Optical system suitable for stage beam lamp and stage lamp with the same

Abstract

The utility model discloses an optical system suitable for stage light beam lamp. The optical system includes the focusing lens module, the middle lens module and the front lens module who sets gradually from object side to image side along the optical axis direction, and the front lens module, the middle lens module all have positive focal power, and the focusing lens module has negative focal power, the front lens module includes at least one front group lens piece, and the image side surface of front group lens piece is the convex surface, the middle lens module includes the third lens piece, the second lens piece and the first lens piece who sets in order along the optical axis direction, and the first and second lens piece are all meniscus positive lens, and the third lens piece is meniscus negative lens, and the second and third lens piece are glued and are connected as an integral structure, and the focusing lens module includes at least one focusing lens piece, and the focusing lens module is translated before and after along the optical axis between the middle lens module and the light source, to adjust the spot definition to different projection distance. The utility model can shorten the length of overall optical path while guaranteeing the spot definition and the beam sharpness.

Description

Technical Field

[0001] This utility model belongs to the field of stage lighting technology, specifically relating to an optical system and stage lighting fixture suitable for stage beam lights. Background Technology

[0002] In the field of lighting equipment, the sharpness of the light spot is a crucial indicator for evaluating lens performance. The sharpness of the light spot directly determines the sharpness of the light beam projected by the stage light and the fullness of the prism effect. The sharper the light spot of the stage light, the more distinct and sharp the edges of the projected light beam, which can accurately delineate the target area on the stage, creating a visually impactful light and shadow effect for the stage performance. At the same time, a full prism effect can produce a rich variety of optical patterns, greatly enhancing the artistic atmosphere and viewing experience of the stage performance, and meeting the diverse lighting effect needs of different styles of stage performances. For example, in the prior art, Chinese Patent No. CN201636699 discloses an LED stage lighting optical system. This optical system includes LED beads, a first condenser lens, a second condenser lens, an aperture, a color wheel, a pattern sheet, a first imaging lens, a focusing lens, and a second imaging lens, which can achieve scaling of the light spot pattern while ensuring its sharpness.

[0003] However, in practical applications, existing stage lighting optical systems still have shortcomings in their optical structure design. Generally, to ensure that stage lights meet specific optical performance requirements, their light emission angle is usually designed to be less than 2°. This small light emission angle determines that the lenses equipped with stage lights belong to the category of telephoto lenses. The characteristics of telephoto lenses mean that the light path needs to travel a long distance inside the lamp to achieve the desired optical effect. A longer light path results in a relatively long lamp head. From an aesthetic point of view, an excessively long lamp head makes the overall shape of the lamp appear uncoordinated and unattractive. From a practical application point of view, a larger lamp head increases the size and weight of the lamp, causing great inconvenience to the handling, installation, and debugging of the lamp.

[0004] Therefore, how to optimize the optical structure design and effectively shorten the size of the lamp body and lamp head to achieve miniaturization of the lamp body while ensuring key optical performance indicators such as the clarity of the light spot and the light output angle of the stage lamp has become an urgent technical problem to be solved in the field of stage lighting technology. Summary of the Invention

[0005] In response to the problems in related technologies, this utility model proposes an optical system and stage lighting fixture suitable for stage beam lights, so as to overcome the above-mentioned technical problems existing in the existing related technologies. This utility model can solve the problems of unclear light spots and unsharp beams in existing beam lights, and at the same time, it can shorten the overall optical path length and have a smaller arrangement gap than beam light lenses with equivalent performance, which is conducive to the miniaturization of stage lighting fixtures.

[0006] The technical solution of this utility model is implemented as follows: an optical system suitable for stage beam lights, including a focusing lens module, a middle lens module and a front lens module arranged sequentially from the object side to the image side along the optical axis, wherein the object side of the focusing lens module is provided with a light source;

[0007] The front lens module and the middle lens module both have positive optical power, and the focusing lens module has negative optical power.

[0008] The front lens module includes at least one front lens group, and the image side of the front lens group is convex.

[0009] The middle lens module includes a third lens, a second lens, and a first lens arranged sequentially along the optical axis. The first lens is close to the front lens module, and the third lens is close to the focusing lens module. The first and second lenses are both meniscus positive lenses, and the third lens is a meniscus negative lens. The second and third lenses are bonded together as a single structure.

