Endoscope zoom structure and zoom method based on linear ampere force balance zoom

Abstract

The application discloses a linear ampere force balance zoom endoscope zoom structure and zoom method, which comprises an outer lens barrel, an inner lens barrel and a moving lens, the outer periphery of the inner lens barrel is fixed with a plurality of magnets, the outer periphery of the outer lens barrel is wound with one or more coil groups, each coil group comprises a plurality of single coils arranged along the axis of the outer lens barrel, each single coil in the same coil group is respectively independently connected with an external circuit, and the single coils in different coil groups are one-to-one corresponding and connected in series, when the moving lens is in a balance state, the single coils conducting in each coil group have opposite direction currents, and the length of the magnet along the axis of the outer lens barrel is less than or equal to the maximum distance between the conducting single coils. The application controls the current direction of different single coils, so that the magnet reaches ampere force balance at different positions, and as long as the current of the single coil is stable, the magnet can be stably positioned at the balance position, and the structure is simple, safe and high in positioning precision.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an endoscope zoom structure and zoom method with linear Ampere force balanced zoom. Background Art

[0002] The zoom structure of an endoscope achieves focal length changes by adjusting the position of the moving lens along the optical axis. The traditional method is to use a mechanical structure and manually drive the moving lens to move. This driving method has a slow response speed and low positioning accuracy.

[0003] There are also methods in the prior art that use electric drive to adjust the movable lens, but most of them use electromagnets to drive. One solution is to arrange the electromagnets on both sides of the movable lens, such as the zoom structure disclosed in Patent No. CN111897086A. The displacement of the movable lens is controlled by adjusting the current of the two electromagnets. This solution is difficult to control the movable lens. A slight change in current will cause the movable lens to shake, and the visual effect is poor when the medical staff operates. Another solution is to embed the electromagnet on the outer barrel, such as the zoom structure disclosed in Patent No. CN115670350A. In this case, the cooperation of a spring is required to balance the electromagnetic force and the elastic force to make the movable lens reach a stable state. This structure has many parts, and the assembly difficulty and production cost are relatively high.

[0004] In addition, in the prior art, the electrically driven endoscope zoom structure is located inside the lens barrel to connect to the external circuit, which makes it difficult to connect wires and also poses a safety hazard.

[0005] Therefore, it is necessary to design an endoscope zoom structure that is safer, simple in structure and capable of precise positioning. Summary of the Invention

[0006] In order to solve the technical problems of the existing endoscope zoom structure, which has complex structure, low positioning accuracy and low safety, the present invention provides an endoscope zoom structure and zoom method with linear Ampere force balance zoom to solve the above problems.

[0007] The technical solution adopted by the present invention to solve its technical problems is: an endoscope zoom structure with linear Ampere force balanced zoom, including an outer barrel, an inner barrel located inside the outer barrel, and a movable lens that moves synchronously with the inner barrel, the outer circumference of the inner barrel is fixed with a plurality of magnets, the outer circumference of the outer barrel is wound with one or more coil groups, each of the coil groups includes a plurality of single coils arranged along the axial direction of the outer barrel, each single coil in the same coil group is independently connected to an external circuit, and the single coils in different coil groups are connected in series one by one, when the movable lens is in a balanced state, the single coils in each coil group have currents in opposite directions, and the length of the magnet along the axial direction of the outer barrel is less than or equal to the maximum distance between the single coils that are conducted.

[0008] In an optional embodiment of the present invention, when the movable lens is in a balanced state, the circuit containing only two single coils in each coil group is conductive, and the current directions are opposite, and the length of the magnet along the axial direction of the outer barrel is less than or equal to the distance between the two single coils.

[0009] In an optional embodiment of the present invention, each coil group is provided with three or more single coils.

[0010] In an optional embodiment of the present invention, the two single coils in the conductive circuit are adjacent to each other or are separated by a single coil.

[0011] In an optional embodiment of the present invention, the width of each single coil is equal. The length of the magnet along the axial direction of the outer barrel is less than or equal to the sum of the widths of the two single coils.

