Electronic ND filter

Abstract

This utility model discloses an electronic ND filter, including a frame, a lens, a control board, a power supply, and an adjustment knob. The frame has a first receiving groove, within which the lens, control board, and power supply are all placed. The lens, power supply, and adjustment knob are all connected to the control board, with the adjustment knob exposed outside the frame and capable of relative rotation. The lens includes first and second glass carriers and first and second liquid crystals. Each glass carrier has a sandwich layer, with the liquid crystals correspondingly placed within the sandwich layers. Conductive films are provided on opposite sidewalls of the two sandwich layers, with the liquid crystals in contact with the conductive films, which are electrically connected to the control board. Rotating the adjustment knob changes the voltage of the conductive films, thereby altering the direction of liquid crystal molecule movement to adjust the light transmittance. Each rotation of the knob switches between different levels, corresponding to different light transmittance. This structure achieves multi-level ND effects without changing the filter, saving operation steps and time, avoiding damage to the lens or filter during disassembly, and is suitable for fast-paced shooting scenarios, meeting the needs of efficient shooting.

Description

Technical Field

[0001] This utility model relates to the field of photographic equipment technology, specifically to an electronic ND filter. Background Technology

[0002] Cameras often require ND filters to adjust the amount of light entering the camera to suit different shooting scenarios. However, changing ND filters on current cameras requires removing the current filter and then installing the target filter, a cumbersome process that not only prolongs preparation time but also increases the risk of scratching the lens or filter surface during removal, affecting image quality. Especially in fast-paced outdoor shooting scenarios, frequent filter changes can cause users to miss shooting opportunities, failing to meet the needs of efficient shooting. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention provides an electronic ND filter.

[0004] The present invention discloses an electronic ND filter, comprising: a frame, a lens, a control board, a power supply, and an adjustment knob. The frame has a first receiving groove, and the lens, the control board, and the power supply are all disposed in the first receiving groove. The lens, the power supply, and the adjustment knob are all connected to the control board. The adjustment knob protrudes outside the frame and can rotate relative to the frame. The lens includes a first glass carrier, a second glass carrier, a first liquid crystal and a second liquid crystal, the first glass carrier and the second glass carrier are connected, the first glass carrier and the second glass carrier respectively have a first interlayer and a second interlayer, and the first liquid crystal and the second liquid crystal are respectively disposed in the first interlayer and the second interlayer. Conductive films are provided on the two opposite sidewalls in the first interlayer and the two opposite sidewalls in the second interlayer. The first liquid crystal and the second liquid crystal are in contact with the conductive films, and the conductive films are electrically connected to the control board.

[0005] According to one embodiment of the present invention, the first glass carrier includes a first glass body and a second glass body, the first glass body and the second glass body are spaced apart and form a first interlayer, a first liquid crystal body is disposed between the first glass body and the second glass body, a conductive film is provided on the side of the first glass body facing the second glass body, a conductive film is provided on the side of the second glass body facing the first glass body, and the second glass body is connected to the second glass carrier.

[0006] According to one embodiment of the present invention, an anti-fingerprint film and / or an anti-reflective film are provided on the side of the first glass body away from the first liquid crystal body.

[0007] According to one embodiment of the present invention, an anti-fingerprint film is provided on the side of the second glass body away from the first liquid crystal body.

[0008] According to one embodiment of the present invention, the second glass carrier includes a third glass body and a fourth glass body, the third glass body and the fourth glass body are spaced apart and form a second interlayer, the second liquid crystal body is disposed between the third glass body and the fourth glass body, a conductive film is provided on the side of the third glass body facing the fourth glass body, a conductive film is provided on the side of the fourth glass body facing the third glass body, and the second glass body is connected to the third glass body.

[0009] According to one embodiment of the present invention, the side of the third glass body away from the second liquid crystal body is provided with an anti-fingerprint film and / or an anti-reflective film.

[0010] According to one embodiment of the present invention, the side of the fourth glass body away from the second liquid crystal body is provided with an anti-fingerprint film and / or an anti-reflective film.

[0011] According to one embodiment of the present invention, it further includes an adapter ring, a locking rod, and a limiting block. The adapter ring is disposed on the mirror frame, the locking rod is screwed to the adapter ring, the limiting block is slidably disposed on the mirror frame, and the limiting block abuts against the end of the locking rod. The locking rod pushes the limiting block to abut against the end face of the adapter ring to limit the adapter ring.

