Fresnel lens and film and television lamp equipment

Abstract

The utility model discloses a Fresnel lens and movie and television lamp equipment, and relates to the technical field of movie and television lighting equipment, the Fresnel lens is used for being matched with a movie and television lamp for use, the movie and television lamp is provided with a plurality of COB light sources, the Fresnel lens comprises a shell, a lens assembly and a driving part, the shell is used for being connected with the movie and television lamp, a containing cavity is defined by the shell, and the shell is further provided with a mounting groove; the lens assembly is contained in the containing cavity and comprises an installation support and a plurality of Fresnel lenses, the installation support is arranged in the containing cavity, the Fresnel lenses are installed on the installation support at intervals, the driving part is arranged in the installation groove and is in transmission connection with the installation support, and the driving part is used for driving the installation support to move in the front-back direction. The plurality of Fresnel lenses are close to or far away from the COB light source in the front-back direction, and the front-back direction is parallel to the light emitting direction of the COB light source. According to the technical scheme, an electric focusing function can be realized, so that the use experience of a user is improved.

Description

Technical Field

[0001] The present application relates to the technical field of film and television lighting equipment, and in particular to a Fresnel lens and a film and television lighting device using the Fresnel lens. Background Art

[0002] Fresnel lenses can refract the scattered light emitted by the light source, making the light more concentrated, thereby improving the utilization rate of the light source and effectively improving the illumination.

[0003] In related technologies, in order to produce a focused beam, multiple light sources in cinematic lighting are each equipped with a Fresnel lens. However, current Fresnel lenses are fixed relative to the light source and lack a focusing function, making it impossible to control the size of the light range and further increase the brightness of the light. Utility Model Content

[0004] The embodiments of the present application provide a Fresnel lens and a film and television lighting device, which can realize an electric focusing function to enhance the user experience.

[0005] In a first aspect, an embodiment of the present application provides a Fresnel lens for use with a film and television light having multiple COB light sources. The Fresnel lens includes a housing, a lens assembly, and a driver.

[0006] The housing is used to connect with the movie light and encloses a receiving cavity. The housing also has a mounting groove. The lens assembly is received in the receiving cavity and includes a mounting bracket and a plurality of Fresnel lenses. The mounting bracket is disposed in the receiving cavity. The plurality of Fresnel lenses are spaced apart and mounted on the mounting bracket. The driving member is disposed in the mounting groove and is in transmission connection with the mounting bracket.

[0007] The driving member is used to drive the mounting bracket to move along the front-to-back direction so that the multiple Fresnel lenses are close to or away from the COB light source along the front-to-back direction, and the front-to-back direction is parallel to the light emitting direction of the COB light source.

[0008] In some embodiments, the driving member is a driving motor; the Fresnel lens further includes a screw assembly;

[0009] The screw assembly is arranged in the accommodating cavity, and includes a screw and a screw nut sleeved on the screw, the screw is connected to the drive motor in a transmission manner and extends along the front-to-back direction, and the screw nut is fixedly connected to the mounting bracket;

[0010] Wherein, under the drive of the driving member, the screw rod can be threadably matched with the screw rod nut, so that the screw rod nut rotates relative to the screw rod to drive the mounting bracket to move along the front-rear direction.

[0011] In some embodiments, the screw assembly includes a plurality of screw rods; the Fresnel lens further includes a transmission assembly, the transmission assembly is disposed in the accommodating cavity, and includes a driving wheel, a plurality of driven wheels, and a transmission structure;

[0012] The driving wheel is mounted on the output shaft of the driving motor, the plurality of driven wheels are in one-to-one transmission cooperation with the screws of the screw assembly, and the transmission structure is sleeved on the driving wheel and the plurality of driven wheels to connect the driving wheel with the plurality of driven wheels;

[0013] Wherein, the plurality of driven wheels are arranged at intervals along the circumference of the mounting bracket.