[0012] In an optional embodiment of the present invention, when the movable lens is in a balanced state, the two single coils with currents in opposite directions generate Ampere forces in opposite directions on the magnet.

[0013] In an optional embodiment of the present invention, the inner lens barrel is made of weak magnetic material.

[0014] In an optional embodiment of the present invention, a front lens barrel assembly and a rear lens barrel assembly fixed to the outer lens barrel are further included, and the outer diameter of each single coil is equal to the outer diameter of the front lens barrel assembly and the rear lens barrel assembly.

[0015] In an optional embodiment of the present invention, the outer lens barrel includes a barrel and shoulders located at one or both ends of the barrel and protruding radially outward, the coil assembly abuts against one of the shoulders, and the outer diameter of the shoulder is equal to the outer diameter of the coil assembly.

[0016] In an optional embodiment of the present invention, the outer circumference of the inner barrel has a plurality of mounting grooves for accommodating magnets.

[0017] The present invention provides a zoom method, which uses the above-mentioned linear Ampere force balance zoom endoscope zoom structure and includes the following steps:

[0018] S11: setting an initial equilibrium state, wherein the magnet maintains equilibrium under the action of two single coils in the same coil group with current flowing in opposite directions;

[0019] S12: Select the two single coils that need to be energized in the end according to the adjustment position of the magnet. When the magnet is located within the magnetic field range of the two single coils that are finally energized, a new single coil in the same coil group is turned on in the direction in which the magnet is expected to move, and the energization direction of the single coil is the same as the energization direction of the single coil that is closer to it in step S11; when the magnet is outside the magnetic field range of the two single coils that are finally energized, each single coil is turned on in the direction in which the magnet is expected to move.

[0020] S13: Adjust the current of the single coil energized in step S12 to move the magnet in the expected direction.

[0021] S14: gradually increase the current of the single coil at the end that was newly turned on in step S12 until it is equal to the current of the single coil farther away from it in step S11; at the same time, gradually reduce the current of the single coil in the middle until its current is zero.

[0022] The present invention further provides a zoom method, which uses the above-mentioned linear Ampere force balance zoom endoscope zoom structure and includes the following steps:

[0023] S21: Setting an initial equilibrium state, wherein the magnet maintains equilibrium under the action of two adjacent single coils in the same coil group and energized in opposite directions;

[0024] S22: energizing an adjacent single coil in the direction of the expected movement of the magnet, with the current flowing in the same direction as the closest single coil in step S21; then adjusting the current in the energized single coil to cause the magnet to move in the expected direction;

[0025] S23: Gradually increase the current of the newly turned-on single coil in step S22 until it is equal to the current of the single coil farther away from it in step S21; at the same time, gradually reduce the current of the single coil in the middle until its current is zero, so that the magnet moves toward the newly turned-on single coil by a distance of half the width of the single coil.

[0026] The beneficial effects of the present invention are:

[0027] (1) The present invention winds multiple single coils around the outside of the outer barrel. By controlling the current direction of different single coils, the magnet can achieve Ampere force balance at different positions. As long as the current of the single coil is stable, the magnet can be stabilized in the equilibrium position. Compared with the electric drive structure of the existing technology, the present invention has a simple structure, high safety and high positioning accuracy.

[0028] (2) The present invention can realize continuous step-by-step movement of the moving lens in a certain direction by sequentially changing the on-off state of adjacent single coils.

[0029] (3) The present invention can be provided with multiple coil groups, and the single coils between different coil groups are connected in series one by one, which can reduce the external control circuit and simplify the control method. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below with reference to the accompanying drawings and examples.

[0031] Figure 1 This is an exploded view of a specific embodiment of the endoscope zoom structure with linear Ampere force balance zoom according to the present invention;

[0032] Figure 2 is an axial cross-sectional view of a specific embodiment of the endoscope zoom structure with linear Ampere force balance zoom according to the present invention;

[0033] Figure 3 is a schematic diagram of the equilibrium position of the magnet when it is driven by the first single coil and the second single coil;

[0034] Figure 4 The magnet is made of Figure 3 The equilibrium position shown shifts to Figure 5 Schematic diagram of current changes during the equilibrium position shown;

[0035] Figure 5 is a schematic diagram of the equilibrium position of the magnet when it is driven by the first single coil and the third single coil;

[0036] Figure 6 Schematic diagram of the equilibrium position of the magnet when it is driven by the second single coil and the third single coil.

