Variable focus lens arrangement for photographic lamps and photographic lamps

Abstract

The application discloses a zoom lens device of a photographic lamp and the photographic lamp, and relates to the technical field of photographic lamps, in particular to a zoom lens device of a photographic lamp and the photographic lamp. The zoom lens device of the photographic lamp comprises a fixed shell, a light source mounting portion is arranged at one end of the fixed shell, and the other end of the fixed shell is open; a movable shell is arranged in a sleeved mode with the fixed shell, and the movable shell can move along the axial direction of the fixed shell; a lens is arranged at one end of the movable shell away from the light source mounting portion; and a first reflector is arranged in a mode that the inner wall surface of the first reflector is a reflecting surface, and the two ends of the first reflector are open, one end of the first reflector is connected with the light source mounting portion, and the other end of the first reflector is connected with the lens. According to the technical scheme, the lens is arranged on the movable shell, the lens can move along with the movable shell to achieve zooming, meanwhile, the first reflector is arranged, one end of the first reflector is connected with the light source, and the other end of the first reflector is connected with the lens, so that the light loss between the light source and the lens can be reduced, and the light intensity can be increased.

Description

Technical Field

[0001] This invention relates to the field of photographic lighting equipment, and particularly to a variable focus lens device for a photographic light and a photographic light. Background Technology

[0002] Currently, the commonly used zoom lens devices on photographic lights, such as Fresnel lenses, use a convex mirror and a Fresnel lens to zoom the light through a spiral movement. Its main drawback is that the light loss is relatively large. The main reasons for the light loss include: the light emitted by the light source is refracted after passing through multiple lenses, resulting in light loss; in addition, the light can be absorbed by the housing, causing the surface temperature of the housing to be very high, which brings inconvenience to the use process. Summary of the Invention

[0003] This invention provides a variable focus lens device for a photographic lamp and a photographic lamp, aiming to solve the problem of high light loss in existing variable focus lens devices.

[0004] To achieve the above objectives, the first aspect of the present invention provides a variable focus lens device for a photographic lamp, comprising:

[0005] The housing is fixed, with a light source mounting section at one end for mounting the light source, and an open end for mounting the light source;

[0006] A movable housing is sleeved with the fixed housing, and the movable housing can move relative to the fixed housing along its axial direction;

[0007] A lens is mounted on the end of the movable housing away from the light source mounting portion; and

[0008] The first reflector has a reflective inner wall and openings at both ends. One end is connected to the light source mounting part, and the other end faces the lens.

[0009] In some embodiments, the movable housing is connected to the fixed housing via a guide assembly that guides it along its axial direction.

[0010] In some embodiments, the guiding assembly includes at least one guide shaft disposed on the fixed housing and at least one guide block disposed on the movable housing, wherein the guide shaft and the guide block correspond one-to-one, and each guide block is slidably connected to its corresponding guide shaft.

[0011] In some embodiments, a rotating housing is further included. Both the movable housing and the fixed housing are cylindrical structures. The movable housing is sleeved on the outside of the fixed housing, and the rotating housing is sleeved on the outside of the movable housing. The rotating housing and the movable housing are screwed together by a threaded guide structure. The fixed housing is provided with a limiting structure to restrict the axial movement of the rotating housing.

[0012] In some embodiments, the diameter of the first reflector from the port near the light source mounting portion to the port near the lens gradually increases, and the angle of inclination of the sidewall of the first reflector ranges from 45 to 80 degrees.

[0013] In some embodiments, a reflective layer is provided on the inner side of the first reflector, the reflective layer being composed of a plurality of fish-scale-shaped reflective sheets spliced ​​together.

[0014] In some embodiments, the diameter of the port of the first reflector near the lens is larger than the diameter of the lens.

[0015] In some embodiments, the light source mounting part is a light mixing box structure, and a pearl glass and / or a spherical diffuser is provided at its light outlet.

[0016] In some embodiments, a second reflector is further included, which is connected to the inner side of the movable housing and sleeved on the outer side of the first reflector, and the second reflector moves with the movable housing.

