributed around.

The same holds true for focus/focus L1, L2, L3, and L4.

Only the L/lens Ll and L3 corresponding to the light point T1.73 are the first.
Illustrated in the figure.

However, all the symbols used Ll, L2, L3, L4
is represented by a dashed line in FIG.

As shown in FIG. 3, the centers of lenses L1 to L4 are
It lies on a circumference C having the same radius d and centered on the axis A of the holding sleeve 11.

As described above, the same applies to the light spots T1, T2, T3, and T4 and the light sources P1, P2, P3, and P4 that are their sources.

In fact, to take advantage of the magnification equal to /, each focusing lens L1, L2, L3, L4 holds three!
11, at twice the focal length, more precisely,
Light spots T1, T2, T3, T4 are arranged at twice the focal length with respect to the cross section to be formed in their vicinity, and corresponding point light sources PL, P2 . P3 and P4 are also arranged at twice the focal length with respect to focus/distortion points L1, L2, L3, and L4.

As shown in FIG. 3, each focusing lens L1, L2, L
3. L4 has a cover C1 that shields each half of the L4,
C2, C3, C4 are combined, one half of which is defined by the diameter cutting the axis IRA of the retaining sleeve 11.

These (D covers CI, C2, C3, C4 belong to the same cover 20 common to all the focusing lenses L1, L2, L3, L4, and the cover 20 is the focusing lens L1, L
2. Half-moon cutouts Dl, D2 at L3 and L4,
It is equipped with D3 and D4.

These cutouts Dl, D2, D:D4 are circular and oriented in the same direction.

The cutouts D1 to D4 are the same, and the focus/Zoo L1,
Each is formed by a semicircle with a radius smaller than the radius of L2, L3, L4 and a diameter cutting toward the axis of the retaining sleeve 11.

As easily understood: 1. Light spots T1, T2, T3, T
4 (formed at the holding sleeve 11 as described above) is for the lens 10 that is about to be lifted out, on one of seven of its surfaces S1 and S2, in the vicinity thereof, or inside the lens lO. That's a certain point.

For the desired centering, these light spots T1, T2, T3 distributed circumferentially around the axis A of the holding sleeve 11
, lens 1 that should be centered on the point that is more specific than T4VC
All operations are performed as if the point effectively belonged to zero.

The support 22 with the centering gear 10 mounted thereon is associated with the holding sleeve 11.

Support 22 does not form part of the invention and is well known per se and will not be described in detail here.

In FIG. 1, this support 22 is simply indicated by a dash-dotted line.

Briefly, the support body 22 moves the lens 10 to be exposed 'II in three directions. These directions are two directions, one parallel to the axis A of the holding sleeve 11 and the other in a plane perpendicular to this axis A and mutually orthogonal.

In the illustrated example, the plane mirror 15 is formed by a wedge-shaped sheet, the front surface of which forms a reflective surface "6, and the rear surface 23 encompassing an angle a with the front surface.

As a variant, the plane mirror 15 may be formed by an ordinary mirror, which is suitably mounted on a tiltable support by its rear face 23, with the rear face 23 forming a support surface on the support.

According to the illustrated embodiment, the rotational axis R of the plane mirror 15, which is perpendicular to the rear surface 23 of the plane mirror 15, is a point on the front surface on the axis A of the holding sleeve 11, that is, the reflective surface 16 of the plane mirror 15.
passes through the center of rotation CR.

The angle a between the perpendicular line N drawn to the reflective surface 16 and the rotational axis R of the plane mirror 150 is a small angle.

Angle a is preferably less than 50.

In the illustrated example, the rotation axis Rfi is rotatably integrated with the output shaft of the synchronous motor 24.

Furthermore, in the illustrated example, the analyzer 17 includes a photovoltaic cell 25,
a diaphragm 26 on the upstream side of the photovoltaic cell 25;
The photovoltaic cell 25 is located generally on the axis A, taking into account the reflection by the plane mirror 15, and is located along the slit (
(on axis A) forms a fixed reference point 18 of the device.

As shown in FIG. 1 by the dashed line, the photovoltaic cell 25 is coupled to an incremental encoder 28, which is itself operated by a synchronous motor.

D is the distance from the rotation center CR of the reflective surface 16 of the plane mirror 15 to the diaphragm 26.

The angle a and distance are determined as follows. That is, the position of the plane mirror 15 and the point light source PIX P2 shown in FIG. 1.4,
P3, P4, the fixed reference point 18 for a given value of the radius d of the circumference along which the focusing lenses Ll, L2, L3, L4 and the corresponding light points T1, T2, T3, T4 are distributed. Plane mirror 1 of the slit of the diaphragm 26 to be formed
In other words, the image at No. 5 is on the axis of the seven focusing lenses, for example, the focusing lens Ll as shown.
A corresponding light point T1 emerges from the analyzer 17 by means of a plane mirror 15.
The distance ygo is determined so that the light beam directed toward passes through the slit as shown by the solid line in FIG.