[0037] In the figure, 1, outer lens barrel, 101, barrel body, 102, boss, 2, inner lens barrel, 3, movable lens, 4, magnet, 5, coil group, 501, first single coil, 502, second single coil, 503, third single coil, 6, front lens barrel assembly, 601, front lens barrel, 602, first lens, 603, second lens, 7, rear lens barrel assembly, 701, rear lens barrel, 702, third lens, 8, mounting slot, 9, single coil. DETAILED DESCRIPTION

[0038] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0039] like Figure 1-Figure 3As shown, a linear Ampere force balanced zoom endoscope zoom structure includes an outer barrel 1, an inner barrel 2 located inside the outer barrel 1, and a movable lens 3 that moves synchronously with the inner barrel 2. A plurality of magnets 4 are fixed to the outer circumference of the inner barrel 2. One or more coil groups 5 are wound around the outer circumference of the outer barrel 1. Each coil group 5 includes a plurality of single coils 9 arranged axially along the outer barrel 1. Each single coil 9 in the same coil group 5 is independently connected to an external circuit, and the single coils 9 in different coil groups 5 are connected in series one by one. When the movable lens 3 is in a balanced state, the single coils 9 that are turned on in each coil group 5 have currents in opposite directions, and the length of the magnet 4 along the axial direction of the outer barrel 1 is less than or equal to the maximum distance between the turned-on single coils 9.

[0040] Because the currents in the two single coils 9 in the coil assembly 5 flow in opposite directions, Ampere forces acting on the magnet 4 in opposite directions are generated. When the magnet 4 is positioned midway between the two single coils 9, the Ampere forces are balanced. By adjusting the energization conditions of the different single coils 9, the magnet 4 can be moved to different positions. Furthermore, because the coils are wound around the exterior of the outer barrel 1 and are completely exposed, wire connections are convenient. Furthermore, the coils are separated from the internal structure of the endoscope, eliminating the risk of electrical leakage. Structurally and dimensionally, the coils can be wound directly around the outer barrel 1, eliminating the need for grooves to be machined on the surface of the outer barrel 1, thereby reducing installation and production costs. Furthermore, the coils occupy a small radial dimension, and the maximum dimension of the endoscope is similar to that of the lens, enabling a miniaturized design of the endoscope.

[0041] The length limit of the magnet 4 is to prevent a part of the magnet 4 from exceeding the Ampere force range of the energized single coil 9, causing unstable force and thus failing to drive the magnet 4 to move in the specified direction.

[0042] Only one group of coil groups 5 can be provided, that is, each single coil 9 is connected to a loop. When multiple groups of coil groups 5 are provided, the single coils 9 in the same group of coil groups 5 are arranged in sequence. When the magnet 4 moves inside one group of coil groups 5, the single coils 9 in the other coil groups 5 are farther away from the magnet 4 and have less influence on the Ampere force of the magnet 4. Providing multiple groups of coil groups 5 can reduce the number of external loops. For example, if two groups of coil groups 5 are provided, the single coils 9 between the coil groups 5 can be connected in series one by one. Therefore, with the same number of single coils 9, the number of external loops can be reduced by half.

[0043] It should be noted that since the movable lens 3 and the magnet 4 are both mounted on the inner barrel 2, the movement of the magnet 4 is the movement of the movable lens 3 and the inner barrel 2, and the movable lens 3 being in a balanced state means that the magnet 4 and the inner barrel 2 are in a balanced state.

[0044] The inner lens barrel 2 is preferably made of weak magnetic material to improve the adjustment sensitivity.

