TW201326788A - Method for adjusting optical visual field - Google Patents

Abstract

A method for adjusting optical visual field comprises: a photoelectric coupler, a lens, and a transmission source. The present invention is applicable to an optic inspection apparatus, where the lens is located in front of the photoelectric coupler and the transmission source projects to a reflection element and is reflected to an object to be detected and then get incident to the lens and the photoelectric coupler. The lens and the photoelectric coupler form a first included angle with respect to a normal line. A reflection line made by the reflection element to the object to be detected forms a third included angle with respect to the normal line. The reflection element and a line parallel to the normal line form a second included angle. The present invention uses the third included angle of the reflection element to carry out shifting and adjusting of the position and angle in the horizontal and vertical directions so as to improve the drawback of the known techniques that directly makes positional adjustment on the transmission source device that is bulky and difficult to move and also to accomplish brightness adjustment of visual field with respect to the transmission source through minute adjustment of a reflection element that is thin, light-weighted, and compact.

Description

Optical field adjustment method

The invention relates to an optical field adjustment method, in particular to the purpose of adjusting the brightness of the light and dark field of the emission light source by horizontally traversing the third angle sandwiched by the reflective lens element.

The principle of bright field observation is to uniformly irradiate the light on the object to be tested, to capture the observation mode of the transmitted object or the reflected light, and then calculate the contrast value of the observed image from the corresponding value of the light transmittance or reflectance of the article. The most basic method of observation.

The principle of dark field observation is that the light is not directly irradiated on the object to be tested through the dark field concentrating mirror, but only the light is obliquely incident on the object to be tested, and the diffracted light generated by the internal reflection of the condensing lens is irradiated on the surface of the object to be tested, so only the light is captured. The scattered light on the surface of the object, through which the background is dark and the subject emits light.

In practical applications, the test equipment usually refers to a sample of a mirror-like material such as a printed circuit board, a liquid crystal panel of various sizes, a semiconductor wafer, a die or a wafer, an illumination lens, or a transparent glass. Scattered light reflected from tiny flaws or bumps can be clearly seen by the instrument. This is called dark field observation. In some specific cases, the board, LCD panel, wafer, lens or glass are related. Samples with mirror materials have very small defects that are invisible to the naked eye and irregularities. They cannot be detected in time by ordinary bright field observation. At this time, dark-field observations must be applied to the micro-defects of the object to be tested through high-sensitivity precision detection devices. Point out.

For the adjustment method of the conventional emission light source, please refer to Fig. 1, which is a schematic diagram of the optical state simulation of the prior art. Firstly, the working distance between the transmitting light source 1 and the linear scanning image capturing system is fixed, and then the angle of the image capturing system is fixed, that is, the angle between the incident light path of the camera 2 and the lens 3 and the object 4 to be detected and the left side of the first normal line 5 is θ11. Then, by moving the light source 1 component position moving program, the light source system is aligned and fixed to the right angle θ12, and adjusted to the bright field (light reflection) or dark field (light diffusion) state by the actual needs of the operator, or The dark and dark field of view is the middle area between the light and dark fields.

Through the above description, it is known that the adjustment of the brightness and dark field state of the conventional light source system must directly complete the calibration procedure by using the position of the moving light source 1 component. When the volume and weight of the object to be tested are larger, the volume and weight of the component of the light source 1 will be relatively larger. This will make the operation more inconvenient and the calibration accuracy will be affected.

The purpose of the invention is to adjust the position and angular movement of the third angle between the reflective element and the normal extension line through the design of the reflective lens to improve the direct and large-sized emission in the conventional technology. The lack of position adjustment of the light source machine can adjust the brightness of the field of view to the emission source only by fine-tuning the thin and light reflective elements.

In order to achieve the above object, the present invention is an optical field adjustment method comprising: a photocoupler, a lens and an emission source; the invention is applied to an optical detection device, the lens is located in front of the photocoupler, and the emission source is projected After being reflected by a reflective element, it is reflected onto the object to be tested, and then incident on the lens and the photocoupler. The lens and the photocoupler form a first angle with the normal, and the reflective element is reflected to the reflection line and the normal line of the object to be tested. A third angle, the reflective element forms a second angle with the normal parallel extension line.

The invention mainly adopts the design of the reflective lens to dispose the reflective element on the projection path of the emission source, and the reflection path reflected from the reflective element to the object to be tested forms a third angle with the normal line, and the reflective element and the normal line extend parallel to the normal line. A second angle is also formed. When the object to be tested needs to be adjusted for the light and dark field of view, the angle of the third angle to be displaced is first calculated by the following mathematical equation, and then the position and angle of the reflection element are directly transmitted and adjusted by the horizontal and vertical directions. The reflective element is fine-tuned to the third angle of movement calculation value and the adjustment angle calculated by the mathematical equation, thereby completing the adjustment of the field of view of the emission source.

(90 degrees - 2 * θ2) = θ3

In addition, since the reflective component is made of a reflective lens material, the reflection efficiency is better and the energy loss of the light source is low. Even if the calculated adjustment angle value is extremely small, the position of the horizontal and vertical directions can be easily achieved by the thin and light reflective element. Angle adjustment purpose.

In order to make those skilled in the art understand the technical content of the present invention and implement it, and according to the disclosure, the patent scope and the drawings, the related objects and advantages of the present invention can be easily understood by those skilled in the art. The detailed features and advantages of the present invention will be described in detail in the embodiments.

