TWI813173B - Automatic focusing and imaging system and method、microscope - Google Patents

Abstract

An automatic focusing and imaging system for a microscope comprises a focal length adjustment module and an imaging module. The focal length adjustment module has an optical module for converting the light emitted by the first light source into a linear beam. The linear beam is transmitted from a first optical element to the focal plane of the specimen, and the specimen is set along the XY direction. A second optical element reflects the linear beam which is transmitted from the focal plane to a first sensor to obtain a focused image. According to the position value of the focused image, the arithmetic unit controls an actuator to adjust the Z-direction position of a first optical element. The imaging module has a third optical element to project the light emitted by the second light source to the imaging plane, and a fourth optical element to image the light reflected from the imaging plane to the second sensor to obtain the target image.

Description

Automatic focusing and imaging system and method, microscope

The present invention relates to an automatic focusing and imaging system for a microscope, particularly a system for fast focusing and imaging of electronic products.

Microscopes have high image magnification characteristics, which can magnify small objects for observation. Because of the high magnification, the depth of field (Depth of field) range is relatively small, and the user needs to spend time adjusting the distance between the objective lens and the object being observed. Only then can the object being observed be clearly seen. Since the focus plane on the market is the imaging plane, the autofocus system on the market can quickly adjust the distance between the objective lens and the object being observed. Users do not need to spend too much time to obtain clear images. image.

However, current electronic products are designed for special functions, such as under-screen cameras, LED glass substrate packaging, and LCD panel packaging (Chip on glass, Film on glass). Most of the relevant electronic components are placed on a dielectric material, which must be inspected. The electronic components need to penetrate the dielectric material before they can be observed. If you use the autofocus system on the market, it is not easy to achieve the purpose of rapid focusing, or multiple procedures are required to complete the focusing, resulting in a decrease in production efficiency.

Based on the above deficiencies, the purpose of the present invention is to provide an automatic focusing system, especially a fast focusing and image capturing focusing system for electronic products.

According to the object of the present invention, an automatic focusing and imaging system is provided, which includes a focus adjustment module and an optical module for converting light emitted by a first light source into a linear beam. The linear beam passes through a first optical element. transmitted to a focal plane of an object to be measured, the object to be measured is arranged along an XY direction, and a second optical element transmits the linear beam reflected from the focal plane to a first sensor to obtain a focus image, a computing unit controls an actuator to adjust a Z-direction position of the first optical element according to the position value of the focus image, and an imaging module has a third optical element to convert a light emitted by a second light source Projecting to an imaging plane of the object to be measured, and a fourth optical element imaging the light reflected by the imaging plane to a second sensor to obtain a target image, wherein the focus plane and the imaging plane The planes are different planes.

There is also a first light splitting element and a second light splitting element located on the light path between the focus plane and the first sensor. The first light splitting element is used to pass part of the linear beam to the second light splitting element. The second beam splitting element reflects part of the linear beam to the first optical element and transmits the part of the linear beam to the focus plane by the first optical element. The second beam splitting element allows the beam to pass from the focus plane. The portion of the linear beam that is reflected back to the first optical element is reflected to the first splitting element, and the first splitting element allows the portion of the linear beam to be reflected to the second optical element and transmitted to the second optical element by the second optical element. First sensor.

Wherein the second spectroscopic element and a third spectroscopic element are located on the light path between the second sensor and the imaging plane and between the third optical element and the imaging plane, the The third light splitting element is used to reflect part of the light from the second light source to the second light splitting element. The second light splitting element transmits part of the light to the first optical element and the first optical element transmits part of the light. The second light splitting element allows the part of the light reflected back from the imaging plane to the first optical element to be transferred to the third light splitting element. The third light splitting element allows the part of the light to be The image is imaged to the second sensor through the fourth optical element.

Preferably, the imaging module also has a light-absorbing plate and a first reflective element. The first reflective element reflects part of the light from the second light source after passing through a third light-splitting element to the light-absorbing plate.

Preferably, there is also a third light source and a second reflective element. The second reflective element reflects a light ray of the third light source to a fourth light splitting element. The fourth light splitting element reflects the third light source. Part of the light is reflected to the first optical element, the first optical element transmits the light to the imaging plane, and the third light source is high-power laser light.

Preferably, the distance between the focus plane and the imaging plane is between 0 mm and 10 mm.

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

The present invention also provides a microscope with the aforementioned automatic focusing and imaging system.

The invention also includes an automatic focusing and imaging method, which includes the following steps:

(a) Focus steps:

(a1) Generate a straight beam;

(a2) The linear beam is transmitted to a pair of focal planes of an object to be measured through a first optical element and then reflected to a first sensor to obtain a focused image;

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

(a4) Determine the focus state based on the position value; and

(a5) Adjust a Z-direction position of the first optical element according to the determination result of step (a4);

(b) Image acquisition steps:

(b1) Generate a light ray

(b2) Project the light to an imaging plane of the object to be measured and reflect it to a second sensor to form a target image, and the focus plane and the imaging plane are different planes;

(b3) Allow a second sensor to obtain the target image.

