Zooming projection lamp lens

Abstract

The invention discloses a zoom projection lamp lens, which comprises a front fixed lens group with positive focal power, a zoom lens group with negative focal power, a diaphragm, a compensation lens group and a rear fixed lens group with positive focal power which are sequentially arranged from an image surface side to a projection side along an optical axis direction, the focal length F (1) of the front fixed lens group, the focal length F (2) of the zoom lens group and the focal length F (4) of the compensation lens group meet the following conditional expressions:-3 < F (1) / F (2) <-2; f (4) / F (2) is more than-1 and less than-0.3; the diaphragm and the compensation lens group can move synchronously along the optical axis direction and keep fixed relative positions. The zoom lens group and the compensation lens group are close to each other or far away from each other, so that the light-emitting field angle of the lens can be adjusted, patterns can be clearly projected on the basis that the light-emitting field angle of the lens is flexible and adjustable, and the projection requirements of different background patterns during shooting are met; and meanwhile, the device has the advantages of compact structure, small size, light weight and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and particularly to a zoom projection lamp lens. Background Art

[0002] At present, pattern projection devices are deeply loved by a large number of photography enthusiasts and practitioners. They use a high-brightness lighting system and then, through an imaging lens, display various patterns, which are used as shooting objects or shooting backgrounds.

[0003] Traditional pattern projection devices have a single projection field angle and can only be applied to a single scene. Photographers often need to purchase multiple devices to meet the shooting requirements of different projection field angles, increasing the cost of pattern projection photography. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of the single projection field angle of the projection lens in the prior art, so as to provide a zoom projection lamp lens.

[0005] To solve the above technical problem, the technical solution of the present invention is as follows:

[0006] A zoom projection lamp lens includes a front fixed lens group with positive optical power, a zoom lens group with negative optical power, a diaphragm, a compensation lens group, and a rear fixed lens group with positive optical power, which are sequentially arranged along the optical axis direction from the image plane side to the projection side; the focal lengths of the front fixed lens group, the zoom lens group, and the compensation lens group satisfy the following conditional expressions:

[0007] −3 < F(1) / F(2) < −2;

[0008] −1 < F(4) / F(2) < −0.3;

[0009] Wherein, F(1) is the focal length of the front fixed lens group, F(2) is the focal length of the zoom lens group, and F(4) is the focal length of the compensation lens group;

[0010] The zoom lens group and the compensation lens group move closer to or away from each other along the optical axis direction to adjust the focal length of the zoom projection lamp lens, and further adjust the range of the light exit field angle of the zoom projection lamp lens.

[0011] Furthermore, the diaphragm and the compensation lens group can move synchronously along the optical axis direction and maintain a fixed relative position.

[0012] Furthermore, when the zoom lens group moves along the optical axis, the compensation lens group and the diaphragm both move in the opposite direction along the optical axis to offset the image plane movement caused by the movement of the zoom lens group.

[0013] Further, the front fixed lens group includes a first lens with positive optical power; the zoom lens group includes a second lens with negative optical power; the compensation lens group includes a third lens with positive optical power, a fourth lens with negative optical power, a fifth lens with negative optical power, and a sixth lens with positive optical power, which are arranged in sequence from the image side to the projection side along the optical axis direction; the rear fixed lens group includes a seventh lens with positive optical power.

[0014] Further, the adjustment range of the light-emitting field angle of the zoom projection lamp lens is 18° - 36°.

[0015] Further, on one side of the rear fixed lens group, a projection object, a collimation component, and a light source are arranged in sequence along the optical axis direction; the collimation component is used to turn the light emitted by the light source into parallel light and then emit it onto the projection object.

[0016] Further, the distance between the projection object and the rear fixed lens group along the optical axis direction is adjustable.

[0017] Further, the maximum clear aperture diameter of the projection object is 50 - 60 mm.

[0018] Further, the maximum aperture of the zoom projection lamp lens does not exceed 117 mm, and the length of the zoom projection lamp lens does not exceed 340 mm.

