TW202208912A - Method for assembling optical lens can improve problem of bad imaging quality caused by excessive eccentricity error in lenses and reduce manufacturing costs at the same time - Google Patents

Abstract

A method for assembling optical lens includes a detection step, comprising: defining a reference line passing through the center point of a reference surface and dividing the reference surface into two blocks; receiving a light beam from a light source passing through each of the optical lenses according to the image sensing element so as to obtain a first imaging point, obtaining a second imaging point after rotating the optical lenses to a second position, obtaining a third imaging point after rotating the optical lenses to a third position; calculating a position of a center of a circle passing through the first imaging point, the second imaging point, and the third imaging point; dividing the optical lens into two groups corresponding to two regions based on positions of the center of the circle. The method further includes an assembling step comprising steps of disposing at least two optical lenses belonging to one of the two groups within the optical lens at a lens barrel and arranging at least two optical lenses belonging to another within the two groups of the optical lenses at another lens barrel.

Description

Optical lens assembly method

The invention relates to optical lenses; in particular, it refers to a lens eccentricity detection and lens assembly method.

It is known that when an optical lens is manufactured or system assembled, if the optical axis does not coincide with the rotational symmetry axis, an eccentricity error will occur, resulting in many image imaging and imaging quality problems. There are two types of measurement methods: mechanical measurement method and optical measurement method, depending on the accuracy.

The so-called optical measurement method, in the detection, penetrates the lens to be measured through the incident light and rotates the lens to be measured around a rotating axis. A circular light spot movement track is seen on the screen, and the eccentricity of the lens to be tested can be calculated from the aforementioned light spot movement track. However, although the eccentricity of the measuring lens can be calculated by the above-mentioned optical measurement method, generally if the lens is detected to be eccentric, in order to avoid affecting the image quality, it can only be discarded as an unqualified product, which will inevitably lead to waste of resources and cost. Therefore, how to screen out the offset lens before assembling the optical lens, and still provide good imaging quality without increasing the manufacturing cost, is an urgent problem to be solved by the inventor.

In view of this, an object of the present invention is to provide an optical lens assembly method, which can screen out the offset lens and provide good imaging quality after assembly.

In order to achieve the above object, an optical lens assembly method provided by the present invention includes a detection step of respectively performing a plurality of optical lenses, wherein the detection step includes:

A. define a reference plane, the reference plane has a center point, define at least one reference line passing through the center point and the at least one reference line divides the reference plane into at least two blocks;

B. An image sensing element receives a light beam from a light source passing through each of the optical lenses, captures a first image from the image output by the image sensing element, and obtains a first imaging point according to the first image, wherein The light source projects light beams along a first axis, each of the optical lenses is arranged at a first position, and the first axis passes through the center point of the reference plane and the center of each of the optical lenses;

C. After each optical lens is rotated from the first position to a second position with a rotation axis as the axis, a second image is captured from the image output by the image sensor, and a first image is obtained according to the second image Two imaging points, the rotation axis is parallel to the first axis;

D. After each optical lens rotates to a third position with the rotation axis as the axis, a third image is captured from the image output by the image sensing element, and a third imaging point is obtained according to the third image, the the third position is different from the first position and the second position;

E. According to the first imaging point, the second imaging point and the third imaging point, calculate the center position of a circle passing through the first imaging point, the second imaging point and the third imaging point, the center position of the circle Corresponding to at least one of the two blocks;

F. Divide each of the optical lenses into at least two types, wherein the optical lens of one type corresponds to one of the at least two blocks at the center of the circle, and the optical lens of the other type corresponds to at least two blocks at the center of the circle the other of them; and

An assembly step, including:

At least two of the optical lenses belonging to one of at least two types are arranged in a lens barrel.

The effect of the present invention is that, through the optical lens assembly method of the present invention, the optical lenses can be paired, so that the optical lenses whose circle centers are located in the same block can be arranged in the same lens barrel, thereby improving the quality of the optical lenses. The lens has the problem of poor image quality due to excessive eccentricity error, and at the same time, it can reduce the manufacturing cost of the optical lens.

