阅读说明：本技术 一种色差对焦模块、系统及方法 (Chromatic aberration focusing module, system and method ) 是由 吴身健 梁伟 于 2021-08-23 设计创作，主要内容包括：本发明提出了一种色差对焦模块、系统及方法,涉及光学仪器技术领域。一种色差对焦模块,用于显微镜对被观测物体的自动对焦,显微镜内具有观测被观测物体的光路,包括：发光单元；轴向色差单元,包括光纤和第一镜片组,光纤插设于第一镜片组中,光纤与发光单元连接,接收发光单元发出的光；分光单元,分光单元与光纤连接,将光纤中的光经显微镜光路传递至被观测物体,并接收被观测物体反射的光；垂轴色差单元,被观测物体反射的光经过垂轴色差单元后产生垂轴色差分布；接收单元,接收单元接收经过垂轴色差单元的光。通过分析接收到的色差分布就可以计算出被测物体的离焦量,从而驱动显微镜实现自动对焦。(The invention provides a chromatic aberration focusing module, a chromatic aberration focusing system and a chromatic aberration focusing method, and relates to the technical field of optical instruments. A chromatic aberration focusing module for automatically focusing a microscope on an observed object, the microscope having an optical path for observing the observed object therein, comprising: a light emitting unit; the axial chromatic aberration unit comprises an optical fiber and a first lens group, the optical fiber is inserted in the first lens group, and the optical fiber is connected with the light-emitting unit and receives light emitted by the light-emitting unit; the light splitting unit is connected with the optical fiber, transmits light in the optical fiber to an observed object through a microscope light path, and receives light reflected by the observed object; the vertical axis chromatic aberration unit is used for generating vertical axis chromatic aberration distribution after light reflected by the observed object passes through the vertical axis chromatic aberration unit; and the receiving unit receives the light passing through the vertical axis chromatic aberration unit. Through analyzing the received chromatic aberration distribution, the defocusing amount of the measured object can be calculated, and therefore the microscope is driven to realize automatic focusing.)

1. A chromatic aberration focusing module for automatically focusing a microscope on an observed object, the microscope having therein an optical path for observing the observed object, comprising:

a light emitting unit;

the axial chromatic aberration unit comprises an optical fiber and a first lens group, the optical fiber is inserted into the first lens group, and the optical fiber is connected with the light-emitting unit and receives light emitted by the light-emitting unit;

the light splitting unit is connected with the optical fiber, transmits light in the optical fiber to an observed object through a microscope light path, and receives light reflected by the observed object;

the vertical axis chromatic aberration unit generates vertical axis chromatic aberration distribution after light reflected by the observed object passes through the vertical axis chromatic aberration unit;

a receiving unit that receives the light passing through the vertical axis color difference unit.

2. The chromatic aberration focusing module of claim 1, wherein the light splitting unit is configured as a dichroic beam splitter.

3. The chromatic aberration focusing module of claim 2, wherein the wavelength of the light reflected by the dichroic beamsplitter is between 700nm-1000nm or 436nm-700nm or 360nm-436 nm.

4. The chromatic aberration focusing module of claim 1, wherein the optical fiber is provided as a single or multiple optical fibers, and when the optical fiber is provided as multiple optical fibers, the optical fibers are arranged in a row.

5. The chromatic aberration focusing module of claim 1, further comprising a second lens group disposed between the homeotropic chromatic unit and the receiving unit.

6. The chromatic aberration focusing module of claim 5, wherein the vertical axis chromatic aberration Δ Y of the light passing through the second lens group is between 1nm and 6 nm.

7. The chromatic aberration focusing module of claim 5, wherein the receiving unit is a CMOS image sensor, and the angle between the CMOS image sensor and the optical axis of the second lens group is set as θ, θ ═ Δ L₁(f₂/f₁)²Wherein, Δ L₁Is the axial chromatic aberration of the first lens group, f₂Is the focal length of the second lens group, f₁Is the focal length of the first lens group.

8. A chromatic aberration focusing system comprising a microscope and the chromatic aberration focusing module of any one of claims 1-7.