[0012] According to one embodiment of the present invention, the control board has a display module, the frame has a display hole that connects the first receiving groove to the outside, and the display module is disposed in the display hole.

[0013] According to one embodiment of the present invention, a calibration membrane is also included, which is disposed between the first glass carrier and the second glass carrier.

[0014] The beneficial effects of this invention are that by rotating the adjustment knob, the voltage value on the conductive film of the control board is changed, thereby changing the molecular motion direction of the first and second liquid crystals and realizing the adjustment of light transmittance. Each rotation of the adjustment knob will adjust one level, corresponding to different light transmittance. In this way, the effects of different levels of ND filters can be obtained when changing filters, saving the steps and time of changing filters. At the same time, it can also avoid damage to the lens or filter surface caused by disassembling the filter. In addition, it is also beneficial for application in fast-paced shooting scenarios, meeting the needs of efficient shooting. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram illustrating the application scenarios of electronic ND filters; Figure 2 This is a schematic diagram illustrating another application scenario for electronic ND filters; Figure 3 This is a schematic diagram showing the split state of an electronic ND filter; Figure 4 This is a schematic diagram showing another split state of an electronic ND filter; Figure 5 This is a schematic diagram of the cross-sectional structure of the lens; Figure 6 This is a schematic diagram showing the connection between the first glass substrate, the conductive film, and the FPC. Figure 7 This is a schematic diagram of the film's spectrum.

[0016] Explanation of reference numerals in the attached figures 1. Frame; 11. First receiving slot; 12. Display hole; 13. Base shell; 14. Front panel; 15. Second receiving slot; 2. Lens; 21. First glass carrier; 211. First interlayer; 212. First glass body; 2121. Lug; 213. Second glass body; 22. Second glass carrier; 221. Second interlayer; 222. Third glass body; 223. Fourth glass body; 23. First liquid crystal; 24. Second liquid crystal; 25. Conductive film; 3. Control board; 31. Display module; 4. Power supply; 5. Adjust the knob; 6. Adapter ring; 7. Locking rod; 8. Limit block; 9. Calibration membrane; 10. Camera; 20. Remote control; 30. Anti-reflective film; 40. Anti-fingerprint film; 50. Flexible circuit board. Detailed Implementation

[0017] The following drawings will disclose several embodiments of this utility model. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit this utility model. That is, in some embodiments of this utility model, these practical details are not essential. In addition, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.

[0018] Furthermore, in this utility model, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the utility model. They are merely used to distinguish components or operations described with the same technical terms and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0019] like Figures 1-4 As shown, Figure 1 This is a schematic diagram illustrating the application scenarios of electronic ND filters; Figure 2 This is a schematic diagram illustrating another application scenario for electronic ND filters; Figure 3 This is a schematic diagram showing the split state of an electronic ND filter; Figure 4 This is a schematic diagram showing another disassembled state of the electronic ND filter. The electronic ND filter includes a frame 1, a lens 2, a control board 3, a power supply 4, and an adjustment knob 5. The frame 1 serves as a support, and the lens 2, control board 3, and power supply 4 are all housed within the frame 1. Both the lens 2 and the power supply 4 are connected to the control board 3, and the power supply 4 provides power to the control board 3. Current can flow between the lens 2, control board 3, and power supply 4. The adjustment knob 5 is located on the control board 3, with a portion of it protruding outside the frame 1. In use, the adjustment knob 5 can rotate relative to the frame 1. Rotating the adjustment knob 5 changes the operation of the control board 3, thereby altering the voltage value at the lens 2. Figure 1 and Figure 2 An electronic ND filter can be fitted onto the lens of camera 10 to improve the shooting effect of camera 10.

[0020] In practical applications, the frame 1 includes a base shell 13 and a front panel 14, which are detachably connected and together form a first receiving groove 11. The lens 2, control board 3, and power supply 4 are all located within the first receiving groove 11, and the adjustment knob 5 protrudes from the base shell 13. Furthermore, the base shell 13 has a display hole 12, which connects the first receiving groove 11 to the outside. The control board 3 has a display module 31 located within the display hole 12. During use, the current setting of the electronic ND filter can be observed through the display module 31.

[0021] Furthermore, the bottom shell 13 also has a second receiving groove 15, which connects to the first receiving groove 11 and the outside. The adjustment knob 5 is located inside the second receiving groove 15 and can rotate within the second receiving groove 15. Specifically, the second receiving groove 15 is located on the side adjacent to the display hole 12.

