JP3595117B2 - Array element inspection method and array element inspection apparatus - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for inspecting an array element in which a plurality of elements are arranged in a predetermined arrangement and an apparatus for inspecting an array element, and more particularly to a method suitable for inspecting a position of a fiber in a fiber array block.
[0002]
[Prior art]
As a conventional method of inspecting an array element, for example, the entire array element is photographed by a CCD camera or the like, and the position of each element is obtained by performing image processing on the photographed signal. Alternatively, each element is detected by a moving stage, and the relative position of the element is obtained from the moving amount of the stage.
[0003]
[Problems to be solved by the invention]
Although the conventional inspection method is configured as described above, in recent years, the miniaturization of elements has progressed, and the positional accuracy of elements has been required to be 1 μm or less.
[0004]
In this regard, in image processing using a CCD camera, since the entirety of a plurality of elements are photographed as they are, the photographing range is limited in order to obtain high resolution. It is limited to the range of μm.
[0005]
On the other hand, when a moving stage is used, it is possible to expand the measurement range, but the stage must be moved with high accuracy, so that the inspection apparatus becomes very expensive.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide an array element inspection method and an array element inspection apparatus capable of solving the problems of the prior art and inspecting the position of the array element with high resolution in a wide range and relatively inexpensively. is there.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a first array element inspection method of the present invention is a method of detecting the positions of a plurality of elements arranged in an array using optical detection means, Light from the elements is extracted by a lens array having a plurality of lenses whose optical axes corresponding to the elements are arranged substantially parallel to each other, and the light from each lens of the lens array is received by the detection means by an imaging lens. An image is formed in a region, an image of the formed element is detected, and the position of each element is obtained from a detection signal.
[0008]
Since the light of the plurality of elements is formed into an image in the light receiving region of the detecting means, the inspection can be performed over a wide area with high resolution and the measurement can be performed at a relatively low cost, as compared with a method of directly photographing the plurality of elements. If there is no error in the measurement system, such as a case where there is no pitch error in the plurality of elements, the images of the plurality of elements are formed at predetermined positions (the same point, etc.) in the light receiving area of the detecting means. In the case where an image is formed, an image is formed shifted from the predetermined position, and the quality of the array element can be easily determined from the shift amount.
[0009]
Further, in the second array element inspection method according to the present invention, the plurality of elements have optical axes substantially parallel to each other, and the i-th element (i = 1 to N, N is an element) in a plane perpendicular to the optical axis. Of the element) is (Xo_i, Yo_iThe first array element inspection method for detecting the position of array elements arranged in an array as shown in the following expression, wherein the focus corresponds to each of the plurality of elements and is equal to an optical axis substantially parallel to each other. Distance f₁Are located in a plane perpendicular to the optical axis of each lens, the coordinates of the optical axis of the i-th lens are (Xl_i, Yl_i), And a focal length f for imaging light from each lens of the lens array.₂And an imaging lens.
[0010]
Then, when an image of each element is formed on a detection surface in a light receiving area of the detection means perpendicular to an optical axis of a lens constituting the lens array by the lens array and the imaging lens, a plurality of images are formed. By arranging the lens array and the imaging lens with respect to the elements so as to satisfy the following equations (1) to (3), light from the i-th element among the plurality of elements is transmitted to i in the lens array. The extracted light is taken out by the second lens, and the taken out light is taken into a desired position (Xs_i, Ys_i), An image of each formed element is detected, and the position of each element is obtained from a detection signal.
[0011]
Xo_i− (K × Xl_i) = Xs_i/ M (1)
Yo_i− (K × Yl_i) = Ys_i/ M (2)
η = {(k-1) × (β + ξ) -1} × β / ｛ξ × (k-1) -1｝ (3)
However,
k: The distance between each element and the first principal point of the lens in the lens array corresponding to each element is f₁Value divided by
β: focal length f of the imaging lens₂To f₁Value divided by
ξ: Focal length f from the distance between the second principal point of each lens of the lens array and the first principal point of the imaging lens₁And f₂Subtract the distance f₁Value divided by
η: distance between the second principal point of the imaging lens and the detection surface is f₁Value divided by
M: Magnification of an optical system composed of a lens array and an imaging lens, which is expressed as M = −β / {1+ (1-k) ×}.
