Illuminating device for bacterial colony counting instrument
By employing a combined light source design of a dome-shaped uniform reflector and LED lights in the colony counter, the problem of unclear colony imaging caused by top-tilted lighting was solved, achieving efficient and clear colony imaging and accurate counting results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI PANMAI TECH CO LTD
- Filing Date
- 2025-07-01
- Publication Date
- 2026-05-19
AI Technical Summary
The top-tilted illumination technology of existing colony counters cannot effectively improve the reflection intensity of colony light paths, resulting in unclear imaging, especially for opaque or low-transmittance samples, which affects the recognition and judgment of the counting software.
The system employs a combination of a dome-shaped diffuser and LED lights, designed to illuminate the colonies with near-vertical light, reducing diffuse light consumption and increasing surface reflection feedback. Directional illumination is achieved by adjusting the angle of the light-blocking plate and LED beads, ensuring that the light is concentrated and reflected to the camera.
It improves the clarity and contrast of colony imaging, enhances the software's ability to identify colonies, and reduces counting errors, especially significantly improving the imaging effect of small and thin colonies.
Smart Images
Figure CN224263513U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to an illumination device for a colony counter. Background Technology
[0002] Fully automated colony counters detect colonies by capturing images or videos of samples with a camera and then using software algorithms to identify and count the colonies within the images. Therefore, the appropriate light source directly affects the quality of the colony imaging and consequently, the results of the software's colony counting calculations. Since dark agar colony samples with poor light transmittance and opaque filter paper / membrane colony samples cannot be illuminated by bottom-transmitted light, severely impacting the imaging of colonies in the samples, a top-light source should be used. An efficient top-light source is crucial for high-quality sample imaging; therefore, it is a key technology for fully automated colony counters to achieve high-quality imaging of opaque or poorly transparent samples.
[0003] Meanwhile, bacterial colonies are clusters of bacterial cells. Due to the high refractive properties of bacteria and the reflective nature of their dense cell walls, dense and fine bacterial cell clusters exhibit diffuse reflection of incident light after complex reflections and refractions. This reduces the intensity of light returning along the optical path of the camera, ultimately resulting in unclear images of the colonies.
[0004] In existing technologies, the top-light source illumination technology of fully automated colony counters significantly improves the clarity of camera images by minimizing diffuse reflection from colonies and thus increasing the intensity of light reflection along the colony's light path. Current technologies, such as tilted illumination from both sides of the LED light strip and vertical illumination from a ring-shaped uniform LED, cannot effectively increase the intensity of light reflected from the colony's light path, resulting in insufficient colony imaging and hindering software recognition and judgment.
[0005] The optical path scheme that uses a top-tilted illumination of bacterial colonies has the following disadvantages:
[0006] ① A colony is formed by the accumulation of transparent and dense micron-sized bacterial cells. It has a complex internal refraction and reflection mechanism for incident light from the outside, which ultimately forms a comprehensive light feedback form that integrates reflection and diffuse scattering.
[0007] ②The surface of the colony is mainly spherical or wavy, and it exhibits more complex optical feedback changes in response to incident light compared to flat objects;
[0008] ③ When the top-tilted light enters the colony, the specular reflection light is a high-intensity optical feedback, but its spherical and wavy surface characteristics result in very little specular reflection light entering the camera;
[0009] ④ When light is incident on the colony from the top at an angle, the diffuse scattering produced by the colony is a weak-intensity optical feedback. This means that in the central part of the colony, due to the thicker bacterial cell layer, there are more bacterial cells that generate diffuse scattering, resulting in a relatively large amount of diffuse scattering light entering the camera. However, at the edge of the colony, due to the thinner bacterial cell layer and fewer bacterial cells, the amount of diffuse scattering is low, and the amount of light entering the camera is significantly reduced. This results in unclear imaging of the colony edge, causing the colony counting software to make misjudgments at the colony identification level, leading to deviations in the counting results.
[0010] ⑤ When light is incident on colonies at an angle from the top, the diffuse scattering of light is very low for small or thin colonies, making them difficult to image. This causes the colony counting software to fail to capture the colony signal, resulting in inaccurate counting results.