[0022] Please refer to the following: Figure 5 and Figure 6 , Figure 5 This is a schematic diagram of the cross-sectional structure of lens 2; Figure 6 This is a schematic diagram showing the connection between the first glass carrier 21, the conductive film 25, and the FPC. The lens 2 includes a first glass carrier 21, a second glass carrier 22, a first liquid crystal 23, a second liquid crystal 24, and multiple conductive films 25. The first glass carrier 21 is connected to the second glass carrier 22. The first liquid crystal 23 is disposed on the first glass carrier 21, and the second liquid crystal 24 is disposed on the second glass carrier 22. Part of the conductive film 25 is disposed between the first liquid crystal 23 and the first glass carrier 21, and another part of the conductive film 25 is disposed between the second liquid crystal 24 and the second glass carrier 22. The conductive film 25 is electrically connected to the control board 3. During operation, current can flow through the conductive film 25 to change the voltage value at the first liquid crystal 23 and the second liquid crystal 24, thereby changing the direction of molecular motion within the first liquid crystal 23 and the second liquid crystal 24. In this embodiment, in the initial state, the polarization direction of the first liquid crystal 23 is orthogonal to the polarization direction of the second liquid crystal 24. Then, as the adjustment knob 5 is rotated to different positions, the molecular motion direction of the first liquid crystal 23 and the second liquid crystal 24 is changed, causing the angle between the polarization direction of the first liquid crystal 23 and the polarization direction of the second liquid crystal 24 to change, thereby changing the light transmittance.

[0023] In a specific application, the first glass carrier 21 has a first interlayer 211, with conductive films 25 provided on both opposite sidewalls within the first interlayer 211. A first liquid crystal 23 is disposed within the first interlayer 211 and is in contact with the conductive films 25. The second glass carrier 22 has a second interlayer 221, with conductive films 25 provided on both opposite sidewalls within the second interlayer 221. A second liquid crystal 24 is disposed within the second interlayer 221 and is in contact with the conductive films 25.

[0024] Specifically, the first glass carrier 21 includes a first glass body 212 and a second glass body 213, which are arranged opposite each other at intervals. The interval between the first glass body 212 and the second glass body 213 forms a first interlayer 211. A conductive film 25 is provided on the side of the first glass body 212 facing the second glass body 213. Similarly, a conductive film 25 is also provided on the side of the second glass body 213 facing the first glass body 212. The first liquid crystal 23 is located between the first glass body 212 and the second glass body 213, and the first liquid crystal 23 is in contact with the conductive film 25 on the first glass body 212 and the conductive film 25 on the second glass body 213.

[0025] Please review Figure 6 The first glass body 212 has outwardly extending lugs 2121, and the surface of the lugs 2121 is also provided with a conductive film 25. A flexible printed circuit board 50 (FPC) is provided on the conductive film 25. The flexible printed circuit board 50 is connected to the control board 3. The lugs 2121 and the FPC facilitate the electrical connection between the conductive film 25 and the control board 3. In addition, the second glass body 213 can also be provided with a similar structure.

[0026] Please review Figure 5 Preferably, an anti-reflection film 30 (AR film, Anti-Reflection film) is provided on the side of the first glass body 212 away from the first liquid crystal body 23; or an anti-fingerprint film 40 (AF film, Anti-Fingerprint film) is provided on the side of the first glass body 212 away from the first liquid crystal body 23; or an anti-reflection film 30 and an anti-fingerprint film 40 are stacked on the side of the first glass body 212 away from the first liquid crystal body 23.

[0027] The second glass carrier 22 includes a third glass body 222 and a fourth glass body 223. The third glass body 222 is connected to the second glass body 213. The third glass body 222 and the fourth glass body 223 are arranged opposite each other with a gap between them. The gap between the third glass body 222 and the fourth glass body 223 forms a second interlayer 221. A conductive film 25 is provided on the side of the third glass body 222 facing the fourth glass body 223. Similarly, a conductive film 25 is also provided on the side of the fourth glass body 223 facing the third glass body 222. The second liquid crystal 24 is located between the third glass body 222 and the fourth glass body 223, and the second liquid crystal 24 is in contact with the conductive film 25 on the third glass body 222 and the conductive film 25 on the fourth glass body 223, respectively.