X, Y axes: coordinate axes having a direction perpendicular to the direction of the optical axis (Z-axis direction) of the lens constituting the lens array, and orthogonal to each other, (Xo_i, Yo_i), (Xl_i, Yl_i), (Xs_i, Ys_i) Are also based on the common X and Y coordinate axes.
As described above, since the image of each element can be formed at an arbitrary position on the inspection surface, it is possible to observe a plurality of elements at once. Further, by determining the parameters in the above equation (3), even if lenses having the same focal length are used, the magnification of the optical system can be changed, and by changing the sign of the magnification, erect and inverted element images can be obtained. Can be freely selected.
[0012]
In the second array element inspection method, if light from each element is focused on substantially the same point on the detection surface, the measurement system can be configured without a movable portion, and highly accurate position detection can be performed. When the optical system composed of the lens array and the imaging lens is arranged so as to be an afocal system, と な り = 0, and the magnification M does not depend on k and is not affected by the error of k. It is less likely to be received and accurate measurement is possible. In the first and second array element inspection methods, when light from the array element is taken out as substantially parallel light by the lens array (that is, when tandem arrangement with k = 1), an image is formed with the lens array. Since the light becomes parallel light between the lens and the lens, it is possible to construct an accurate measurement system which is not affected by the size of ξ and is not affected by an error. Furthermore, setting ξ = 0 and k = 1 enables more accurate measurement.
[0013]
A first array element inspection apparatus of the present invention is an apparatus for performing the first array element inspection method, wherein the array element inspection apparatus detects positions of a plurality of elements arranged in an array. A lens array having a plurality of lenses whose optical axes respectively corresponding to the plurality of elements are arranged substantially in parallel with each other, and for forming an image of light from each lens of the lens array in a light receiving region of the detecting means. At least one imaging lens, detection means for detecting an image of the formed element, and an arithmetic circuit for obtaining a position of each element from a detection signal of the detection means; A lens and the detection means are arranged so as to form an image of light from each lens of the lens array in a light receiving area of the detection means.
[0014]
It is preferable that the image of the element be photographed by, for example, a CCD camera or detected by a split type photodiode. Since the light of a plurality of elements is formed into an image in the light receiving area of the detection means, it is possible to provide a measurement system having no movable part including a lens array, an imaging lens, the detection means, and an arithmetic circuit. Yes, the position can be detected with high accuracy.
[0015]
Further, a second array element inspection apparatus of the present invention is an apparatus for performing the second array element inspection method, wherein a plurality of elements have optical axes substantially parallel to each other, and The coordinate of the i-th element (i = 1 to N, N is the number of elements) in a plane perpendicular to the plane is (Xo_i, Yo_iIn the first array element inspection apparatus for detecting the positions of array elements arranged in an array as shown in the following expression, the focal length f is equal to an optical axis substantially parallel to each of the plurality of elements.₁The coordinates of the optical axis of the i-th lens are in a plane perpendicular to the optical axis of each lens.
(Xl_i, Yl_i), And the light from the lens array is coupled to the detection surface in the light receiving area of the detection means perpendicular to the optical axis of the lens constituting the lens array. Focal length f to be imaged₂And an imaging lens.
[0016]
Further, the arrangement of the lens array and the imaging lens with respect to the plurality of elements is represented by the following equation.
By setting so as to satisfy the relations (1) to (3), light from the i-th element of the plurality of elements is transmitted to the detection surface by the i-th lens and the imaging lens in the lens array. The desired position (Xs_i, Ys_i), And a detecting means for detecting the formed image of each element, and an arithmetic circuit for obtaining the position of each element from the detection signal of the detecting means.