[0011] The above-mentioned drawbacks are all caused by the top-tilted lighting technique. However, the colony counter uses top-tilted lighting to avoid obstructing the light path of the camera vertically above. Therefore, the existing technology cannot provide high-quality colony imaging images, and thus cannot improve the accuracy of colony counting experiments required by the experiment. Summary of the Invention
[0012] The purpose of this invention is to provide an illumination device for a colony counter, which addresses and compensates for the shortcomings of current technology, and provides an optical solution for matching top illumination to achieve the best imaging effect of colonies against opaque or low-transparency backgrounds.
[0013] To achieve the above technical objectives, this utility model provides an illumination device for a colony counter, which is arranged on the upper part of the colony counter and located between the camera and the sample culture dish. The illumination device includes a dome-shaped uniform light reflector and an LED light assembly. The lower surface of the main body of the dome-shaped uniform light reflector is a concave arc-shaped reflective surface, which covers the sample culture dish area. The center of the reflective surface has a lens opening corresponding to the camera. The dome-shaped uniform light reflector also has a sidewall extending downwards along the edge of the reflective surface. The LED light assembly is arranged on the inner sidewall, and its illumination source only illuminates the reflective surface area upwards. The illumination source is reflected by the reflective surface to form near-vertical light rays that enter the sample culture dish area and are then reflected again to the camera, thus forming an optimal illumination path.
[0014] This invention provides an illumination device for a colony counter. It uses a dome-shaped uniform light reflection light source to illuminate the sample. The dome-shaped uniform light reflection can generate near-vertical light. The refraction angle of the near-vertical light after it is incident on the colony is close to zero, which can reduce the light consumption caused by diffuse scattering and form light feedback with an intensity close to the surface reflection. At the same time, the reflection from the colony surface is accumulated, and finally more light is fed back to the camera compared with the top tilted light. This makes the colony and the background in the image have a strong contrast, which is conducive to the software to identify the colony.
[0015] As a further improvement, the sidewall extends inward at an inward angle, and the end of the sidewall also has a horizontally arranged light-blocking plate. The LED light group is an embedded light group. By adjusting the tilt angle between the light-blocking plate and the lamp holder of the LED light group, the LED light group can form uniform and directional illumination on the reflective surface of the dome light reflector.
[0016] As a further improvement, the LED beads of the LED light group adopt an outer edge concealment design, the beads are tilted towards the reflective surface at a corresponding angle, and the light direction is restricted by the light blocking plate, so that the light only illuminates the reflective surface.
[0017] As a further improvement, the sample culture dish is arranged with colonies and agar. The curvature of the reflective surface is designed according to the refractive index of the colonies, the curvature of the colony surface, and the refractive index of the agar. Then, the optical path distance between the camera and the sample culture dish is determined according to the panoramic imaging of the sample culture dish by the camera, so that approximately parallel light rays perpendicular to the sample culture dish are generated. The approximately parallel light rays illuminating the colonies on the sample culture dish can generate a strong reflected light signal into the field of view of the camera.
[0018] As a further improvement, the optical path distance between the LED light group and the sample culture dish is determined according to the optimal illumination optical path. Based on the lens parameters of the camera, the distance between the camera and the dome light reflector is located with panoramic imaging of the sample culture dish under minimal distortion. Then, the lens opening size is determined with panoramic imaging of the camera as the reference.
[0019] As a further improvement, the outer surface of the dome light reflector and the light-blocking plate are coated with a black matte coating, and the inner arc surface of the reflective surface is uniformly coated with a nano-light-diffusing coating.
[0020] Accordingly, this utility model also provides a colony counter, which includes the camera and the sample base for placing the sample culture dish, which are longitudinally connected by a column. The column is also equipped with an illumination device for the colony counter provided by this utility model.
[0021] As a further improvement, the camera, the dome reflector of the lighting device, and the sample base are respectively fixed to the column by positioning brackets. The length of the positioning brackets should ensure that the centers of the camera, the dome reflector, and the positioning base are located above the light path.
[0022] As a further improvement, the sample base has a raised positioning ring in the middle, and the inner wall of the positioning ring makes positioning contact with the bottom of the sample culture dish to ensure that the center of the sample culture dish is located on the optical path axis.
[0023] As a further improvement, the positioning ring is an arc shape that fits the bottom of the sample culture dish and has an obtuse-angled opening to facilitate quick placement and positioning of the culture dish. The surface of the positioning bracket, the surface of the column, and the surface of the sample base all have a matte black treatment layer to reduce stray light signal interference in the detection area.