[0028] Specifically, the third glass body 222 and / or the fourth glass body 223 may be provided with the same lugs 2121 and FPC structure as the first glass body 212, so that they can be connected to the control board 3. In addition, the side of the third glass body 222 away from the second liquid crystal 24 may also be provided with an anti-reflective film 30 and / or an anti-fingerprint film 40, and the side of the fourth glass body 223 away from the second liquid crystal 24 may also be provided with an anti-reflective film 30 and / or an anti-fingerprint film 40.

[0029] Preferably, the electronic ND filter further includes a calibration film 9, which is disposed between the second glass body 213 and the third glass body 222. By setting the calibration film 9, the problem of a greenish tint caused by short-wavelength absorption in the electronic ND filter during photography can be solved, resulting in higher color reproduction and more accurate color reproduction in the photographs. In this embodiment, the calibration film 9 is composed of multiple layers of high-refractive-index material H and multiple layers of low-refractive-index material L stacked alternately. The high-refractive-index material H is Ti3O5, TiO2, Nb2O5, or Ta2O5, etc.; the low-refractive-index material L is SiO2. In specific applications, multiple layers of high-refractive-index material H and multiple layers of low-refractive-index material L are prepared on the side of the second glass body 213 near the third glass body 222 using a coating process. The specific preparation process of the calibration film 9 will be described below: Step 1: Perform ultrasonic cleaning on the second glass body 213 The second glass body 213 is cleaned using a 10-15 tank ultrasonic cleaner, with the total cleaning time controlled between 2-10 minutes, which can be flexibly adjusted according to the degree of contamination of the second glass body 213. Specifically, the first three tanks use alkaline or acidic cleaning agents to remove stubborn oil stains, fingerprints, and oxidation impurities from the surface of the second glass body 213; subsequent tanks use ultrapure water to remove residual cleaning agents and microparticles. This staged, reagent-based cleaning method achieves layered removal of contaminants from the surface of the second glass body 213, avoiding the problem of incomplete cleaning by a single method, and providing a substrate surface free of impurities and residues for subsequent coating. Thoroughly removing oil stains, dust, fingerprints, and chemical impurities from the surface of the second glass body 213 prevents impurities from becoming trapped between the film layer and the substrate during subsequent coating, which could lead to decreased film adhesion, pinholes, delamination, and other defects. This ensures a stable bond between the film layer and the second glass body 213 substrate, laying a clean foundation for subsequent coating processes.

[0030] Step 2: Drying the second glass body 213 The cleaned second glass substrate 213 is treated with hot air drying or centrifugal drying to avoid damage to the substrate. The drying and centrifugation time is controlled between 2-10 minutes to ensure complete evaporation of moisture from the surface of the second glass substrate 213 without deformation. Residual cleaning moisture on the surface of the second glass substrate 213 is quickly removed to prevent it from interfering with the film deposition process after entering the vacuum coating environment. Drying the second glass substrate 213 prevents moisture from evaporating during vacuum coating and mixing with the vapors of the high-refractive-index material H and the low-refractive-index material L, which could lead to defects such as bubbles and particles in the film. It also prevents moisture from chemically reacting with the second glass substrate 213 or the coating material, ensuring that the subsequent film adheres uniformly and densely to the surface of the second glass substrate 213 and guarantees stable optical performance.

[0031] Step 3: Equipment and Material Preparation Before Coating High-refractive-index material H and low-refractive-index material L are placed separately into dedicated evaporation crucibles in the vacuum coating machine, ensuring that the two materials are placed separately and that the crucible positions are precisely aligned with the emission path of the 8kV high-voltage electron gun. The vacuum coating machine chamber door is closed, and the equipment baking system is activated to heat the coating machine to 100-300℃. Simultaneously, the vacuum pumping system is activated to evacuate the coating machine to a vacuum level of 9.0E-3Pa to 1.0E-4Pa. The 8kV high-voltage electron gun is activated, and parameters such as electron beam intensity and focusing position are adjusted to ensure that the electron beam can be stably focused on the surface of the coating material in the evaporation crucible. This step provides a suitable temperature, high vacuum environment, precise material supply, and stable energy output for the core film coating, ensuring that the film is deposited according to design requirements. The high vacuum environment significantly reduces oxygen and nitrogen molecules in the air, preventing them from colliding with the vapor of the coating material and causing film defects, while also reducing film oxidation, ensuring film density and optical stability. A suitable temperature environment optimizes the evaporation state of the coating material, improving the film deposition quality. By separating high and low refractive index materials to avoid component mixing, and adjusting electron gun parameters to ensure stable material evaporation, a foundation is provided for subsequent precise deposition of film layers according to the designed thickness, avoiding the impact of material contamination or energy instability on film performance.

