Optical imaging device capable of removing out-of-focus signal

Abstract

The utility model discloses an optical imaging device capable of removing out-of-focus signals. The optical imaging device comprises a lighting module and an imaging module. The illumination module comprises an LED for providing illumination light and excitation light, a collimating lens for converting divergent light of the LED into collimated light, a fly's-eye lens for dodging the illumination light, a focusing lens for focusing the fly's-eye lens, a prism group for shifting an optical axis of the illumination light by a certain angle, and a DMD for editing an illumination light pattern; the plane mirror is used for changing the angle of an optical axis of illumination light; and the field lens is used for changing divergent light reflected by the DMD into collimated light. The imaging module comprises a barrel lens for focusing and a camera for image acquisition. The spectroscope and the objective lens are commonly used for the illumination module and the imaging module. According to the device provided by the invention, the final signal image without the background light can be calculated through the four signal images obtained in sequence.

Description

Technical Field

[0001] The utility model relates to the field of imaging, and more specifically, to an optical imaging device capable of removing defocus signals. Background Art

[0002] In the field of imaging, during the process of image acquisition of a sample with three-dimensional features, since not all of the sample surface is at the focal plane height, the stray light generated at the defocus position will interfere with the signal characteristics at the focal plane position. Compared with the pictures collected by conventional microscopic imaging, the pictures obtained by removing the defocus signals have obvious advantages in subsequent operations such as image recognition, analysis, and processing, which can effectively improve the analysis efficiency and reduce the influence of stray light on image analysis. Further, during the three-dimensional reconstruction process after layer-by-layer scanning through different focal planes, using the original pictures with defocus signals removed also has obvious advantages compared with the pictures without defocus signals removed.

[0003] Confocal imaging uses a point scanning method to obtain the optical signals at the sample position and generates the picture information of the sample through calculation. Since a small hole is used inside to block the optical signals at the defocus height, its fixed small hole size cannot flexibly adjust the longitudinal resolution of the image. Summary of the Utility Model

[0004] In view of the above technical problems in the related art, the utility model provides an optical imaging device capable of removing defocus signals, which can solve the above problems.

[0005] To achieve the above technical objectives, the technical solution of the utility model is realized as follows:

[0006] An optical imaging device capable of removing defocus signals, characterized in that: it includes an illumination module and an imaging module. The illumination module includes an LED arranged at the top, a collimating mirror arranged below the LED, a fly-eye lens arranged below the collimating mirror, a focusing lens arranged below the fly-eye lens, a prism group arranged below the focusing lens, a DMD arranged on the side of the prism group, a plane mirror arranged below the prism group, and a field lens arranged on the side of the plane mirror. The imaging module includes a camera arranged at the top, a tube lens arranged at the bottom of the imaging module, and a lens module arranged below the imaging module. The lens module includes a beam splitter arranged on the upper side of the lens module and an objective lens arranged on the lower side of the lens module, and a sample is arranged below the objective lens.

[0007] Further, the prism group is arranged at a certain angle offset along the optical axis.

[0008] Further, the coaxiality deviation between the installation of the fly-eye lens and the focusing lens is less than 0.03°, and the displacement deviation of the installation is less than 0.05 mm.

[0009] Advantages of the present utility model: The device of this application can calculate the final signal image with background light removed through four signal pictures obtained in sequence. Description of the Drawings

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0011] The following further details the present utility model with reference to the drawings.

[0012] Figure 1 is the optical module structure for removing background light of an optical imaging device capable of removing defocus signals according to an embodiment of the present utility model;

[0013] Figure 2 is the illumination spot image according to an embodiment of the present utility model, where white represents the illuminated area and black represents the non-illuminated area, which are I1, I2, I3, I4 from left to right;

[0014] Figure 3 is the sample image corresponding to the illumination light according to an embodiment of the present utility model, which are S1, S2, S3, S4 from left to right;

[0015] Figure 4 is the sample image according to an embodiment of the present utility model;

[0016] Figure 5 is the sample image collected corresponding to illumination light with different phases according to an embodiment of the present utility model.

[0017] From left to right, they are S1, S2, S3, S4 respectively;

[0018] Figure 6 is the partial image of hair as the sample according to an embodiment of the present utility model. The left figure is the sample image taken using conventional full-field illumination; the right figure is the sample image taken using the device of the present utility model;

[0019] In the figure:

[0020] 1. Illumination module; 2. Imaging module; 3. Lens module; 101. LED; 102. Collimating mirror; 103. Fly-eye lens; 104. Focusing lens; 105. Prism group; 106. DMD; 107. Plane mirror; 108. Field lens; 201. Camera; 202. Barrel lens; 301. Beam splitter; 302. Objective lens; 401. Sample. Detailed implementation mode

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present invention.

[0022] As Figure 1 shown, it includes an illumination module and an imaging module. The illumination module includes an LED that provides illumination light and excitation light, a collimating mirror that collimates the divergent light of the LED, a fly-eye lens that homogenizes the illumination light, a focusing lens that focuses the fly-eye lens, a prism group that offsets the optical axis of the illumination light by a certain angle, a DMD that edits the illumination light pattern, a plane mirror that changes the angle of the optical axis of the illumination light, and a field lens that collimates the divergent light reflected by the DMD.