[0010] The focusing lens module includes at least one focusing lens; the focusing lens module is translated back and forth along the optical axis between the intermediate lens module and the light source to adjust the clarity of the light spot at different projection distances.

[0011] Furthermore, the object-side surface of the first lens is concave, and its image-side surface is convex; the object-side surface of the second lens is flat, and its image-side surface is convex; the object-side surface of the third lens is concave, and its image-side surface is flat.

[0012] Furthermore, the object-side surface of the front lens group is flat; the object-side surface of the focusing lens is concave, and its image-side surface is flat.

[0013] Furthermore, the refractive index of the second lens is n3, and the refractive index of the third lens is n4, wherein n3 ≤ n4;

[0014] Furthermore, the refractive index of the front lens group is n1, the refractive index of the first lens is n2, and the refractive index of the focusing lens is n5; wherein, 1.40≤n1≤1.70, 1.40≤n2≤1.70, 1.40≤n3≤1.60, 1.60≤n4≤1.90, and 1.40≤n5≤1.70.

[0015] Further, the focal length of the front lens group is f1, the focal length of the first lens is f2, the focal length of the second lens is f3, the focal length of the third lens is f4, and the focal length of the focusing lens is f5, wherein 100mm≤f1≤400mm; 200mm≤f2≤500mm; 50mm≤f3≤300mm; -200mm≤f4≤-50mm; -800mm≤f5≤-200mm.

[0016] Furthermore, the lens module also includes a lens housing, a front pressure ring, and a spacer ring. The third lens, the second lens, and the first lens are all placed inside the lens housing. The front pressure ring is located at the connection between the first lens and the lens housing and is used to fix the first lens. The spacer ring is located between the first lens and the second lens and abuts against the first and second lenses respectively, and is used to fix the first and second lenses. The medium between the first lens and the second lens is air or a vacuum.

[0017] Furthermore, it also includes an imaging aperture located on the same optical axis, which is located between the focusing lens and the light source. The light emitted by the light source passes through the imaging aperture before propagating to the focusing lens.

[0018] Furthermore, the light emission angle range of the optical system is 1.45°-1.55°, and is preferably 1.50° in this invention.

[0019] Furthermore, the first lens and the second lens are made of the same optical material, while the third lens is made of a different optical material than the first lens;

[0020] Furthermore, both the first and second lenses are made of crown glass, and the third lens is made of flint glass.

[0021] A stage lighting fixture includes a lamp head having the aforementioned optical system;

[0022] It also includes a drive unit connected to the focusing lens module, the drive unit being used to drive the focusing lens module to translate back and forth along the optical axis between the middle lens module and the light source;

[0023] Furthermore, the drive unit can be a conventional focusing motor, which is simple in structure and easy to control.

[0024] Furthermore, both the front lens module and the middle lens module in this invention are configured to maintain a fixed position relative to the housing or reference structure of the lamp head, and do not undergo relative displacement during the normal operation of the optical system.

[0025] The beneficial effects of this utility model are:

[0026] In this invention, the combined design of the focusing lens module, the middle lens module, and the front lens module reduces aberrations such as spherical aberration and coma in the optical system. This results in a clearer and sharper image of the projected light spot, less relative brightness deviation between the beam center and edge, and a more uniform and full beam. It can form narrow-angle rays and also features high brightness, strong penetration, and long range. Furthermore, the lens combination of this optical system reduces the overall length of the optical path, making the structure of the entire optical system more compact and facilitating the miniaturization of stage lighting fixtures. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the optical system of this utility model;

[0028] Figure 2 This is a cross-sectional view of the optical system of this utility model;

[0029] Figure 3 This is a schematic diagram of the optical path structure of the optical system of this utility model;

[0030] Figure 4 This is a cross-sectional view of the optical path of the optical system of this utility model;

[0031] Figure 5 This is a schematic diagram of the optical path of the front lens group, the middle lens module, and the focusing lens of this utility model.

[0032] Figure 6 This is a field curvature diagram of the optical system of this utility model;

[0033] Figure 7 This is a distortion diagram of the optical system of this utility model;

[0034] Figure 8 This is the axial chromatic aberration diagram of the optical system of this utility model;

[0035] Figure 9 This is a chromatic aberration diagram of the optical system of this invention.