[0014] In some embodiments, the driven wheels and the screw rod assemblies each include four, and the four driven wheels are in one-to-one transmission cooperation with the screw rods of the four screw rod assemblies;

[0015] The mounting bracket is arranged in a square shape, and the four screw rod assemblies are respectively arranged at the four corners of the mounting bracket.

[0016] In some embodiments, the transmission structure is a transmission belt, and the transmission assembly further includes a tensioning structure;

[0017] The tensioning structure is used to abut against the transmission belt to put the transmission belt in a tensioned state.

[0018] In some embodiments, the tensioning structure includes a tensioning wheel and a positioning wheel, and the tensioning wheel and the positioning wheel are respectively located on opposite sides of the driving wheel;

[0019] The tensioning wheel is used to abut against the transmission belt so that the transmission belt is in a tensioned state, and the positioning wheel is used to abut against the transmission belt so that the transmission belt forms a raised portion, and the raised portion contacts the driving wheel.

[0020] In some embodiments, the mounting bracket includes a bracket body and a clamping member;

[0021] The frame body is in transmission connection with the driving member and has a plurality of mounting positions. The clamping member is detachably connected to the frame body to cooperate with the frame body to clamp and fix the plurality of Fresnel lenses in a one-to-one correspondence on the plurality of mounting positions.

[0022] In some embodiments, the frame body is provided with a first connection hole, the clamping member is provided with a second connection hole; the mounting bracket further comprises a threaded fastener;

[0023] The threaded fastener is sequentially passed through the first connection hole and the second connection hole, so that the clamping member is threadedly connected to the frame body.

[0024] In some embodiments, the video light is provided with a first contact assembly, and the Fresnel lens further includes a circuit board and a second contact assembly electrically connected to the circuit board, wherein the circuit board is disposed in the mounting slot and electrically connected to the driving member, and the second contact assembly is disposed in the mounting slot and partially exposed outside the mounting slot, wherein the second contact assembly is configured to be electrically connected to the first contact assembly;

[0025] And / or, the housing is further provided with a heat dissipation window, and the heat dissipation window is communicated with the accommodating cavity.

[0026] In a second aspect, an embodiment of the present application provides a film and television lighting device, comprising a film and television lighting device and the Fresnel lens as described above, wherein the film and television lighting device has multiple COB light sources, and the housing is detachably connected to the film and television lighting device;

[0027] The light emitted by one of the COB light sources passes through one of the Fresnel lenses and then is emitted outward.

[0028] The Fresnel lens and cinema light device according to the embodiments of the present application utilize a driver to drive the lens assembly to move back and forth along the front-to-back direction of the cinema light, thereby achieving the electric focus adjustment function of the Fresnel lens. This facilitates operation and provides a superior user experience. Furthermore, in this embodiment, multiple Fresnel lenses are mounted on the same mounting bracket, and the mounting bracket is driven to move by the driver. Therefore, the driver can simultaneously drive the multiple Fresnel lenses to move synchronously. This drive control achieves a high synchronization rate and eliminates the need for multiple drivers to drive each Fresnel lens in a one-to-one correspondence. This simplifies the structure of the Fresnel lens, allowing for a smaller size and lighter weight, making it easier for users to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0030] Figure 1 This is a structural diagram of a film and television lighting device according to an embodiment of the present application;

[0031] Figure 2 for Figure 1 The structural diagram of the film and television light shown in FIG.

[0032] Figure 3 for Figure 1 The schematic diagram of the exploded structure of the Fresnel lens shown;

[0033] Figure 4 for Figure 1 The structure diagram of the Fresnel lens shown is in a working state;

[0034] Figure 5 for Figure 1 The structure diagram of the Fresnel lens shown is in another working state;

[0035] Figure 6 for Figure 1 A schematic diagram of a cross-sectional structure of a Fresnel lens is shown;

[0036] Figure 7 for Figure 1 Another cross-sectional structural diagram of the Fresnel lens shown;

[0037] Figure 8 for Figure 7 A schematic structural diagram of the lens assembly shown;

[0038] Figure 9 for Figure 8 The structural diagram of the frame body shown;

[0039] Figure 10 for Figure 8 The schematic diagram of the structure of the clamping part is shown.

