Zoom microscope system based on PB liquid crystal lens
By using a microscope system based on PB liquid crystal lenses, optical zoom without mechanical movement is achieved through an electronic control system and a liquid crystal zoom component. This solves the problems of observation error and image quality in traditional microscopes, and achieves miniaturized and efficient optical zoom effects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-25
- Publication Date
- 2026-03-03
AI Technical Summary
Traditional microscopes lack automatic optical zoom capabilities, leading to observation errors and decreased image quality. Furthermore, existing digital zoom methods may result in significant image noise and are unable to achieve a wide range of optical zoom within a small optical length without increasing system weight.
A variable-focus microscope system based on PB liquid crystal lenses is adopted. Optical zoom is achieved through a liquid crystal zoom component, which includes a transparent substrate, transparent electrodes, multilayer liquid crystal lenses and a sealing layer. Different focal length combinations are achieved by controlling the voltage changes of the liquid crystal lenses using an electronic control system. Zooming without mechanical movement is achieved by combining an electronic control device and a polarization switch.
It achieves a wide range of optical zoom within a small overall optical length, avoiding the complexity and increase in size of the mechanical structure, improving image quality and operational efficiency, and supporting fast and accurate focal length adjustment.
Smart Images
Figure CN223966763U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of microscopy, and more specifically, to a variable-focus microscope system based on a PB liquid crystal lens. Background Technology
[0002] A microscope is an instrument primarily used to magnify tiny objects visible to the naked eye. Microscopes are divided into optical microscopes and electron microscopes: the optical microscope was first invented in 1590 by the Dutchman Jansen. Modern optical microscopes can magnify objects up to 1600 times, with a minimum resolution limit of 1 / 2 wavelength. The mechanical tube length of domestically produced microscopes is generally 160 mm.
[0003] Traditional microscopes generally lack automatic optical zoom capabilities. Zooming is typically achieved manually or mechanically, which leads to movement of the observed object along the z-axis, introducing observational errors. Digital zoom, on the other hand, can result in reduced image quality and increased image noise, negatively impacting observation. Therefore, a device is needed that can support a wide range of optical zoom within a small optical length without significantly increasing the overall weight of the zoom system. Utility Model Content
[0004] To overcome the shortcomings of the existing system, this application provides a zoom microscope system based on a PB liquid crystal lens, which can solve the problem of the above-mentioned device that can support a wide range of optical zoom in a small total optical length without significantly increasing the total weight of the zoom system.
[0005] The technical solution adopted by the embodiments of this application to solve its technical problem is: a variable focus microscope system based on PB liquid crystal lens, including a microscope part.
[0006] The microscope includes a base, an arm on the base, a tube on the arm, an eyepiece and an objective lens mounted at the top and bottom of the tube respectively, a liquid crystal zoom assembly inside the eyepiece and the objective lens, and a stage mounted on the base directly below the tube.
[0007] The liquid crystal zoom assembly includes a transparent substrate, a transparent electrode, a multilayer liquid crystal lens, and a sealing layer. The transparent substrate, the transparent electrode, and the liquid crystal lens are disposed inside the lens barrels of the eyepiece and the objective lens. The sealing layer seals the transparent substrate, the transparent electrode, and the multilayer liquid crystal lens.
[0008] In one specific implementation, the transparent substrate is made of a material with high light transmittance.
[0009] In one specific embodiment, the thickness of the transparent substrate is 0.5-1.1 mm.
[0010] In one specific implementation, the transparent electrode is made of indium tin oxide thin film.
[0011] In one specific implementation, the liquid crystal lens is provided in multiple layers, and each liquid crystal lens is made of a nematic liquid crystal material with a fast response speed.
[0012] In one specific implementation, the sealing layer is made of epoxy resin adhesive, and a vacuum sealing process is used for peripheral sealing.
[0013] In one specific embodiment, each of the liquid crystal lenses includes a polarization switch and a liquid crystal zoom lens, the liquid crystal zoom lens being mounted on a substrate on one side of the polarization switch.
[0014] In one specific implementation, an electronic control device is installed inside the lens arm, and the electronic control device is electrically connected to the liquid crystal zoom component.