9. A chromatic aberration focusing method is characterized by comprising the following steps:

step S1: the light emitting unit emits white light;

step S2: the white light is transmitted to the light splitting unit through the optical fiber, and axial chromatic aberration is generated after the white light passes through the first lens group;

step S3: the light splitting unit transmits light with axial chromatic aberration to an observed object through an optical path in the microscope and receives reflected light;

step S4: light reflected by the observed object passes through a vertical axis chromatic aberration unit to generate vertical axis chromatic aberration;

step S5: the receiving unit receives light with axial chromatic aberration and vertical chromatic aberration;

step S6: and calculating the defocusing amount of the observed object according to the received color difference information.

10. The chromatic aberration focusing method of claim 9, wherein between the step S4 and the step S5, the method further comprises the step S41: the light generating the vertical axis chromatic aberration expands the distribution of the vertical axis chromatic aberration through the second lens group.

Technical Field

The invention belongs to the technical field of optical instruments, and particularly relates to a chromatic aberration focusing module, a chromatic aberration focusing system and a chromatic aberration focusing method.

Background

In an industrial machine, the system consists of an automatic focusing system and a microscope system, and the microscope system provides a set of epi-illumination and imaging system. The automatic focusing system enables the microscope to be always aligned to the object plane under the support of the driving system, so that clear imaging is realized, and defects are detected.

At present, most of automatic focusing systems of industrial machine microscopes adopt WDI and MSG laser focusing modules, and the system is characterized in that a 635nm laser light source is adopted, so that a 635nm bright spot can be formed on the surface of a measured object, if a 635nm cut-off method is adopted, the imaging wave band can only reach 600nm, the whole imaging is in bluish green, the distribution of imaging colors is influenced, the imaging quality is poor, and the interpretation result is influenced.

Disclosure of Invention

The invention aims to provide a chromatic aberration focusing module and method which can not influence the imaging quality of a microscope and a microscope system applying the chromatic aberration focusing module aiming at the problems in the prior art.

The purpose of the invention can be realized by the following technical scheme: a chromatic aberration focusing module for automatically focusing a microscope on an observed object, the microscope having an optical path for observing the observed object therein, comprising:

a light emitting unit;

the axial chromatic aberration unit comprises an optical fiber and a first lens group, the optical fiber is inserted into the first lens group, and the optical fiber is connected with the light-emitting unit and receives light emitted by the light-emitting unit;

the light splitting unit is connected with the optical fiber, transmits light in the optical fiber to an observed object through a microscope light path, and receives light reflected by the observed object;

the vertical axis chromatic aberration unit generates vertical axis chromatic aberration distribution after light reflected by the observed object passes through the vertical axis chromatic aberration unit;

a receiving unit that receives the light passing through the vertical axis color difference unit.

As a further improvement of the present invention, the light splitting unit is configured as a dichroic beam splitter.

As a further improvement of the invention, the wavelength of the light reflected by the dichroic beam splitter is between 700nm and 1000nm or 436nm and 700nm or 360nm and 436 nm.

As a further improvement of the present invention, the optical fiber is provided as a single fiber or a plurality of fibers, and when the optical fiber is provided as a plurality of fibers, the optical fibers are arranged in a row.

As a further improvement of the present invention, the apparatus further includes a second lens group, and the second lens group is disposed between the vertical axis chromatic aberration unit and the receiving unit.

As a further improvement of the invention, the vertical axis chromatic aberration delta Y of the light passing through the second lens group is between 1nm and 6 nm.

As a further improvement of the present invention, the receiving unit is a CMOS image sensor, and an angle between the CMOS image sensor and the optical axis of the second lens group is set to θ, and θ is Δ L1(f2/f1)2, where Δ L1 is an axial chromatic aberration of the first lens group, f2 is a focal length of the second lens group, and f1 is a focal length of the first lens group.

The invention also provides a chromatic aberration focusing system, which comprises a microscope and the chromatic aberration focusing module.

The invention also provides a chromatic aberration focusing method, which comprises the following steps:

step S1: the light emitting unit emits white light;

step S2: the white light is transmitted to the light splitting unit through the optical fiber, and axial chromatic aberration is generated after the white light passes through the first lens group;

step S3: the light splitting unit transmits light with axial chromatic aberration to an observed object through an optical path in the microscope and receives reflected light;

step S4: light reflected by the observed object passes through a vertical axis chromatic aberration unit to generate vertical axis chromatic aberration;

step S5: the receiving unit receives light with axial chromatic aberration and vertical chromatic aberration;

step S6: and calculating the defocusing amount of the observed object according to the received color difference information.