[0040] Description of Figure Numbers:

[0041] 100. Fresnel lens; 10. Housing; 10A. Accommodating cavity; 10B. Mounting slot; 10C. Heat dissipation window; 20. Lens assembly; 21. Mounting bracket; 211. Frame body; 211A. First connecting hole; 212. Clamping member; 212A. Second connecting hole; 22. Fresnel lens; 30. Driving member; 31. Driving motor; 40. Screw assembly; 41. Screw; 42. Screw nut; 50. Transmission assembly; 51. Driving wheel; 52. Driven wheel; 53. Transmission structure; 531. Transmission belt; 5311. Raised portion; 54. Tensioning structure; 541. Tensioning wheel; 542. Positioning wheel; 60. Second contact assembly; 70. Circuit board; 300. Film and television lighting equipment; 310. Film and television lighting; 320. COB light source; 330. First contact assembly.

[0042] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of this application clearer, the following part will further describe the embodiments of this application in detail with reference to the accompanying drawings.

[0044] When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application, as detailed in the appended claims.

[0045] In the description of this application, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances. In addition, in the description of this application, unless otherwise specified, "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the relevant listed items.

[0047] Please refer to Figure 1-Figure 7 The present application proposes a film and television lighting device 300 . In an embodiment of the present application, the film and television lighting device 300 includes a film and television light 310 and a Fresnel lens 100 .

[0048] The cinema light 310 includes multiple COB light sources 320. The COB light sources 320 include a metal substrate and multiple LED chips, which are packaged on the metal substrate to form a high-density, high-power integrated light source. In this embodiment, the multiple COB light sources 320 can be arranged in a matrix. This arrangement can be used to increase the power of the cinema light 310. It is understood that the cinema light 310 of this embodiment integrates multiple COB light sources 320. For example, the number of COB light sources 320 can be four, so the cinema light 310 is effectively a four-head lamp. The four COB light sources 320 can achieve a rated power of 2500W. Of course, this embodiment is not limited to this. The number of COB light sources 320 can also be nine, twelve, or other numbers. The number of COB light sources 320 can be selected based on the actual power required by the cinema light 310.

[0049] The Fresnel lens 100 is designed to be used in conjunction with a cinema light 310. Specifically, the cinema light 310 and the Fresnel lens 100 are detachably connected. When the Fresnel lens 100 is connected to the cinema light 310, light emitted by the multiple COB light sources 320 of the cinema light 310 passes through the Fresnel lens 100 before being emitted to the outside world. It is understood that the Fresnel lens 100 can increase the light intensity emitted by the multiple COB light sources 320 of the cinema light 310, thereby effectively improving the illumination of the cinema light 310.

[0050] The Fresnel lens 100 includes a housing 10, a lens assembly 20, and a driver 30. The housing 10 can be square or circular to provide a more regular shape and facilitate manufacturing. The housing 10 can be made of metal, offering advantages such as light weight and high strength. The shape and material of the housing are not specifically limited. The housing 10 is used to connect to the cinema light 310, meaning that the housing 10 is detachably connected to the cinema light 310. The housing 10 defines a receiving cavity 10A and has a mounting slot 10B.

[0051] The lens assembly 20 is housed within the accommodating cavity 10A and includes a mounting bracket 21 and a Fresnel lens 22. The mounting bracket 21 serves to mount the multiple Fresnel lenses 22. The mounting bracket 21 can be square in shape to provide a more regular structure and facilitate manufacturing. The mounting bracket 21 can also be made of metal to provide greater structural strength. The mounting bracket 21 is disposed within the accommodating cavity 10A.

[0052] The surface of the Fresnel lens 22 is provided with concentrically arranged serrated grooves to achieve light focusing. Multiple Fresnel lenses 22 are installed at intervals on the mounting bracket 21. It is understood that light emitted by each COB light source 320 passes through each Fresnel lens 22 before being emitted outward.