[0036] Marker explanation:

[0037] 1. Front lens element; 2. Middle lens module; 21. First lens element; 22. Second lens element; 23. Third lens element; 24. Lens housing; 25. Front pressure ring; 26. Spacer ring; 3. Focusing lens element; 4. Light source; 5. Imaging aperture. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0039] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0040] like Figure 1-5 As shown, this embodiment provides an optical system suitable for stage beam lights, including a focusing lens module, a middle lens module 2 and a front lens module arranged sequentially from the object side to the image side along the optical axis. The object side of the focusing lens module is provided with a light source 4.

[0041] The front lens module and the middle lens module 2 both have positive optical power, and the focusing lens module has negative optical power;

[0042] It should be noted that: positive optical power gives the front lens module the optical function of converging light, and the positive optical power of the middle lens module 2 works together with the positive optical power of the front lens module to achieve the convergence and transmission of the beam; the focusing lens module uses the divergence effect generated by negative optical power to adjust the focal length of the beam emitted from the light source 4.

[0043] The front lens module includes at least one front lens group 1, and the image side of the front lens group 1 is convex.

[0044] The middle lens module 2 includes a third lens 23, a second lens 22, and a first lens 21 arranged sequentially along the optical axis. The first lens 21 is close to the front lens module, and the third lens 23 is close to the focusing lens module. The first and second lenses are both meniscus positive lenses, and the third lens 23 is a meniscus negative lens. The second lens 22 and the third lens 23 are bonded together as a single structure, which helps to reduce axial chromatic aberration.

[0045] The focusing lens module includes at least one focusing lens 3; the focusing lens module is translated back and forth along the optical axis between the middle lens module 2 and the light source 4 to adjust the clarity of the light spot at different projection distances.

[0046] In this embodiment, the combined design of the focusing lens module, the middle lens module 2, and the front lens module reduces aberrations such as spherical aberration and coma in the optical system. This results in a clearer and sharper image of the projected light spot, less relative brightness deviation between the beam center and edge, and a more uniform and full beam. It can form narrow-angle light rays and also features high brightness, strong penetration, and long range. Furthermore, the lens combination of this optical system reduces the overall length of the optical path, making the structure of the entire optical system more compact and facilitating the miniaturization of stage lighting fixtures.

[0047] Specifically, the object side of the first lens 21 is concave and its image side is convex; the object side of the second lens 22 is flat and its image side is convex; the object side of the third lens 23 is concave and its image side is flat.

[0048] Specifically, the object side of the front lens group 1 is flat; the object side of the focusing lens 3 is concave, and its image side is flat.

[0049] Specifically, the refractive index of the second lens 22 is n3, and the refractive index of the third lens 23 is n4, where n3≤n4;

[0050] More specifically, the refractive index of the front lens group 1 is n1, the refractive index of the first lens 21 is n2, and the refractive index of the focusing lens 3 is n5; wherein, 1.40≤n1≤1.70, 1.40≤n2≤1.70, 1.40≤n3≤1.60, 1.60≤n4≤1.90, and 1.40≤n5≤1.70;

[0051] By precisely limiting the refractive indices of the front lens 1, first lens 21, second lens 22, third lens 23, and focusing lens 3, such as setting specific ranges like 1.40≤n1≤1.70 and satisfying the relationship n3≤n4, the refraction and propagation of light between the lenses can be finely controlled, effectively optimizing the light convergence or divergence effect, thereby significantly reducing the aberrations of the optical system, improving image clarity and beam quality, and making the light spot projected by the stage beam lights sharper and more uniform, meeting the stringent requirements of stage performances for high-quality beams.

[0052] Specifically, the focal length of the front lens group 1 is f1, the focal length of the first lens 21 is f2, the focal length of the second lens 22 is f3, the focal length of the third lens 23 is f4, and the focal length of the focusing lens 3 is f5, wherein 100mm≤f1≤400mm; 200mm≤f2≤500mm; 50mm≤f3≤300mm; -200mm≤f4≤-50mm; -800mm≤f5≤-200mm;

[0053] The aforementioned focal length limitation allows each lens in the optical system to scientifically regulate and coordinate the light according to its specific focal length. Among them, the positive focal length lens effectively converges the light, while the negative focal length lens reasonably diverges the light. This design can reduce various aberrations such as spherical aberration and coma in the optical system, greatly improve the clarity and sharpness of the image, and at the same time ensure uniform brightness at the center and edge of the beam.