[0017]
Xo_i− (K × Xl_i) = Xs_i/ M (1)
Yo_i− (K × Yl_i) = Ys_i/ M (2)
η = {(k-1) × (β + ξ) -1} × β / ｛ξ × (k-1) -1｝ (3)
However,
k: The distance between each element and the first principal point of the lens in the lens array corresponding to each element is f₁Value divided by
β: focal length f of the imaging lens₂To f₁Value divided by
ξ: Focal length f from the distance between the second principal point of each lens of the lens array and the first principal point of the imaging lens₁And f₂Subtract the distance f₁Value divided by
η: distance between the second principal point of the imaging lens and the detection surface is f₁Value divided by
M: Magnification of an optical system composed of a lens array and an imaging lens, which is expressed as M = −β / {1+ (1-k) ×}.
X, Y axes: coordinate axes having a direction perpendicular to the direction of the optical axis (Z-axis direction) of the lens constituting the lens array, and orthogonal to each other, (Xo_i, Yo_i), (Xl_i, Yl_i), (Xs_i, Ys_i) Are also based on the common X and Y coordinate axes.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0019]
FIG. 1 is a schematic view of the configuration of an array element inspection apparatus according to the present invention, which comprises a lens array 2, an imaging lens 3, a CCD camera 4, and a computer 5 as an arithmetic circuit having a display device.
[0020]
The array element to be inspected is a fiber array 1 having a diameter of 125 μm arranged in a line at a pitch of 250 μm. FIG. 8 shows the appearance of a fiber array block 15 constituting the fiber array 1.
[0021]
As an objective lens for converting the light from the fiber array 1 into parallel light, an integrated lens array 2 which is a refraction lens was used. This is for ensuring the pitch accuracy level of the lens 2b constituting the lens array 2 to be substantially the same as that of the fiber 1b of the fiber array 1. The lens array 2 is manufactured by etching a quartz substrate using a lithography technique, and has a pitch of 250 μm, a diameter of 246 μm, and a focal length of 2 mm. By using the lithography technique, a pitch error of an accuracy of 0.1 μm or less is obtained. The fiber end face 1a was set at the focal plane of the lens array 2.
[0022]
An achromatic lens having a focal length of 40 mm and a diameter of 30 mm was used as the imaging lens 3, and a CCD camera 4 as an image detecting means was installed at the image side focal position. The fiber end face images are formed by the corresponding lens arrays 2 and imaging lenses 3 in the light receiving area of the CCD camera 4, more specifically, at substantially the same point on the photographing surface. The magnification is determined by the ratio of the focal lengths of the lens array 2 and the imaging lens 3, and is 20 times in the present embodiment. The pixel size of the CCD camera 4 is 11 × 13 μm, and the resolution per pixel is 0.55 and 0.65 μm. Further, the image processing is performed by the computer 5 to perform the interpolation processing, and the resolution is set to 1/10 of the above value. The image formation position is obtained by image processing in units of one pixel, and the pixel unit is converted into a length unit based on the pixel size, and a relative position of the image formation position obtained in the length unit is obtained. If the fiber array 1 is accurately arranged at a pitch of 250 μm, the images of the fiber end faces are all formed at the same point. Image. This is processed by the computer 5 to determine the quality of the fiber array 1. The calculation result and the image of the fiber 1b are displayed on the display device of the computer 5.
[0023]
In the above embodiment, the image formed by the imaging lens 3 is captured directly by the CCD camera 4. However, a magnifying optical system, for example, a lens may be interposed therebetween, so that the resolution can be further improved.
[0024]
Alternatively, as shown in FIG. 2, the screen 16 may be arranged on the first image plane of the imaging lens 3 and an image thereof may be taken. By capturing the image projected on the screen, a clearer image can be detected.