[0024] This utility model provides a software system for a colony counter that provides strong, clear, accurate, efficient, and timely feedback signals for colony optical signals. It is also easy to integrate with the automatic code reading technology of a fully automatic colony counter and the colony counting software. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the optical path of this utility model;
[0026] Figure 2 This is a schematic diagram of the structure of this utility model;
[0027] Figure 3 This is a side view of the colony counter of this utility model;
[0028] Figure 4 This is a front view of the colony counter of this utility model.
[0029] Figure labels: 1. Camera, 2. Sample petri dish, 3. Dome reflector, 4. LED light group, 5. Reflective surface, 6. Lens opening, 7. Side wall, 8. Light blocking plate, 9. Colony, 10. Agar, 20. Colony counter, 21. Column, 22. Sample base, 23. Positioning bracket, 24. Positioning ring. Detailed Implementation
[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0031] like Figures 1 to 4As shown, this utility model provides an illumination device for a colony counter, which is arranged on the upper part of the colony counter 20 and located between the camera 1 and the sample culture dish 2. The illumination device includes a dome light reflector 3 and an LED light group 4. The lower surface of the main body of the dome light reflector 3 is a concave arc-shaped reflective surface 5. The reflective surface covers the area of the sample culture dish 2. The center of the reflective surface 5 has a lens opening 6 corresponding to the camera 1. The dome light reflector 3 also has a side wall 7 extending downward along the edge of the reflective surface. The LED light group 4 is arranged on the inner side wall 7 and its illumination light source only illuminates the area of the reflective surface 5 upward. The illumination light source is reflected by the reflective surface 5 to form a near-vertical light that enters the area of the sample culture dish 2 and is reflected again to the camera 1 to form an optimal illumination light path.
[0032] This invention provides an illumination device for a colony counter. It uses a dome-shaped uniform light reflection light source to illuminate the sample. The dome-shaped uniform light reflection can generate near-vertical light. The refraction angle of the near-vertical light after it is incident on the colony is close to zero, which can reduce the light consumption caused by diffuse scattering and form light feedback with an intensity close to the surface reflection. At the same time, the reflection from the colony surface is accumulated, and finally more light is fed back to the camera compared with the top tilted light. This makes the colony and the background in the image have a strong contrast, which is conducive to the software to identify the colony.
[0033] As a further improvement, the sidewall 7 extends inward at an inward angle, and the end of the sidewall 7 also has a horizontally arranged light-blocking plate 8. The LED light group 4 is an embedded light group. By adjusting the tilt angle between the light-blocking plate 8 and the lamp holder of the LED light group 4, the LED light group 4 can form uniform light directional illumination on the reflective surface 5 of the dome light reflector 3.
[0034] As a further improvement, the LED beads of the LED light group 4 adopt an outer edge concealment design. The beads are tilted towards the reflective surface 5 at a corresponding angle, and the light direction is restricted by the light blocking plate 8, so that they only illuminate the reflective surface 5.
[0035] As a further improvement, the sample culture dish 2 is arranged with colonies 9 and agar 10. The curvature of the reflective surface 5 is designed according to the refractive index of the colonies, the curvature of the colony surface, and the refractive index of the agar. Then, the optical path distance between the camera and the sample culture dish is determined according to the panoramic imaging of the sample culture dish by the camera, so that approximately parallel light rays perpendicular to the sample culture dish are generated. The approximately parallel light rays illuminating the colonies on the sample culture dish can generate a strong reflected light signal into the field of view of the camera.
[0036] As a further improvement, the optical path distance between the LED light group 4 and the sample culture dish is determined according to the optimal illumination optical path. Based on the lens parameters of the camera, the distance between the camera and the dome light reflector 3 is located with panoramic imaging of the sample culture dish under minimal distortion. Then, the lens opening size is determined with panoramic imaging of the camera as the reference.
[0037] As a further improvement, the outer surface of the dome light reflector 3 and the light blocking plate 8 are sprayed with a black matte coating, and the inner arc surface of the reflective surface 5 is uniformly sprayed with a nano-light-diffusing coating.
[0038] Accordingly, this utility model also provides a colony counter, which includes a camera 1 and a sample base 22 for placing the sample culture dish 2, which are longitudinally connected by a column 21. The column 21 is also equipped with an illumination device for the colony counter provided by this utility model.