In order to describe the present invention more clearly, preferred embodiments are given and described in detail with the drawings as follows. Please refer to FIG. 1 , which is a lens inspection device 1 , the lens inspection device 1 includes a light source 10 , a clamping fixture 20 , an image sensing element 40 and a signal processing unit 60 , the light source 10 is along a first axis A reticle parallel beam is projected to X, and the clamping fixture 20 is used to clamp an optical lens L to be tested and rotate with a rotation axis S as the axis, and the rotation axis S is parallel to the first axis X, The image sensing element 40 is a photographing device with a photo-coupler (CCD) for receiving the light beam from the light source 10 passing through the optical lens L to be tested. The signal processing unit 60 is connected to the image sensing element 40 . The signal processing unit 60 is used for performing image processing on the image output by the image sensing element 40 .

Please refer to FIG. 2 , which is a flowchart of an optical lens assembly method according to a preferred embodiment of the present invention. The optical lens assembly method is performed by the above-mentioned lens detection device 1 , and the optical lens assembly method includes the following steps:

A detection step is respectively performed on the plurality of optical lenses, wherein the detection step includes:

Step S101 , define a reference plane P, the reference plane P has a center point C, define a reference line passing through the center point C, as shown in FIG. 3 , the reference line includes a first reference line L1 and a second reference line Line L2, the first reference line L1 and the second reference line L2 perpendicularly intersect at the center point C, and divide the reference plane P into a first area A1, a second area A2, and a third area block A3 and a fourth block A4;

Step S102, the image sensing element 40 receives the light beam from the light source 10 passing through the optical lenses L, the signal processing unit 60 captures a first image from the image output by the image sensing element 40, and according to the first image A first imaging point P1 is obtained from an image, wherein the light source 10 projects light beams along the first axis X, each optical lens L is set at a first position, and the first axis X passes through the reference plane P The center point C and the center of each optical lens L;

Step S103 , after each optical lens L is rotated from the first position to a second position with the rotation axis S as the axis, the signal processing unit 60 captures a second image from the image output by the image sensing element 40 , and obtain a second imaging point P2 according to the second image; in this embodiment, each optical lens L is rotated from the first position to the second position by a first angle, and the first angle is 10~ 15 degrees. In practice, the rotation angle of each optical lens L from the first position to the second position can also be other angles, and is not limited to the above 10-15 degrees.

Step S104, after each optical lens L rotates to the third position with the rotation axis S as the axis, the signal processing unit 60 captures a third image from the image output by the image sensing element 40, and according to the third position The three images obtain a third imaging point P3, and the third position is different from the first position and the second position; in this embodiment, each of the optical lenses L is rotated from the second position by a second angle to The third position and the second angle are 10-15 degrees. In practice, the rotation angle of each optical lens L from the second position to the third position can also be other angles, not the above-mentioned 10-15 degrees. In addition, in this embodiment, the first angle is equal to the second angle as an example for illustration, and in other embodiments, the first angle may not be equal to the second angle.

Step S105 , please refer to FIG. 3 , the signal processing unit 60 calculates the first imaging point P1 and the second imaging point through the first imaging point P1 , the second imaging point P2 and the third imaging point P3 according to the first imaging point P1 , the second imaging point P3 The position of the center C1 of a circle between P2 and the third imaging point P3, the position of the center C1 corresponds to one of the first block A1, the second block A2, the third block A3 and the fourth block A4 By;

Step S106, according to the block corresponding to the reference plane P at the position of the center C1, each of the optical lenses L corresponds to the first block A1, the second block A2, the third block A3 and the fourth block A4 is divided into four categories, including the first category, the second category, the third category and the fourth category. For example, if the position of the center C1 of the optical lens L to be tested is in the second area as shown in FIG. 3 Block A2, the optical lens L to be tested is classified into the second category. Similarly, if the position of the center C1 of the optical lens to be tested is located in the first block A1, the optical lens to be tested is classified into the second category. into the first category.