[0025]
In the above-described embodiment, the focal position of the lens array 2 is configured to be outside the lens substrate 2a constituting the lens array 2. However, the focal point is formed on the substrate surface, and the end surface of the fiber array 1 is formed. May be configured to adhere to the lens substrate 2a. This facilitates positioning and alignment when setting the element to be measured. Further, since each fiber 1b is disposed so as to be at the focal position of the corresponding lens 2b, it is possible to form an image at the same point with a simple optical system.
[0026]
In the above-described embodiment, the case where the images of all the fibers 1b are formed simultaneously has been described. However, as shown in FIG. 3, for example, the light-shielding plate 6 provided with one pinhole 7 is connected to the fiber array 1 and the lens array 2 May be provided movably in a direction orthogonal to the optical axis, and the fiber 1b may be imaged one by one using the pinhole 7 of the light shielding plate 6. This makes it possible to measure the position of each fiber 1b. In addition, it is also possible to provide a plurality of pinholes and perform position measurement in units of a plurality of fibers. The pinhole may be provided between the lens array 2 and the imaging lens 3.
[0027]
Alternatively, as shown in FIG. 4, a wavelength filter 8 having a different wavelength for each fiber 1b is arranged in front of the lens array 2, and by using this wavelength filter 8, it becomes possible to distinguish each fiber 1b by color. (Note that the wavelength filter 8 may be disposed behind the lens array 2.) Further, as shown in FIG. 5, if a wavelength tunable filter 9 is used between the lens array 2 and the imaging lens 3, the transmission wavelength can be reduced. By controlling, the fiber 1b can be identified even with a monochrome CCD camera. The tunable filter 9 can be constituted by a liquid crystal filter. Instead of arranging the wavelength tunable filter 9 between the lens array 2 and the imaging lens 3 as described above, a wavelength tunable light source (not shown) is used for illuminating the element as illumination means for transmitting or reflecting the element. May be.
[0028]
In the above embodiment, the case where a refraction type lens is used as the objective lens has been described. However, in order to obtain higher light collection efficiency, a diffraction type lens 10 as shown in FIG. 6A may be used. . Using a diffractive lens increases design freedom compared to a refractive lens.
[0029]
Although the inspection target can be applied to opaque ones, if the inspection target is an optical fiber that transmits light, light (monochromatic or white light) should be incident from the opposite side of the inspection surface and the emitted light should be imaged. Thereby, the position of the core can be detected more accurately. In particular, in this case, if a beam position detecting means such as a split type photodiode is used as the detecting means, the structure becomes simple. For example, as shown in FIG. 7, each optical fiber is formed into an image at a middle point (corresponding to the same point) of the four-division type photodiode 12, and the light received from each optical fiber detected by each photodiode 12a is received. The difference in the amount is taken by the comparator 13, and the result of the comparison is input to the arithmetic circuit 14, and the deviation of each optical fiber from the same point is checked from the difference in the amount of received light. Thereby, the structure can be simplified as compared with the image processing, and the position can be detected at high speed and at low cost.
[0030]
Next, another embodiment of the present invention will be described. FIG. 9 is a diagram showing each parameter in the optical system of the array element inspection device. Also in this embodiment, the image of each fiber 21 of the fiber array to be inspected is formed by the corresponding lens 22 and the imaging lens 23 of the lens array, and the position of the formed image of the fiber 21 is determined by the CCD. The configuration is obtained using a camera and a computer. Note that FIG. 9 shows only one fiber 21 of the fiber array and one lens 22 of the lens array opposed thereto.
[0031]
The number of the fibers 21 of the fiber array arranged in a line is eight, and the coordinates of the i-th (i = 1 to 8, the fiber 21 at one end is the first) fiber is (Xo_i, Yo_i). Further, the coordinates of the i-th lens 22 of the lens array provided to face the i-th fiber 21 are represented by (Xl_i, Yl_i).