[0053] The driving member 30 may be a driving motor 31, wherein the driving member 30 is disposed in the mounting groove 10B and is in transmission connection with the mounting bracket 21. The driving member 30 is used to drive the mounting bracket 21 to move along the front-to-back direction of the movie light 310, so that the multiple Fresnel lenses 22 are close to or away from the COB light source 320 of the movie light 310 along the front-to-back direction, thereby realizing the electric focusing function of the Fresnel lens 100. The front-to-back direction is parallel to the light emitting direction of the COB light source 320 of the movie light 310, and the front-to-back direction here can be combined with Figure 7 To understand, Figure 7 The right side is the front, the left side is the back, Figure 7 The left side of the medium Fresnel lens 100 is connected to the cinema light 310 , so the direction from right to left is the direction from front to back, and the direction from left to right is the direction from back to front.

[0054] It can be understood that when the Fresnel lens 22 is close to the COB light source 320 of the movie light 310 in the front-to-back direction, the Fresnel lens 100 is used in a focusing state, that is, the light from the COB light source 320 is refracted by the Fresnel lens 22 to form collimated light, which can provide key lighting for the shooting scene or simulate a daylight scene; and when the Fresnel lens 22 is away from the COB light source 320 of the movie light 310 in the front-to-back direction, the Fresnel lens 100 is used in a flooding state, that is, the COB light source 320 is refracted by the Fresnel lens 22 to form a large-angle, uniform and soft flood light spot, which makes the Fresnel lens 100 suitable for a variety of usage scenarios.

[0055] The technical solution of this application utilizes a driver 30 to drive the lens assembly 20 to move back and forth along the front-to-back direction of the cinema light 310, thereby achieving the electric focus function of the Fresnel lens 100. This facilitates operation and provides a superior user experience. Furthermore, in this embodiment, multiple Fresnel lenses 22 are mounted on the same mounting bracket 21, and the mounting bracket 21 is driven by the driver 30. Therefore, the driver 30 can simultaneously drive the multiple Fresnel lenses 22 to move synchronously. This drive control achieves a high synchronization rate and eliminates the need for multiple drivers 30 to drive each Fresnel lens 22 one by one. This simplifies the structure of the Fresnel lens 100, allowing for a smaller size and lighter weight, making it easier for users to use.

[0056] Please refer to Figure 1-Figure 3 In some embodiments, the cinema light 310 is provided with a first contact assembly 330. The Fresnel lens 100 further includes a circuit board 70 and a second contact assembly 60 electrically connected to the circuit board 70. The circuit board 70 is disposed within the mounting slot 10B and is electrically connected to the driver 30. It is understood that the circuit board 70 controls and drives the driver 30.

[0057] The second contact assembly 60 is disposed within the mounting slot 10B and partially exposed outside the mounting slot 10B. The second contact assembly 60 is configured to electrically connect to the first contact assembly 330. Thus, when the first contact assembly 330 and the second contact assembly 60 are in conductive contact, the cinema light 310 can provide electrical energy to the Fresnel lens 100. With this arrangement, during use, after the cinema light 310 is externally powered, the user can simultaneously power the Fresnel lens 100 using the cinema light 310, eliminating the need for a separate power supply box to power the Fresnel lens 100. This allows the driver 30 of the Fresnel lens 100 to drive the mounting bracket 21 to move, thereby achieving the electric focus function.

[0058] When some higher-power cinema lights 310 are in operation, the light emitted by the COB light source 320 carries a large amount of heat. Therefore, when the light passes through the Fresnel lens 22, the Fresnel lens 22 absorbs the heat of the light, and then the heat is transferred to the housing 10, causing the temperature of the Fresnel lens 100 to be too high.