[0045] When the movable lens 3 is in a balanced state, the loops containing at least two single coils 9 in the coil assembly 5 must be conducting, and the two single coils 9 must generate Ampere forces in opposite directions on the magnet 4. Alternatively, multiple conducting single coils 9 can be used to apply Ampere forces to the magnet 4. For ease of operation, the present invention only conducts two single coils 9, and in this case, the length of the magnet 4 must be less than or equal to the distance between the two single coils 9. The direction of the Ampere force is related to the direction of the current. Preferably, the two single coils 9 with opposite current directions generate Ampere forces in opposite directions on the magnet 4, that is, both single coils 9 push the magnet 4 toward each other, so that the magnet 4 is stably positioned between the two single coils 9.

[0046] The magnets 4 are preferably arranged in an array along the circumferential direction, so that the radial force on the inner barrel 2 can be balanced, the inner barrel 2 and the outer barrel 1 can be kept on the same axis, and the inner barrel 2 can only reciprocate along the axial direction. Figure 1 As shown, the outer periphery of the inner barrel 2 has a plurality of mounting grooves 8 for accommodating the magnets 4 .

[0047] The endoscope generally includes a front lens barrel assembly 6 and a rear lens barrel assembly 7 fixed to the outer lens barrel 1. Figure 1 As shown, the front lens barrel assembly 6 includes a front lens barrel 601 and a first lens 602 and a second lens 603 installed in the front lens barrel 601, and the rear lens barrel assembly 7 includes a rear lens barrel 701 and a third lens 702 located in the rear lens barrel 701. The front lens barrel 601 and the rear lens barrel 701 are respectively installed at the two ends of the outer lens barrel 1.

[0048] In order to reduce the radial size of the endoscope, it is preferred that the outer diameter of each single coil 9 is equal to the outer diameter of the front barrel assembly 6 and the rear barrel assembly 7. This can be achieved by the following assembly structure: the outer barrel 1 includes a barrel body 101 and a radially outward protruding shoulder 102 located at one end or both ends of the barrel body 101. The coil group 5 abuts against one of the shoulders 102, and the outer diameter of the shoulder 102 is equal to the outer diameter of the coil group 5. Figure 2 As shown, the left end of the barrel 101 is provided with a shoulder 102, and the coil assembly 5 is arranged close to the shoulder 102 at the left end. Due to the thinning design of the barrel 101, the coil assembly 5 does not protrude from the surface of the endoscope, so that the coil assembly 5, the shoulder 102 and the outer surfaces of the front barrel 601 and the rear barrel 701 can remain flush.

[0049] In order to achieve the translation of the magnet 4 , three or more single coils 9 need to be provided in each coil group 5 , so that the switching of the current conditions of different single coils 9 can be achieved.

[0050] The width of each single coil 9 can be designed according to actual needs. Generally, the width of each single coil 9 is selected to be equal so that the Ampere force generated when equal current is passed is also equal. The width of the single coil 9 refers to the size of the single coil 9 along the axial direction of the outer barrel 1.

[0051] The present invention provides a zoom method for translating the entire structure formed by the endoscope barrel 2, the magnet 4, and the movable lens 3 from a certain equilibrium position to any other equilibrium position. The method uses the above-mentioned linear Ampere force balanced zoom endoscope zoom structure and includes the following steps:

[0052] S11: Setting an initial equilibrium state. The magnet 4 maintains equilibrium under the action of two single coils 9 with opposite current flow directions in the same coil group 5. The initial equilibrium position is defined as the first equilibrium position.

[0053] S2: Based on the adjusted position of magnet 4, the two single coils 9 that ultimately need to be energized are selected. When magnet 4 is within the magnetic field range of the two ultimately energized single coils 9, a new single coil 9 in the same coil group 5 is energized in the direction of magnet 4's expected movement. When magnet 4 is outside the magnetic field range of the two ultimately energized single coils, each single coil 9 is energized in the direction of magnet 4's expected movement. Here, it is defined that magnet 4 needs to be adjusted to the second equilibrium position. Assume there is only one coil group 5 with a total of six single coils 9. At the first equilibrium position, the first and second leftmost single coils 9 are energized, placing magnet 4 at the first and second single coils 9. The second equilibrium position is at the fourth and fifth single coils 9. If magnet 4 at the first equilibrium position is within the magnetic field range of the fourth and fifth single coils 9, the fourth and fifth single coils 9 can be directly energized. If magnet 4 at the first equilibrium position is not within the magnetic field range of the fourth and fifth single coils 9, the third through fifth single coils 9 (i.e., all single coils 9 to the right of the first equilibrium position) need to be energized simultaneously, thereby slowly guiding magnet 4 to the right of the second equilibrium position.