[0032]
Further, with respect to each fiber 21 of the fiber array, the arrangement of each lens 22 of the lens array and the imaging lens 23 substantially satisfies the following equations (1) to (3), and Is extracted by the i-th lens 22 and the extracted light is extracted by the imaging lens 23 at a desired position (Xs_i, Ys_i). (Here, the XY axis is a coordinate axis having a direction perpendicular to the direction of the optical axis (Z-axis direction) of the imaging lens 23 and orthogonal to each other, (Xo_i, Yo_i), (Xl_i, Yl_i) And (Xs_i, Ys_i) Are also based on a common XY coordinate axis. )
Xo_i− (K × Xl_i) = Xs_i/ M (1)
Yo_i− (K × Yl_i) = Ys_i/ M (2)
η = {(k-1) × (β + ξ) -1} × β / ｛ξ × (k-1) -1｝ (3)
However,
k: The distance between each element and the first principal point of the lens in the lens array corresponding to each element is f₁Value divided by
β: focal length f of the imaging lens₂To f₁Value divided by
ξ: Focal length f from the distance between the second principal point of each lens of the lens array and the first principal point of the imaging lens₁And f₂Subtract the distance f₁Value divided by
η: distance between the second principal point of the imaging lens and the detection surface is f₁Value divided by
M: magnification of an optical system composed of a lens array and an imaging lens, and magnification M = −β / {1+ (1-k) ×}
It is. The distances in the Z-axis direction are all the focal length f of the lens 22 as described above.₁Standardized by Equation (3) satisfies the condition that the imaging point is constant even if the light from the element is not parallel to the Z axis but is inclined.
[0033]
In FIG. 9, the light beam indicated by the solid line is an ideal light beam trajectory when arranged as designed, and the light beam indicated by the dashed line is the light beam when the fiber 21 is displaced (the i-th light beam at this time). The coordinates of the fiber 21 are (X'o_i, Y 'o_i)).
[0034]
The fiber array of this embodiment is also the same as the embodiment of FIG. 1 in which fibers 21 having a diameter of 125 μm are arranged at a pitch of 250 μm. The lens array also has a diameter246 μmA lens 22 having a focal length of 3 mm is provided at a pitch of 250 μm, and is manufactured by a lithography technique with a pitch error of 0.1 μm or less. Further, in this embodiment, the end face of the fiber 21 is set to the focal plane of the lens 22 (hence, k = 1). A lens having a focal length of 300 mm was used as the imaging lens 23, and a CCD camera was installed at the image-side focal position. Further, ξ was set to about −130 (note that ξ can be determined irrespective of the expressions (1) to (3), and the optical system can be made smaller by making ξ negative). The pixel size of the CCD is 11 × 13 μm, the resolution per pixel is 0.11 and 0.13 μm, as in the above embodiment, and further, by performing interpolation processing with a computer, the resolution is 1/10 of the above value. I have.
[0035]
An end face image of each fiber 21 is formed at a substantially central position on the imaging surface of the CCD camera by the corresponding lens 22 and imaging lens 23, respectively. Since the tandem arrangement is k = 1, the magnification M is the ratio f of the focal lengths of the lens 22 and the imaging lens 23.₂/ F₁In this embodiment, the magnification is 100 times.
[0036]
If the fibers 21 of the fiber array are precisely arranged at a pitch of 250 μm, the images of the end faces of the fibers 21 are all formed at almost the same point. An image is formed at a position shifted by twice the distance (expression
(Refer to (1) and (2)). (By setting k = 1, the error due to the optical system can be suppressed to 0.02 μm or less.) In order to separate the image of each fiber 21, a slit is provided on the incident side of the fiber 21, and one slit is formed at a time. Light is made incident only on the fiber 21 and the slits are scanned to sequentially detect the position of each fiber, and image processing is performed by a computer to determine the quality of each fiber in the fiber array. .