In that case, mathematical calculations have shown that the radius d1 distance and the angle tJ[ja defined above are approximately related to each other by the following equation.

As a result of the above, for the position of the plane mirror 15 shown in FIGS. 1 to q, only the light beam emitted to the light point L1 is
The light beam passes through the slit of the diaphragm 26 that firmly forms the gauge point 18, reaches the photovoltaic cell 25, and is emitted at a light point T:3 diametrically opposite the light point TI in FIG. 1, as shown by the broken line. , the light beams emitted to the light points TIXT3 and T4 are captured by the diaphragm 26.

When the plane mirror 15 is rotated by /g0° with respect to its previous position (see FIG. 5), only the light beam from the light spot T3 passes through the slit tf of the diaphragm 26.

To simplify the explanation of the centering method according to the invention, it is assumed that everything takes place in the image plane P, which is a plane perpendicular to the axis A and containing the image 26' of the diaphragm 26 with respect to the plane mirror 15.

This plane, that is, the image plane P, is represented by a seven-dot chain line in FIG. 11:3.

This forms the plane of FIG.

In FIG. 6, D'1, D'2, D'3, D'4 (j shown by solid lines are completely attached to the retaining sleeve 11 when the lens is not supported or even if the lens is present). This is an image of cutouts D'l, D2, Dp3, and D4 that occur on the image plane P when the image plane P is centered.

Images D'tS[)'2, D'3, and D'4 are light points TIXT
2. This is a light spot caused by the luminous flux emitted at T3.74.

When the plane mirror 15 rotates around the rotation axis IwR, the image of the slit of the diaphragm 26 forming the fixed reference point 18 by the plane mirror 15 rotates around the axis A in the image plane P according to the circumference of the radius d. .

During the /rotation of the plane mirror 15, in the image plane 18', the image of the slit of the diaphragm 16 forming the fixed reference point 18 appears as if successively sweeping through each of the light spots of the images D'l to D'4. A situation occurs.

In reality, the light beams emitted to the light points T1, T2, T3, T4 are transferred to the diaphragm 26 as a result of the /rotation of the plane mirror 15.
It sweeps seven times and passes through the slit of the diaphragm 26 that forms the fixed reference point 18.

According to the invention, the time of passage of the light beam at the fixed reference point 18 is recorded and, as a function of this passage time, the time of passage of the light beam at the support 2
2, the lens 10 to be centered is driven in contact with the holding sleeve 11.

Light spots Tl, T2, T3, T4ij, axis #j of holding sleeve 11! The C1 plane mirrors 5 distributed along the same circumference around A are rotationally integrated with the output shaft of the synchronous motor 24, and are driven at a constant speed by the synchronous motor 24, so
If the lens 10 is properly extended, the time it takes for the light beams emitted at each of the above-mentioned light points to pass through the fixed reference point 18 will be equal.

Therefore, in FIG. 7, in which time t is plotted on the horizontal axis and voltage V is plotted on the vertical axis, the signals sent out by the photovoltaic cells 25 of the distribution device 17 have regular intervals.

This interval is suitably measured from the falling edge of the signal as shown. The falling edge of this part is the focusing lens L.
1, C2, and 3, cover CI related to C4, C2,
The configuration of the present invention described with reference to FIG. 3 for C3 and C4 accommodates the rapid transition from bright to dark for each luminous flux.

An incremental encoder 28, which periodically generates signals in response to continuous rotation of the output shaft of the synchronous motor 24, generates successive signals M1, M2 based on the luminous fluxes emitted at the light points Tl, T2, T3, T4. , M3, and M4 can be identified with respect to the origin 0.

If the lens 10 is centered about the axis A of the retaining sleeve 11, then these signals will be regularly spaced tl, t2, t3, t4, as described above with respect to FIG.

On the other hand, is the lens 10 offset IL with respect to the axis A of the holding sleeve 11? If it is, the intervals will be uneven as shown in Figure 7.

Actually, referring to FIG.
, D3, D4, D'l, D'2, D'3, D'4 are no longer distributed symmetrically about the axis A.

Therefore, as shown in FIG. 9, the intervals tl, t2, t3, t
4 becomes irregular.

By identifying the corresponding signals, it is determined in which direction the lens 10 should be moved at right angles to the axis A of the holding sleeve 11 in order to ensure a constant signal time interval and the desired centering. It will be done.