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

a1~a5, a: focus steps

b1~b3, b: imaging steps

h: imaging distance

z: distance between the first optical element and the focus plane

10:First light source

101: Straight beam

11: Optical module

13:First sensor

15:Arithmetic unit

17: Actuator

20:Second light source

22: Second sensor

31: First spectroscopic element

32: Second spectroscopic element

33: The third spectroscopic element

41:First optical element

42: Second optical element

43:Third optical element

44: The fourth optical element

51:Focus plane

52:Imaging plane

61: First reflective element

62:Light absorbing plate

71: The fourth spectroscopic element

72: Second reflective element

73:Third light source

Figure 1 is a light path diagram of the first embodiment of the present invention.

FIG. 2 is a schematic diagram of the focus image obtained by the first sensor of the present invention.

Figure 3 is a diagram showing a linear relationship between the x position of the focused image and the position of the first optical element in the Z direction.

FIG. 4 is a schematic diagram of a focus image obtained by the first sensor according to the second embodiment of the present invention.

Figure 5 is a light path diagram of the third embodiment of the present invention.

Figure 6 is a light path diagram of the fourth embodiment of the present invention.

Figure 7 is a flow chart of the automatic focusing and imaging method of the present invention.

In order to clearly illustrate the specific implementation, structure and effects of the present invention, examples are provided and described with the drawings as follows: Please refer to Figure 1, which illustrates an automatic focusing and imaging system, including a focus adjustment module and an imaging module. The focus adjustment module has an optical module 11 for converting light emitted by a first light source 10. Converted into a linear beam 101, the linear beam 101 is transmitted to a focal plane 51 of an object to be measured through a first optical element 41, the object to be measured is arranged along an XY direction, and a second optical element 42 is ejected from the The linear beam 101 reflected by the focus plane 51 is transmitted to a first sensor 13 to obtain a focused image. A computing unit 15 controls an actuator 17 to adjust a Z of the first optical element 41 according to the position value of the focused image. Directional position, the computing unit 15 performs image processing and analysis. The computing unit 15 may be, but is not limited to, a programmable signal processing element such as a CPU, DSP, FPGA, or mixed signal processor.

To further explain, the focus adjustment module also has a first light splitting element 31 and a second light splitting element 32 located on the light path between the focus plane 51 and the first sensor 13. The first light splitting element 31 is used for To transmit part of the linear beam 101 to the second spectroscopic element 32 , the second spectroscopic element 32 reflects part of the linear beam 101 to the first optical element 41 and the first optical element 41 transmits the linear beam The part of the linear beam 101 that is reflected from the focus plane 51 back to the first optical element 41 is reflected to the first light splitting element 31 by the second beam splitting element 32 . , the first spectroscopic element 31 allows part of the linear beam 101 to be reflected to the second optical element 42, and the second optical element 42 transmits part of the linear beam 101 to a first sensor 13 to form a second optical path. And the first sensor 13 is allowed to obtain a focused image. The first light source 10 may be a laser light or a light emitting diode (LED), and the first sensor 13 may be a line scan camera or an area camera. The first optical element 41 and the second optical element 42 are optical lenses.

The imaging module has a third optical element 43 that projects a light emitted by a second light source 20 to an imaging plane 52 of the object to be measured, and a fourth optical element 44 that passes through the imaging plane 52 The reflected light is transmitted to a second sensor 22 to obtain a target image. The second light source 20 is a light emitting diode (LED) of visible light or infrared light. The second sensor 22 is a line scan camera or an area sensor. camera. The third optical element 43 and the fourth optical element 44 are optical lenses. The focus plane 51 and the imaging plane 52 are different planes.

To further explain, the second light splitting element 32 and a third light splitting element 33 are located in the light path between the second sensor 22 and the imaging plane 52 and between the third optical element 43 and the imaging plane 52 above, the third light splitting element 33 is used to reflect part of the light from the second light source to the second light splitting element 32, and the second light splitting element 32 transmits part of the light to the first optical element 41 and is transmitted from the second light splitting element 32 to the first optical element 41. The first optical element 41 transmits part of the light to the imaging plane 52 to form a third optical path. The second light splitting element 32 allows the part of the light reflected back from the imaging plane 52 to the first optical element 41 to pass to The third light splitting element 33 allows a part of the light to be transmitted to a fourth optical element 44, and the fourth optical element 44 images part of the light to the second sensor 22 to form a third light splitting element 33. Four optical paths are used to enable the second sensor 22 to obtain the target image.