[0037]
FIG. 10 shows an embodiment in which the arrangement of the lenses 22 of the lens array is adjusted so that end images of the fibers 21 are formed at different positions on the detection surface. In this embodiment, as shown in FIG. 10A, the lenses 22 of the lens array are arranged in the X-axis direction at a constant pitch of approximately 250 μm corresponding to each fiber 21 as in the above-described embodiment. The position of the lens 22 is not exactly at a constant pitch, and the eight lenses 22 are moved from the fixed pitch position ((0 μm, 0 μm), (250 μm, 0 μm), (500 μm, 0 μm),. , Y. The position coordinates of the first lens 22 are (0-15 μm, 10 μm), and the position coordinates of the second to eighth lenses 22 are (250−10). 15 μm, −10 μm), (500-7.5 μm, 0 μm), (750 μm, 10 μm), (1000 μm, −10 μm), (1250 + 7.5 μm, 0 μm), (1500+ 5 [mu] m, 10 [mu] m), is set to (1750 + 15 μm, -10 μm). Other conditions are the same as the embodiment of FIG 9.
[0038]
If each lens 22 is accurately arranged at a fixed pitch position and each fiber 21 is not displaced, the image of each fiber 21 is located at the center position of the imaging surface (detection surface) 30 of the CCD camera (FIG. 10B). (Point C). However, in this embodiment, since the position of each lens 22 is shifted from the fixed pitch position as described above, the image 31 (32 is an image of the core) of the end face of each fiber 21 is shown in FIG. As shown in FIG. For example, considering the image forming position of the first fiber 21, the position of the first lens 22 facing this fiber 21 (assuming that there is no displacement) is −15 μm in the X direction from a fixed pitch position. , And +10 μm in the Y direction, Xs is obtained from the above equations (1) and (2).₁= −100 × (Xo₁-Xl₁), Ys₁= −100 × (Yo₁-Yl₁And an image is formed at a position shifted from the center point C of the imaging surface 30 by −1.5 mm in the X direction and +1.0 mm in the Y direction. As described above, since the images 31 of the respective fibers are dispersed and formed on the imaging surface 30, eight images can be observed simultaneously, and there is no need to move the slit as in the above embodiment. .
[0039]
In the above embodiment, the number of imaging lenses is one, but a plurality of lenses may be combined to form an imaging lens. In this case, the imaging lens is considered as one imaging lens synthesized by a plurality of lenses. The invention can be applied.
[0040]
Further, in the above embodiment, the fiber arrays arranged at equal intervals have been described. However, the arrangement may be unequal, and the object to be inspected may be a semiconductor laser, a light emitting diode, or the like in addition to the fiber. May be arranged.
[0041]
【The invention's effect】
As described in detail above, according to the array element inspection method of the present invention, each array element is imaged at a predetermined position (substantially the same point or the like) or a desired arrangement in the light receiving region of the detecting means. The inspection can be performed over a wide range with high resolution, and the quality of the array element can be inspected relatively inexpensively from the positional deviation amount of the formed element image. In particular, when the light of a plurality of elements is focused on substantially the same point, it can be easily determined whether or not the plurality of elements have a pitch error or the like based on the positional displacement of the images. Further, when an image of each element is formed in a desired arrangement on the inspection surface, a plurality of elements can be observed at one time.
[0042]
According to the array element inspection apparatus of the present invention, the light of a plurality of elements is imaged at a predetermined position (substantially the same point or the like) or a desired arrangement in the light receiving region of the detecting means. It is possible to provide a measurement system having no movable part composed of an image lens, detection means, and an arithmetic circuit, and highly accurate position detection can be realized with a simple structure.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of an array element inspection device of the present invention.
FIG. 2 is a schematic sectional view showing an embodiment in which a screen is arranged after an imaging lens.
FIG. 3 is a schematic configuration diagram showing an embodiment in which a light shielding plate provided with a pinhole is movably arranged in front of a lens array.
FIG. 4 is a schematic configuration diagram showing an embodiment of an array element inspection device in which a wavelength filter is arranged before a lens array.
FIG. 5 is a schematic configuration diagram showing an embodiment of an array element inspection device in which a wavelength filter is arranged before a lens array and a wavelength variable filter is arranged after the lens array.