[0015] The advantages of the embodiments of this application are:
[0016] 1. No mechanical movement: Compared with traditional mechanical zoom systems, this invention requires no mechanical movement, avoids complex mechanical structures, and reduces the size and maintenance costs of the system.
[0017] 2. High-speed electronic control adjustment: Through the design of the electronic control system, different focal length combinations can be achieved by controlling the power-on and power-off of each layer of liquid crystal zoom lens.
[0018] 3. Compact design: The LCD zoom lens used is very thin, which will not increase the size of the device, so as to achieve zoom while keeping the device small. Attached Figure Description
[0019] Figure 1 A schematic diagram of a variable focus microscope system based on a PB liquid crystal lens provided for an embodiment of this application;
[0020] Figure 2 This is a schematic diagram of the exploded structure of the liquid crystal zoom component provided in the embodiments of this application;
[0021] Figure 3 A schematic diagram illustrating the imaging relationship between the liquid crystal zoom component and the objective lens provided in an embodiment of this application;
[0022] Figure 4 A schematic diagram illustrating the working principle of the multilayer liquid crystal lens provided in the embodiments of this application;
[0023] Figure 5 A schematic diagram illustrating the working principle of the multilayer liquid crystal lens provided in this application embodiment;
[0024] Figure 6 A diagram of the control module for the liquid crystal zoom component provided in an embodiment of this application.
[0025] In the diagram: 110-base; 120-stage; 130-arm; 140-eyepiece; 150-objective lens; 160-liquid crystal zoom assembly; 161-liquid crystal lens; 1611-polarization switch; 1612-liquid crystal zoom lens; 162-transparent substrate; 163-transparent electrode; 164-sealing layer. Detailed Implementation
[0026] The technical solution in this application embodiment is to solve the problem of the above-mentioned device that can support a large range of optical zoom within a small total optical length, and without significantly increasing the overall weight of the zoom system. The general idea is as follows:
[0027] Please see Figures 1-6 A variable-focus microscope system based on a PB liquid crystal lens, including a microscope section.
[0028] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 The microscope includes a base 110, an arm 130 mounted on the base 110, and a microscope tube mounted on the arm 130. An eyepiece 140 and an objective lens 150 are mounted at the top and bottom of the microscope tube, respectively. A liquid crystal zoom assembly 160 is installed inside the microscope tube, located within the eyepiece 140 and objective lens 150. A stage 120 is mounted directly below the microscope tube on the base 110. The liquid crystal zoom assembly 160 includes a transparent substrate 162, a transparent electrode 163, a multilayer liquid crystal lens 161, and a sealing layer 164. The transparent substrate 162, transparent electrode 163, and liquid crystal lens 161 are disposed inside the microscope tube of the eyepiece 140 and objective lens 150. The sealing layer 164 seals the transparent substrate 162, transparent electrode 163, and multilayer liquid crystal lens 161. Notably, there is no mechanical movement: compared to traditional mechanical zoom systems, this invention eliminates the need for mechanical movement, avoiding complex mechanical structures and reducing system size and maintenance costs. High-speed electronic adjustment: Through the design of the electronic control system, different focal length combinations can be achieved by controlling the power-on and power-off of each layer of liquid crystal zoom lens 1612. Compact design: The liquid crystal zoom lens 1612 itself is very thin, which does not increase the size of the device, achieving zoom while maintaining the miniaturization of the device.
[0029] The transparent substrate 162 is made of a material with high light transmittance. The thickness of the transparent substrate 162 is 0.5-1.1mm. It can be made of optical-grade borosilicate glass or polycarbonate (PC) material, with a light transmittance of over 98%, excellent optical uniformity and flatness, providing stable physical support for the internal structure and ensuring that light passes through without distortion.
[0030] The transparent electrode 163 uses an indium tin oxide (ITO) thin film. The ITO thin film has a sheet resistance of less than 20 Ω / □ and a transmittance of over 90% in the visible light band. The electrode is divided into a common electrode (a uniform conductive layer covering the entire surface) and a driving electrode (divided into regions according to the design, such as ring or strip electrodes). It is precisely formed by photolithography to ensure that the electric field distribution is accurate and controllable.