As a further improvement of the present invention, between the step S4 and the step S5, a step S41 is further included: the light generating the vertical axis chromatic aberration expands the distribution of the vertical axis chromatic aberration through the second lens group.

Based on the technical scheme, the embodiment of the invention can at least produce the following technical effects:

1. the light with the axial chromatic aberration and the vertical axis chromatic aberration is generated by the axial chromatic aberration unit and the vertical axis chromatic aberration unit, and is received by the receiving unit, and then the defocusing amount of the measured object can be calculated by analyzing the received chromatic aberration distribution, so that the microscope is driven to realize automatic focusing;

2. the light splitting unit is a color splitting light splitter, so that only light with a certain wavelength range can be transmitted to a measured object through a microscope light path to adapt to different microscope systems;

3. the wavelength range of light transmitted by the color separation spectroscope is set to be 700nm-1000nm or 436nm-700nm or 360nm-436nm, so that the switching of three different working modes of near infrared, visible light and near ultraviolet is realized;

4. by arranging the optical fibers as a single fiber or a plurality of fibers, the switching between single-point focusing and multi-point focusing can be realized;

5. the second lens group is arranged between the vertical axis chromatic aberration unit and the receiving unit, so that light of each wave band is imaged on the CMOS to be in discrete distribution, and the distribution of vertical axis chromatic aberration is expanded;

6. the vertical axis chromatic aberration delta Y of the light passing through the second lens group is set to be between 1nm and 6nm, so that the vertical axis chromatic aberration delta Y is suitable for the size of a common CMOS;

7. the included angle between the CMOS image sensor and the optical axis of the second lens group is set to be theta and delta L₁(f₂/f₁)²The CMOS can completely receive light of each wave band;

8. by the chromatic aberration focusing method, the problem that laser focusing can generate bright spots or the image is blue-cyan is solved, and the automatic focusing of the microscope is realized without reducing the imaging quality of the microscope.

Drawings

Fig. 1 is a schematic diagram of a chromatic aberration focusing module.

FIG. 2 is a schematic diagram of a microscope system employing a chromatic aberration focusing module.

In the figure, 100, a light emitting unit; 200. an axial chromatic aberration unit; 210. an optical fiber; 220. a first lens group; 300. a light splitting unit; 400. a vertical axis color difference unit; 410. a second lens group; 500. and a receiving unit.

Detailed Description

It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly. Moreover, descriptions of the present invention as relating to "first," "second," "a," etc. are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit ly indicating a number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise. In the present invention, unless otherwise expressly stated or limited, the terms "connected," "secured," and the like are to be construed broadly, and for example, "secured" may be a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations. In addition, the technical solutions in the embodiments of the present invention may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination of technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

The following is a specific embodiment of the present invention, and the technical solution of the present invention is further described with reference to fig. 1-2, but the present invention is not limited to this embodiment.

The invention discloses a chromatic aberration focusing module, comprising: a light emitting unit 100, an axial chromatic aberration unit 200, a light splitting unit 300, a vertical axis chromatic aberration unit 400, and a receiving unit 500. The light emitting unit 100 emits white light, the axial chromatic aberration unit 200 generates axial chromatic aberration distribution, the light splitting unit 300 transmits the light to a measured object through a microscope light path and receives light reflected by the measured object within a certain wavelength range, the light reflected by the measured object generates vertical axis chromatic aberration distribution after passing through the vertical axis chromatic aberration unit 400, and the receiving unit 500 receives the light with the axial chromatic aberration and the vertical axis chromatic aberration. The light with axial chromatic aberration and vertical chromatic aberration is generated by the axial chromatic aberration unit 200 and the vertical chromatic aberration unit 400 and received by the receiving unit 500, and the defocusing amount of the object to be measured can be calculated by analyzing the received chromatic aberration distribution, so that the microscope is driven to realize automatic focusing.

