TWI730880B - Optical lens assembly method - Google Patents

Abstract

A method for assembling an optical lens includes a detection step, including: defining a reference line to pass through the center point of the reference surface and dividing the reference surface into two blocks; obtaining the first light beam according to the image sensor element received from the light source and passing through each optical lens For an imaging point, each optical lens rotates to the second position to obtain the second imaging point; each optical lens rotates to the third position to obtain the third imaging point, and calculates through the first imaging point, the second imaging point and the third imaging point The position of the center of the circle of dots; the corresponding two blocks of each optical lens are divided into two types according to the falling point of the center position; and the assembly steps include: arranging at least two of the optical lenses belonging to one of the two types in the optical lens In a lens barrel, at least two optical lenses belonging to the other of the two types of optical lenses are arranged in the other lens barrel.

Description

Optical lens assembly method

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

It is known that during the production or system assembly of an optical lens, if the optical axis does not coincide with the rotational symmetry axis, eccentricity errors will occur and cause many image imaging and imaging quality problems. Therefore, before assembly, the optical axis of the lens is generally checked for deviation The displacement and eccentricity error measurement methods are divided into two types: mechanical measurement method and optical measurement method depending on the accuracy.

The so-called optical measurement method, in the detection, through the incident light penetrating the lens to be measured and rotating the lens to be measured with a rotation axis, if the lens to be measured is eccentric, it will be in the photo charge coupled device (CCD) 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 through the above-mentioned optical measurement method, generally if the eccentricity of the lens is detected, in order to avoid affecting the imaging quality, it can only be discarded as a defective product, which will inevitably cause waste of resources and cost. Therefore, how to screen out the offset lens before assembling the optical lens and provide good imaging quality without increasing the manufacturing cost is a problem that the inventor urgently needs to solve.

In view of this, the 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-mentioned objective, an optical lens assembly method provided by the present invention includes a detection step of a plurality of optical lenses respectively, wherein the detection step includes:

A. Define a reference surface, the reference mask has a center point, at least one reference line passes through the center point, and the at least one reference line divides the reference surface into at least two blocks;

B. An image sensor element receives a light beam passing through each optical lens from a light source, the image output by the image sensor element captures a first image, and obtains a first imaging point according to the first image, wherein The light source projects a light beam along a first axis, each of the optical lenses is set 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 of the optical lenses 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 element, and a first image is obtained from the second image Two imaging points, the rotation axis is parallel to the first axis;

D. After each of the optical lenses is rotated to a third position about the axis of rotation, the image output by the image sensor element captures a third image, and obtains a third imaging point 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, and the center position of the circle Corresponds to one of at least two blocks;

F. Divide each of the optical lenses into at least two types. One type of the optical lens has the center position corresponding to one of at least two blocks, and the other type of the optical lens has the center position corresponding to at least two blocks 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 with the center of the circle in the same block can be set in the same lens barrel, thereby improving the optical lens The lens has the problem of poor image quality due to excessive eccentricity error, and at the same time can reduce the manufacturing cost of the optical lens.

In order to explain the present invention more clearly, the preferred embodiments are described in detail in conjunction with the drawings as follows. Please refer to FIG. 1, which is a lens detection device 1. The lens detection device 1 includes a light source 10, a clamping fixture 20, an image sensor 40 and a signal processing unit 60. The light source 10 is along a first axis. Projecting a cross-line parallel beam to X, the clamping fixture 20 is used to clamp an optical lens L to be tested to rotate with a rotation axis S as the axis, and the rotation axis S is parallel to the first axis X, The image sensor element 40 is a photographing device with a photoelectric coupling element (CCD) for receiving the light beam from the light source 10 through the optical lens L to be tested. The signal processing unit 60 is connected to the image sensor element 40. The signal processing unit 60 is used for performing image processing on the image output by the image sensor 40.

Please cooperate with 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 through the above-mentioned lens detection device 1. The optical lens assembly method includes the following steps:

A plurality of optical lenses are respectively subjected to a detection step, wherein the detection step includes:

Step S101: Define a reference plane P. The reference plane P has a center point C. A reference line passes 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 the reference plane P is divided into a first area A1, a second area A2, and a third area Block A3 and a fourth block A4;

In step S102, the image sensing element 40 receives the light beam from the light source 10 through each of the optical lenses L, the signal processing unit 60 captures a first image from the image output by the image sensing element 40, and based on the first image An image acquires a first imaging point P1, where the light source 10 projects a light beam along the first axis X, each of the optical lenses 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;

In 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 sensor 40 , And obtain a second imaging point P2 according to the second image; in this embodiment, each of the optical lenses 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 aforementioned 10-15 degrees.

In step S104, after each of the optical lenses 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 sensor 40, and according to the first image A third imaging point P3 is obtained from the three images, 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 by a second angle from the second position to In the third position, the second angle is 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 instead of the above-mentioned 10-15 degrees. In addition, for limitation, in this embodiment, the first angle is equal to the second angle as an example. In other embodiments, the first angle may not be equal to the second angle.

Step S105, please cooperate with FIG. 3, the signal processing unit 60 calculates through the first imaging point P1, the second imaging point according to the first imaging point P1, the second imaging point P2, and the third imaging point P3. The position of the center C1 of the circle of 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 where the position of the circle center C1 corresponds to the reference plane P, correspond each of the optical lenses L to the first block A1, the second block A2, the third block A3, and the fourth block A4 is divided into four categories, including category 1, category 2, category 3, and category 4. For example, if the center C1 of the optical lens L to be tested is located in the second zone as shown in Figure 3 Block A2, the optical lens L to be tested is classified into the second type. Similarly, if the position of the center C1 of another optical lens to be tested falls on the first block A1, then the other optical lens to be tested is Divided into the first category.

