JP2010085628A - Method and device for adjusting optical system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten an optical axis adjustment time, and to improve adjustment accuracy. <P>SOLUTION: A first shift amount is obtained as the shift amount of a first output pair obtained by defining two incident heights of three or more incident heights of the optical system 3 as a first incident height pair and receiving each of a pair of light beams incident from the first incident height pair with an image surface of the optical system 3. A second shift amount is obtained as the shift amount of a second output pair obtained by receiving each of a pair of light beams incident from a second incident height pair different from the first incident height pair from among the three or more incident heights of the optical system 3 with the image surface of the optical system 3. The position of the optical system 3 is adjusted on the basis of the first and second shift amounts. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical system adjustment method and apparatus.

Conventionally, optical adjustment of an imaging optical system composed of a plurality of optical blocks is performed by finely adjusting the amount of eccentricity of a specific optical block. In other words, the image of the point light source at a predetermined position is formed on the image sensor by the image forming optical system to be adjusted, and the specific image forming optical system is selected so that the point image displayed on the monitor is as clean as possible. The position of the optical block is adjusted manually.
Prior art documents related to the invention of this application include the following.
The 4th Pencil of Light Shino Tsuruta New Technology Communications 1997

  However, in the conventional adjustment method described above, it is not known in which direction the specific optical block may be moved, so that it is converged in a good position while moving by trial and error. However, this method takes time for adjustment. Since there is no quantitative property, there is a problem that there are variations among the adjusters and the quality is not stable.

(1) According to the first aspect of the present invention, two of the three or more incident heights of the optical system are defined as the first incident height pair, and each of the pair of light beams incident from the first incident height pair Of the first output pair obtained by receiving the light on the image plane of the optical system as a first shift amount, and the first incident height pair of the three or more incident heights of the optical system Is obtained as a second deviation amount by calculating a deviation amount of the second output pair obtained by receiving each of a pair of light beams incident from different second incident height pairs on the image plane of the optical system. In this optical system adjustment method, the position of the optical system is adjusted based on a second shift amount.
(2) The invention according to claim 2 is the optical system adjustment method according to claim 1, wherein the first incident height pair is different from the first incident height of the optical system. The second incident height is a pair, and the two incident height pairs are a pair of a third incident height and the second incident height different from the first and second incident heights.
(3) The invention according to claim 3 is the optical system adjustment method according to claim 2, wherein the second incident height is an incident height corresponding to an optical axis of the optical system.
(4) The invention of claim 4 is the optical system adjustment method according to claim 2 or 3, wherein the first and second shift amounts with respect to the first and third incident heights are displayed, and The position of the optical system is adjusted based on the display.
(5) The invention of claim 5 is the optical system adjustment method according to any one of claims 1 to 4, wherein the adjustment amount of the position of the optical system is determined based on the first and second deviation amounts. Ask.
(6) The invention according to claim 6 is the optical system adjustment method according to claim 5, wherein the first and second shift amounts include a power of the variable having an incident height of the optical system as a variable. And the adjustment amount is obtained based on the coefficient of the even-order term of the function.
(7) The invention according to claim 7 is the optical system adjustment method according to claim 3, wherein a relationship of the adjustment amount with respect to the first and second shift amounts is stored in advance, and the adjustment amount is based on the relationship. Ask for.
(8) According to an eighth aspect of the present invention, in the optical system adjustment method according to any one of the first to seventh aspects, the first and second shift amounts are obtained for each of the light beams having a plurality of wavelengths.
(9) According to the ninth aspect of the present invention, two of the three or more incident heights of the optical system are defined as the first incident height pair, and each of the pair of light beams incident from the first incident height pair Of the first output pair obtained by receiving the light on the image plane of the optical system as a first shift amount, and the first incident height pair of the three or more incident heights of the optical system is measured. Measuring means for measuring, as a second shift amount, a shift of the second output pair obtained by receiving each of a pair of light beams incident from a second pair of incident heights different from the second light amount on the image plane of the optical system; An optical system adjustment apparatus comprising: an adjustment unit that adjusts a position of the optical system based on the first and second shift amounts by the measurement unit.
(10) The invention of claim 10 provides a light beam by providing a microlens array in which first and second microlenses are arranged, and at least three light receiving elements for each of the first and second microlenses. The light receiving element array for receiving light and the at least three light receiving elements corresponding to the first microlens are selected from different first and second light receiving elements, and at least the first microlens corresponding to the second microlens. Selection means for selecting the third and fourth light receiving elements corresponding to the first and second light receiving elements among the three light receiving elements, and the light beam from the optical system is received by the first light receiving element. And the first light train based on the output obtained by receiving the light beam by the third light receiving element and receiving the light beam by the second light receiving element. And a second signal sequence based on the output obtained by receiving the light beam by the fourth light receiving element, and measuring a deviation amount between the first signal sequence and the second signal sequence. By changing the measurement means and the light receiving element pair selected by the selection means, the measurement means adjusts the position of the optical system based on the plurality of deviation amounts. An optical system adjustment apparatus including an adjustment unit.