[0039] As a further improvement, the camera, the dome reflector 3 of the lighting device, and the sample base 22 are respectively fixed to the column by positioning brackets. The length of the positioning brackets should ensure that the centers of the camera, the dome reflector, and the positioning base are located above the light path.
[0040] As a further improvement, the sample base 22 has a raised positioning ring 24 in the middle, and the inner wall of the positioning ring is in positioning contact with the bottom of the sample culture dish 2 to ensure that the center of the sample culture dish 2 is located on the optical path axis.
[0041] As a further improvement, the positioning ring is an arc shape that fits the bottom of the sample culture dish 2 and has an obtuse-angled opening to facilitate quick placement and positioning of the culture dish. The surface of the positioning bracket, the surface of the column, and the surface of the sample base 22 all have a matte black treatment layer to reduce stray light signal interference in the detection area.
[0042] This utility model provides a software system for a colony counter that provides strong, clear, accurate, efficient, and timely feedback signals for colony optical signals. It is also easy to integrate with the automatic code reading technology of a fully automatic colony counter and the colony counting software.
[0043] In a preferred embodiment of this invention, a dome-shaped uniform light reflection light source is used to illuminate the sample. The dome-shaped uniform light reflection can generate near-vertical light rays. The refraction angle of the near-vertical light rays after incident on the colony is close to zero, which can reduce the light consumption caused by diffuse scattering and form a light feedback with an intensity close to the surface reflection. At the same time, the reflection of the colony surface is accumulated, and finally more light is fed back to the camera compared with the top tilted light rays, so that the colony and the background have a strong contrast in the image, which is conducive to the software to identify the colony.
[0044] This invention designs the curvature of the dome-shaped uniform light reflector based on the refractive index of the colony, the curvature of the colony surface, and the refractive index of agar, reducing the incident angle and minimizing light consumption due to diffuse scattering from the colonies. The LED beads of the dome-shaped uniform light reflector feature a concealed outer edge design, with the beads tilted at a corresponding angle towards the dome reflector. A light-shielding structure restricts the direction of the light, ensuring it only illuminates the dome-shaped uniform light reflector, preventing direct irradiation of the sample culture and avoiding light spots that could affect the software's identification and judgment of the colonies.
[0045] This invention addresses the need for efficient illumination of colonies on opaque or low-transmittance culture dishes in a colony counter. The design employs a dome-shaped uniform light reflector. The curvature of the dome-shaped reflector is designed based on the colony's refractive index, surface curvature, and agar refractive index. The optical path distance between the camera and the culture dish is determined based on panoramic imaging of the sample. The optimal illumination path of the dome-shaped reflector is then used to determine the optical path distance between the dome-shaped reflector and the culture dish. Finally, the lens aperture size of the dome-shaped reflector is determined to ensure it does not obstruct camera imaging. This results in the optimal optical structure for illuminating the colony sample with the dome-shaped uniform light reflector.
[0046] Its working principle: The LED light assembly of the dome homogeneous reflector is an embedded light assembly. The tilt angle between the light-blocking plate and the lamp holder directs the light assembly towards the dome homogeneous reflector. The inner arc surface of the dome homogeneous reflector is uniformly coated with a nano-homogenizing coating, and the curvature of the arc surface is customized according to the design drawings. The distance between the dome homogeneous reflector and the sample culture dish is determined based on experimental data, enabling it to generate approximately parallel light rays perpendicular to the sample culture dish. This light irradiates the colonies on the sample culture dish, producing a strong reflected light signal that enters the camera's field of view. Based on the camera's lens parameters, the distance between the camera and the dome homogeneous reflector is determined with minimal distortion, using the panoramic imaging of the sample culture dish as a reference. The lens aperture of the dome homogeneous reflector is then adjusted to ensure it does not obstruct the camera's view.
[0047] The device and structural features of this utility model include:
[0048] a. The camera, dome reflector, and sample culture dish positioning base are fixed to the column by positioning brackets.
[0049] b. The length of the positioning bracket should ensure that the centers of the camera, the dome reflector, and the sample culture dish positioning base are located above the optical path.
[0050] c. The maximum diameter and curvature of the dome reflector should meet the requirements of the design drawings.