[0054] Specifically, the lens module 2 further includes a lens housing 24, a front pressure ring 25, and a spacer ring 26. The third lens 23, the second lens 22, and the first lens 21 are all placed inside the lens housing 24. The front pressure ring 25 is located at the connection between the first lens 21 and the lens housing 24 to fix the first lens 21. The spacer ring 26 is located between the first lens 21 and the second lens 22 and abuts against the first and second lenses respectively to fix the first and second lenses. The medium between the first lens 21 and the second lens 22 is air or a vacuum.

[0055] The coordinated design of the lens housing 24, the front pressure ring 25, and the spacer ring 26 securely houses the third, second, and first lenses within the lens housing 24. The front pressure ring 25 precisely fixes the first lens 21, while the spacer ring 26 effectively fixes the first and second lenses 22, ensuring high stability of the lens positions and greatly reducing the risk of optical performance fluctuations caused by lens displacement. At the same time, the use of air or vacuum as a medium between the first lens 21 and the second lens 22 reduces light loss and aberrations caused by uneven medium, thereby significantly improving the imaging quality and reliability of the optical system and ensuring stable and high-quality output of the stage beam lights.

[0056] Specifically, it also includes an imaging aperture 5 located on the same optical axis. The imaging aperture 5 is located between the focusing lens 3 and the light source 4. The light emitted by the light source 4 passes through the imaging aperture 5 before propagating to the focusing lens 3.

[0057] It should be noted that the imaging aperture 5 is configured to restrict the propagation path of the light emitted by the light source 4, so that only light within a preset angle range passes through and is projected onto the focusing lens 3, thereby reducing aberrations caused by non-target light and improving the imaging resolution of the optical system.

[0058] Specifically, the light emission angle range of the optical system is 1.45°-1.55°, and in this embodiment, it is preferably 1.50°;

[0059] Under these narrow-angle light emission conditions, the light is more concentrated during propagation, avoiding premature light divergence due to excessively large angles, which would otherwise require a longer optical path to achieve a specific beam effect. Moreover, the smaller light emission angle effectively shortens the optical path length of the entire optical system, making the optical path layout more compact and reasonable. This not only saves space but also provides strong support for the miniaturization design of stage beam lights.

[0060] Specifically, the first lens 21 and the second lens 22 are made of the same optical material, while the third lens 23 is made of a different optical material than the first lens 21;

[0061] More specifically, the first lens 21 and the second lens 22 are both made of crown glass, and the third lens 23 is made of flint glass;

[0062] It should be noted that crown glass has excellent optical uniformity and low light absorption characteristics. The fact that the first and second lenses are made of the same material ensures that the characteristics of light are consistent when it propagates between them, effectively reducing internal light loss and aberrations. When combined with flint glass, crown glass can compensate for each other by utilizing their different dispersion characteristics, significantly reducing the axial and lateral chromatic aberration of the optical system, greatly improving the clarity and color reproduction of the image, and making the light spots projected by the stage beam lights have purer colors and sharper edges.

[0063] A stage lighting fixture includes a lamp head having the aforementioned optical system;

[0064] It also includes a drive unit connected to the focusing lens module, the drive unit being used to drive the focusing lens module to translate back and forth along the optical axis between the middle lens module 2 and the light source 4;

[0065] More specifically, the drive unit can be a conventional focusing motor, which is simple in structure and easy to control.

[0066] Specifically, in this embodiment, both the front lens module and the middle lens module 2 are configured to maintain a fixed position relative to the housing or reference structure of the lamp head, and do not undergo relative displacement during the normal operation of the optical system.

[0067] The field curvature and distortion diagrams of the optical system described in this embodiment in practical applications are as follows: Figure 6-7 As shown in the diagram. In the field curvature plot, the horizontal axis represents the defocus amount in mm, and the vertical axis represents the image height in mm. In the distortion plot, the horizontal axis represents the distortion value as a percentage, and the vertical axis represents the image height in mm. According to... Figure 6It can be seen that the optical system has a small field curvature and high imaging quality, achieving good sharpness and detail, with consistent sharpness at the edges and center; and according to Figure 7 It can be seen that the distortion value is small and the image is not distorted.