[0031] Multiple liquid crystal lenses 161 are provided, each using a nematic liquid crystal material with a fast response speed. The nematic liquid crystal material can be, for example, the MLC series from Merck. The encapsulation thickness is precisely controlled by spacers (such as polyimide microspheres with a diameter of 2-5 μm). In the absence of an electric field, the liquid crystal molecules are aligned in parallel, resulting in uniform light propagation characteristics. When an electric field is applied, the molecular orientation changes with the electric field strength, thereby modulating the phase or refraction of light.
[0032] The sealing layer 164 uses epoxy resin adhesive, combined with vacuum sealing technology for peripheral sealing. During sealing, the internal pressure inside the lens barrel is <10. -3 Pa prevents the liquid crystal lens 161 from oxidizing upon contact with air, ensuring long-term stability and a lifespan of over 100,000 hours.
[0033] Please see Figure 4 and Figure 5 Each liquid crystal lens 161 includes a polarization switch 1611 and a liquid crystal zoom lens 1612, with the zoom lens 1612 mounted on a substrate on one side of the polarization switch 1611. It can achieve both converging and diverging effects on incident light, i.e., it has both positive and negative refractive powers and focal lengths. In actual devices, the polarization switch 1611 and the geometric phase liquid crystal zoom lens 1612 are tightly bonded together. Alternatively, the zoom lens 1612 can be directly fabricated on a substrate on one side of the polarization switch 1611. Without loss of generality, assuming the incident light is right-handed circularly polarized, when the polarization switch 1611 is closed (no voltage applied), the right-handed light passing through the polarization switch 1611 still exits as right-handed light. However, the transmitted light, after passing through the geometric phase liquid crystal zoom lens 1612, becomes both converging and left-handed polarized. When polarization switch 1611 is turned on (voltage is applied), the incident right-handed circularly polarized light is switched to left-handed circularly polarized light by polarization switch 1611. After passing through the geometric phase liquid crystal zoom lens 1612, the left-handed circularly polarized light is converted back to right-handed circularly polarized light and diverges. The case where the incident light is left-handed circularly polarized light is similar. The polarization switch 1611 can be set with different AC voltages according to the requirements of actual response speed and other indicators.
[0034] Using this liquid crystal zoom lens 1612, zoom functionality can be achieved without mechanical movement.
[0035] First, let the spacing between each liquid crystal zoom lens 1612 be as follows: Furthermore, conventional lenses are added before or after the liquid crystal zoom lens group 1612 for correction, with an interval of [missing value], where [missing value] is generally set as small as possible. The liquid crystal zoom lens 1612 is placed after the conventional lens. The positive or negative refractive power of the liquid crystal lens is controlled by whether or not a voltage is applied to each liquid crystal zoom lens 1612. For a liquid crystal zoom lens group 1612 with n lenses, a total of [missing value] refractive power changes can be achieved.
[0036] For a design requiring equally spaced diopter variations, assuming the diopter variation interval is a variable parameter, for a given left-handed or right-handed circularly polarized incident light, the diopter of each lens can be set to a proportional distribution with a common ratio of 2, i.e., the diopter of the 1st, 2nd, 3rd, ..., nth liquid crystal zoom lenses are successively... A conventional lens is placed before or after the liquid crystal zoom lens group 1612 to achieve light focusing. The diopter of the conventional corrective lens is set to a certain value, which can be achieved by controlling the polarization switch 1611 of each liquid crystal zoom lens 1612. arrive to arrive, with Equally spaced changes in diopter allow for optical zoom. This is achieved through proper settings. , The variable 'n' allows for different diopter intervals and maximum diopter requirements. Decreasing 'n' enables finer diopter adjustment, increasing 'n' expands the supported maximum diopter range, and increasing 'n' allows for diopter centering under different conditions.
[0037] The method for controlling the diopter of the liquid crystal zoom lens 1612 is as follows, assuming the target zoom diopter to be set is... The method for setting up the polarization switch 1611 is as follows: Let for The integer that is rounded down, when hour, Pick ;when If so, then take 0. Then... Convert to binary, using the first bit as the least significant bit. For If the i-th bit is 1, the zoom component driver module drives the i-th polarization switch 1611 to be on; otherwise, it is off.