The optical lens assembly method includes an assembly step S201 , including: disposing at least two optical lenses belonging to the first, second, third and fourth types of the optical lenses in a lens barrel, respectively. For example, a user can select at least two optical lenses that he needs from a plurality of optical lenses belonging to the first category and set them in a lens barrel. Similarly, the user can choose to belong to the second category, the third category or the fourth category. At least two required optical lenses are selected from the plurality of optical lenses to be set in different lens barrels, whereby, through the optical lens assembly method of the present invention, these optical lenses can be paired, so that the center of the circle falls in the same block. The optical lens can be arranged in the same lens barrel, so as to improve the problem of poor image quality caused by the large eccentric error of the lens in the optical lens, and at the same time, the manufacturing cost of the optical lens can be reduced.

It is worth mentioning that, in this embodiment, the reference line includes the first reference line L1 and the second reference line L2, and the first reference line L1 and the second reference line L2 perpendicularly intersect at the center Point C, and divide the reference plane P into the first block A1, the second block A2, the third block A3 and the fourth block A4 as an example, in other embodiments, the reference line may also be One or more than two, for example, when the reference line is one, the reference line passes through the center point and the reference line divides the reference surface into two blocks, including a first block and a second block, the center of the circle The position corresponds to one of the two blocks, and each optical lens corresponding to the first block and the second block is divided into two categories, including the first category and the second category. In the second block, the optical lens to be tested is classified into the second category. Similarly, if the center of the other optical lens to be tested falls in the first block, the other optical lens to be tested is classified into the first category. Then, at least two optical lenses belonging to the first type are arranged in a lens barrel, and at least two optical lenses belonging to the second type are arranged in another lens barrel, which can also improve the imaging of the lenses in the optical lens due to excessive eccentricity errors. The purpose of the problem of poor quality.

It should be noted that the optical lens assembly method includes performing an image processing on the first image, the second image and the third image respectively, and the image processing includes binarization processing, image processing as shown in FIG. 6 to FIG. 9 Dilation processing, image erosion processing and image thinning processing are performed to obtain the first imaging point P1, the second imaging point P2 and the third imaging point P3 respectively. In this embodiment, the first image (in conjunction with FIG. 4 ) of the image processing is performed in sequence in the order of binarization processing (in accordance with Figure 5), image expansion processing (in accordance with Figure 6), image erosion processing (in accordance with Figure 7), and image thinning processing (in accordance with Figure 8). .

In this embodiment, the acquisition of a first imaging point P1, a second imaging point P2 and a third imaging point P3 is taken as an example for illustration. In other embodiments, the detection step includes repeating step S104 to acquire complex numbers. three third imaging points P3, the third imaging points P3 are different from each other (see FIG. 9 ), and step S105 includes calculating according to the first imaging point P1 , the second imaging point P2 and the third imaging points P3 The position of the center C2 of the circle passing through the first imaging point P1, the second imaging point P2 and the third imaging points P3 can be obtained. By obtaining a plurality of third imaging points, the accuracy of the calculated position of the center C2 can be improved. .

To sum up, through the optical lens assembly method of the present invention, the optical lenses can be paired, so that the optical lenses whose circle centers are located in the same block can be arranged in the same lens barrel, thereby improving the lens in the optical lens. The problem of poor image quality due to excessive eccentricity error can also reduce the manufacturing cost of the optical lens.

The above descriptions are only preferred feasible embodiments of the present invention, and any equivalent changes made by applying the description of the present invention and the scope of the patent application should be included in the patent scope of the present invention.

[this invention] 1: Detection device 10: Light source 20: Clamping jig 40: Image Sensing Components 60 signal processing unit A1: The first block A2: Second block A3: The third block A4: Fourth block C: center point C1,C2: center of circle L: Optical lens L1: first reference line L2: Second reference line P: reference surface P1: first imaging point P2: Second imaging point P3: The third imaging point S: Rotary axis X: the first axis S101, S102, S103, S104, S105, S106, S201: Steps

FIG. 1 is a schematic diagram of a lens inspection device. FIG. 2 is a flowchart of an optical lens assembly method according to a preferred embodiment of the present invention. FIG. 3 is a schematic diagram of a reference plane of the above preferred embodiment. FIG. 4 is a first image photograph of the above preferred embodiment. FIG. 5 is a first image photograph of the above preferred embodiment. FIG. 6 is a photo of the first image after binarization processing according to the above preferred embodiment. FIG. 7 is a photograph of the first image of the above preferred embodiment subjected to image expansion processing. FIG. 8 is a photograph of the first image of the above preferred embodiment subjected to image thinning processing. FIG. 9 is an image photograph of the first imaging point, the second imaging point and a plurality of third imaging points in the above preferred embodiment.