[0023] The imaging module includes a barrel lens for focusing and a camera for image acquisition.

[0024] And a beam splitter and an objective lens that are shared by the illumination module and the imaging module.

[0025] The above collimating mirror is placed behind the LED light-emitting surface and is used to collimate the divergent light of the LED.

[0026] The above fly-eye lens is placed behind the collimating mirror and is used to further homogenize the collimated light of the LED and constrain the shape of the illumination spot to be consistent with the reflection size of the DMD.

[0027] The above focusing lens is placed behind the fly-eye lens and is used to clearly focus the divergent light spot of the fly-eye lens on the DMD reflection surface.

[0028] The above prism group is placed behind the focusing lens and is used to offset the optical axis of the illumination light by a certain angle relative to the focal plane. The final angle between the optical axis and the focal plane is 56°, which is adapted to the deflection angle of the DMD.

[0029] The above DMD is placed on one side of the prism group. The DMD is composed of a plurality of individually controllable micro-mirrors. The micro-mirrors are divided into two deflection states: ON and OFF. The deflection state of the micro-mirrors in the DMD is controlled by the high and low levels of the circuit. When in the ON state, the incident light is reflected by the micro-mirror, and the optical axis of the reflected light is perpendicular to the DMD plane. When in the OFF state, the incident light is reflected at another angle and does not enter the preset illumination optical path. By controlling the deflection states of each micro-mirror surface, different-shaped illumination spots can be provided for the sample.

[0030] The above-mentioned plane mirror is placed behind the prism group and the DMD, and forms an angle of 45° with the illumination optical axis, and is used to deflect the illumination light by 90°.

[0031] The above-mentioned field lens is placed behind the plane mirror, collimates the divergent light reflected by the DMD and enters the objective lens.

[0032] The above-mentioned beam splitter is used to reflect the illumination light and allow the imaging optical signal to pass through.

[0033] The above-mentioned objective lens is used to focus the illumination light in a parallel light state, and the shape after focusing is the same as the lens distribution shape of the DMD in the ON state, and the size is enlarged or reduced proportionally according to the parameters of the objective lens.

[0034] The above-mentioned objective lens is also used to collect the optical signal of the sample and transmit the optical signal to the camera. The optical signal reflected or generated by the sample can pass through the beam splitter.

[0035] The above-mentioned tube lens is used to focus the imaging optical signal on the camera photosensitive surface.

[0036] The above-mentioned camera is placed at the focal plane position of the tube lens, converts the optical signal of the sample into an electrical signal and saves it as a picture.

[0037] Using the above device, control the deflection state of the DMD micromirrors to sequentially form the arrangements of four phases. After the illumination light is reflected by the DMD, the illumination lights of four-phase arrangements are sequentially formed: I1, I2, I3, I4. Among them, the two phase states of I1 and I2 are complementary, the two phase states of I3 and I4 are complementary, and I1 and I3 differ by 1 / 4 phase period.

[0038] Use the above camera to sequentially obtain the sample pictures corresponding to the four-phase illumination lights: S1, S2, S3, S4.

[0039] Use the above pictures for calculation, and the calculation method is as follows:

[0040] Subtract the gray matrix of the S1 picture from the gray matrix of the S2 picture, and take the absolute value, denoted as f(x),

[0041] f(x)=ABS(S1 - S2)

[0042] Subtract the gray matrix of the S3 picture from the gray matrix of the S4 picture, and take the absolute value, denoted as g(x),

[0043] g(x)=ABS(S3 - S4)

[0044] Compare the gray values of the corresponding elements of f(x) and g(x) and select the larger value to record in the new matrix Image(x)

[0045] Image(x)=max[f(x), g(x)]

[0046] Image(x) is the sample signal image after removing background stray light;

[0047] In Embodiment 1 of the present application, as Figure 1 shown, LED 101 is fixed on the optical flat plate, and the collimator 102 is fixed behind LED 101. Turn on LED 101 and adjust the position of the collimator 102 so that the light of LED 101 becomes collimated light.

[0048] As Figure 1 shown, the fly-eye lens 103 and the focusing lens 104 are installed, and the coaxiality deviation of the installation is less than 0.03°, and the displacement deviation of the installation is less than 0.05 mm.

[0049] As Figure 1 shown, the prism group 105 and the DMD 106 are installed. Adjust the positions of the fly-eye lens 103 and the focusing lens 104 along the optical axis so that the rectangular light spot generated by the fly-eye lens 103 is focused on the surface of the micromirror reflection array of the DMD 106, and adjust the position of the DMD 106 so that its reflection surface coincides with the position of the rectangular light spot generated by the fly-eye lens 103. Turn off LED 0101.