In practice, the radius d can be set to a small value, for example on the order of 3 m.

Theoretically, a phase-convex shape that minimizes aberrations is most preferable, but for easy installation, focusing lenses L1, L2, L3,
A plano-convex lens may be used for L4.

However, this is not absolute.

In order to reduce the volume of the device, the focal length of the focusing lens is preferably small, for example on the order of 2S.

The diameter of the light spot formed by the images -D'1 to D'4 in the image plane P depends on the magnification of the lens, and the diameter of the light spot formed by the images -D'1 to D'4 in the image plane P depends on the magnification of the lens.
Depends on the overall distance between 0 and 0.

This distance is preferably small enough so that overlapping light spots do not occur which would disrupt the measurements and make them inaccurate.

In reality, the distance from the holding sleeve 1'1 to the rotation center CR of the plane mirror 15 is approximately equal to the distance D from the rotation center CR to the diaphragm 26 (for example, it may be on the order of SO length).

Diaphragm 2 forming fixed reference point 18 of analyzer 17
The diameter of the slit 6 affects the measurement accuracy.

This diameter may be of the order of 70 μm, for example.

However, the numerical values shown above do not limit the present invention.

The invention is not limited by the particular configuration described above, but many variations are possible, in particular with regard to the number of light spots used and the manner in which they are formed.

Although it is clearly advantageous to rotate the plane mirror at a constant speed in addition to recording the time of passage of the light beam through a fixed reference point of the analyzer, this is also not absolutely essential.

As a variant, the rotation speed of the plane mirror can be programmed according to a suitable predetermined law, and the time of passing through a fixed reference point can be determined accordingly.

Using the slit of the diaphragm as a fixed reference point for transit time is particularly advantageous when the analytical device used uses a photovoltaic cell as described above, but more fixed reference points may also be used.

Furthermore, the scope of application of the present invention is not limited to spherical concave-convex lenses, and this lens is only selected to simplify the explanation of the method of the present invention.

Thus, the centering method and device according to the invention applies equally to spherical-cylindrical lenses, spherical-toric lenses or more generally aspheric lenses of revolution.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a centering device according to the present invention, FIG.
The figure is a detailed view of the part marked ■ in Figure 1, and Figure 3 is a detailed view of the part marked ■ in Figure 1.
915 is an explanatory view showing how the centering device according to the present invention is used, and FIG. 6 is a cross-sectional view taken along the line -■. Fig. 7 is a diagram showing the optical image observed when there is no lens or when the lens is accurately centered; Waveform diagrams showing the waveforms of the signals, Figures 6.7 and 9 show the case where the lens is present and not accurately centered, respectively.
FIG. 2 is a cross-sectional view and a waveform diagram corresponding to the figure. Explanation of symbols 10... Lens, 11... Holding sleeve, 15...
・Plane mirror, 16...Reflecting surface, 17...Analyzer, 1
8... Fixed gauge point, A, R... Axis line, N... Perpendicular line,
TI, T2, T3, T4...light spot, a...angle.

Claims (1)