[0054] S13: Adjust the current of the two single coils 9 energized in step S12 to move the magnet 4 in the expected direction.

[0055] S14: Gradually increase the current in the newly connected single coil 9 at the end, which was turned on in step S12, until it equals the current in the single coil 9 farther away from it in step S11. Simultaneously, gradually decrease the current in the single coil 9 in the middle until it reaches zero. During this current change, the direction of the current in each single coil 9 remains unchanged. By adjusting the current, the magnet 4 gradually moves toward the second equilibrium position. Simultaneously, the current in the final, unneeded coil 9 is gradually reduced to zero through the slow change in current, while the current in the two single coils 9 that are finally energized gradually increases to maximum and balances, thus ensuring stable translation of the magnet 4.

[0056] The present invention also proposes a step-by-step zoom method, wherein the step-by-step method means that the distance moved by the magnet 4 each time is equal. The method adopts the above-mentioned linear Ampere force balance zoom endoscope zoom structure, and includes the following steps:

[0057] S21: Set the initial equilibrium state. The magnet 4 is kept in equilibrium by the action of two adjacent single coils 9 in the same coil group 5 and with opposite currents.

[0058] S22: Turn on the adjacent single coil 9 in the expected moving direction of the magnet 4, and the power-on direction of the single coil 9 is the same as the power-on direction of the single coil 9 that is closer to it in step S21; then adjust the current of the energized single coil 9 to make the magnet 4 move in the expected direction.

[0059] S23: Gradually increase the current of the newly turned-on single coil 9 in step S22 until it is equal to the current of the single coil 9 farther away from it in step S21; at the same time, gradually reduce the current of the single coil 9 in the middle until its current is zero, so that the magnet 4 moves toward the newly turned-on single coil 9 by a distance of half the width of the single coil 9.

[0060] The main principle of the step-by-step zoom method is that the width of each single coil 9 is the same, and adjacent single coils 9 are energized alternately.

[0061] The working principle thereof is described below according to a specific embodiment of the present invention.

[0062] like Figure 1 and Figure 2 As shown, a linear Ampere force balanced zoom endoscope zoom structure includes an outer barrel 1, an inner barrel 2 located inside the outer barrel 1, and a movable lens 3 that moves synchronously with the inner barrel 2. Six magnets 4 are fixed to the outer circumference of the inner barrel 2, and two groups of coil groups 5 are wound around the outer circumference of the outer barrel 1. Each group of coil groups 5 includes three single coils 9 arranged axially along the outer barrel 1. For the convenience of description, the three single coils 9 are named as the first single coil 501, the second single coil 502 and the third single coil 503 in sequence. The three single coils 9 are independently connected to the external circuit, and the single coils 9 in different coil groups 5 are connected in series one by one, that is, the two first single coils 501 are connected in series to the external circuit, the two second single coils 502 are connected in series to the external circuit, and the two third single coils 503 are connected in series to the external circuit.

[0063] The width of each single coil 9 is equal. In order to reduce the axial length of the outer barrel 1, the length of the magnet 4 should be as small as possible. In this embodiment, the length of the magnet 4 is equal to the width of two single coils 9. As long as the circuit of two adjacent single coils 9 or two single coils 9 separated by one single coil 9 is connected, the force balance of the magnet 4 can be achieved.

[0064] Regardless of whether it is a step-by-step zoom method or a non-step-by-step zoom method, during the transformation of the magnet 4 from the first equilibrium position to the second equilibrium position, the single coils 9 corresponding to the first equilibrium position and the second equilibrium position need to be turned on, and the offset of the magnet 4 is achieved by gradually adjusting the current size and direction.