  According to the present invention, the imaging optical system can be easily adjusted.

  FIG. 1 shows a configuration of an imaging optical system adjusting apparatus according to an embodiment. As shown in FIG. 2, the imaging optical system adjusting apparatus 1 according to the embodiment is configured to adjust the light from the chart image displayed on the display surface of the chart image display apparatus 2 in different parts of the imaging optical system 3 to be adjusted. Light is received through the pupil, the amount of deviation of these chart images is detected, the spherical aberration of the imaging optical system 3 is measured, and the optical adjustment of the imaging optical system 3 to be adjusted is made based on the spherical aberration of the measurement result. Do. Here, the image shift amount detected by the aberration measuring device 4 represents the lateral aberration of the imaging optical system 3 in which the center of the partial pupil is the incident height of the light beam.

  In this embodiment, the imaging optical system 3 to be adjusted is composed of a first optical block 3a and a second optical block 3b, and the imaging optical system is adjusted by adjusting the position of the second optical block 3b. 3 shows an example in which the optical adjustment 3 is performed.

  The imaging optical system adjustment device 1 includes an aberration measurement device 4, an adjustment signal creation device 5, and a position adjustment device 6. The aberration measuring device 4 receives the chart image through different partial pupils of the imaging optical system 3 and detects the shift amount of these chart images to measure the spherical aberration of the imaging optical system 3. The adjustment signal creation device 5 creates an adjustment signal for the imaging optical system 3 based on the measurement result by the aberration measurement device 4 and outputs the adjustment signal to the position adjustment device 6. The position adjusting device 6 adjusts the position of the second optical block 3b of the imaging optical system 3 to be adjusted according to the adjustment signal from the adjustment signal generating device 5.

  The chart image display device 2 is installed on the opposite side of the imaging optical system adjustment device 1 across the imaging optical system 3 to be measured, and displays a chart (pattern) in which black bars are arranged as shown in FIG. To do. The chart is a single-line edge chart as shown in FIG. 3 (a), preferably a multi-line edge chart having a plurality of boundaries as shown in FIGS. 3 (b) and 3 (c), and a false focus. In order to avoid this, it is desirable to use a chart in which the width and arrangement interval of the black bars are changed and the arrangement period changes.

  4A and 4B show the configuration of the aberration measuring apparatus 4 of the imaging optical system adjusting apparatus 1, wherein FIG. 4A is a transverse sectional view thereof, and FIG. 4B is a front view as viewed from the imaging optical system 3 side. The aberration measuring device 4 has a microlens array 41 in which a plurality of microlenses (for example, L1 to L6 in this embodiment) are arranged in a row and a plurality of light receiving elements (for example, S1 to S6 in this embodiment) in a row. The light receiving element array 42 is provided, and the light beam incident from the imaging optical system 3 is received by the light receiving elements S1 to S6 via the microlenses L1 to L6. The numbers of microlenses and light receiving elements are not limited to this example. In this embodiment, the light receiving elements S1 to S6 are described by taking a light receiving element in which a plurality of light receiving parts are arranged in a matrix of 8 vertical and 8 horizontal, as an example. The number and arrangement are not limited to this embodiment.

  Here, the detection principle of the image shift amount will be described with reference to FIG. In order to make the explanation easy to understand, in FIG. 5, the aberration measuring device 4 includes a microlens array in which five microlenses L1 to L5 are arranged in a row and five light receiving elements S1 to S5 in a row. In the following description, the light receiving element array is provided. On the pupil plane of the imaging optical system 3 to be adjusted, five partial pupils A, B, C, D, and E are set on a straight line passing through a point that intersects the optical axis of the imaging optical system 3. The partial pupil C is a partial pupil centered on the intersection with the optical axis of the imaging optical system 3.