[0038] By adjusting the diopter of each of the liquid crystal zoom lenses 1612, a non-equidistant diopter adjustment configuration can also be achieved.
[0039] An electronic control device is installed inside the telescope arm 130, and this device is electrically connected to the liquid crystal zoom assembly 160. The electronic control device acts as the "nerve center," receiving operational commands (such as adjusting focus and brightness) and converting them into electrical signals. It controls the light intensity of the light source and drives the liquid crystal zoom assembly 160 to change the focus. For example, when observing specimens of different thicknesses, the user inputs the focus parameters through the operating interface, and the electronic control device adjusts the liquid crystal molecule arrangement in real time to quickly and accurately achieve focus, eliminating the need for manual knob rotation and improving operational efficiency and image quality.
[0040] In practical design, the liquid crystal zoom component 160 needs to be properly embedded in the optical path, and the electronic control module needs to be integrated into the microscope arm 130 or base 110 to ensure that, with the traditional structure, the overall stability of the microscope is maintained while the function is upgraded.
[0041] The electronic control unit includes a control circuit, a power supply module, an input interface, and a signal processing unit. The control circuit uses a high-performance microcontroller (such as the STM32F4 series) as its core, with a built-in PID (proportional-integral-derivative) algorithm, which can quickly calculate the corresponding voltage waveform based on input commands (such as focal length). An integrated D / A converter (12-bit precision) converts the digital signal into an analog voltage (0-5V adjustable), which is then amplified by an operational amplifier (such as OPA2277) to drive the LCD zoom component 160. The power supply module receives a general-purpose DC power supply (such as 12V / 2A) and outputs a stable low-noise voltage (3.3V, 5V) through a DC-DC converter chip (such as TPS5430). Combined with an LC filter circuit (L=10μH, C=100μF), it filters out high-frequency noise (suppression ratio >60dB), ensuring power purity and preventing interference with the control of the LCD zoom component 160. Input Interface: Supports multiple interaction methods, such as a capacitive touch knob (integrated rotary encoder, 100 steps / revolution resolution) for real-time input of focus parameters; equipped with a Bluetooth 5.0 module (e.g., HC-08) or a Wi-Fi module (ESP8266) for wireless connection to a computer / mobile app to receive remote control commands (e.g., autofocus program). Signal Processing Unit: Includes a 16-bit ADC (e.g., ADS1115) for high-precision analog-to-digital conversion of input signals (e.g., knob position, feedback voltage), with a sampling rate of 860 SPS, ensuring the control circuit obtains accurate input information for fine-tuning.
[0042] Electrical connection: The electronic control device is connected to the liquid crystal zoom component 160 via a flexible printed circuit board (FPC). The FPC is only 0.1mm thick, possessing high flexibility, allowing for flexible wiring within a limited space, and achieving low impedance (<0.5Ω) signal transmission, ensuring that the voltage signal reaches the transparent electrode 163 quickly and without attenuation. Control process: When the user rotates the touch knob or sends a command via the APP, the input interface transmits the signal to the control circuit. The microcontroller calculates the voltage required to drive the electrode based on the built-in focal length-voltage mapping algorithm (established through experimental calibration using a three-dimensional lookup table). For example, when observing a 10μm thick sample, the control circuit outputs a 2.5V peak-to-peak sinusoidal voltage, driving the liquid crystal layer to form a gradually changing electric field with a high center and low edge, causing the liquid crystal molecules to gradually change their tilt angle from 80° at the center to 20° at the edge, constructing an equivalent focal length adjustable "liquid crystal lens 161" to achieve light focusing adjustment. Simultaneously, through image sharpness feedback (such as a focus evaluation algorithm based on gradient functions), the voltage is finely adjusted in real time to ensure focusing accuracy at the 0.1μm level. In terms of synergistic advantages, compared to traditional mechanical zoom (where the coarse focus knob moves 10mm per revolution, the fine focus knob moves 0.1mm per revolution, and the repeatability error is approximately 0.1mm), the LCD zoom assembly 160, driven by an electronic control device, has no mechanical transmission parts, eliminating problems such as mechanical wear and return gaps. It achieves a repeatability accuracy of 0.1μm, a response time of <100ms, and can seamlessly integrate automation functions (such as linking with microscope image analysis software to automatically complete multi-layer scanning focusing).