Referring to Figure 2, there is shown a schematic diagram of the optical state simulation of the first embodiment of the present invention. The present invention is mainly applied to an optical detecting device, comprising: a photocoupler 21, a lens 22 and an emission source 23; the lens 22 is located in front of the photocoupler 21, and the emission source 23 is projected onto a reflective element 24 and then reflected to On the object 25, and then incident on the lens 22 and the photocoupler 21, the beam path of the object 25 to the lens 22 and the photocoupler 21 forms a first angle θ1 with the second normal line 26, and the reflective element 24 reflects The reflection line of the object to be tested 25 and the second normal line 26 form a third angle θ3, wherein the horizontal surface of the object to be tested 25 is perpendicular to the second normal line 26, and the reflection element 24 and the second normal line 26 extend parallel lines. Then a second angle θ2 is formed.

In this embodiment, through the lens design of the reflective element 24, when the emission source 23 is to be adjusted for the projection state of the bright field or the dark field, the reflection element is obtained by a mathematical equation of (90 degrees - twice the second angle) = the third angle. The third angle θ3 between the 24 and the second normal line 26 is required to move the position distance value and the adjustment angle in the horizontal or vertical direction. The calculation is completed, and only the fine adjustment of the reflection element 24 can adjust the brightness of the field of view of the emission source 23. The mathematical equations for the three-angle θ3 displacement distance and adjustment angle are listed below:

(90 degrees - 2 * θ2) = θ3

Since the reflective element 24 of the present invention is composed of a reflective lens material, the reflection efficiency is good and the energy loss of the light source is low, and the first angle formed by the beam path of the object 25 to the lens 22 and the photocoupler 21 and the second normal line 26 is formed. After the adjustment of θ1 is fixed, the first angle θ1 is a fixed value of the image capturing system. Therefore, even if the calculated value of the third angle θ3 is extremely small, the horizontal and vertical directions can be easily achieved by the thin and light reflective element 24. For position and angle calibration purposes, there is no need to consider how to fine tune the components of the emission source, and the calibration accuracy is more accurate.

Please refer to FIG. 3, which is a schematic diagram of the optical state simulation of the horizontal position of the reflective element in the second embodiment of the present invention. As described in the foregoing first embodiment, when the light source 23 is to be fine-tuned for the light and dark field, the angle of the third angle θ3 is obtained via a mathematical equation, and then the reflective element 24 is moved in the horizontal direction position to make the field of view of the light source 23 Shading has the best angle of the image system.

Please refer to FIG. 4, which is a schematic diagram of the optical state simulation for the vertical adjustment of the vertical direction of the reflective element according to the third embodiment of the present invention. This embodiment is substantially the same as the second embodiment described above, except that when the third angle θ3 is used to obtain the value of the angle to be finely adjusted by using the mathematical equation, the reflective element 24 is moved in the vertical direction and the position is obtained, thereby obtaining the emission source 23. The best view brightness.

Therefore, through the above detailed embodiment, the lens design of the reflective element 24 of the present invention can effectively optimize the visual field brightness of the image capturing system angle of the transmitting light source 23, and the calibration precision is more accurate, and the overall improvement is improved. It is known that the technique directly moves the emission source 23 and the component is lacking and inconvenient.

The embodiments are described to illustrate the features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the present invention and to implement the present invention without limiting the scope of the present invention. Equivalent modifications or modifications made by the spirit of the disclosure should still be included in the scope of the claims described below.

1. . . Emission source

2. . . camera

3. . . Lens

4. . . Analyte

5. . . First normal

Θ11. . . Angle on the left

Θ12. . . Right angle

twenty one. . . Photocoupler

twenty two. . . lens

twenty three. . . Emission source

twenty four. . . Reflective element

25. . . Analyte

26. . . Second normal

Θ1. . . First angle

Θ2. . . Second angle

Θ3. . . Third angle

Figure 1 is a schematic diagram of the optical state simulation of the prior art.

Fig. 2 is a schematic view showing the optical state simulation of the first embodiment of the present invention.

Fig. 3 is a schematic view showing the optical state simulation of the horizontal displacement of the reflective element in the second embodiment of the present invention.

Fig. 4 is a schematic view showing the optical state simulation of the vertical adjustment of the angle of the reflective element in the third embodiment of the present invention.

twenty one. . . Photocoupler

twenty two. . . lens

twenty three. . . Emission source

twenty four. . . Reflective element

25. . . Analyte

26. . . Second normal

Θ1. . . First angle

Θ2. . . Second angle

Θ3. . . Third angle

Claims (6)

An optical field adjustment method is applied to an optical detecting device, comprising: a photocoupler; a lens located in front of the photocoupler; and an emission light source projected onto a reflective element and reflected to be tested And then incident on the lens and the photocoupler, the lens and the photocoupler form a first angle with the normal, and the reflection line reflected by the reflective element to the object to be tested forms a third angle with the normal, the reflective element and the method The parallel line of the line forms a second angle, and the brightness of the field of view of the light source is adjusted through the position calibration procedure of the reflective element. The adjustment method is to adjust the position and angle of the third angle between the horizontal and vertical directions. The optical field adjustment method according to claim 1, wherein the third angle of displacement calculation formula is (90 degrees - twice the second angle) = the third angle. The optical field adjustment method according to claim 2, wherein the third angular displacement angle calculation formula is (90 degrees - 2 * θ2) = θ3. The optical field adjustment method according to claim 1, wherein the reflective element is made of a lens material. The optical field of view adjustment method of claim 1, wherein the first angle is a fixed value of the adjustment of the image taking system. The optical field of view adjustment method of claim 1, wherein the horizontal surface of the object to be tested is perpendicular to the normal.