After the aforementioned linear light beam reaches the first sensor 13 through the first optical path and the second optical path for focusing, the light from the second light source reaches the second sensor 22 through the third optical path and the fourth optical path for image capture. Autofocus and imaging process.

For further explanation, please refer to FIG. 2 , which is a focus image obtained by the first sensor 13 . The focus image obtained by the first sensor 13 is a linear light spot. When the Z-direction position of the first optical element 41 changes (that is, affects The distance z between the first optical element 41 and the focus plane 51 changes), The linear spot will move along the X direction on the first sensor 13, so the computing unit 15 will control the Z direction position of the first optical element 41 according to the position of the focused image so that the second sensor 22 can obtain a clear image. . In other implementations, the linear beam 101 can also be in a shape other than a strip, such as a triangle, an arc, or a circle, as long as it can form a light spot for measurement on the first sensor 13 .

Please refer to Figure 3. The actuator 17 adjusts the position value of the first optical element 41 based on the following formula:

C，C是第一光學元件41的數值孔徑，a、k為校正常數，z是第一光學元件41與對焦平面51之間的距離，x是第一感測器13上的對焦影像位置，當該對焦影像在x1位置時，對應第一光學元件41在Z方向位置z1，當對焦影像在x2位置時，對應第一光學元件41在Z方向位置z2，當對焦影像在x3位置時，對應第一光學元件41在Z方向位置z3，以此類推，該對焦影像的x位置與第一光學元件41在Z方向位置呈線性關係。 in

C , C is the numerical aperture of the first optical element 41, a and k are calibration constants, z is the distance between the first optical element 41 and the focus plane 51, x is the focused image position on the first sensor 13, When the focus image is at the x1 position, it corresponds to the first optical element 41 being at the Z direction position z1. When the focus image is at the x2 position, it corresponds to the first optical element 41 being at the Z direction position z2. When the focus image is at the x3 position, it corresponds to The first optical element 41 is at position z3 in the Z direction, and by analogy, the x position of the focused image has a linear relationship with the position of the first optical element 41 in the Z direction.

Please refer to FIG. 4 for a second embodiment of the present invention. In the second embodiment, when the imaging plane of the object to be measured is at an unequal height plane, the focused image on the first sensor 13 is processed digitally. , can be decomposed into one or more line segments for local positioning (line segments A, B, C in the figure), whereby the user can set any x, y position on the imaging plane 52 to correspond to the imaging distance h (i.e. focus plane and the imaging plane), in the embodiment of the present invention, the distance between the focus plane and the imaging plane is between 0 mm and 10 mm, and the distance between the first optical element 41 and the focus plane 51 z is greater than the aforementioned imaging distance h.

Please refer to FIG. 5 for a third embodiment of the present invention. In the third embodiment, the imaging module also has a light-absorbing plate 62 and a first reflective element 61. The light emitted by the second light source 20 passes through the third optical element. After the element 43 is transmitted to the third light splitting element 33, part of the light will be reflected to the second light splitting element 32, and the other part of the light will pass through the first reflective element 61, and be reflected to the light absorbing plate 62 through the first reflective element 61 and absorbed. The formation of the fifth optical path can prevent light from being reflected to the second sensor 22 and affect the imaging screen, and can improve the contrast of the target image.

Please refer to FIG. 6 , which is a fourth embodiment of the present invention. In the fourth embodiment, there is also a third light source 73 and a second reflective element 72 . The light emitted by the third light source 73 is a high-power laser light greater than 10W. , the laser light is reflected to a fourth spectroscopic element 71 through the second reflective element 72, and the fourth spectroscopic element 71 reflects part of the laser light to the imaging plane 52. In this way, the object to be measured can be directly detected by the laser light. The object is processed (that is, the imaging plane 52 is the processing plane), thereby improving the convenience of use.

The third light splitting element 33, the second light splitting element 32 and the first optical element 41 are all located on the light path of the imaging plane 52 and the fourth light splitting element 71, and the laser light is reflected to the fourth light splitting element through the second reflective element 72. Spectroscopic element 71. The fourth spectroscopic element 71 reflects part of the laser light to the fourth optical element 44. The fourth optical element 44 transmits the laser light to the third spectroscopic element 33. The third spectroscopic element 33 reflects part of the laser light. to the second spectroscopic element 32, which transfers part of the laser light to the first optical element 41, and finally the first optical element 41 transfers the laser light to the imaging plane 52 to form a sixth optical path, whereby Laser processing can be performed directly on the object to be tested, reducing the user's cost of processing the object after moving it and improving convenience.