[0017] In some embodiments, the second reflector and the first reflector satisfy the following relationship:

[0018] When the second reflector moves the longest axial distance relative to the first reflector, light rays at least half the intensity angle of the light source directly illuminate the lens.

[0019] In some embodiments, the movable housing has an annular step recessed at one end away from the light source mounting portion, the lens is placed in the annular step, and a pressure plate is provided on the side of the lens away from the annular step, the pressure plate being screwed to the movable housing.

[0020] In some embodiments, the lens includes a Fresnel lens.

[0021] A second aspect of the present invention provides a photographic lamp, including a light source and a variable focus lens device for the photographic lamp as described in any one of claims 1-9.

[0022] The present invention provides a zoom lens device and a photographic light, wherein the lens is mounted on a movable housing and can move with the movable housing to achieve zoom. At the same time, a first reflector is provided, one end of which is connected to the light source and the other end of which is connected to the lens. The reflector can reduce light loss between the light source and the lens and increase the light intensity. Attached Figure Description

[0023] Figure 1 This is a schematic cross-sectional view of an embodiment of the variable focus lens device of the present invention. Figure 1 ;

[0024] Figure 2 for Figure 1 A partially exploded structural diagram of the variable focus lens device;

[0025] Figure 3 for Figure 1 A schematic diagram of the focusing mechanism of the variable focus lens device;

[0026] Figure 4 for Figure 1 Axial view of the variable focus lens device;

[0027] Figure 5 This is a schematic cross-sectional view of an embodiment of the variable focus lens device of the present invention. Figure 2 ;

[0028] Figure 6 for Figure 5 A partially exploded structural diagram of the variable focus lens device;

[0029] Figure 7 for Figure 5 A schematic diagram of the focusing mechanism of the variable focus lens device;

[0030] Figure 8 for Figure 5 Axial view of the variable focus lens device;

[0031] Figure 9 This is a partially exploded structural diagram of the movable housing in the lens device of the present invention;

[0032] Figure 10 This is a schematic diagram of the structure of the first reflector of the present invention;

[0033] Figure 11 This is a schematic diagram of the structure of the light source mounting part of the present invention;

[0034] Figure 12 This is a schematic diagram of the optical path of the lens device of the present invention;

[0035] Figure 13 This is a schematic diagram showing the relationship between the light intensity angle and the structural dimensions of the present invention. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0038] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0039] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0040] See Figures 1-12 As shown, the present invention proposes a variable focus lens device for a photographic lamp, comprising:

[0041] The housing 10 has a light source mounting part 101 at one end and an open end at the other end.

[0042] The movable housing 20 is sleeved with the fixed housing 10, and the movable housing 20 can move relative to the fixed housing 10 along its axial direction.

[0043] Lens 30 is mounted on the end of movable housing 20 away from the light source mounting portion 101; and

[0044] The first reflector 40 has a reflective inner wall and is open at both ends. One end is connected to the light source mounting part 101, and the other end faces the lens 30.

[0045] In this embodiment, the light source 60 is detachably installed in the light source mounting part 101, allowing the user to replace different light sources 60 according to actual needs. In related technologies, the application of metal halide lamps is becoming increasingly sophisticated, resulting in a series of lamps ranging from 200 watts to 20 kilowatts based on different light source power. Additionally, there are spotlights using carbon arc lamps as light sources, also known as carbon spotlights. While carbon spotlights have complex mechanical structures, are heavy, bulky, and produce cyanide gas and smoke pollution, their high luminous intensity and wide beam projection area allow for high illuminance, making them currently difficult to replace with other types of lamps. In some embodiments, the light source 60 can be fixedly installed in the light source mounting part 101.

[0046] Light emitted from light source 60 is irradiated by lens 30, which has the function of adjusting the irradiation effect. For example, lens 30 can make the irradiated light softer, making it more suitable for applications in photography. Movable housing 20 can move relative to fixed housing 10 along its axial direction to move lens 30 away from or closer to light source 60, thereby enabling the photographic light to focus and adjusting the light intensity according to the focus change. Furthermore, this embodiment also includes at least one reflector, such as the first reflector 40 described above. One end of the first reflector 40 is connected to light source 60, and the other end faces lens 30. Figure 12 , Figure 13 As shown, after the light is emitted from the light source 60, it is refracted in the first reflector 40 and finally shines out of the camera lamp through the lens 30.