[0051] d. Apply a nano-uniform light coating to the inner arc surface of the dome uniform light reflector. The particle size of the nano-uniform light coating material should meet the design requirements, the color of the nano-uniform light coating should meet the design requirements, the nano-uniform light coating should have good and stable compatibility with the material of the dome uniform light reflector, and the spray atomization degree and coating thickness of the nano-uniform light coating should meet the design requirements.
[0052] e. The aperture size of the lens hole on the dome diffuser should meet the design requirements.
[0053] f. The width of the light-blocking plate at the bottom of the dome diffuser should meet the design requirements.
[0054] g. The tilt angle of the embedded LED light group on the dome diffuser should meet the design requirements.
[0055] h. The positioning bracket should ensure that the distance between the camera and the dome diffuser meets the design requirements.
[0056] i. The positioning support should ensure that the distance between the dome reflector and the sample culture dish meets the design requirements.
[0057] j. The sample culture dish positioning base uses raised positioning rings to position the culture dish, ensuring that the culture center is located on the optical path axis.
[0058] k. The positioning ring on the sample culture dish positioning base is an arc-shaped design that fits the bottom of the culture dish, with an obtuse-angled opening, which facilitates quick placement and positioning of the culture dish.
[0059] l. The outer surface of the dome uniform light reflector, the surface of the dome uniform light reflector light shield, the surface of the positioning bracket, and the surface of the column are all treated with matte black finish to reduce stray light signal interference in the detection area.
[0060] The fabrication and installation of the supporting components for the dome uniform light reflection optical path system of this utility model are as follows:
[0061] a. Precision machining of the dome diffuser according to the process drawings;
[0062] b. Precisely drill lens holes on the dome diffuser according to the process drawings;
[0063] c. Apply a matte black coating to the outer surface of the dome diffuser and the light-blocking plate according to the design requirements;
[0064] d. Spray a nano-uniform light coating onto the inner surface of the dome reflector according to design requirements;
[0065] e. Install the embedded LED light assembly and connect the circuit according to the process drawings;
[0066] f. Install the light-blocking plate onto the dome diffuser according to the process drawings;
[0067] g. Precision machine the columns, positioning brackets, and sample bases according to the process drawings, and spray all of them with a matte black coating on the outer surface;
[0068] h. Install the positioning bracket and sample base on the column according to the process drawings;
[0069] i. Install the camera and connect the cables;
[0070] j. Install the dome diffuser and connect the cables;
[0071] k. Install the sample base;
[0072] l. Overall optical path laser calibration, fine-tuned using positioning adjustment screws to ensure consistent optical data;
[0073] m. Overall dust removal and dust-free packaging.
[0074] This invention can be optimized into a fully automatic colony counter, employing automatic code reading technology and a series of automatic machine intelligent vision technologies. It eliminates the need for human intervention throughout the process, self-corrects errors, and has the ability to learn and train to improve the algorithm model, achieving a technological breakthrough in unmanned code reading and decoding. It adopts a software system that is fully integrated with the colony counting software, which can completely avoid the data matching problem between the sample code information collected by the external handheld code reader and the colony counter software, ensuring good data integrity and avoiding dependence on the supply and maintenance of external equipment.
[0075] This invention is applicable to the illumination of colonies in opaque or low-transparency samples. It features strong colony light signal feedback; the dome-shaped uniform light reflection optical system significantly reduces the energy consumption of light scattering generated within the colony by large-angle incident light, thereby enhancing the colony light signal feedback intensity. It provides clear imaging of colony edges; the dome-shaped uniform light reflection optical system further enhances the colony light signal feedback intensity and improves the image clarity of thin, flat colony edges. It can also image small colonies; the dome-shaped uniform light reflection optical system enhances the colony light signal feedback intensity and improves the image clarity of thin, flat colonies. Furthermore, it can image thin, flat colonies; the dome-shaped uniform light reflection optical system enhances the colony light signal feedback intensity and improves the image clarity of thin, flat colonies.
[0076] The Dome Uniform Light Reflection Colony Illumination Technology significantly improves the clarity of colony imaging, particularly for small and thin colonies. Its innovative technology utilizes a dome-shaped curvature specifically designed for colony culture dish samples. It also employs a nano-uniform light coating to enhance illumination efficiency. Furthermore, it employs a coaxial light path imaging technique. Finally, it can be integrated into a fully automated colony counter with a built-in information code reader.
