Automatic focusing and image acquisition systems and methods, microscopes

Abstract

This application provides an automatic focusing and image acquisition system for a microscope, including a focal length adjustment module, an optical module for converting light emitted from a first light source into a straight beam, the straight beam being transmitted to the focusing plane of the object under test via a first optical component, the object under test being positioned along the XY direction, and a second optical component transmitting the straight beam reflected from the focusing plane to a first sensor to acquire a focused image, a computing unit controlling an actuator to adjust the Z-direction position of the first optical component according to the position value of the focused image, and an image acquisition module having a third optical component projecting light emitted from a second light source onto the image acquisition plane of the object under test, and a fourth optical component imaging the light reflected from the image acquisition plane onto a second sensor to acquire a target image.

Description

Technical Field

[0001] This application relates to an automatic focusing and image acquisition system for microscopes, and more particularly to a system for rapid focusing and image acquisition for electronic products. Background Technology

[0002] Microscopes have a high image magnification, which can magnify small objects for observation. However, due to the high magnification, the depth of field is relatively small. Users need to spend time adjusting the distance between the objective lens and the object to see the object clearly. In contrast, autofocus systems on the market can quickly adjust the distance between the objective lens and the object because the focusing plane is the image plane. Users do not need to spend too much time to obtain a clear image.

[0003] However, for special functional designs, such as under-display cameras, LED glass substrate packaging, and LCD panel packaging (Chip on glass, Film on glass), most current electronic products place related electronic components on a dielectric material. To inspect these electronic components, it is necessary to penetrate the dielectric material for observation. If commercially available autofocus systems are used, it is not easy to achieve fast focusing, or multiple procedures are required to complete focusing, resulting in a decrease in production efficiency. Summary of the Invention

[0004] The technical problem to be solved by this application is to provide an automatic focusing and image acquisition system, including a focal length adjustment module, having an optical module for converting light emitted from a first light source into a straight beam, the straight beam being transmitted to a pair of focal planes of an object under test via a first optical component, and a second optical component transmitting the straight beam reflected from the focal planes to a first sensor to acquire a pair of focused images, a computing unit controlling an actuator to adjust the Z-direction position of the first optical component according to the position value of the focused image, and an image acquisition module, having a third optical component projecting light emitted from a second light source onto an image acquisition plane of the object under test, and a fourth optical component imaging the light reflected from the image acquisition planes onto a second sensor to acquire a target image.

[0005] It also includes a first beam splitter and a second beam splitter located on the light path between the focusing plane and the first sensor. The first beam splitter is used to transmit a portion of the straight beam to the second beam splitter. The second beam splitter reflects a portion of the straight beam back to the first optical component, and the first optical component transmits the portion of the straight beam to the focusing plane. The second beam splitter allows a portion of the straight beam reflected back from the focusing plane to the first optical component to be reflected back to the first beam splitter. The first beam splitter allows a portion of the straight beam to be reflected back to the second optical component, and the second optical component transmits it to the first sensor.

[0006] The second beam splitter and the third beam splitter are located on the light path between the second sensor and the imaging plane and between the third optical component and the imaging plane. The third beam splitter is used to reflect part of the light from the second light source to the second beam splitter. The second beam splitter transmits part of the light to the first optical component, and the first optical component transmits part of the light to the imaging plane. The second beam splitter allows part of the light reflected from the imaging plane back to the first optical component to be transmitted to the third beam splitter. The third beam splitter allows part of the light to be imaged onto the second sensor through the fourth optical component.

[0007] Preferably, the imaging module also has a light-absorbing plate and a first reflective component, the first reflective component reflecting a portion of the light from the second light source after passing through a third beam splitter onto the light-absorbing plate.

[0008] Preferably, it also includes a third light source and a second reflective component, the second reflective component reflecting a beam of light from the third light source to a fourth beam splitter, the fourth beam splitter reflecting a portion of the beam of light from the third light source to the first optical component, and the first optical component transmitting the beam of light to the imaging plane, wherein the third light source is a high-power laser beam.

[0009] Preferably, the distance between the focusing plane and the image capturing plane is between 0 mm and 10 mm.

[0010] Preferably, the first light source is a laser or a light-emitting diode, and the second light source is a light-emitting diode.

[0011] This application also includes a microscope having the aforementioned autofocus and image acquisition system.

[0012] This application also includes an autofocus and image acquisition method, which comprises the following steps:

[0013] (a) Focusing steps:

[0014] (a1) produces a straight beam of light;

[0015] (a2) The straight beam is transmitted through a first optical component to a pair of focal planes of an object under test and then reflected to a first sensor to obtain a pair of focal images;

[0016] (a3) Obtain a position value of the focused image;

[0017] (a4) Determine the focus status based on the value at that position; and

[0018] (a5) Adjust the Z-direction position of the first optical component according to the determination result of step (a4);

[0019] (b) Image acquisition steps:

[0020] (b1) produces a ray of light;

[0021] (b2) The light is projected onto an image plane of the object to be measured and reflected to a second sensor to form a target image;

[0022] (b3) Enable a second sensor to acquire the image of the target.