[0019] Further, the total weight of other parts of the zoom projection lamp lens except the light source does not exceed 1400 g.

[0020] The technical solution of the present invention has the following advantages:

[0021] By moving the zoom lens group and the compensation lens group closer to or farther away from each other along the optical axis direction, the adjustment of the light-emitting field angle size of the zoom projection lamp lens can be realized, meeting the projection requirements of different background patterns during shooting; moreover, the diaphragm and the compensation lens group always maintain a fixed relative position, which is beneficial to improving the stability of the lens image plane illuminance, and clearly projecting the pattern on the basis of realizing the flexible adjustment of the lens light-emitting field angle; at the same time, the optical powers of the front fixed lens group, the zoom lens group, and the compensation lens group are specifically controlled to satisfy: -3 < F(1) / F(2) < -2; -1 < F(4) / F(2) < -0.3; this is beneficial to realizing a certain zoom ratio and not increasing the aperture and total length of the lens due to the too long moving distance of the lens group, making the lens have the advantages of compact structure, small volume, light weight, and low cost. Description of the Drawings

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is the optical structure diagram when the field of view angle of the zoom projection lamp lens in the embodiment of the present invention is 18°;

[0024] Figure 2 It is the optical structure diagram when the field of view angle of the zoom projection lamp lens in the embodiment of the present invention is 36°;

[0025] Figure 3 It is the field curvature and distortion diagram when the field of view angle of the zoom projection lamp lens in the embodiment of the present invention is 18°;

[0026] Figure 4 It is the field curvature and distortion diagram when the field of view angle of the zoom projection lamp lens in the embodiment of the present invention is 36°.

[0027] Explanation of reference numerals: 1. Front fixed lens group; 2. Zoom lens group; 3. Diaphragm; 4. Compensation lens group; 5. Rear fixed lens group; 6. Projection object; 7. Collimation assembly; 8. Light source; LI. First lens; L2. Second lens; L3. Third lens; L4. Fourth lens; L5. Fifth lens; L6. Sixth lens; L7. Seventh lens. Specific embodiments

[0028] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the drawings. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0030] An embodiment of the present invention provides a zoom projection lamp lens, which is used to flexibly change different field angles of view, and can clearly project patterns on the premise of realizing this function, and has the advantages of small device volume, light weight, low price, etc.

[0031] Refer to Figure 1 As shown in FIG. -4, the zoom projection lamp lens includes a front fixed lens group 1, a zoom lens group 2, a diaphragm 3, a compensation lens group 4, a fixed lens group 5, a projection object 6, a collimation assembly 7, and a light source 8, which are arranged in sequence from the image plane side to the projection side along the optical axis. Among them, the front fixed lens group 1, the zoom lens group 2, the diaphragm 3, the compensation lens group 4, the rear fixed lens group 5, and the projection object 6 together constitute an imaging lens.

[0032] In this embodiment, the front fixed lens group 1 includes a first lens L1 with a positive optical power. The zoom lens group 2 includes a second lens L2 with a negative optical power. The diaphragm 3 is arranged between the zoom lens group 2 and the compensation lens group 4. The compensation lens group 4 includes a third lens L3 with a positive optical power, a fourth lens L4 with a negative optical power, a fifth lens L5 with a negative optical power, and a sixth lens L6 with a positive optical power, which are arranged in sequence from the image plane side to the projection side along the optical axis; among them, the third lens L3 and the fourth lens L4 are a group of lenses, and the fifth lens L5 and the sixth lens L6 are a group of lenses. The fixed lens group 5 includes a seventh lens L7 with a positive optical power.

[0033] Among them, the focal length distribution relationship of the front fixed lens group 1, the zoom lens group 2, and the compensation lens group 4 satisfies the following relationship: -3 < F(1) / F(2) < -2; -1 < F(4) / F(2) < -0.3; F(1) represents the focal length of the front fixed lens group 1, F(2) represents the focal length of the zoom lens group 2, and F(4) represents the focal length of the compensation lens group 4.