[0032] Step 4: Cross-deposition of core membrane layers Based on the physical principles of refractive index calculation and Maxwell's equations, and utilizing the optical properties of materials with high and low refractive indices, multiple layers are cross-deposited on the surface of the second glass body 213 in the following order and thickness, with the thickness accuracy controlled in real time by a film thickness monitoring instrument: A low-refractive-index L-film was deposited with a thickness of 92.02 nm. A high-refractive-index H film was deposited with a thickness of 25.03 nm. A low-refractive-index L-film was deposited with a thickness of 23.38 nm. A high-refractive-index H film was deposited with a thickness of 67.67 nm. A low-refractive-index L-film was deposited with a thickness of 27.14 nm. A high-refractive-index H film was deposited with a thickness of 21.36 nm. A low-refractive-index L-film was deposited with a thickness of 105.46 nm. A high-refractive-index H film was deposited with a thickness of 30.28 nm. A low-refractive-index L-film was deposited with a thickness of 15.65 nm. A high-refractive-index H film was deposited with a thickness of 64.84 nm. A low-refractive-index L-film was deposited with a thickness of 58.31 nm. A high-refractive-index H film layer with a thickness of 9.72 nm was deposited.

[0033] like Figure 7 As shown, Figure 7 This is a schematic diagram of the film's spectrum. By staggered stacking of high- and low-refractive-index films and precise thickness design, the reflectivity of the 480nm-550nm green band is precisely controlled using the interference effect of light, resulting in an average reflectivity range of 5%-15% in this band. This reduces the transmittance of green light to the second glass element 213, thereby correcting the green tint issue caused by short-wavelength absorption in electronic ND filters, improving the color reproduction of the second glass element 213, and making the colors in the captured images more accurate.

[0034] Preferably, step five involves applying an AF film layer for protective treatment. After the core film layer is deposited, a vacuum environment is maintained, and an AF film layer is deposited on top of the core film layer using a dedicated evaporation source, with the film thickness controlled at 10nm. This provides physical protection and surface function optimization for the core film layer, extending the lifespan of the second glass body 213 and improving the user experience. The protective treatment imparts hydrophobic properties to the second glass body 213, allowing water droplets to easily slide off and preventing adhesion, thus reducing the impact of water stains on transmittance. It also reduces fingerprints and oil adhesion, facilitating daily cleaning. Furthermore, it enhances the surface hardness and abrasion resistance of the second glass body 213, effectively resisting minor scratches and preventing damage to the core film layer that could lead to decreased optical performance or cosmetic scratches, ensuring the long-term stable use of the second glass body 213.

[0035] Please review Figures 1-4The electronic ND filter also includes an adapter ring 6, a locking rod 7, and a limiting block 8. The adapter ring 6 is located on the side of the bottom shell 13 away from the panel 14. The locking rod 7 is threadedly connected to the bottom shell 13, and the limiting block 8 is slidably connected to the bottom shell 13. The limiting block 8 is also connected to the end of the locking rod 7. In use, by rotating the locking rod 7, the locking rod 7 can be moved towards the adapter ring 6. The locking rod 7 will push the limiting block 8 to move towards the adapter ring 6 as well. Then, the limiting block 8 moves to the side of the adapter ring 6 away from the bottom shell 13, and the limiting block 8 limits the adapter ring 6 to prevent it from falling out of the bottom shell 13. Finally, the adapter ring 6 is connected to the lens of the camera 10, thus completing the assembly of the electronic ND filter and the camera 10.

[0036] In another embodiment, the control board 3 also has a wireless module (not shown in the figure), which is compatible with the remote control 20. The remote control 20 can be used to adjust the gear position, making it more convenient for the user to operate.

[0037] In this embodiment, both the first liquid crystal 23 and the second liquid crystal 24 are made of existing liquid crystal materials; the control board 3 is an existing circuit board structure, and the display module 31, wireless module, charging module, and switch module contained in the circuit board structure are all existing technologies. The power supply 4 is an existing battery product.