  Considering the lens surfaces of the microlenses L1 to L5 (shown by broken lines in FIG. 5) as image shift detection surfaces, consider the images formed on the lens surfaces of the microlenses L1 to L5. Regarding the light beam that has passed through the partial pupil C of the imaging optical system 3, the light that contributes to the image formed on the lens surfaces of the microlenses L1, L2, L3, L4, and L5 is received by each of the light receiving elements S1, S2, S3, S4, Light is received by the light receiving portions c (1), c (2), c (3), c (4), and c (5) in S5. Here, the detection images of the light receiving portions c (1), c (2), c (3), c (4), c (5) by the light beam that has passed through the partial pupil C of the imaging optical system 3 are represented by {c (i)} (i = 1, 2, 3, 4, 5).

  Similarly, with respect to the light beam that has passed through the partial pupil A of the imaging optical system 3, the light that contributes to the image formed on the lens surfaces of the microlenses L1, L2, L3, L4, and L5 is received by each of the light receiving elements S1, S2, S3. , S4, S5 are received by the light receiving portions a (1), a (2), a (3), a (4), a (5), and the detection images of these light receiving portions are {a (i)} ( i = 1, 2, 3, 4, 5). Regarding the light beam that has passed through the partial pupil B of the imaging optical system 3, the light that contributes to the image formed on the lens surfaces of the microlenses L1, L2, L3, L4, and L5 is received by each of the light receiving elements S1, S2, S3, S4, The light receiving portions b (1), b (2), b (3), b (4), and b (5) in S5 receive the light, and the detected images of these light receiving portions are {b (i)} (i = 1). , 2, 3, 4, 5).

  Regarding the light beam that has passed through the partial pupil D of the imaging optical system 3, the light that contributes to the image formed on the lens surfaces of the microlenses L1, L2, L3, L4, and L5 is received by each of the light receiving elements S1, S2, S3, Light is received by the light receiving portions d (1), d (2), d (3), d (4), and d (5) in S4 and S5, and the detection images of these light receiving portions are {d (i)} (i = 1, 2, 3, 4, 5). Regarding the light beam that has passed through the partial pupil E of the imaging optical system 3, the light that contributes to the image formed on the lens surfaces of the microlenses L1, L2, L3, L4, and L5 is received by each of the light receiving elements S1, S2, S3, S4, The light receiving portions e (1), e (2), e (3), e (4), e (5) in S5 receive the light, and the detected images of these light receiving portions are {e (i)} (i = 1). , 2, 3, 4, 5).

  Now, as shown in FIG. 6A, the light rays obtained from the object point O at the incident height positions A, B, C, D and E of the imaging optical system 3 are reflected on the image plane I. , Respectively, are incident at positions a, b, c, d, and e. The amount of positional deviation Sac of the incident positions a, b, d, e on the image plane I of the light beam incident on each position A, B, D, E with respect to the incident position c on the image plane I of the light beam incident on the paraxial C. , Sbc, Sdc, and Sec are lateral aberrations. Then, in order to obtain the positional shift amounts Sac, Sbc, Sdc, and Sec, an image shift detection device as shown in FIGS. 4 and 5 is used.

  Next, a displacement amount Sac of the image {a (i)} with respect to the image {c (i)} is calculated. Similarly, the deviation amount Sbc of the image {b (i)} with reference to the image {c (i)}, the deviation amount Sdc of the image {d (i)}, and the deviation amount Sec of the image {e (i)} Calculate each.

Such a shift amount between the two images is obtained as follows, for example. Here, a description will be given assuming that the signal sequences related to the two images are {a (i)}, {b (i)} (i = 1, 2,...). First, the correlation amount C (N) of the signal sequences {a (i)} and {b (i)} regarding the two images is calculated by the following equation.
C (N) = Σ | a (i) −b (i) | (1)
In the equation (1), Σ represents a total operation of i = pL to qL, and N = i−j is a signal sequence shift amount for two images, that is, an image shift amount of the two images. Based on the discretely obtained correlation amount C (N), a shift amount (image shift amount) L that gives the minimum value of the continuous correlation amount is obtained by a three-point interpolation method. Here, assuming that the correlation amount at the shift amount N is C0, the correlation amount at the shift amount (N−1) is Cr, and the correlation amount at the shift (N + 1) is Cf, the shift amount (image shift). (Quantity) L is determined by equation (2).
DL = 0.5 · (Cr−Cf),
E = max {Cf-C0, Cr-C0},
L = N + DL / E (2)