[0023] The other effects and embodiments of this application are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a light path diagram of the first embodiment of this application;

[0026] Figure 2 This is a schematic diagram of the focused image obtained by the first sensor in this application;

[0027] Figure 3 It is a graph showing the linear relationship between the x-position of the focused image and the Z-direction position of the first optical component;

[0028] Figure 4 This is a schematic diagram of the focused image obtained by the first sensor in the second embodiment of this application;

[0029] Figure 5 This is a light path diagram of the third embodiment of this application;

[0030] Figure 6 This is a light path diagram of the fourth embodiment of this application;

[0031] Figure 7 This is a flowchart of the automatic focusing and image acquisition method of this application.

[0032] Symbol Explanation

[0033] A, B, C: Local line segments of the focused image

[0034] a1~a5, a: focusing steps; b1~b3, b: image acquisition steps

[0035] h: Imaging distance; 10: First light source; 101: Straight beam

[0036] z: Distance between the first optical component and the focal plane

[0037] 11: Optical module; 13: First sensor; 15: Computation unit

[0038] 17: Actuator; 20: Second light source; 22: Second sensor

[0039] 31: First beam splitter; 32: Second beam splitter; 33: Third beam splitter.

[0040] 41: First optical component; 42: Second optical component; 43: Third optical component

[0041] 44: Fourth optical component; 51: Focusing plane; 52: Image-taking plane

[0042] 61: First reflective component; 62: Light-absorbing plate; 71: Fourth beam-splitting component

[0043] 72: Second reflector component; 73: Third light source Detailed Implementation

[0044] In the embodiments described below, the positional relationships include: up, down, left, and right. Unless otherwise specified, they are all based on the direction shown by the components in the diagram.

[0045] Please see Figure 1The diagram illustrates an autofocus and image acquisition system, comprising a focus adjustment module and an image acquisition module. The focus adjustment module has an optical module 11 for converting light emitted from a first light source 10 into a straight beam 101. The straight beam 101 is transmitted via a first optical component 41 to a pair of focal planes 51 of an object under test, the object under test being positioned along an XY direction. A second optical component 42 transmits the straight beam 101 reflected from the focal planes 51 to a first sensor 13 to acquire a pair of focused images. A processing unit 15 controls an actuator 17 to adjust the Z-direction position of the first optical component 41 according to the position value of the focused image. The processing unit 15 performs image processing and analysis. The processing unit 15 may be, but is not limited to, a programmable signal processing component such as a CPU, DSP, FPGA, or mixed signal processor.

[0046] Further explanation: the focus adjustment module also has a first beam splitter 31 and a second beam splitter 32 located on the light path between the focusing plane 51 and the first sensor 13. The first beam splitter 31 is used to transmit a portion of the straight beam 101 to the second beam splitter 32. The second beam splitter 32 reflects a portion of the straight beam 101 to the first optical component 41, and the first optical component 41 transmits a portion of the straight beam 101 to the focusing plane 51 to form a first light path. The second beam splitter 32 allows a portion of the straight beam 101 reflected from the focusing plane 51 back to the first optical component 41 to be reflected back to the first beam splitter 31. The first beam splitter 31 allows a portion of the straight beam 101 to be reflected back to the second optical component 42. The second optical component 42 transmits a portion of the straight beam 101 to the first sensor 13 to form a second light path and enable the first sensor 13 to acquire a focused image. The first light source 10 can be a laser or a light-emitting diode (LED), and the first sensor 13 is a line scan camera or a surface camera. The first optical component 41 and the second optical component 42 are optical lenses.

[0047] The imaging module has a third optical component 43 that projects light emitted from a second light source 20 onto an imaging plane 52 of the object under test, and a fourth optical component 44 that transmits the light reflected from the imaging plane 52 to a second sensor 22 to obtain a target image. The second light source 20 is a light-emitting diode (LED) that emits visible or infrared light, and the second sensor 22 is a line scan camera or a surface camera. The third optical component 43 and the fourth optical component 44 are optical lenses.