[0065] When using the stepping zoom method, when a long distance needs to be moved, the magnet 4 is translated multiple times by repeatedly switching different single coils 9 until it reaches the specified position. Compared with the non-stepping zoom method, the control procedure of the stepping zoom method is simpler and more standardized.

[0066] The specific working process is as follows:

[0067] like Figure 3 As shown, currents of equal magnitude and opposite directions are passed through the first single coil 501 and the second single coil 502. The directions of the currents are as follows: Figure 3 As shown, Figure 3 Only the direction of current flow in the left coil group 5 is indicated. In fact, the first single coil 501 and the second single coil 502 in the two coil groups 5 are both energized with currents of equal magnitude and opposite directions. However, the Ampere force generated by the right coil group 5 is weaker and can be ignored because it is farther away from the magnet 4. The first single coil 501 generates an Ampere force to the right, and the second single coil 502 generates an Ampere force to the left. The magnet 4 is at Figure 3 The inner lens barrel 2, magnet 4, and movable lens 3 are in an equilibrium position and are subjected to equal and opposite Ampere forces. When the overall structure formed by the inner lens barrel 2, magnet 4, and movable lens 3 (hereinafter referred to as the movable lens barrel assembly) shifts, the Ampere forces exerted by the first and second single coils 501, 502, and magnet 4 change in magnitude and become no longer equal. This Ampere force returns the movable lens barrel assembly to its equilibrium position.

[0068] When the movable lens barrel assembly needs to be moved to the right, firstly the third single coil 503 is supplied with a current in the same direction as the second single coil 502, and the current of the second single coil 502 is gradually reduced (e.g. Figure 4 As shown in the figure), the current of the first single coil 501 is greater than the sum of the currents of the second single coil 502 and the third single coil 503, so that the magnet 4 can be pulled to the right, thereby achieving a continuous zoom effect. Figure 5 The second single coil 502 does not pass current, and the currents in the first single coil 501 and the third single coil 503 are equal.

[0069] Then, the second single coil 502 is fed with a current in the same direction as the first single coil 501, and the current of the first single coil 501 is gradually reduced. The current of the third single coil 503 is less than the sum of the currents of the second single coil 502 and the first single coil 501. In this way, the magnet 4 can be pulled to the right until the equilibrium position of the movable barrel assembly becomes Figure 6 The first single coil 501 is not energized, and the currents of the second single coil 502 and the third single coil 503 are equal. In this way, one movement cycle of the movable lens barrel assembly is completed.

[0070] When needed from Figure 6 When the movable lens barrel assembly continues to move rightward from the position shown, a current in the same direction as that in the third single coil 503 can be passed through the first single coil 501, gradually reducing the current in the third single coil 503. Simultaneously, the currents in the first and second single coils 501, 502 are controlled so that the second single coil 502 can push the magnet 4 rightward. Finally, the movable lens barrel assembly stops between the second single coil 502 of the left coil group 5 and the first single coil 501 of the right coil group 5. Using this current control method, the movable lens barrel assembly can be moved to any position.

[0071] Continuously follow Figure 3 → Figure 4 → Figure 5 → Figure 6 ...by changing the current, the movable lens barrel assembly can be driven continuously to the right.

[0072] Continuously follow Figure 6 → Figure 5 → Figure 4 → Figure 3 ...by changing the current, the movable lens barrel assembly can be driven continuously to the left.

[0073] In the description of the present invention, it should be understood that the terms "length", "width", "left", "right", "inside", "outside", "axial", "radial", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0074] Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the term "connected" should be understood broadly. For example, it can mean a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0075] In this specification, the schematic representations of the terms do not necessarily refer to the same embodiment. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments.