  If the image shift amounts Sac, Sbc, Sdc, and Sec calculated in this way are arranged, the lateral aberration of the imaging optical system 3 in which the centers of the partial pupils A, B, C, D, and E are incident on the light rays, respectively. As shown in FIG. 6B, a lateral aberration diagram based on the partial pupil C can be drawn. Note that a method of rewriting from a lateral aberration diagram to a longitudinal aberration diagram is well known, and a description thereof will be omitted. A microcomputer (not shown) of the aberration measuring apparatus 1 calculates the spherical aberration characteristic of the imaging optical system 3 based on the amount of deviation detected by the aberration measuring apparatus 4.

  As described above, according to the aberration measuring apparatus 4 of the embodiment, the spherical aberration characteristic of the imaging optical system 3 to be adjusted can be easily measured, and the light receiving element array 42 of the aberration measuring apparatus 4 can be used. Since the output image signal is processed using a computer, high-speed measurement is possible.

  In the above-described embodiment, the image shift amounts Sac, Sbc between the partial pupil C and the other partial pupils A, B, D, E with reference to the partial pupil C on the optical axis of the imaging optical system 3. , Sdc, and Sec are detected, and the spherical aberration of the imaging optical system 3 is measured based on these image shift amounts. However, the partial pupil pair in which the image shift amount between adjacent partial pupils is obtained. The amount of image shift may be obtained according to the combination of the above and spherical aberration may be measured. For example, in the example shown in FIG. 5, the image shift amount Sab between the partial pupils A and B, the image shift amount Sbc between the partial pupils B and C, the image shift amount Scd between the partial pupils C and D, The image deviation amount Sde between the partial pupils D and E may be obtained, and the spherical aberration may be measured based on these image deviation amounts.

  In the embodiment described above, an example of the image shift detection device 4 using a microlens array in which a plurality of microlenses are arranged in a row and a light receiving element array in which a plurality of light receiving elements are arranged in a row has been shown. As shown in FIG. 7, an image shift amount may be detected using a microlens array in which a plurality of microlenses are arranged in a two-dimensional manner and a light receiving element array in which a plurality of light receiving elements are arranged in a two-dimensional manner. Good. In the modification shown in FIG. 7, a plurality of microlenses and a plurality of light receiving elements are arranged differently in even columns and odd columns (arranged by shifting half the pitch in the horizontal direction of the microlenses in even columns and odd columns), A two-dimensional array is formed. In this case, spherical aberration in a plurality of directions of the imaging optical system 3 can be measured by switching the chart direction as shown in FIGS. 3B and 3C using a chart rotating device or the like.

  Further, as shown in FIG. 8, the image shift amount obtained by the even-numbered light receiving element rows 51 and the image shift amount obtained by the odd-numbered light receiving element rows 52 with respect to the same pupil pair are averaged, and the pupil The aberration measurement accuracy can be further improved by measuring the spherical aberration by obtaining the average deviation amount for each pupil pair while changing the pair. Further, as shown in FIG. 9, the image shift amount obtained from the even-numbered light receiving element rows 53 and the image shift amount obtained from the odd-numbered light receiving element columns 54 with respect to the same pupil pair are averaged. By measuring the spherical aberration by obtaining the average deviation amount for each pupil pair while changing the pair, the aberration measurement accuracy can be further improved in the vertical direction (direction rotated by 90 degrees from the detection direction in FIG. 8). it can.

  Furthermore, as shown in FIG. 10, if the chart surface is illuminated by an illumination device 21 having a light source of a specific wavelength such as red R, green G, and blue B, the spherical aberration characteristic of the imaging optical system 3 at the specific wavelength is measured. can do. Furthermore, if the chart is displayed on the display and rotated or the color is changed, the chart can be displayed simply.

  Here, as a method of measuring the characteristics of the imaging optical system using the microlens array and the light receiving element array, a method of measuring the wavefront aberration of the pupil plane of the imaging optical system is known. In order to measure the wavefront aberration of the pupil plane of the imaging optical system, a two-dimensional microlens array is placed near or equivalent to the pupil plane, and a two-dimensional light receiving element array is placed behind it. The direction of the light ray incident on each microlens is detected from the position of the point image on the two-dimensional light receiving element array, thereby detecting the wavefront on the pupil plane. This method is a method of detecting a wavefront on the pupil plane.