[0043] When installing the liquid crystal zoom assembly 160, optical axis consistency is ensured through a precision mechanical structure (such as a high-precision sleeve with concentricity <5μm). Thermal insulation materials (such as PTFE gaskets) are used to prevent temperature changes from affecting liquid crystal performance, and the shape of the liquid crystal zoom assembly 160 is adapted to the internal shape of the microscope tube. Electronic control integration: The electronic control device is installed inside the microscope arm 130, using an aluminum alloy heat dissipation shell (thermal resistance <2℃ / W) to ensure long-term operational stability. Touch-sensitive knobs replace traditional mechanical knobs, maintaining a simple operating interface. Internal circuitry is isolated by a shielding layer (such as copper foil shielding with shielding effectiveness >30dB) to prevent electromagnetic interference from affecting optical control. This deep integration allows the microscope to retain its classic appearance and basic operating habits while achieving a leap in performance through advanced liquid crystal optics and electronic control technology, meeting the demands of modern microscopic observation for high precision, automation, and rapid response.
[0044] Combining liquid crystal zoom technology with 3D technology in microscopy enables high-precision and rapid three-dimensional microscopic imaging. Rapid focal length switching: The liquid crystal zoom component 160 has a millisecond-level response speed, allowing for rapid switching between different focal lengths in a very short time compared to traditional mechanical focusing. This meets the needs of rapid imaging of multiple focal planes in 3D scanning and reduces the impact of sample dynamic changes (such as cell movement) on imaging. High-precision depth control: The electronic control device can precisely regulate the liquid crystal layer voltage to achieve sub-micron-level focal length adjustment (e.g., 0.1μm step size), ensuring the positional accuracy of each focal plane in 3D scanning and improving the resolution of 3D reconstruction. Seamless integration with automation: Linked with 3D imaging software, it automatically executes the scanning process without manual intervention, suitable for batch 3D analysis of complex samples. Control process: 1. Parameter setting: Users set the 3D scanning range (e.g., from 10μm to 50μm below the sample surface) and focal length step size (e.g., 0.2μm) through software. 2. Automatic scanning: The electronic control device drives the liquid crystal zoom component 160 to change the focal length sequentially according to the preset step size. Each focus adjustment triggers the camera to acquire a 2D image of that focal plane. 3. Image caching: Acquired 2D images are temporarily stored in memory, awaiting subsequent processing. 4. 3D reconstruction: After all images are acquired, the software uses an algorithm to synthesize multiple 2D images into a 3D model, supporting interactive observation such as rotation and scaling. Core algorithms: Focus evaluation algorithm (e.g., gradient function method): Calculates the grayscale gradient value of each image, with the formula G=∑x,y(∂x∂I)2+(∂y∂I)2, where I is the image grayscale value. The image is clearest when the gradient value G is maximum, thus determining the optimal focal plane for each position. Image registration algorithm (e.g., SIFT feature matching): Extracts feature points from images of different focal planes (e.g., scale-invariant feature transform SIFT), calculates the translation and rotation between images by matching feature points, aligns the images, and eliminates small displacement errors during the scanning process. 3D reconstruction algorithms (such as volume rendering) treat aligned 2D image sequences as voxels in three-dimensional space. They calculate properties such as transparency and color between voxels through interpolation and synthesize a three-dimensional image using ray casting. The formula is C=∫0LT(x,y,z)⋅S(x,y,z)dz, where T is transparency, S is voxel color, and L is the ray casting length. By integrating these techniques, microscopes can quickly and accurately generate three-dimensional images of samples, widely applied in materials science (such as nanostructure analysis) and life sciences (such as three-dimensional cell morphology research), providing a more powerful tool for exploring the microscopic world.
[0045] This invention uses an electrically controllable zoom microscope system that combines multiple liquid crystal zoom lenses 1612 and conventional lenses. Each lens can be fixed at a specific focal length after the polarization switch 1611 is turned on or off, while the focal length variation range between different layers is different. Furthermore, conventional lenses are added before or after the liquid crystal zoom lens 1612 group.