[0047] The technical solution provided by this invention involves mounting a lens 30 on a movable housing 20. The lens 30 can move with the movable housing 20 to achieve zoom. Simultaneously, a first reflector 40 is provided, with one end connected to the light source 60 and the other end connected to the lens 30. The first reflector 40 reduces light loss during light transmission between the light source 60 and the lens 30, increasing the light intensity. Furthermore, the first reflector 40 can block light from being absorbed by the side wall of the fixed housing 10, thereby reducing the side wall temperature of the fixed housing 10 and improving the user experience.

[0048] In some embodiments, such as Figure 1-3 As shown, the movable housing 20 is connected to the fixed housing 10 via a guide assembly that guides it along its axial direction.

[0049] In this embodiment, to facilitate the axial movement of the movable housing 20 relative to the fixed housing 10, a guide assembly is provided between the movable housing 20 and the fixed housing 10 for connection. During the guided movement, the movable housing 20 and the fixed housing 10 always have a projected overlap area; that is, the movable housing 20 cannot detach from the fixed housing 10 during the guided movement, thus forming a connected illumination path between the fixed housing 10 and the movable housing 20.

[0050] In some embodiments, such as Figure 1-3 As shown, the guide assembly includes at least one guide shaft 102 disposed on the fixed housing 10 and at least one guide block 201 disposed on the movable housing 20. The guide block 201 corresponds one-to-one with the guide shaft 102, and each guide block 201 is slidably connected to its corresponding guide shaft 102.

[0051] In this embodiment, the guide movement of the movable housing 20 is achieved by utilizing the assembly relationship between the guide shaft 102 and the guide block 201. The first reflector 40, the movable housing 20, and the fixed housing 10 are sequentially fitted together from the inside to the outside of the photographic lamp. The inner side of the fixed housing 10 extends to form a guide shaft mounting platform 101. The guide shaft 102 is mounted on the inner side of the fixed housing 10 via the guide shaft mounting platform 101. The guide block 201 is located on the outer side of the movable housing 20 and is assembled with the guide shaft 102 so that the guide block 201 can move along the guide shaft 102. In some preferred embodiments, three guide shafts 102 are provided, arranged around the fixed housing 10, and the lines connecting the three guide shafts 102 to the central axis of the fixed housing 10 form three included angles, each of which is 120 degrees. The movable housing 20 is provided with three guide blocks 201 corresponding to the three guide shafts 102 to increase the stability of the movable housing 20 during sliding. Each guide block 201 is connected to each guide shaft 102 via a sliding bearing.

[0052] It should be noted that the movable housing 20 can also be set on the outside of the fixed housing 10. Accordingly, the positions of the guide shaft 102 and the guide block 201 need to be adjusted. In this case, the outer side of the fixed housing 10 extends to form a guide shaft mounting platform 101 for mounting the guide shaft 102. The guide block 201 is set on the inner side of the movable housing 20, and the guide block 201 is assembled with the guide shaft 102.

[0053] In some embodiments, the guide component can also be configured in other ways, see [link / reference]. Figure 1-3 As shown, the inner wall of the fixed housing 10 has a limiting groove 103 extending axially therein, and the outer wall of the movable housing 20 forms a limiting block 202. The limiting block 202 can be engaged in the limiting groove 103 and move along it. The movable housing 20 is connected to the fixed housing 10 through the assembly of the limiting block 202 and the limiting groove 103, which also allows the movable housing 20 to move axially relative to the limiting groove 103. Similar to the cooperation between the guide block 201 and the guide shaft 102, multiple sets of limiting grooves 103 and limiting blocks 202 are provided between the movable housing 20 and the fixed housing 10. Similarly, the movable housing 20 can also be located inside or outside the fixed housing 10, adapting the orientation of the limiting groove 103 and the limiting block 202.