  On the other hand, the aberration measurement method according to the present invention detects an image shift amount using a microlens array and a light receiving element array arranged in the vicinity of the image forming surface, and the aberration of the image forming optical system based on the image shift amount. And is completely different from the above-described conventional method for measuring the wavefront.

  Conventionally, a method for measuring the spherical aberration of the imaging optical system is known, and this measurement method will be described with reference to FIG. A first point image 104 formed by a light beam 101 incident on the imaging optical system 100 at an incident height h being incident on a first surface 103 perpendicular to the optical axis 102 in the vicinity of the focal plane of the imaging optical system 100; A second point image 106 formed by being incident on the second surface 105 perpendicular to the optical axis 102 slightly away from the surface is obtained, and a straight line connecting the centroid of the first point image 104 and the centroid of the second point image 106 is the light. The position z (h) intersecting the axis is obtained, the incident height h of the light beam is sequentially changed to obtain the position z (h), and the position z (h) with respect to the incident height h is plotted to obtain the spherical aberration of the imaging optical system. taking measurement.

  However, all of the conventional aberration measuring methods described above must be performed manually, and there is a problem that it is very complicated and requires a lot of man-hours. On the other hand, according to the aberration measurement method of the embodiment described above, the spherical aberration of the optical system can be measured easily and in a short time.

  After measuring the lateral aberration of the imaging optical system 3 by the aberration measuring device 4, the adjustment signal generating device 5 calculates a physical quantity related to the symmetry of the aberration from a plurality of image shift amounts, and the result is based on the physical quantity related to the aberration symmetry. An adjustment signal for adjusting the second optical block 3b (see FIG. 1) of the image optical system 3 is created.

  12 and 13 show an example of the aberration characteristic f (x) obtained from the aberration measuring device 4, the horizontal axis x represents the image height, and the vertical axis y represents the image shift amount. As shown in FIG. 12, when the aberration characteristic f (x) is point-symmetric with respect to the origin (the intersection of the image shift detection surface shown in FIG. 2 and the optical axis of the imaging optical system 3), the aberration is related to the optical axis. No further adjustment is required. On the other hand, as shown in FIG. 13, when the aberration characteristic f (x) is not point-symmetric with respect to the origin, the aberration is not a target with respect to the optical axis. Therefore, it is necessary to adjust the position of the second optical block 3b to be adjusted in the imaging optical system 3 so that the aberration characteristic becomes the characteristic shown in FIG. Several adjustment methods will be described below.

<First adjustment method>
First, a coefficient obtained by expanding the aberration characteristic f (x) obtained from the aberration measuring device 4 to “power” of the image height x is obtained. Assuming that the aberration characteristic f (x) is expressed under the condition of f (0) = 0, the aberration characteristic f (x) is expressed as follows.
f (x) = a1 · x + a2 · x ² + a3 · x ³ + a4 · x ⁴ + a5 · x ⁵ + (3)
In equation (3), the first-order term of x represents the amount related to the defocus amount and is ignored. Since odd-order terms other than the first-order term of x represent components that are point-symmetric with respect to the origin, there is no problem with aberration symmetry with respect to the optical axis.

  If the imaging optical system 3 is decentered, the coefficients a2, a4,. In the first adjustment method, the physical quantity relating to the aberration characteristic is the coefficient a2, a4,... Of these even-order terms of x when the aberration characteristic f (x) is developed to the power of the image height x, or these It is a linear combination of coefficients.

  The adjustment signal generating device 5 is point-symmetric with respect to the origin of the adjustment signal in which the coefficients a2, a4,... An adjustment signal for adjusting the aberration characteristic f (x) with respect to the optical axis is generated and sent to the position adjustment device 6. The position adjusting device 6 adjusts the position of the second optical block 3b of the imaging optical system 3 according to this adjustment signal. The aberration measuring device 4 measures the aberration after adjustment by the position adjusting device 6 and outputs the aberration characteristic f (x), and the adjustment signal generating device 5 generates an adjustment signal based on the new aberration characteristic f (x). That is, feedback control is performed so that the aberration characteristic f (x) of the imaging optical system 3 becomes an ideal characteristic shown in FIG.