The optical lens assembly method includes an assembly step S201, including: arranging at least two optical lenses of the first type, the second type, the third type, and the fourth type among the optical lenses in a lens barrel, respectively. For example, the user can select at least two optical lenses from a plurality of optical lenses belonging to the first category and set them in a lens barrel. Similarly, the user can belong to the second, third or fourth category. Select at least two optical lenses required from the plurality of optical lenses to be respectively arranged in different lens barrels, thereby, through the optical lens assembly method of the present invention, the optical lenses can be paired, so that the center of the circle is located in the same block The optical lens can be set in the same lens barrel to improve the poor image quality of the lens due to excessive eccentricity error, and reduce the manufacturing cost of the optical lens.

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 plane 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. The first block and the second block corresponding to each optical lens are divided into two types, including the first and second types. If the center of the optical lens to be tested is located at In the second block, the optical lens to be tested is classified as the second type. In the same way, 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 as the first At least two optical lenses belonging to the first category are set in one lens barrel, and at least two optical lenses belonging to the second category are set 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 image processing on the first image, the second image, and the third image. The image processing includes binarization, image processing, and image processing as shown in FIGS. 6-9. Expansion processing, image erosion processing, and image thinning processing 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 ) The image processing is carried out in sequence in the order of binarization processing (with Figure 5), image expansion processing (with Figure 6), image erosion processing (with Figure 7) and image thinning processing (with Figure 8) .

In this embodiment, taking a first imaging point P1, a second imaging point P2, and a third imaging point P3 as an example is described. In other embodiments, the detection step includes repeating step S104 to obtain a plurality of Three third imaging points P3, the third imaging points P3 are different from each other (in conjunction with 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 is obtained. By obtaining a plurality of third imaging points, the accuracy of the calculated position of the center C2 can be improved .

In summary, through the optical lens assembly method of the present invention, these optical lenses can be paired, so that the optical lenses with the center of the circle in the same block can be placed in the same lens barrel, thereby improving the lens in the optical lens The problem of poor image quality due to excessive eccentricity error, and at the same time can reduce the manufacturing cost of the optical lens.

The above are only the preferred and feasible embodiments of the present invention. Any equivalent changes made by applying the specification 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 fixture 40: Image sensor 60: signal processing unit A1: The first block A2: The second block A3: The third block A4: The fourth block C: center point C1, C2: Center of circle L: Optical lens L1: The first reference line L2: Second reference line P: Reference surface P1: the first imaging point P2: Second imaging point P3: Third imaging point S: Rotation axis X: first axis S101, S102, S103, S104, S105, S106, S201: steps

Figure 1 is a schematic diagram of a lens detection device. 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 the reference plane of the above-mentioned preferred embodiment. Figure 4 is the first image of the above preferred embodiment. Figure 5 is the first image of the above preferred embodiment. Fig. 6 is a photo of the first image in the above preferred embodiment that has been binarized. FIG. 7 is a photo of the first image of the above preferred embodiment after image expansion processing. FIG. 8 is a photo of the first image of the above preferred embodiment after 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 of the above-mentioned preferred embodiment.

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

Claims (9)

An optical lens assembly method, comprising the following steps: a plurality of optical lenses are respectively subjected to a detection step, wherein the detection step includes: A. Define a reference surface, the reference mask has a center point, and defines at least one reference line to pass through the center Point and the at least one reference line divides the reference plane into at least two blocks; B. an image sensor element receives a light beam passing through each of the optical lenses from a light source, and an image output by the image sensor element captures one A first image, and a first imaging point is obtained according to the first image, wherein the light source projects a light beam along a first axis, each of the optical lenses is set at a first position, and the first axis passes through the reference The center point of the surface and the center of each optical lens; C. After each optical lens is rotated from the first position to a second position with a rotation axis as the axis, an image output by the image sensor element is captured A second image, and a second imaging point is obtained according to the second image, 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, the The image output by the image sensor captures a third image, and obtains a third imaging point according to the third image, 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, and the center position corresponds to at least two blocks F. Divide each of the optical lenses into at least two types, where the optical lens of one type corresponds to one of the at least two blocks at the center position of the circle, and the optical lens of the other type corresponds to the center position of the circle There should be at least the other of the two blocks; 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 method for assembling an optical lens according to claim 1, wherein the assembling step includes arranging at least two of the optical lenses belonging to the other of at least two types in another lens barrel. The optical lens assembly method according to claim 1, including repeating step D to obtain a plurality of third imaging points, the third imaging points are different from each other, and step E includes performing step D according to the first imaging point, the second imaging point and the second imaging point. The imaging point and the third imaging points calculate the center positions of the circles passing through the first imaging point, the second imaging point, and the third imaging points. The optical lens assembly method according to claim 1, wherein the at least one reference line includes 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. Step F includes a zone that falls on the reference surface according to the center position of each optical lens Block, 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 optical lenses belonging to the At least two of the type of the first block, the type of the second block, the type of the third block, and the type of the fourth block are respectively arranged in a lens barrel. The method for assembling an optical lens according to claim 1, comprising performing image processing on the first image, the second image, and the third image respectively, and the image processing includes 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 according to claim 1, comprising rotating each of the optical lenses by 10-15 degrees from the first position to the second position. The optical lens assembly method according to claim 1, comprising rotating each of the optical lenses by 10-15 degrees from the second position to the third position. The method for assembling an optical lens according to claim 1, comprising rotating each optical lens from the first position by a first angle to the second position, and rotating each optical lens from the second position by a second angle to the first position. In three positions, the first angle is equal to the second angle. The optical lens assembly method according to claim 1, wherein the light source projects a cross beam along the first axis.

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