S101, S102, S103, S104, S105, S106, S201: Steps

Claims (9)

An optical lens assembly method, comprising the following steps: A detection step is respectively performed on the plurality of optical lenses, wherein the detection step includes: A. define a reference plane, the reference plane has a center point, define at least one reference line passing through the center point and the at least one reference line divides the reference plane into at least two blocks; B. An image sensing element receives a light beam from a light source passing through each of the optical lenses, captures a first image from the image output by the image sensing element, and obtains a first imaging point according to the first image, wherein The light source projects light beams along a first axis, each of the optical lenses is arranged at a first position, and the first axis passes through the center point of the reference plane and the center of each of the optical lenses; C. After each optical lens is rotated from the first position to a second position with a rotation axis as the axis, a second image is captured from the image output by the image sensor, and a first image is obtained according to the second image Two imaging points, the rotation axis is parallel to the first axis; D. After each optical lens rotates to a third position with the rotation axis as the axis, a third image is captured from the image output by the image sensing element, and a third imaging point is obtained according to the third image, the the third position is different from the first position and the second position; E. According to the first imaging point, the second imaging point and the third imaging point, calculate the center position of a circle passing through the first imaging point, the second imaging point and the third imaging point, the center position of the circle Corresponding to at least one of the two blocks; F. Divide each of the optical lenses into at least two types, wherein the optical lens of one type corresponds to one of the at least two blocks at the center of the circle, and the optical lens of the other type corresponds to at least two blocks at the center of the circle the other of them; and An assembly step, including: At least two of the optical lenses belonging to one of at least two types are arranged in a lens barrel. The optical lens assembling method of claim 1, wherein the assembling step comprises that at least two of the optical lenses belonging to the other one of at least two types of the optical lenses are disposed in another lens barrel. The optical lens assembling method of claim 1, comprising repeatedly performing step C to obtain a plurality of third imaging points, the third imaging points being different from each other, and step E comprising according to the first imaging point, the second imaging point The imaging point and the third imaging points calculate the position of the center of a circle passing through the first imaging point, the second imaging point and the third imaging points. The optical lens assembling method of claim 1, wherein the at least one reference line comprises a first reference line and a second reference line, the first reference line and the second reference line perpendicularly intersect at the center point, and The reference surface is divided into a first block, a second block, a third block and a fourth block, and step F includes the region falling on the reference surface according to the position of the center of each optical lens each of the optical lenses corresponding to the first block, the second block, the third block and the fourth block is divided into four categories; and the assembling step includes the steps of assembling the optical lenses belonging to the At least two of the optical lenses in the category of the first block, the category of the second block, the category of the third block and the category of the fourth block are respectively arranged in a lens barrel. The optical lens assembling method as claimed in claim 1, comprising respectively performing an image processing on the first image, the second image and the third image, the image processing including binarization processing, image expansion processing, and image expansion processing and image thinning processing to obtain the first imaging point, the second imaging point and the third imaging point respectively. The optical lens assembly method as claimed in claim 1, comprising rotating each of the optical lenses from the first position to the second position by 10-15 degrees. The optical lens assembly method of claim 1, comprising rotating each of the optical lenses from the second position to the third position by 10-15 degrees. The optical lens assembly method as claimed in claim 1, comprising rotating each of the optical lenses from the first position to the second position by a first angle, and rotating each of the optical lenses from the second position to the second position by a second angle In three positions, the first angle is equal to the second angle. The optical lens assembly method as claimed in claim 1, wherein the light source projects a cross beam along the first axis.

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