  It should be noted that efficient adjustment is possible if a conversion table for converting the physical quantity relating to the above-mentioned aberration symmetry into an adjustment amount is created in advance by calculation or experiment, and the adjustment amount is determined using this conversion table.

<< Second adjustment method >>
In this second adjustment method, the adjustment signal generating device 5 stores in advance a table representing the adjustment amount for the aberration characteristics as shown in FIG. 14 in a built-in memory (not shown), and from this table data, the aberration measuring device. An aberration characteristic close to the aberration characteristic measured by 4 is searched, and the position adjustment device 6 performs adjustment according to the adjustment amount corresponding to the aberration characteristic of the search result.

  The aberration characteristic of the completely adjusted imaging optical system is recorded as g5 (x), and the adjustment amount in the case of this aberration characteristic g5 (x) is recorded as d5 = 0. From this state, the aberration characteristic measured when the position is adjusted by the adjustment amount d6 = Δ is g6 (x), and the aberration characteristic g6 (x) and the adjustment amount d6 are recorded in association with each other. Similarly, the aberration characteristic measured when the adjustment amount is d7 = 2Δ is recorded as g7 (x), and the aberration characteristic measured when the adjustment amount is d8 = 3Δ is recorded as g8 (x). . The aberration characteristic measured when the adjustment amount is d4 = −Δ is recorded as g4 (x), and the aberration characteristic measured when the adjustment amount is d5 = −2Δ is recorded as g5 (x). Then, the aberration characteristic measured when the adjustment amount is d6 = −3Δ is recorded as g6 (x). In this way, a table of aberration characteristics and adjustment amounts shown in FIG. 14 is created and stored in the built-in memory of the adjustment signal generator 5.

When the aberration measuring device 4 measures the aberration characteristic f (x) of the imaging optical system 3 to be adjusted, the measured aberration characteristic g (i = 1, 2,...) And the measured aberration characteristic f (x). The difference Ci is calculated.
Ci = Σ | gi (x) −f (x) | (4)
In the equation (4), x is the incident height (image height) of incident light from the center of the optical axis of the imaging optical system, and x = 1, 2, 3,. Σ represents the sum of discrete values of x. The difference Ci is calculated by the equation (4) for all aberration characteristics gi on the data table, and the adjustment amount di corresponding to the difference Ci indicating the minimum value is adopted. The position adjusting device 6 adjusts the position of the second optical block 3b of the imaging optical system 3 by the adopted adjustment amount di.

The aberration characteristic gi indicating the true minimum value and the adjustment amount di may be calculated by interpolation. Further, since it is necessary to compare the lateral aberration under the same defocus amount in the equation (4), the coefficient a1 of the first-order term when the measured aberration characteristic f (x) is expanded to the above equation (3). Thus, it is necessary to align the detection positions of the aberration characteristics so that the coefficient b1 of the first-order term when the table data gi (x) is expanded to the power as in the following equation is the same.
gi (x) = b1 · x + b2 · x 2 + b3 · x 3 + b4 · x 4 + ··· ··· (5)
Various methods can be considered for this, but the aberration detection surface is adjusted to a position where the coefficient b1 of the first-order term in equation (5) is equal to the coefficient a1 of the first-order term in equation (3), and a1 is replaced with b1. Compare.

  In the above-described embodiments and their modifications, all combinations of the embodiments or the embodiments and the modifications are possible. For example, as described with reference to FIGS. 7 to 9, the spherical aberration of the imaging optical system may be measured in a plurality of directions, and optical adjustment may be performed in each of these directions.

  According to the above-described embodiment and its modifications, the following operational effects can be achieved. First, (1) the imaging optical system can be accurately adjusted in a short time. Also, (2) an accurate adjustment amount can be determined. Furthermore, (3) optical adjustment can be performed easily in a short time.