[0059] Based on this, please refer to Figure 4-Figure 5 In some embodiments, the housing 10 further defines a heat dissipation window 10C, which is in communication with the accommodating cavity 10A. This allows airflow to absorb heat from the Fresnel lens 22 as it passes through the lens, and then flows to the outside through the heat dissipation window 10C, thereby rapidly dissipating heat from the Fresnel lens 100. This prevents users from getting burned when touching the housing 10 of the Fresnel lens 100, thereby improving user safety.

[0060] Please refer to Figure 3-Figure 7 In some embodiments, the driving member 30 is a driving motor 31. The Fresnel lens 100 further includes a screw assembly 40, which is disposed within the accommodating chamber 10A and includes a screw 41 and a screw nut 42 sleeved on the screw 41. The screw 41 is drivingly connected to the driving motor 31 and extends in the front-to-back direction. The screw nut 42 is fixedly connected to the mounting bracket 21. The screw 41 has an external thread, and the screw nut 42 has an internal thread that mates with the external thread. Driven by the driving member 30, the screw 41 can be threadedly engaged with the screw nut 42, so that the screw nut 42 rotates relative to the screw 41, driving the mounting bracket 21 to move in the front-to-back direction, thereby causing the multiple Fresnel lenses 22 to move closer to or further away from the movie light 310 in the front-to-back direction.

[0061] Exemplarily, the drive motor 31 is connected to the screw rod 41 through a coupling to achieve transmission cooperation with the screw rod 41. In this way, when the drive motor 31 is working, it can drive the screw rod 41 to rotate, so that the screw rod 41 can drive the mounting bracket 21 to move back and forth in the front and rear directions through the screw nut 42.

[0062] In this embodiment, by cooperating with the drive motor 31 and the screw assembly 40, high-precision movement of the mounting bracket 21 in the front-to-back direction can be achieved, and the screw assembly 40 has a good load capacity and can bear the weight of the lens assembly 20, so that the lens assembly 20 can move stably.

[0063] Please refer to Figure 3-Figure 7 In some embodiments, the screw assembly 40 includes a plurality of screw assemblies 40 , which are arranged at intervals along the circumference of the mounting bracket 21 .

[0064] The Fresnel lens 100 further includes a transmission assembly 50, which is disposed within the accommodating chamber 10A and includes a driving wheel 51, a plurality of driven wheels 52, and a transmission structure 53. The driving wheel 51 is mounted on the output shaft of the drive motor 31. The plurality of driven wheels 52 are in one-to-one transmission engagement with the plurality of screws 41 of the screw assembly 40, wherein the plurality of driven wheels 52 are arranged at intervals along the circumference of the mounting bracket 21. The transmission structure 53 is sleeved on the driving wheel 51 and the plurality of driven wheels 52 to provide a transmission connection between the driving wheel 51 and the plurality of driven wheels 52. The transmission structure 53 may be a transmission belt 531 or a transmission chain, etc., which is not limited in this embodiment.

[0065] Thus, when the drive motor 31 is operating, the driving wheel 51 can begin to rotate, thereby driving the transmission structure 53 to move, causing the multiple driven wheels 52 to start rotating, and then the multiple screw rods 41 can rotate, thereby achieving the front-to-back movement of the mounting bracket 21. In this embodiment, the provision of the transmission assembly 50 can drive the multiple screw rods 41 to move, and the provision of multiple screw rods 41 can further improve the stability of the mounting bracket 21 during movement.

[0066] Please refer to Figure 3-Figure 7 Furthermore, the driven wheels 52 and the screw rod assembly 40 each include four, and the four driven wheels 52 are in one-to-one transmission cooperation with the screw rods 41 of the four screw rod assemblies 40.

[0067] Among them, the mounting bracket 21 is arranged in a square shape, and the four screw rod assemblies 40 are respectively arranged at the four corners of the mounting bracket 21. In this way, the four screw rod assemblies 40 can provide a good bearing effect for the square mounting bracket 21, thereby ensuring the stability of the mounting bracket 21 when moving.