The present invention also has a microscope with the aforementioned automatic focusing and imaging system. Please refer to Figure 7. The automatic focusing and imaging method of the automatic focusing and imaging system includes the following steps:

(a) Focus steps:

(a1) The first light source 10 emits a light and generates a linear beam 101 through an optical module 11;

(a2) The linear beam 101 is transmitted to a focal plane 51 of an object to be measured through a first optical element 41 and then reflected to a first sensor 13 to obtain a focused image;

(a3) The computing unit 15 obtains a position value of the focused image;

(a4) The computing unit 15 determines the focus state based on the position value; and

(a5) The computing unit 15 controls the actuator 17 to adjust a Z-direction position of the first optical element 41 according to the determination result of step (a4); and

(b) Image acquisition steps:

(b1) The second light source 20 generates a light

(b2) Project the light to an imaging plane 52 of the object to be measured and reflect it to a second sensor 22 to form a target image;

(b3) Allow the second sensor 22 to obtain the target image.

h: imaging distance

z: distance between the first optical element and the focus plane

10:First light source

101: Straight beam

11: Optical module

13:First sensor

15:Arithmetic unit

17: Actuator

20:Second light source

22: Second sensor

31: First spectroscopic element

32: Second spectroscopic element

33: The third spectroscopic element

41:First optical element

42: Second optical element

43:Third optical element

44: The fourth optical element

51:Focus plane

52:Imaging plane

Claims (10)

An automatic focusing and imaging system includes: a focus adjustment module, which has an optical module for converting light emitted by a first light source into a linear beam, and the linear beam is transmitted to a waiting object through a first optical element. A pair of focal planes of the object and a second optical element transmit the linear beam reflected from the focal plane to a first sensor to obtain a focused image, and an arithmetic unit numerically controls an actuator according to the position of the focused image. Adjust a Z-direction position of the first optical element; and an imaging module having a third optical element that projects a light emitted by a second light source to an imaging plane of the object to be measured, and a fourth The optical element images the light reflected by the imaging plane to a second sensor to obtain a target image, wherein the focus plane and the imaging plane are different planes. The automatic focusing and imaging system of claim 1, further comprising a first light splitting element and a second light splitting element located on the light path between the focus plane and the first sensor, the first light splitting element The element is used to transmit part of the linear beam to the second spectroscopic element. The second spectroscopic element reflects part of the linear beam to the first optical element and the first optical element transmits part of the linear beam to The focus plane, the second light splitting element allows a portion of the linear beam reflected from the focus plane back to the first optical element to be reflected to the first light splitting element, and the first light splitting element allows a portion of the linear beam to be reflected to the third two optical elements, and are transmitted from the second optical element to the first sensor. The automatic focusing and imaging system of claim 2, wherein the second light splitting element and a third light splitting element are located between the second sensor and the imaging plane and the third optical element and the imaging plane On the light path between planes, the third light-splitting element is used to reflect part of the light from the second light source to the second light-splitting element, and the second light-splitting element reflects part of the light A portion of the light is transmitted to the first optical element and a portion of the light is transmitted by the first optical element to the imaging plane. The second light splitting element allows a portion of the light to be reflected back from the imaging plane to the first optical element. Passed to the third light splitting element, the third light splitting element allows part of the light to be imaged to the second sensor through the fourth optical element. The automatic focusing and imaging system as described in claim 1, wherein the imaging module also has a light-absorbing plate and a first reflective element, and the first reflective element passes the light from the second light source through a third light splitter. The part of the light behind the element is reflected to the light-absorbing plate. The automatic focusing and imaging system of claim 1, further comprising a third light source and a second reflective element, the second reflective element reflects a light ray of the third light source to a fourth light splitting element, the The fourth light splitting element reflects part of the light from the third light source to the first optical element, and the first optical element transmits the light to the imaging plane. The automatic focusing and imaging system of claim 5, wherein the third light source is high-power laser light. The automatic focusing and imaging system as described in claim 1, wherein the distance between the focus plane and the imaging plane is between 0mm and 10mm. The automatic focusing and imaging system of claim 1, wherein the first light source is laser light or a light-emitting diode, and the second light source is a light-emitting diode. A microscope having an automatic focusing and imaging system as described in any one of claims 1 to 8. An automatic focusing and imaging method includes the following steps: (a) focusing step: (a1) generating a straight beam; (a2) Pass the linear beam through a first optical element to a pair of focal planes of an object to be measured and then reflect it to a first sensor to obtain a focused image; (a3) Obtain a position value of the focused image; (a3) Obtain a position value of the focused image; (a3) a4) determine the focus state according to the position value; and (a5) adjust a Z-direction position of the first optical element according to the determination result of step (a4); and (b) imaging step: (b1) generate a light; ( b2) project the light to an imaging plane of the object to be measured and reflect it to a second sensor to form a target image, and the focus plane and the imaging plane are different planes; and (b3) enable the second The sensor obtains the target image.