[0050] As Figure 1 shown, the camera 201 and the tube lens 202 are installed. Turn on the camera 201, place a collimator in front of the tube lens 202, and adjust the position of the tube lens 202 along the optical axis so that the image of the collimator in the camera 201 is clear. Fix the position of the tube lens 202 and remove the collimator.

[0051] As Figure 1 shown, the plane mirror 107, the field lens 108, the beam splitter 301, and the objective lens 302 are installed. Turn on LED 101 and set all the micromirrors of the DMD 106 to the ON state. Adjust the height of the objective lens 302 so that the surface of the sample stage is clearly imaged in the camera.

[0052] As Figure 1 Figure 2 shown, control the DMD 106 to display the image of the illumination light I1. Adjust the position of the field lens 108 along the optical axis so that the contour of the illumination light stripe is clear.

[0053] As Figure 1 shown, set all the micromirrors of the DMD 106 to the ON state. At this time, all the sample areas within the imaging optical path field of view are illuminated. Place the sample 401 and adjust the distance of the objective lens 302 relative to the sample so that the sample plane to be observed is clear.

[0054] As Figure 2 、 Figure 5As shown, the mirror array of DMD106 is opened according to the distribution of I1, and the camera 201 is controlled to obtain the corresponding picture S1. The mirror array of DMD106 is opened according to the distribution of I2, and the camera 201 is controlled to obtain the corresponding picture S2. In turn, the mirror array of DMD106 is opened according to I3 and I4 to obtain the corresponding pictures S3 and S4.

[0055] Calculate f(x), g(x), and Image(x) according to the corresponding formula. Image(x) is the image after removing the background.

[0056] As Figure 6 shown, Figure 6 On the left is the image taken using traditional full-field illumination. The reflected light of the sample and the sample platform at the defocus position is collected by the imaging optical path and reflected in the final image. Figure 6 On the right is the final image taken using the device of the present invention. All the stray light generated by the out-of-focus samples in the image is effectively removed.

[0057] In Example 1 of the present application, the resolution of the used camera 201 is 6240*4168, and the actually used resolution is 6000*4000.

[0058] In Example 1, the mirror array of the used DMD106 is 1920*1080, and the actually used one is 1500*1000 in the middle.

[0059] As Figure 1 shown, through the optical path projection of the field lens 108 and the objective lens 302, there is a corresponding relationship between the DMD106 mirror array distribution and the sample position. For a simplified explanation, if the 50*50 array of mirrors in the upper right corner of the usage area (1500*1000) of DMD106 is in the ON state, then the illumination light generated by LED101 is reflected by the ON area of DMD106 and, through the optical action of the field lens 108 and the objective lens 302, the corresponding area in the lower left corner of the sample is illuminated.

[0060] As Figure 1 shown, through the projection action of the objective lens 302 and the camera 201, there is a corresponding relationship between the sample position and the photosensitive surface of the camera 201. For a simplified explanation, if the lower left corner of the sample observation area is illuminated, through the projection action of the objective lens 302 and the camera 201, a light spot will be generated in the upper right corner corresponding to the camera 201.

[0061] In summary, there is a coordinate corresponding relationship among DMD106, the sample observation area, and the camera 201.

[0062] The image Image(x) obtained from Example 1 can be further analyzed. By setting a grayscale threshold or using an analysis and positioning method, the coordinate information of the image Image(x) in the in-focus region can be determined. Using the above coordinate information in the in-focus region as feedback, control DMD106 to set the micromirror array corresponding to the in-focus region R to the to-be-activated state. Let the new SI1 = I1 ∩ R,..., SI4 = I4 ∩ R. Obtain a new four-phase illumination array.

[0063] Illuminating with the above new four-phase and obtaining S1,..., S4 and calculating Image(x), an image signal with higher contrast can be obtained.

[0064] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An optical imaging device capable of removing defocus signals, characterized in that: It includes an illumination module (1) and an imaging module (2). The illumination module (1) includes an LED (101) disposed at the top. A collimating mirror (102) is disposed below the LED (101). A fly-eye lens (103) is disposed below the collimating mirror (102). A focusing lens (104) is disposed below the fly-eye lens (103). A prism group (105) is disposed below the focusing lens (104). A DMD (106) is disposed on the side of the prism group (105). A plane mirror (107) is disposed below the prism group (105). A field lens (108) is disposed on the side of the plane mirror (107). The imaging module (2) includes a camera (201) disposed at the top. A tube lens (202) is disposed at the bottom of the imaging module (2). A lens module (3) is disposed below the imaging module (2). The lens module (3) includes a beam splitter (301) disposed on the upper side of the lens module (3) and an objective lens (302) disposed on the lower side of the lens module (3). A sample (401) is disposed below the objective lens (302).

2. The optical imaging device capable of removing defocus signals according to claim 1, wherein: The prism group (105) is disposed at a certain angle offset along the optical axis.

3. The optical imaging device capable of removing defocus signals according to claim 1, characterized in that: The coaxiality deviation of the installation of the fly-eye lens (103) and the focusing lens (104) is less than 0.03°, and the displacement deviation of the installation is less than 0.05 mm.

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