[Claims] ill In a centering method in which the lens IO is centered in a state in which the lens IO is supported by the holding sleeve 1 by one surface thereof, the lens IO is appropriately distributed circularly around the axis A of the holding sleeve 11. A plurality of points of light (Tl, T2,
T8. T4. ) and the plane mirror 15 with the reflective surface 16 inclined with respect to the axis A, the light point TI
, T2, T8, and ■4 toward the analyzer 17; rotating the plane mirror 15 around an axis R that forms an angle a with the perpendicular N drawn to the reflecting surface 16; recording the transit time of the light beam passing through the fixed reference point 18 of the lens, and moving the lens lO in contact with the retaining sleeve 11 as a function of the transit time by means of which the desired centering of the lens is obtained. Featured centering method. (2) Regularly distributing the light spots T1, T2, T8, ■4 along the same circumference around the axis A of the holding sleeve 11, rotating the plane f & 15 at a constant speed, and A patent characterized in that the lens 10 is moved in contact with the holding sleeve 11 until the transit times for the light beams from points Tl, T2, T8, and ■4 to pass through the fixed reference point 18 of the analyzer 17 are equal. Claims No. il
Centering method described in +. (3) A point on the reflective surface 16 that includes a slight angle to the perpendicular N drawn to the reflective surface 16 of the plane mirror 150 and is on the axis A of the holding sleeve 11, that is, an axis that passes through the rotation center CR of the reflective surface, Selecting the axis of rotation R of the plane mirror 15 and formula 6% (where a is the axis of rotation R of the plane mirror 15 and its reflecting surface 16
(which is the angle formed by the perpendicular line N to
Selecting the radius d associated with the distance between R and the fixed reference point 18 of the analyzer 17 as the radius d of the circumference on which the light points Tl, T2, T8, ■4 are distributed. Characteristic Claim No. 21 (21) A device comprising a battery 25 and a diaphragm 26 on the upstream side thereof is selected as the analyzer 17, and the slit of the diaphragm 26 is Fixed reference point 1 of analyzer ■7
Claim No. 8 (1)
The centering method according to any one of items (3) to (3). (5) The photovoltaic cell of the analyzer is connected to an incremental coder driven by a motor that rotates the plane mirror.
How to put out. 161 Half of the lens L is hidden by the cover 20
1, L2, L3, and L4, each of the above light points Tl, T2
, T8, ■4, the half of which is defined by a diameter cutting the axis A of the retaining sleeve 11. Centering method. (7) A centering device for a lens 10 of the type having a retaining sleeve 11 for supporting the lens IO by one surface thereof, on one side of the retaining sleeve 11,
illumination means for forming a plurality of light spots T1, T2, T8, 4 circularly distributed around the axis A of the holding sleeve 11 at the holding sleeve 11;
On the other side of 1 it has a plane mirror on the axis of the holding sleeve 11 and an analysis device 17 transverse to said axis of the holding sleeve 11, said plane mirror being inclined with respect to the axis A and reflecting the plane mirror. mounted for rotation about an axis R that includes an angle a formed between it and the normal N to the surface 16;
The centering device is characterized in that the analyzer receives a beam of light emitted from the light points Tl4T2, T3, and {circle over (4)} whose direction changes as it is reflected by a plane mirror 15, and is equipped with a fixed reference point 18. (8) The above-mentioned illumination means are point light sources 'p1, P2, P
8.P4 For example, the scope of claims characterized in that an electroluminescent diode and a focusing lens L1%L2, L3, 4 are provided for each light point T1, T2, T3, 4 to be formed. Centering device according to paragraph (7). (9) Each of the focusing lenses L1, L2, L3, L4 is located at a distance of 1 times the focal length with respect to the holding bush 11, and the associated light sources PI, P2, P3, P4 are also in focus L1, L2. , L3, L4 The centering device according to claim (8), is arranged at a position a times the focal length with respect to VC. (I(l) Each focusing lens L1% L2, 8, 4 is combined with a carper 20 to hide half of it,
A centering device according to claim 8 or 9, characterized in that the half is defined by a diameter cutting the axis A of the holding sleeve 11. Place the O9 cover 20 on all the focusing lenses L1, L2, L3.
Claim No. 0 characterized in that it is common to 14.
Centering device according to item 0. az Claim No. 1 characterized in that the focusing lenses LL, L2, L8, and L4 are regularly distributed circularly along the same circumference around the axis A of the holding sleeve 11.
The centering device according to item 11. C131, 2 focusing lenses L at 90° intervals
1, L2, L3, and L4 are arranged. 04 Plane mirror 15 located on axis A of holding sleeve 11
The centering device according to any one of claims 7 to 31, wherein the rotational axis R of the plane mirror 15 passes through a point on the reflecting surface 16, that is, the rotation center CR of the reflecting surface. CIS According to any one of claims 7 to 04, the angle a formed between the rotation axis R of the plane mirror 15 and the reflecting surface 16 is made small, and is less than 5 degrees. centering device. aS The centering device according to any one of claims (7) to (a9), characterized in that the rotational axis R of the plane mirror 15 is rotationally integrated with the output shaft of the synchronous motor 24. 117+ A photovoltaic cell 25 and a diaphragm 26 upstream thereof form an analyzer 17, and the diaphragm 2
The centering device according to any one of claims 71-(161), characterized in that the 6 slits form the identification reference points 18. A centering device according to claim 00 or 0η, characterized in that a photovoltaic cell 25 is coupled thereto. The radius d, the distance between the center of rotation CR of the reflective surface 16 of the plane mirror 15 and the diaphragm 26, and the angle a between the rotational axis R of the plane mirror 15 and the perpendicular N drawn to the reflective surface 16 are approximately expressed by the following formula %. Claims No. 02, Q4], No. 9, No. 8, and No. 11η, characterized in that they are mutually related to %.
A centering device according to any of paragraphs. ■ The distance between the rotation center CR of the holding sleeve 11 and the reflective surface 16 of the plane mirror 15 is determined by the distance between the rotation center CR and the diaphragm z.
6. The centering device according to claim Q9, characterized in that the distance is approximately equal to the distance between the centering device and the centering device.