The light emitting unit 100 is provided as an LED lamp bead, which emits white light. The axial chromatic aberration unit 200 includes an optical fiber 210 and a first lens group 220, the optical fiber 210 is inserted into the first lens group 220, one end of the optical fiber 210 is connected to the light emitting unit 100 to receive light emitted from the light emitting unit 100, and the other end of the optical fiber 210 is connected to the light splitting unit 300. The first lens group 220 has a focal length f₁Comprises a plurality of concave lenses or convex lenses arranged in parallel, and axial chromatic aberration DeltaL is generated after white light passes through the first lens group 220₁Axial chromatic aberration is also referred to as longitudinal chromatic aberration. The optical fiber 210 may be provided as a single or a plurality. The plurality of optical fibers may be arranged in a row or in other distributions. The optical fiber in the invention can be replaced by a star point pore plate, the number of the pores on the star point pore plate can be single or multiple, and the multiple pores can be regularly arranged or randomly arranged. The switching of single-point focusing or multi-point focusing can be realized by arranging the optical fiber 210 into a single fiber or a plurality of fibers.

In this embodiment, the spectroscopic unit 300 is configured as a wide-spectrum dichroic spectroscope, and transmits light having a wavelength range of 700nm to 1000nm to the object to be measured, and transmits the returned light to the vertical axis chromatic aberration unit 400. Focal length of microscope objective lens f_{Article (A)}Axial chromatic aberration distribution data Δ L of object space_{Article (A)}＝ΔL₁/(f_{Article (A)}/f₁)². Axial chromatic aberration Δ L of object space_{Article (A)}The sensitivity of the entire focusing system is determined. The invention can also use the color separation spectroscope with the purple light wave band 360-436nm and the visible light wave band 436-700nm,to accommodate various systems. The switching of three different working modes of near infrared, visible light and near ultraviolet is realized by replacing different color separation spectroscopes.

The vertical axis color difference unit 400 is configured as a prism, and allows light returning from the object to be measured to pass through the prism, so that light of each wavelength band is separated, and vertical axis color difference distribution is generated, which is convenient for measurement in the receiving unit 500.

A second lens group 410 is further disposed between the vertical axis chromatic aberration unit 400 and the receiving unit 500, and the focal length of the second lens group 410 is f₂The lens is composed of a plurality of concave lenses or convex lenses which are arranged in parallel, and the vertical axis chromatic aberration delta Y of light passing through the prism is between 1nm and 6nm after the light passes through the second lens group. The selection of the vertical axis aberration, also called magnification aberration, is the core of the design of the aberration focusing module of the present invention by adjusting the material and angle of the prism and the axial aberration Δ L of the second lens group 410₂So that the magnitude of Δ Y can be received by a general CMOS image sensor.

A receiving unit 500 for receiving the light passing through the second lens group 410. The receiving unit 500 is provided as one CMOS image sensor in the present embodiment. The angle between the CMOS image sensor and the optical axis of the second lens group 410 is set to θ, where θ is Δ L₁(f₂/f₁)²Wherein, Δ L₁Is the axial chromatic aberration, f, of the first lens group 220₂Is the focal length, f, of the second lens group 410₁Is the focal length of the first lens group 220. The CMOS image sensor and the optical axis of the second lens group 410 form an included angle theta, so that the CMOS image sensor can completely receive light of each waveband.

The invention also provides a chromatic aberration focusing method, which comprises the following steps:

step S1: the light emitting unit 100 emits white light;

step S2: the white light is transmitted to the color separation spectroscope through the optical fiber 210, and axial chromatic aberration is generated after the white light passes through the first lens group 220;

step S3: the light splitting unit 300 transmits light within a certain wavelength range to a measured object through an optical path in the microscope;

step S4: the light reflected by the measured object passes through the vertical axis chromatic aberration unit 400 to generate vertical axis chromatic aberration;

step S41: the light generating the vertical axis chromatic aberration expands the distribution of the vertical axis chromatic aberration through the second lens group 410;

step S5: the receiving unit 500 receives light having an axial chromatic aberration and a vertical-axis chromatic aberration;

step S6: and calculating the defocusing amount of the measured object according to the received chromatic aberration information.

The invention also provides a chromatic aberration focusing system, which comprises a microscope and the chromatic aberration focusing module. And calculating the defocusing amount of the measured object according to the color difference information received by the color difference focusing module, so that the microscope can carry out automatic focusing under the action of the driving system.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.