[0068] Please refer to Figure 3-Figure 7In some embodiments, the transmission structure 53 is a transmission belt 531 , the inner surface of the transmission belt 531 is formed with internal teeth, and both the driving wheel 51 and the transmission wheel are provided with external teeth that match the internal teeth.

[0069] The transmission assembly 50 further includes a tensioning structure 54, which is configured to abut the transmission belt 531 to maintain a tensioned state. It is understood that if the transmission belt 531 is in a loose state, it is prone to slipping, tooth jumping, and the like. Therefore, in this embodiment, the tensioning structure 54 is provided to tension the transmission belt 531, thereby maintaining the transmission efficiency and stability of the transmission assembly 50.

[0070] See also Figure 6 Furthermore, the tensioning structure 54 includes a tensioning wheel 541 and a positioning wheel 542 , and the tensioning wheel 541 and the positioning wheel 542 are respectively arranged on opposite sides of the driving wheel 51 .

[0071] The tensioning wheel 541 is used to abut the transmission belt 531 to put the transmission belt 531 in a tensioned state, thereby keeping the transmission belt 531 in a tensioned state, thereby ensuring the transmission efficiency and stability of the transmission assembly 50. The positioning wheel 542 is used to abut the transmission belt 531 to form a ridge 5311 on the transmission belt 531, and the ridge 5311 engages with the driving wheel 51. It is understandable that after the transmission belt 531 is abutted by the positioning wheel 542, the transmission belt 531 is formed with the ridge 5311, and the contact between the ridge 5311 and the driving wheel 51 increases the overall contact area between the transmission belt 531 and the driving wheel 51, thereby effectively reducing the probability of tooth skipping between the transmission belt 531 and the driving wheel 51.

[0072] Please refer to Figure 7-10 In some embodiments, the mounting bracket 21 includes a bracket body 211 and a clamping member 212. The bracket body 211, as the main portion of the mounting bracket 21, is transmission-connected to the driving member 30, that is, fixedly connected to the screw nut 42 of the screw assembly 40, so that the screw 41 of the screw assembly 40 can transmission-coordinate with the bracket body 211. The bracket body 211 has multiple mounting positions.

[0073] The clamping member 212 is detachably connected to the frame body 211 to cooperate with the frame body 211 to clamp and fix multiple Fresnel lenses 22 in a one-to-one correspondence on multiple installation positions. The detachable connection between the clamping member 212 and the frame body 211 can be a threaded connection or a snap connection, etc., which is not limited in this embodiment.

[0074] Exemplarily, the clamping member 212 has a step portion, and the step portion cooperates with the frame body 211 to enclose a clamping space with an opening on one side. The Fresnel lens 22 is disposed in the clamping space through the opening to achieve clamping and limiting in two directions.

[0075] Thus, when the Fresnel lens 22 needs to be replaced, the clamping member 212 can be disassembled from the frame body 211 , and the Fresnel lens 22 can be removed from the frame body 211 , so that the Fresnel lens 22 can be replaced or repaired later.

[0076] Please refer to Figures 8-10 Optionally, the frame body 211 is provided with a first connection hole 211A, and the clamping member 212 is provided with a second connection hole 212A. The mounting bracket 21 further includes a threaded fastener (not shown) that is sequentially inserted through the first connection hole 211A and the second connection hole 212A to thread the clamping member 212 into the frame body 211.

[0077] In this embodiment, the clamping member 212 is detachably connected to the frame body 211 by a threaded connection. This connection method can improve the stability of the connection between the clamping member 212 and the frame body 211 and also facilitate the disassembly and assembly between the two.

[0078] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. This is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0079] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A Fresnel lens for use with a film and television light having multiple COB light sources, characterized in that: The Fresnel lens comprises: A housing, used to connect with the movie light and enclose a receiving cavity, and the housing also has a mounting groove; a lens assembly housed in the accommodating cavity and comprising a mounting bracket and a plurality of Fresnel lenses, wherein the mounting bracket is disposed in the accommodating cavity and the plurality of Fresnel lenses are spaced apart and mounted on the mounting bracket; and A driving member is disposed in the mounting groove and is transmission-connected to the mounting bracket; The driving member is used to drive the mounting bracket to move along the front-to-back direction so that the Fresnel lens moves closer to or farther away from the COB light source along the front-to-back direction, and the front-to-back direction is parallel to the light emitting direction of the COB light source.