[0054] Furthermore, the guide assembly also includes a gear adjustment assembly and an adjustment rack (not shown in the figures). The movable housing 20 is sleeved on the outside of the fixed housing 10. The adjustment rack is fixed to the outer wall of the fixed housing 10 along its axial movement direction. The gear adjustment assembly includes a connecting shaft and adjustment gears and adjustment wheels connected to both ends of the connecting shaft, respectively. The connecting shaft passes through the side wall of the movable housing 20 and is rotatably connected to the movable housing 20 via a bearing mounting seat. The adjustment gear is located inside the movable housing 20 and meshes with the adjustment rack. The adjustment wheel is located outside the movable housing 20. When the adjustment wheel is rotated, the meshing position of the adjustment gear and the adjustment rack can be changed, thereby adjusting the relative distance between the movable housing 20 and the fixed housing 10, causing the movable housing 20 to move axially relative to the fixed housing 10. Therefore, the guide assembly can be configured in various forms. In this embodiment, any method that enables the movable housing 20 to move axially relative to the fixed housing 10 should fall within the protection scope of this invention.

[0055] In some embodiments, see Figure 4-7 As shown, it also includes a rotating housing 70. Both the movable housing 20 and the fixed housing 10 are cylindrical structures. The movable housing 20 is sleeved on the outer side wall of the fixed housing 10, and the rotating housing 70 is sleeved on the outer side of the movable housing 20. The rotating housing 70 and the movable housing 20 are screwed together by a threaded guide structure. The fixed housing 10 is provided with a limiting structure to restrict the axial movement of the rotating housing 70.

[0056] In this embodiment, the movable housing 20 is moved by rotation. The rotating housing 70 and the movable housing 20 are assembled by threads. When the rotating housing 70 is rotated, the rotating housing 70 and the movable housing 20 move relative to each other. At this time, if both ends of the rotating housing 70 are limited, the rotating housing 70 can only rotate in a fixed position. Conversely, the movable housing 20 moves, thus achieving the purpose of moving the movable housing 20. Specifically, it can be set that when the rotating housing 70 rotates clockwise, the movable housing 20 extends relative to the camera light, and when the rotating housing 70 rotates counterclockwise, the movable housing 20 retracts relative to the camera light.

[0057] like Figure 4-7As shown, in this embodiment, the rotating housing 70 is used to move the movable housing 20; therefore, the rotating housing 70 is positioned on the outermost side. There are various ways to limit the rotation of the rotating housing 70 so that it rotates in a fixed position. Specifically, in this embodiment, the fixed housing 10 includes a first fixed housing 110 and a second fixed housing 120. The second fixed housing 120 is sleeved on the outside of the first fixed housing 110 and corresponds to the upper section of the fixed housing 10. The movable housing 20 is sleeved outside the first fixed housing 110 and located between the first fixed housing 110 and the second fixed housing 120. The movable housing 20 has a clearance groove 206, allowing the first fixed housing 110 and the second fixed housing 120 to connect through the clearance groove 206, while also enabling relative movement of the movable housing 20. The first fixed housing 110 and the second fixed housing 120 can be integrally formed, or a fixing block 130 can be provided at the clearance groove 206, forming the connection. Furthermore, a rotating housing 70 is fitted onto the outer wall of the movable housing 20 corresponding to the first fixed housing 110. The rotating housing 70 and the movable housing 20 are threaded together. When an extension side extending outward is provided at the bottom end of the first fixed housing 110, the rotating housing 70 can be snapped onto the extension side and the bottom end of the second fixed housing 120, thereby achieving the purpose of rotational focusing after assembly.

[0058] A preferred method for limiting the rotation housing 70 is to provide a limiting rotation groove around the outer side wall of the fixed housing 10, and to assemble and connect the rotation housing 70 with the limiting rotation groove so that the rotation housing 70 can only rotate around the limiting rotation groove. At the same time, the rotation housing 70 is threadedly assembled with the movable housing 20.

[0059] It should be noted that the above-mentioned adjustment actions for relative movement between the fixed housing 10 and the movable housing 20 can all be set to manual or automatic adjustment modes to adapt to different user needs.