[0068] The axial chromatic aberration diagram of the optical system is as follows: Figure 8 As shown, the horizontal axis represents the defocus amount in mm, and the vertical axis represents the normalized pupil. Figure 8 It can be seen that the optical system has a small axial chromatic aberration, and light of different wavelengths can be converged on a single area, resulting in clear imaging.

[0069] The transverse chromatic aberration diagram of the optical system is as follows: Figure 9 As shown, the horizontal axis represents the chromatic aberration amount in μm, and the vertical axis represents the field of view in mm. Figure 9 As can be seen, the chromatic aberration along the vertical axis of the optical system is very small, so that no color edge phenomenon will occur in the edge area of ​​the projected pattern.

[0070] The stage lighting fixture described in this embodiment can solve the problems of unclear light spots and unsharp beams in existing beam lights. At the same time, it can shorten the overall optical path length and has a smaller spacing between beam lights with equivalent performance (i.e., a smaller optical path length space within the lamp head), which is beneficial for the miniaturization of stage lighting fixtures.

[0071] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments disclosed and described above, and some modifications and changes to this utility model should also fall within the protection scope of the claims of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model.

Claims

1. An optical system suitable for stage beam lights, characterized in that, It includes a focusing lens module, a middle lens module, and a front lens module arranged sequentially from the object side to the image side along the optical axis, wherein the object side of the focusing lens module is provided with a light source; The front lens module and the middle lens module both have positive optical power, and the focusing lens module has negative optical power. The front lens module includes at least one front lens group, and the image side of the front lens group is convex. The middle lens module includes a third lens, a second lens, and a first lens arranged sequentially along the optical axis. The first lens is close to the front lens module, and the third lens is close to the focusing lens module. The first and second lenses are both meniscus positive lenses, and the third lens is a meniscus negative lens. The second and third lenses are bonded together as a single structure. The focusing lens module includes at least one focusing lens; the focusing lens module is translated back and forth along the optical axis between the intermediate lens module and the light source to adjust the clarity of the light spot at different projection distances.

2. The optical system according to claim 1, characterized in that, It also includes an imaging aperture located on the same optical axis, which is located between the focusing lens and the light source. The light emitted by the light source passes through the imaging aperture before propagating to the focusing lens.

3. The optical system according to claim 1 or 2, characterized in that, The light emission angle range of the optical system is 1.45°-1.55°.

4. The optical system according to claim 1, characterized in that, The first lens has a concave object side and a convex image side; the second lens has a flat object side and a convex image side; the third lens has a concave object side and a flat image side.

5. The optical system according to claim 1 or 4, characterized in that, The object-side surface of the front lens group is flat; the object-side surface of the focusing lens is concave, and its image-side surface is flat.

6. The optical system according to claim 1, characterized in that, The second lens has a refractive index of n3, and the third lens has a refractive index of n4, where n3 ≤ n4.

7. The optical system according to claim 1, characterized in that, The focal length of the front lens group is f1, the focal length of the first lens is f2, the focal length of the second lens is f3, the focal length of the third lens is f4, and the focal length of the focusing lens is f5, wherein 100mm≤f1≤400mm; 200mm≤f2≤500mm; 50mm≤f3≤300mm; -200mm≤f4≤-50mm; -800mm≤f5≤-200mm.

8. The optical system according to claim 1, characterized in that, The lens module further includes a lens housing, a front pressure ring, and a spacer ring. The third lens, the second lens, and the first lens are all placed inside the lens housing. The front pressure ring is located at the connection between the first lens and the lens housing and is used to fix the first lens. The spacer ring is located between the first lens and the second lens and abuts against the first and second lenses respectively, and is used to fix the first and second lenses. The medium between the first lens and the second lens is air or a vacuum.

9. The optical system according to claim 1, characterized in that, The first and second lenses are made of the same optical material, while the third lens is made of a different optical material than the first lens.

10. A stage lighting fixture, comprising a lamp head, characterized in that, The lamp head has an optical system as described in any one of claims 1-9.

Images