[0076] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A linear Ampere force balanced zoom endoscope zoom structure, characterized by: The invention comprises an outer lens barrel (1), an inner lens barrel (2) located inside the outer lens barrel (1), and a movable lens (3) that moves synchronously with the inner lens barrel (2), wherein a plurality of magnets (4) are fixed to the outer peripheral surface of the inner lens barrel (2), and a plurality of coil groups (5) are wound around the outer peripheral surface of the outer lens barrel (1), each of the coil groups (5) comprising a plurality of single coils (9) arranged along the axial direction of the outer lens barrel (1), each single coil (9) in the same coil group (5) is independently connected to an external circuit, and the single coils (9) in different coil groups (5) are connected in series one by one, and when the movable lens (3) is in a balanced state, the single coils (9) that are turned on in each coil group (5) have currents in opposite directions; When the movable lens (3) is in a balanced state, the circuits containing only two single coils (9) in each coil group (5) are conductive, and the currents are in opposite directions; three or more single coils (9) are provided in each coil group (5); the two single coils (9) in the conductive circuits are adjacent or separated by one single coil (9); the widths of the two single coils (9) are equal, and the length of the magnet (4) along the axial direction of the outer lens barrel (1) is less than or equal to the sum of the widths of the two single coils (9).

2. The linear Ampere force balanced zoom endoscope structure according to claim 1, characterized in that: When the movable lens (3) is in a balanced state, the two single coils (9) with currents in opposite directions generate an Ampere force in the opposite direction on the magnet (4).

3. The linear Ampere force balanced zoom endoscope structure according to claim 1, characterized in that: The inner lens barrel (2) is made of weakly magnetic material.

4. The linear Ampere force balanced zoom endoscope structure according to claim 1, characterized in that: It also includes a front lens barrel assembly (6) and a rear lens barrel assembly (7) fixed to the outer lens barrel (1), and the outer diameter of each single coil (9) is equal to the outer diameter of the front lens barrel assembly (6) and the rear lens barrel assembly (7); The outer lens barrel (1) comprises a barrel (101) and a convex shoulder (102) located at one end or both ends of the barrel (101) and protruding radially outwards. The coil assembly (5) abuts against one of the convex shoulders (102). The outer diameter of the convex shoulder (102) is equal to the outer diameter of the coil assembly (5).

5. A zoom method, characterized in that: The method adopts the endoscope zoom structure with linear Ampere force balance zoom according to any one of claims 1 to 4, comprising the following steps: S11: setting an initial equilibrium state, wherein the magnet (4) maintains equilibrium under the action of two single coils (9) with opposite current flow directions in the same coil group (5); S12: selecting two single coils (9) that are ultimately energized according to the adjusted position of the magnet (4); when the magnet (4) is located within the magnetic field range of the two single coils (9) that are ultimately energized, a new single coil (9) in the same coil group (5) is energized in the direction in which the magnet (4) is expected to move; when the magnet (4) is located outside the magnetic field range of the two single coils that are ultimately energized, each single coil (9) is energized in the direction in which the magnet (4) is expected to move; S13: adjusting the current of the single coil (9) energized in step S12 to move the magnet (4) in the expected direction; S14: gradually increase the current of the single coil (9) at the end that was newly turned on in step S12 until it is equal to the current of the single coil (9) farther away from it in step S11; at the same time, gradually reduce the current of the single coil (9) in the middle until its current is zero.

6. A zoom method, characterized in that: The method adopts the endoscope zoom structure with linear Ampere force balance zoom according to any one of claims 1 to 4, comprising the following steps: S21: setting an initial equilibrium state, wherein the magnet (4) maintains equilibrium under the action of two adjacent single coils (9) in the same coil group (5) and energized in opposite directions; S22: turning on the adjacent single coil (9) in the expected moving direction of the magnet (4), and the energizing direction of the single coil (9) is the same as the energizing direction of the single coil (9) that is closer to it in step S21; then adjusting the current of the energized single coil (9) to make the magnet (4) move in the expected direction; S23: gradually increase the current of the newly turned-on single coil (9) in step S22 until it is equal to the current of the single coil (9) farther away from it in step S21; at the same time, gradually reduce the current of the single coil (9) in the middle until its current is zero, thereby causing the magnet (4) to move toward the newly turned-on single coil (9) by a distance equal to half the width of the single coil (9).

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