[0060] In some embodiments, such as Figure 1-3 As shown, the diameter of the first reflector 40 gradually increases from the port near the light source mounting part 101 to the port near the lens 30, and the tilt angle of the sidewall of the first reflector 40 ranges from 45 to 80 degrees. The first reflector 40 adopts a specific shape and structure, which has a better light-gathering effect on dispersed point light sources, thereby achieving a better visual effect.

[0061] Further, see Figure 10As shown, a reflective layer is provided on the inner side of the first reflector 40. This reflective layer is composed of several fish-scale-shaped reflective sheets 401 spliced ​​together to meet the light intensity angle requirements. In this embodiment, the reflective sheets 401 are made of a bright silver reflective material, which typically has high reflectivity. When light is emitted by the reflective layer, light loss can be reduced and the emitted light intensity can be increased.

[0062] In some embodiments, the diameter of the port of the first reflector 40 near the lens is larger than the diameter of the lens 30, which allows more of the light source's aperture to directly illuminate the lens 30, thereby increasing the light intensity.

[0063] In some embodiments, see Figure 11 As shown, the light source mounting 101 is designed as a light mixing box structure, with a beaded glass 140 and / or a spherical diffuser 150 at its light outlet. The beaded glass 140 or the spherical diffuser 150 can make the emitted light more uniform and softer.

[0064] In some embodiments, such as Figure 1-8 As shown, it also includes a second reflector 50, which is connected to the inner side of the movable housing 20 and sleeved on the outer side of the first reflector 40. The second reflector 50 moves with the movable housing 20.

[0065] In this embodiment, a second reflector 50 is provided so that both sides of the optical path between the light source 60 and the lens 30 are covered by reflectors, further improving the light intensity. It is understood that when not focused, the first reflector 40 can meet the requirement of covering the optical path between the light source 60 and the lens 30. However, after the lens 30 is focused, the movable housing 20 moves axially relative to the fixed housing 10, and the optical path is lengthened. At this time, there may be a situation where the first reflector 40 does not completely cover the optical path, resulting in significant light loss. This uncovered optical path segment corresponds to the extended segment of the movable housing 20. Therefore, after the second reflector 50 is fixedly connected to the inside of the movable housing 20, the second reflector 50 moves with the movable housing 20, thereby covering the optical path not covered by the first reflector 40. The inner wall of the second reflector 50 is also provided with a reflective layer.

[0066] It should be noted that the second reflector 50 satisfies the following relationship: when the second reflector 50 moves the longest distance axially relative to the first reflector 40, light rays with an intensity angle of at least half of the light intensity of the light source directly illuminate the lens 30.

[0067] Reference Figure 13Understandably, when the light source is working, some light rays are reflected by the first reflector 40 and the second reflector 50 on the periphery and then emitted through the lens 30, while some light rays are emitted directly through the lens 30. The longer the distance the second reflector 50 can move, the more light rays are reflected by it, resulting in weaker light intensity. When light rays with a half-intensity angle are emitted directly through the lens 30, the light intensity meets the emission requirements. Therefore, the maximum light-emitting surface diameter of the lens 30 is defined as Q, and the second reflector 50 is moved axially to its limit position, i.e., the moving distance is L. At this point, the diameter of the light spot formed on the lens 30 with a half-intensity angle is S, and S should be less than or equal to Q, meaning that at least half-intensity angle light rays are emitted onto the lens 30.

[0068] In some embodiments, such as Figure 9 As shown, the movable housing 20 has an annular step portion 203 recessed at one end away from the light source mounting portion 101. The lens 30 is placed in the annular step portion 203, and a pressure plate 204 is provided on the side of the lens 30 away from the annular step portion 203. The pressure plate 204 is screwed to the movable housing 20.

[0069] In this embodiment, the lens 30 is movably mounted on the movable housing 20, facilitating the disassembly and replacement of the lens 30. Especially when the lens 30 is damaged, significantly impacting the light output effect, timely replacement of the lens 30 becomes extremely important. In a preferred embodiment, the pressure plate 204 is connected to the movable housing 20 by screws, pressing the lens 30 onto the annular stepped portion 203.