FIGS. 6A and 6B are front views showing an embodiment of an objective lens viewed from an optical axis direction, where FIG. 6A shows an optical system in a normal arrangement, and FIG. 6B shows an off-axis optical system.
FIG. 7 is a schematic configuration diagram showing an embodiment in which a split type photodiode is used as a detection unit.
FIG. 8 is a perspective view of a main part of an embodiment of a fiber array block to be inspected.
FIG. 9 is a diagram showing parameters of an optical system in an embodiment of an array element inspection apparatus according to the present invention.
FIG. 10 shows an embodiment in which the arrangement of each lens of the lens array is adjusted to form an end face image of each fiber at a different position on the detection surface. FIG. 3B is a diagram illustrating an arrangement of lenses, and FIG. 4B is a diagram illustrating an end face image of each fiber dispersedly formed on an imaging surface.
[Explanation of symbols]
1 Fiber array
1b fiber
2 Lens array
2b lens
3 Imaging lens
4 CCD camera
5 Computer
21 Fiber
22 lenses
23 Imaging lens

Claims (6)

A method for detecting the position of a plurality of elements arranged in an array using optical detection means,
Light from the plurality of elements is extracted by a lens array having a plurality of lenses whose optical axes corresponding to the respective elements are arranged substantially parallel to each other, and the light from each lens of the lens array is detected by an imaging lens. An array element inspection method, wherein an image is formed at substantially the same point in the light receiving region of the means, the formed image of the element is detected, and the position of each element is obtained from a detection signal. A method for detecting the position of a plurality of elements arranged in an array using an optical detection means, wherein light from the plurality of elements is arranged so that optical axes corresponding to the respective elements are substantially parallel to each other. The light from each lens of the lens array is taken out by a lens array having a plurality of lenses, and the light from each lens of the lens array is formed into an image in the light receiving area of the detection means by one imaging lens, and the image of the formed element is detected. An array element inspection method in which a position of each element is obtained from a signal, wherein a plurality of elements have optical axes substantially parallel to each other, and an i-th (i = 1) in a plane perpendicular to the optical axis. To N, where N is the number of elements), the positions of the array elements arranged in an array such that the coordinates of the elements are represented as (Xoi, Yoi) are detected, and corresponding to each of the plurality of elements, Equivalent to optical axes almost parallel to each other A lens array in which a plurality of lenses having a focal length f1 are arranged such that the coordinates of the optical axis of the i-th lens are expressed as (Xli, Yli) in a plane perpendicular to the optical axis of each lens. An imaging lens having a focal length f2 for imaging light from each lens of the lens array, and the detection means perpendicular to the optical axis of the lens constituting the lens array by the lens array and the imaging lens. When an image of each element is formed on the surface of the detection surface in the light receiving area, the arrangement of the lens array and the imaging lens with respect to the plurality of elements is set so as to satisfy the following equations (1) to (3). Then, light from the i-th element of the plurality of elements is extracted by the i-th lens in the lens array, and the extracted light is focused on the detection surface at a desired position (Xsi, Ysi) by the imaging lens. And the image An array element inspection method, wherein an image of each element is detected, and a position of each element is obtained from a detection signal.