[0077] It should be understood that the scope of protection sought by this utility model is not limited to the non-limiting embodiments, which are merely illustrative examples. The substantive scope of protection claimed in this application is further embodied in the scope provided by the independent claims and their dependent claims.
Claims
1. An illumination device for a colony counter, arranged above the colony counter (20) and between a camera (1) and a sample culture dish (2), characterized in that: The lighting device includes a dome-shaped reflector (3) and an LED light group (4). The lower surface of the main body of the dome-shaped reflector (3) is a concave arc-shaped reflective surface (5). The reflective surface covers the sample culture dish (2) area. The middle part of the reflective surface (5) has a lens opening (6) corresponding to the camera (1). The dome-shaped reflector (3) also has a sidewall (7) that extends downward along the edge of the reflective surface. The LED light group (4) is arranged on the inner sidewall (7) and its illumination source only illuminates the reflective surface (5) area upward. The illumination source is reflected by the reflective surface (5) to form a near-vertical light that enters the sample culture dish (2) area and is reflected again to the camera (1) to form the optimal illumination light path.
2. The illumination device for a colony counter according to claim 1, characterized in that: The sidewall (7) extends inward at an inward angle, and the end of the sidewall (7) also has a horizontally arranged light-blocking plate (8). The LED light group (4) is an embedded light group. By adjusting the tilt angle between the light-blocking plate (8) and the lamp holder of the LED light group (4), the LED light group (4) forms uniform light directional illumination on the reflective surface (5) of the dome light reflector (3).
3. The illumination device for a colony counter according to claim 2, characterized in that: The LED beads of the LED light group (4) adopt an outer edge concealment design. The beads are tilted towards the reflective surface (5) at a corresponding angle, and the light direction is restricted by the light blocking plate (8) so that they only illuminate the reflective surface (5).
4. The illumination device for a colony counter according to claim 3, characterized in that: The sample culture dish (2) is arranged with colonies (9) and agar (10). The curvature of the reflective surface (5) is designed according to the refractive index of the colonies, the curvature of the colony surface and the refractive index of the agar. The optical path distance between the camera and the sample culture dish is determined according to the panoramic imaging of the sample culture dish by the camera, so that approximately parallel light rays perpendicular to the sample culture dish are generated. The approximately parallel light rays irradiating the colonies on the sample culture dish can generate strong reflected light signals to the field of view of the camera.
5. The illumination device for a colony counter according to claim 4, characterized in that: The optical path distance between the LED light group (4) and the sample culture dish is determined according to the optimal illumination optical path. Based on the lens parameters of the camera, the distance between the camera and the dome light reflector (3) is located with panoramic imaging of the sample culture dish under the minimum distortion state. The size of the lens opening is then determined with panoramic imaging of the camera as the reference.
6. The illumination device for a colony counter according to claim 5, characterized in that: The outer surface of the dome light reflector (3) and the light blocking plate (8) are coated with a black matte coating, and the inner arc surface of the reflective surface (5) is uniformly coated with a nano light-diffusing coating.
7. A colony counter comprising a camera (1) longitudinally mounted and connected by a column (21) and a sample holder (22) for placing the sample culture dish (2), characterized in that: The column (21) is also equipped with a lighting device for a colony counter according to any one of claims 1 to 6.
8. A colony counter according to claim 7, characterized in that: The camera, the dome reflector (3) of the lighting device, and the sample base (22) are respectively fixed to the column by a positioning bracket (23). The length of the positioning bracket (23) should ensure that the center of the camera, the dome reflector, and the positioning base is located above the light path.
9. A colony counter according to claim 8, characterized in that: The sample base (22) has a raised positioning ring (24) in the middle. The inner wall of the positioning ring is in positioning contact with the bottom of the sample culture dish (2) to ensure that the center of the sample culture dish (2) is located on the optical path axis.
10. A colony counter according to claim 9, characterized in that: The positioning ring is an arc shape that fits the bottom of the sample culture dish (2) and has an obtuse angle opening, so as to facilitate quick placement and positioning of the culture dish. The surface of the positioning bracket, the surface of the column, and the surface of the sample base (22) all have a matte black treatment layer to reduce stray light signal interference in the detection area.