[0048] To further explain, the second beam splitter 32 and the third beam splitter 33 are located on the light path between the second sensor 22 and the image-capturing plane 52, and between the third optical component 43 and the image-capturing plane 52. The third beam splitter 33 is used to reflect a portion of the light from the second light source to the second beam splitter 32. The second beam splitter 32 transmits a portion of the light to the first optical component 41, and the first optical component 41 transmits a portion of the light to the image-capturing plane 52 to form a third light path. The second beam splitter 32 allows a portion of the light reflected from the image-capturing plane 52 back to the first optical component 41 to be transmitted to the third beam splitter 33. The third beam splitter 33 allows a portion of the light to be transmitted to a fourth optical component 44. The fourth optical component 44 images a portion of the light onto the second sensor 22 to form a fourth light path and enables the second sensor 22 to acquire the target image.

[0049] The aforementioned straight beam of light reaches the first sensor 13 for focusing via the first and second optical paths, and the light from the second light source reaches the second sensor 22 for image capture via the third and fourth optical paths, which constitutes a complete autofocus and image capture process.

[0050] For further explanation, please refer to Figure 2 The focused image acquired by the first sensor 13 is a straight light spot. When the Z-direction position of the first optical component 41 changes (i.e., the distance z between the first optical component 41 and the focusing plane 51 changes), the straight light spot will move along the X-direction of the first sensor 13. Therefore, the processing unit 15 controls the Z-direction position of the first optical component 41 according to the position of the focused image so that the second sensor 22 can acquire a clear image. In other embodiments, the straight light beam 101 can also be a shape other than a strip, such as a triangle, an arc, or a circle, as long as it can form a measurable light spot on the first sensor 13.

[0051] Please see Figure 3 The actuator 17 adjusts the position of the first optical component 41 according to the following formula:

[0052]

[0053] in C is the numerical aperture of the first optical component 41, a and k are correction constants, z is the distance between the first optical component 41 and the focusing plane 51, and x is the position of the focused image on the first sensor 13. When the focused image is at position x1, it corresponds to position z1 of the first optical component 41 in the Z direction. When the focused image is at position x2, it corresponds to position z2 of the first optical component 41 in the Z direction. When the focused image is at position x3, it corresponds to position z3 of the first optical component 41 in the Z direction, and so on. The x position of the focused image is linearly related to the position of the first optical component 41 in the Z direction.

[0054] Please see Figure 4 In the second embodiment of this application, when the image-taking plane of the object under test is on a plane with unequal height, the focusing image on the first sensor 13 is processed digitally and can be decomposed into one or more line segments for local positioning (line segments A, B, and C in the figure). Therefore, the user can set any x, y position on the image-taking plane 52 to correspond to the image-taking distance h (i.e., the distance between the focusing plane and the image-taking plane). In the embodiment of this application, the distance between the focusing plane and the image-taking plane is between 0 mm and 10 mm, and the distance z between the aforementioned first optical component 41 and the focusing plane 51 is greater than the aforementioned image-taking distance h.

[0055] Please see Figure 5 In the third embodiment of this application, the imaging module further includes a light-absorbing plate 62 and a first reflective component 61. After the light emitted by the second light source 20 is transmitted to the third beam splitter 33 via the third optical component 43, part of the light is reflected to the second beam splitter 32, and the other part of the light penetrates to the first reflective component 61 and is reflected to the light-absorbing plate 62 and absorbed to form a fifth optical path. The formation of the fifth optical path can prevent light from being reflected to the second sensor 22 and affecting the image, and can improve the contrast of the target image.

[0056] Please see Figure 6 In the fourth embodiment of this application, a third light source 73 and a second reflector 72 are further provided. The light emitted by the third light source 73 is a high-power laser light with a power greater than 10W. The laser light is reflected by the second reflector 72 to a fourth beam splitter 71. The fourth beam splitter 71 reflects part of the laser light to the image-taking plane 52. In this way, the object to be tested can be processed directly by the laser light (i.e., the image-taking plane 52 is the processing plane), which improves the convenience of use.

[0057] The third beam splitter 33, the second beam splitter 32, and the first optical component 41 are all located on the light path between the image-capturing plane 52 and the fourth beam splitter 71. The laser light is reflected by the second reflection component 72 to the fourth beam splitter 71. The fourth beam splitter 71 reflects part of the laser light to the fourth optical component 44. The fourth optical component 44 transmits the laser light to the third beam splitter 33. The third beam splitter 33 transmits part of the laser light to the second beam splitter 32. The second beam splitter 32 transmits part of the laser light to the first optical component 41. Finally, the first optical component 41 transmits the laser light to the image-capturing plane 52 to form the sixth optical path. Therefore, laser processing can be performed directly on the object under test, reducing the cost of processing the object after the user moves it and improving convenience.

[0058] This application also includes a microscope having the aforementioned autofocus and image acquisition system; please refer to [link to relevant documentation]. Figure 7 The autofocus and image acquisition method of this autofocus and image acquisition system includes the following steps:

[0059] (a) Focusing steps:

[0060] (a1) The first light source 10 emits a light and generates a straight beam 101 via an optical module 11;

[0061] (a2) The straight beam 101 is transmitted to a pair of focal planes 51 of a test object via a first optical component 41 and then reflected to a first sensor 13 to obtain a pair of focal images.