Xoi− (k × Xli) = Xsi / M (1)
Yoi− (k × Yli) = Ysi / M (2)
η = {(k-1) × (β + ξ) -1} × β / ｛ξ × (k-1) -1｝ (3)
However,
k: value obtained by dividing the distance between each element and the first principal point of the lens in the lens array corresponding to each element by f1 β: value obtained by dividing the focal length f2 of the imaging lens by f1 ξ: lens array Is the distance obtained by subtracting the focal lengths f1 and f2 from the distance between the second principal point of each lens and the first principal point of the imaging lens, and η is the second principal point of the imaging lens and the detection surface. M: the magnification of the optical system composed of the lens array and the imaging lens, and X and Y axes represented by M = −β / {1+ (1-k) ×}: lens The coordinate axes have a direction perpendicular to the optical axis direction (Z-axis direction) of the lenses constituting the array and are orthogonal to each other. Each of (Xoi, Yoi), (Xli, Yli), (Xsi, Ysi) Coordinates are also based on common X and Y coordinate axes 3. The array element inspection method according to claim 1, wherein an optical system including the lens array and the imaging lens is arranged to be an afocal system. 4. The array element inspection method according to claim 1, wherein light from the array element is extracted as substantially parallel light by the lens array. An array element inspection apparatus for detecting the positions of a plurality of elements arranged in an array, comprising: a lens array having a plurality of lenses whose optical axes corresponding to the plurality of elements are arranged substantially parallel to each other; At least one imaging lens for imaging light from each lens of the array in the light receiving area of the detection means, detection means for detecting the image of the formed element, and respective detection signals from the detection means. An arithmetic circuit for determining the position of the element, wherein the lens array, the imaging lens, and the detecting means form light from each lens of the lens array at substantially the same point in a light receiving area of the detecting means. An array element inspection apparatus, which is arranged so as to form an image. An array element inspection apparatus for detecting the positions of a plurality of elements arranged in an array, comprising: a lens array having a plurality of lenses whose optical axes corresponding to the plurality of elements are arranged substantially parallel to each other; One image forming lens for forming an image of light from each lens of the array in a light receiving region of the detecting means, detecting means for detecting an image of the formed element, and each element based on a detection signal of the detecting means And an arithmetic circuit for determining the position of the lens array, the imaging lens, and the detecting means are arranged such that light from each lens of the lens array forms an image in a light receiving area of the detecting means. The plurality of elements have optical axes substantially parallel to each other, and the coordinate of the i-th element (i = 1 to N, N is the number of elements) in a plane perpendicular to the optical axis is (Xoi , Yoi) An array element inspection apparatus for detecting the positions of array elements arranged in an array so that each of the plurality of elements has a focal length f1 equal to an optical axis substantially parallel to each other. Are arranged in such a manner that the coordinates of the optical axis of the i-th lens are expressed as (Xli, Yli) in a plane perpendicular to the optical axis of each lens, and light from the lens array. An imaging lens having a focal length f2 for forming an image on a detection surface in a light receiving area of the detection means perpendicular to an optical axis of a lens constituting the lens array, and a lens array for the plurality of elements. By setting the arrangement of the imaging lens so as to satisfy the following expressions (1) to (3), the light from the i-th element among the plurality of elements is changed to the i-th lens in the lens array. And imaging lens Image is formed at a desired position (Xsi, Ysi) on the detection surface, and a detecting means for detecting the formed image of each element, and the position of each element is determined based on a detection signal of the detecting means. An array element inspection device, comprising: an arithmetic circuit for obtaining the calculated value.
Xoi− (k × Xli) = Xsi / M (1)
Yoi− (k × Yli) = Ysi / M (2)
η = {(k-1) × (β + ξ) -1} × β / ｛ξ × (k-1) -1｝ (3)
Here, k: a value obtained by dividing the distance between each element and the first principal point of the lens in the lens array corresponding to each element by f1 β: a value obtained by dividing the focal length f2 of the imaging lens by f1 ξ: A value η obtained by dividing a distance obtained by subtracting the focal lengths f1 and f2 from the distance between the second principal point of each lens of the lens array and the first principal point of the imaging lens by f1: η: detection of the second principal point of the imaging lens A value obtained by dividing the distance from the surface by f1 M: a magnification of an optical system including a lens array and an imaging lens, and X and Y axes expressed as M = -β / {1+ (1-k) ×} : Coordinate axes having a direction perpendicular to the direction of the optical axis (Z-axis direction) of the lens constituting the lens array and orthogonal to each other, (Xoi, Yoi), (Xli, Yli), (Xsi, Ysi). Are also based on the common X and Y coordinate axes.

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