1 shows a configuration of an aberration measurement apparatus according to an embodiment. Diagram for explaining the measurement principle of aberration Diagram showing example chart Diagram showing the configuration of the aberration measurement device The figure for demonstrating the detection method of the amount of image shifts Diagram showing measurement results of lateral aberration The figure which shows the image shift detection apparatus which arranged the several micro lens and the light receiving element in the two-dimensional form The figure for demonstrating the image shift detection method of the modification by the image shift detection apparatus which arranged the micro lens and the light receiving element two-dimensionally The figure for demonstrating the image shift detection method of the other modification by the image shift detection apparatus which arranged the micro lens and the light receiving element two-dimensionally The figure which shows the modification of a chart image display apparatus The figure for demonstrating the spherical aberration measuring method of the conventional optical system The figure which shows the example of the target aberration characteristic regarding the optical axis The figure which shows the example of the aberration characteristic which is not object regarding the optical axis The figure which shows the table of the adjustment amount with respect to an aberration characteristic

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Imaging optical system adjustment apparatus, 2; Chart image display apparatus, 3; Imaging optical system, 3a; 1st optical block, 3b; 2nd optical block, 4; Aberration measuring apparatus, 5; 6; Position adjusting device, 41; Micro lens array, 42; Light receiving element array

Claims (10)

Two incident heights out of three or more incident heights of the optical system are defined as a first incident height pair, and each of a pair of light beams incident from the first incident height pair is received by the image plane of the optical system. The amount of deviation of the first output pair obtained as described above is obtained as the first amount of deviation,
A pair of light beams incident from a second incident height pair different from the first incident height pair out of three or more incident heights of the optical system are received by the image plane of the optical system. The amount of deviation of the output pair of 2 is obtained as the second amount of deviation,
An optical system adjustment method comprising adjusting the position of the optical system based on the first and second shift amounts. The optical system adjustment method according to claim 1,
The first incident height pair is a pair of a first incident height of the optical system and a second incident height different from the first incident height, and the two incident height pairs are the first incident height pair. And a pair of a third incident height different from the second incident height and the second incident height. In the optical system adjustment method according to claim 2,
The optical system adjustment method, wherein the second incident height is an incident height corresponding to an optical axis of the optical system. In the optical system adjustment method according to claim 2 or 3,
An optical system adjustment method comprising: displaying the first and second shift amounts with respect to the first and third incident heights; and adjusting the position of the optical system based on the display. In the optical system adjustment method according to any one of claims 1 to 4,
An optical system adjustment method, wherein an adjustment amount of the position of the optical system is obtained based on the first and second deviation amounts. In the optical system adjustment method according to claim 5,
The first and second shift amounts are obtained as a function including a power of the variable with the incident height of the optical system as a variable,
An optical system adjustment method, wherein the adjustment amount is obtained based on a coefficient of an even-order term of the function. In the optical system adjustment method according to claim 3,
Storing in advance the relationship of the adjustment amount with respect to the first and second deviation amounts;
An optical system adjustment method, wherein the adjustment amount is obtained based on the relationship. In the optical system adjustment method according to any one of claims 1 to 7,
An optical system adjustment method, wherein the first and second shift amounts are obtained for each of the light beams having a plurality of wavelengths. Two incident heights out of three or more incident heights of the optical system are defined as a first incident height pair, and each of a pair of light beams incident from the first incident height pair is received by the image plane of the optical system. The first output pair shift obtained in this way is measured as the first shift amount, and the second incident height pair different from the first incident height pair among the three or more incident heights of the optical system is measured. Measuring means for measuring a deviation of a second output pair obtained by receiving each of a pair of incident light beams on the image plane of the optical system as a second deviation amount;
An optical system adjustment apparatus comprising: an adjustment unit that adjusts a position of the optical system based on the first and second shift amounts by the measurement unit. A microlens array in which first and second microlenses are arranged;
A light receiving element array that receives at least three light receiving elements for each of the first and second microlenses to receive a light beam;
The first and second light receiving elements different from each other among the at least three light receiving elements corresponding to the first microlens are selected, and the at least three light receiving elements corresponding to the second microlens are selected. Selection means for selecting third and fourth light receiving elements corresponding to the first and second light receiving elements;
Based on the output obtained by receiving the light beam from the optical system with the first light receiving element and the output obtained by receiving the light beam with the third light receiving element, the first signal sequence is obtained. Based on the output obtained by receiving the light beam by the second light receiving element and the output obtained by receiving the light beam by the fourth light receiving element, a second signal sequence is obtained, and the first signal sequence and the Measuring means for measuring a deviation amount from the second signal sequence;
Control means for obtaining a plurality of deviation amounts by the measuring means by changing a light receiving element pair selected by the selecting means;
An optical system adjustment apparatus comprising: an adjustment unit that adjusts a position of the optical system based on the plurality of deviation amounts.

Images