[0062] (a3) The arithmetic unit 15 obtains a position value of the focused image;

[0063] (a4) The processing unit 15 determines the focus state based on the position value; and

[0064] (a5) The arithmetic unit 15 controls the actuator 17 to adjust the Z-direction position of the first optical component 41 according to the determination result of step (a4); and

[0065] (b) Image acquisition steps:

[0066] (b1) The second light source 20 produces a ray of light.

[0067] (b2) The light is projected onto an image plane 52 of the object to be measured and reflected to a second sensor 22 to form a target image;

[0068] (b3) The second sensor 22 acquires the target image.

[0069] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of this application, and are not intended to limit the implementation methods of the technology of this application in any way. Any person skilled in the art may make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in this application, but these should still be regarded as the technology or embodiments that are substantially the same as those of this application.

Claims

1. An automatic focusing and image acquisition system, characterized in that, Include: A focus adjustment module includes an optical module for converting light emitted from a first light source into a straight beam. This straight beam is transmitted via a first optical component to a focal plane of an object under test. A second optical component transmits the straight beam reflected from the focal plane to a first sensor to acquire a focused image. A processing unit controls an actuator to adjust the Z-direction position of the first optical component based on the position value of the focused image. An image acquisition module includes a third optical component that projects a light emitted from a second light source onto an image acquisition plane of the object to be measured, and a fourth optical component that images the light reflected from the image acquisition plane onto a second sensor to obtain a target image, wherein the focusing plane and the image acquisition plane are different planes.

2. The autofocus and image acquisition system according to claim 1, characterized in that, It also includes a first beam splitter and a second beam splitter located on the light path between the focusing plane and the first sensor. The first beam splitter is used to transmit a portion of the straight beam to the second beam splitter. The second beam splitter reflects a portion of the straight beam back to the first optical component and is then transmitted to the focusing plane by the first optical component. The second beam splitter allows a portion of the straight beam reflected back from the focusing plane to the first optical component to be reflected back to the first beam splitter. The first beam splitter allows a portion of the straight beam to be reflected back to the second optical component and is then transmitted to the first sensor by the second optical component.

3. The autofocus and image acquisition system according to claim 2, characterized in that, The second beam splitter and a third beam splitter are located on the light path between the second sensor and the imaging plane and between the third optical component and the imaging plane. The third beam splitter is used to reflect a portion of the light from the second light source to the second beam splitter. The second beam splitter transmits a portion of the light to the first optical component, and the first optical component transmits a portion of the light to the imaging plane. The second beam splitter allows a portion of the light reflected from the imaging plane back to the first optical component to be transmitted to the third beam splitter. The third beam splitter allows a portion of the light to be imaged onto the second sensor via the fourth optical component.

4. The autofocus and image acquisition system according to claim 1, characterized in that, The imaging module also has a light-absorbing plate and a first reflective component, which reflects a portion of the light from the second light source after passing through a third beam-splitting component onto the light-absorbing plate.

5. The autofocus and image acquisition system according to claim 1, characterized in that, It also has a third light source and a second reflective component. The second reflective component reflects a ray of light from the third light source to a fourth beam splitter. The fourth beam splitter reflects a portion of the ray of light from the third light source to the first optical component. The first optical component transmits the ray to the imaging plane.

6. The autofocus and image acquisition system according to claim 5, characterized in that, The third light source is a high-power laser.

7. The autofocus and image acquisition system according to claim 1, characterized in that, The distance between the focusing plane and the image capturing plane is between 0 mm and 10 mm.

8. The autofocus and image acquisition system according to claim 1, characterized in that, The first light source is a laser or a light-emitting diode, and the second light source is a light-emitting diode.

9. A microscope, characterized in that, It has an autofocus and image acquisition system as described in any one of claims 1 to 8.

10. An automatic focusing and image acquisition method, characterized in that, Includes the following steps: (a) Focusing steps: (a1) produces a straight beam of light; (a2) The straight beam is transmitted through a first optical component to a pair of focal planes of an object under test and then reflected to a first sensor to obtain a pair of focal images; (a3) Obtain a position value of the focused image; (a4) Determine the focus status based on the value at that position; and (a5) Adjust the Z-direction position of the first optical component according to the determination result of step (a4); as well as (b) Image acquisition steps: (b1) produces a ray of light; (b2) The light is projected onto an image-capturing plane of the object under test and reflected to a second sensor to form a target image, wherein the focusing plane and the image-capturing plane are different planes; and (b3) The second sensor acquires the image of the target.

Images