[0046] This invention uses an equally spaced zoom assembly, wherein the liquid crystal zoom lens group 1612 is composed of multiple liquid crystal lenses, whose refractive power is distributed in equal proportions. These lenses are placed closely together and are fitted with a conventional lens with a fixed focal length, which is also closely fitted to the lens. The control assembly, based on the target refractive power set by the control system, calculates and controls the zoom assembly drive module to drive the zoom assembly to achieve optical zoom.
[0047] Please see Figure 6 During use, after the user issues a control command, the computational control system calculates the target parameters that need to be zoomed and drives the liquid crystal zoom component 160 to change the focal length. For example, when observing specimens of different thicknesses, the user inputs the focal length parameters through the operation interface, and the electronic control device adjusts the arrangement of liquid crystal molecules in real time to quickly and accurately complete the focusing without the need to manually rotate the knob, thus improving operating efficiency and image quality.
[0048] When this application is used:
[0049] 1. Optical zoom: Optical zoom of different focal lengths is achieved by controlling the opening and closing of the polarization switch 1611, which meets the requirement of obtaining a clear image by optical zoom when the distance between the microscope and the imaging object cannot be adjusted by moving the device or the microscope.
[0050] 2. No mechanical movement: Compared with traditional mechanical zoom systems, this invention requires no mechanical movement, avoids complex mechanical structures, and reduces the size and maintenance costs of the system.
[0051] 3. High-speed electronic control adjustment: Through the design of the electronic control system, different focal length combinations can be achieved by controlling the power-on and power-off of each layer of liquid crystal zoom lens 1612.
[0052] 4. Compact design: The 1612 LCD zoom lens used is very thin and will not increase the size of the device, achieving zoom while keeping the device compact.
[0053] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. A variable focus microscope system based on a PB liquid crystal lens, characterized by, The utility model relates to a microscope, including Microscope part, including base (110), be provided with mirror arm (130) on base (110), be provided with objective lens barrel on mirror arm (130), the top end and bottom end of objective lens barrel are installed with eyepiece (140) and objective lens (150) respectively, liquid crystal zoom component (160) is installed inside the eyepiece (140) and objective lens (150) of objective lens barrel, load table (120) is installed in the just below of base (110) of objective lens barrel; The liquid crystal zoom component (160) includes a transparent substrate (162), a transparent electrode (163), a multi-layer liquid crystal lens (161), and a sealing layer (164). The transparent substrate (162), the transparent electrode (163), and the liquid crystal lens (161) are arranged inside the objective lens barrel of the eyepiece (140) and the objective lens (150). The sealing layer (164) seals the transparent substrate (162), the transparent electrode (163), and the multi-layer liquid crystal lens (161).
2. The PB liquid lens-based variable focus microscope system of claim 1, wherein, The transparent substrate (162) is made of a material with high light transmittance.
3. The PB liquid lens-based variable focus microscope system of claim 1, wherein, The thickness of the transparent substrate (162) is 0.5-1.1mm.
4. The PB liquid lens-based variable focus microscope system of claim 1, wherein, The transparent electrode (163) is made of an indium tin oxide film.
5. The PB liquid lens-based variable focus microscope system of claim 1, wherein, The liquid crystal lens (161) is provided with multiple pieces, each piece of the liquid crystal lens (161) is made of a nematic liquid crystal material with fast response speed.
6. The PB liquid lens-based variable focus microscope system of claim 1, wherein, The sealing layer (164) is made of epoxy resin glue and is peripherally sealed by a vacuum packaging process.
7. The PB liquid lens-based variable focus microscope system of claim 1, wherein, Each piece of the liquid crystal lens (161) includes a polarization switch (1611) and a liquid crystal zoom lens (1612). The liquid crystal zoom lens (1612) is installed on one side substrate of the polarization switch (1611).
8. The PB liquid lens-based variable focus microscope system of claim 1, wherein, An electric control device is installed inside the mirror arm (130) and is electrically connected with the liquid crystal zoom component (160).