[0070] In some embodiments, lens 30 includes a Fresnel lens, which looks like a piece of glass with countless concentric circles (i.e., Fresnel bands) and can achieve the effect of a convex lens. When the projected light source is parallel light, it can maintain the consistency of brightness throughout the image after convergence and projection.

[0071] In this embodiment, the non-threaded surface of the Fresnel lens is typically embossed with various patterns of "tortoise shell" or "honeycomb" to appropriately scatter light, resulting in a soft and uniform illumination effect. Furthermore, the illuminated light field lacks distinct boundaries, facilitating light reception. The beam angle of this photographic light employing a Fresnel lens can be adjusted within the range of 15° to 60°.

[0072] The second aspect of the present invention provides a photographic light, which includes a variable focus lens device of the photographic light provided in the first aspect of the light source. The specific structure of the variable focus lens device of the photographic light is as described in the above embodiments. Since the photographic light adopts all the technical solutions of all embodiments of the variable focus lens assembly of the photographic light described above, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0073] The above description is only a part or preferred embodiment of the present invention. Neither the text nor the drawings should limit the scope of protection of the present invention. All equivalent structural transformations made using the content of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A variable focus lens device for a photographic light, characterized in that, include: The housing is fixed, with a light source mounting section at one end for mounting the light source, and an open end for mounting the light source; A movable housing is sleeved with the fixed housing, and the movable housing can move relative to the fixed housing along its axial direction; The lens is mounted on the end of the movable housing away from the light source mounting portion; as well as The first reflector has a reflective inner wall and is open at both ends. One end is connected to the light source mounting part, and the other end faces the lens. The rotating housing, the movable housing and the fixed housing are both cylindrical structures. The rotating housing is sleeved on the outside of the movable housing. The rotating housing and the movable housing are screwed together by a threaded guide structure. The fixed housing is provided with a limiting structure to restrict the axial movement of the rotating housing. The fixed housing includes a first fixed housing and a second fixed housing, wherein the second fixed housing is sleeved on the outside of the first fixed housing and is located above the first fixed housing; The movable housing is sleeved outside the first fixed housing and located between the first fixed housing and the second fixed housing; the movable housing is provided with a clearance groove so that the first fixed housing and the second fixed housing can be connected through the clearance groove; The rotating housing is located outside the second fixed housing.

2. The variable focus lens device for a photographic light according to claim 1, characterized in that, The diameter of the first reflector gradually increases from the port near the light source mounting part to the port near the lens, and the tilt angle of the side wall of the first reflector ranges from 45 to 80 degrees.

3. The variable focus lens device for a photographic light according to claim 2, characterized in that, The inner side of the first reflector is provided with a reflective layer, which is composed of several fish-scale-shaped reflective sheets spliced ​​together.

4. The variable focus lens device for a photographic light according to claim 1, characterized in that, The diameter of the port of the first reflector near the lens is larger than the diameter of the lens.

5. The variable focus lens device for a photographic light according to claim 1, characterized in that, The light source mounting section is a light mixing box structure, with a beaded glass and / or a spherical diffuser at its light outlet.

6. The variable focus lens device for a photographic lamp according to any one of claims 1-5, characterized in that, It also includes a second reflector, which is connected to the inside of the movable housing and fitted onto the outside of the first reflector, and the second reflector moves with the movable housing.

7. The variable focus lens device for a photographic light according to claim 6, characterized in that, The second reflector satisfies: When the second reflector moves the longest axial distance relative to the first reflector, light rays at least half the intensity angle of the light source directly illuminate the lens.

8. The variable focus lens device for a photographic light according to claim 1, characterized in that, The movable housing has an annular step recessed at one end away from the light source mounting part. The lens is placed in the annular step, and a pressure plate is provided on the side of the lens away from the annular step. The pressure plate is screwed to the movable housing.

9. The variable focus lens device for a photographic light according to claim 1, characterized in that, The lens includes a Fresnel lens.

10. A photographic light, characterized in that, The variable focus lens device includes a light source and a photographic lamp as described in any one of claims 1-9.

Images