[0038] In summary, by rotating the adjustment knob 5, the voltage value on the conductive film 25 of the control board 3 is changed, thereby altering the molecular motion direction of the first liquid crystal 23 and the second liquid crystal 24, thus adjusting the light transmittance. Each rotation of the adjustment knob 5 adjusts the light transmittance by one level. In this way, the effects of different levels of ND filters can be obtained when changing filters, saving the steps and time of filter replacement. At the same time, it can also avoid damage to the lens or filter surface caused by disassembling the filter. In addition, it is beneficial for applications in fast-paced shooting scenarios, meeting the needs of efficient shooting.

[0039] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. An electronic ND filter, characterized in that, include: The frame (1), lens (2), control panel (3), power supply (4) and adjustment knob (5) are provided. The frame (1) has a first receiving groove (11). The lens (2), control panel (3) and power supply (4) are all located in the first receiving groove (11). The lens (2), power supply (4) and adjustment knob (5) are all connected to the control panel (3). The adjustment knob (5) is exposed outside the frame (1) and can rotate relative to the frame (1). The lens (2) includes a first glass carrier (21), a second glass carrier (22), a first liquid crystal (23) and a second liquid crystal (24). The first glass carrier (21) and the second glass carrier (22) are connected. The first glass carrier (21) and the second glass carrier (22) have a first interlayer (211) and a second interlayer (221) respectively. The first liquid crystal (23) and the second liquid crystal (24) are respectively disposed in the first interlayer (211) and the second interlayer (221). Conductive films (25) are provided on the two opposite sidewalls of the first interlayer (211) and the two opposite sidewalls of the second interlayer (221). The first liquid crystal (23) and the second liquid crystal (24) are in contact with the conductive films (25), and the conductive films (25) are electrically connected to the control board (3).

2. The electronic ND filter according to claim 1, characterized in that, The first glass carrier (21) includes a first glass body (212) and a second glass body (213). The first glass body (212) and the second glass body (213) are spaced apart and form a first interlayer (211). A first liquid crystal (23) is disposed between the first glass body (212) and the second glass body (213). A conductive film (25) is provided on the side of the first glass body (212) facing the second glass body (213). A conductive film (25) is provided on the side of the second glass body (213) facing the first glass body (212). The second glass body (213) is connected to the second glass carrier (22).

3. The electronic ND filter according to claim 2, characterized in that, The first glass body (212) has an anti-fingerprint film and / or an anti-reflective film on the side away from the first liquid crystal body (23).

4. The electronic ND filter according to claim 2, characterized in that, The second glass body (213) has an anti-fingerprint film on the side away from the first liquid crystal body (23).

5. The electronic ND filter according to claim 2, characterized in that, The second glass carrier (22) includes a third glass body (222) and a fourth glass body (223). The third glass body (222) and the fourth glass body (223) are spaced apart and form a second interlayer (221). The second liquid crystal body (24) is disposed between the third glass body (222) and the fourth glass body (223). A conductive film (25) is provided on the side of the third glass body (222) facing the fourth glass body (223). A conductive film (25) is provided on the side of the fourth glass body (223) facing the third glass body (222). The second glass body (213) is connected to the third glass body (222).

6. The electronic ND filter according to claim 5, characterized in that, The third glass body (222) has an anti-fingerprint film and / or an anti-reflective film on the side away from the second liquid crystal body (24).

7. The electronic ND filter according to claim 6, characterized in that, The fourth glass body (223) is provided with an anti-fingerprint film and / or an anti-reflective film on the side away from the second liquid crystal body (24).

8. The electronic ND filter according to any one of claims 1-7, characterized in that, It also includes a transition ring (6), a locking rod (7) and a limiting block (8). The transition ring (6) is set on the frame (1), the locking rod (7) is screwed to the transition ring (6), the limiting block (8) is slidably set on the frame (1), and the limiting block (8) abuts against the end of the locking rod (7). The locking rod (7) pushes the limiting block (8) to abut against the end face of the transition ring (6) to limit the transition ring (6).

9. The electronic ND filter according to any one of claims 1-7, characterized in that, The control panel (3) has a display module (31), and the frame (1) has a display hole (12) that connects the first receiving slot (11) to the outside. The display module (31) is located in the display hole (12).

10. The electronic ND filter according to any one of claims 1-7, characterized in that, It also includes a calibration membrane (9), which is disposed between the first glass carrier (21) and the second glass carrier (22).

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