2. The Fresnel lens according to claim 1, wherein: The driving member is a driving motor; the Fresnel lens further comprises: a screw assembly disposed in the accommodating cavity, comprising a screw and a screw nut sleeved on the screw, the screw being transmission-connected to the drive motor and extending along the front-to-back direction, the screw nut being fixedly connected to the mounting bracket; Wherein, under the drive of the driving member, the screw rod can be threadably matched with the screw rod nut, so that the screw rod nut rotates relative to the screw rod to drive the mounting bracket to move along the front-rear direction.

3. The Fresnel lens according to claim 2, wherein: The screw assembly includes a plurality of screw rod assemblies; the Fresnel lens also includes a transmission assembly, which is arranged in the accommodating cavity and includes: A driving wheel is mounted on the output shaft of the driving motor; A plurality of driven wheels, correspondingly and drivingly engaged with the screws of the plurality of screw assemblies; and A transmission structure is sleeved on the driving wheel and the plurality of driven wheels so as to connect the driving wheel with the plurality of driven wheels; Wherein, the plurality of driven wheels are arranged at intervals along the circumference of the mounting bracket.

4. The Fresnel lens according to claim 3, wherein: The driven wheels and the screw rod assemblies each include four, and the four driven wheels are in one-to-one transmission cooperation with the screw rods of the four screw rod assemblies; The mounting bracket is arranged in a square shape, and the four screw rod assemblies are respectively arranged at the four corners of the mounting bracket.

5. The Fresnel lens according to claim 3, wherein: The transmission structure is a transmission belt; the transmission assembly further includes: The tensioning structure is used to abut against the transmission belt to put the transmission belt in a tensioned state.

6. The Fresnel lens according to claim 5, wherein: The tensioning structure includes a tensioning wheel and a positioning wheel, and the tensioning wheel and the positioning wheel are respectively located on opposite sides of the driving wheel; The tensioning wheel is used to abut against the transmission belt so that the transmission belt is in a tensioned state, and the positioning wheel is used to abut against the transmission belt so that the transmission belt forms a raised portion, and the raised portion contacts the driving wheel.

7. The Fresnel lens according to any one of claims 1 to 6, wherein: The mounting bracket includes: A frame body, which is in transmission connection with the driving member and has a plurality of mounting positions; and The clamping member is detachably connected to the frame body to cooperate with the frame body to clamp and fix the multiple Fresnel lenses in a one-to-one correspondence on the multiple installation positions.

8. The Fresnel lens according to claim 7, wherein: The frame body is provided with a first connection hole, and the clamping member is provided with a second connection hole; the mounting bracket further comprises: The threaded fastener is sequentially passed through the first connection hole and the second connection hole so that the clamping member is threadedly connected to the frame body.

9. The Fresnel lens according to any one of claims 1 to 6, wherein: The video light is provided with a first contact assembly, and the Fresnel lens further includes a circuit board and a second contact assembly electrically connected to the circuit board, wherein the circuit board is provided in the mounting slot and electrically connected to the driving member, and the second contact assembly is provided in the mounting slot and partially exposed outside the mounting slot, wherein the second contact assembly is used to be electrically connected to the first contact assembly; And / or, the housing is further provided with a heat dissipation window, and the heat dissipation window is communicated with the accommodating cavity.

10. A film and television lighting device, characterized in that: include: Film and television lights, with multiple COB light sources; and The Fresnel lens according to any one of claims 1 to 9, wherein the housing is detachably connected to the video light; The light emitted by one of the COB light sources passes through one of the Fresnel lenses and then is emitted outward.

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