[0034] It can be understood here that the number of lenses of the zoom projection lens is not limited to seven lenses, and the number of lenses can be further changed. For example, the front fixed lens group 1, the zoom lens group 2, and the rear fixed lens group 5 can also be composed of multiple lenses, as long as the optical powers of all lens groups of the zoom projection lens satisfy the above mathematical relationship.

[0035] The light-emitting field angle range of the zoom projection lens is 18° - 36°, and it is a 2X zoom system. The zoom lens group 2 is movably arranged along the optical axis direction. The aperture 3 and the compensating lens group 4 can move synchronously along the optical axis direction and maintain a fixed relative position during synchronous movement. By moving the zoom lens group 2 and the compensating lens group 4 closer to or farther away from each other along the optical axis direction, the light-emitting field angle of the zoom projection lamp lens can be changed between 18° - 36°. When the zoom lens group 2 moves along the optical axis, the compensating lens group 4 and the aperture 3 both move in the opposite direction along the optical axis to offset the image plane movement caused by the movement of the zoom lens group 2. When the distance between the zoom lens group 2 and the compensating lens group 4 increases, the focal length of the zoom projection lens gradually becomes shorter, the light-emitting field angle becomes larger, and the light spot in the projection area gradually becomes larger; when the distance between the zoom lens group 2 and the compensating lens group 4 decreases, the focal length of the zoom projection lens gradually becomes longer, the light-emitting field angle becomes smaller, and the light spot in the projection area gradually becomes smaller.

[0036] The focusing distance of the zoom projection lamp lens projected onto the wall is from one meter to five meters, which is achieved by changing the distance between the rear fixed lens group 5 and the projection object 6. The maximum clear aperture diameter of the projection object 6 is 50 - 60 mm.

[0037] When the zoom projection lamp lens projects a pattern, the projection object 6 is a pattern sheet composed of different clear apertures. The contour dimensions of the clear apertures of the projection object 6 are relatively large, so the zoom projection lamp lens is a large aberration system; the projection object 6 is a single-color metal device, so there are no high requirements for the chromatic aberration of the zoom projection lamp lens; this greatly reduces the manufacturing cost of the optical glass inside the zoom projection lamp lens. When the zoom projection lamp lens performs ordinary lighting, that is, when pattern projection is not required, the projection object 6 only refers to the light inlet hole of the zoom projection lamp lens and there is no pattern sheet.

[0038] The collimating component 7 is used to turn the light rays emitted by the light source 8 into parallel light and then emit it onto the projection object 6. The collimating component 7 can be a lens group composed of several spherical, aspherical, non-spherical or Fresnel lenses, or a collimating lens or other collimating systems with special-shaped structures. The function of the collimating component 7 is to collect the energy of the light source 8, redistribute the light rays of the light source 8 onto the projection object 6, so that the projected illumination is high and the brightness distribution is uniform.

[0039] The light source 8 is used to provide projection light rays. The light source 8 includes LED light sources, array light sources, other light sources (such as organic light-emitting diodes or laser diode arrays, etc.), and the light source 8 can be a monochromatic light source, a composite light source, white light, or other light sources with adjustable color temperature, color, and power.

[0040] In this embodiment, the maximum aperture of the zoom projection lamp lens does not exceed 117 mm, the total length of the zoom projection lamp lens does not exceed 340 mm, and the total weight of the parts of the zoom projection lamp lens other than the light source 8 does not exceed 1400 g.

[0041] The zoom projection lamp lens provided by the present invention can adjust the size of the light-emitting field angle of the zoom projection lamp lens within the range of 18° - 36° by moving the zoom lens group 2 and the compensating lens group 4 closer to or away from each other along the optical axis direction. When the maximum clear aperture of the projection object 6 is 50 - 60 mm, during the focal length adjustment, the diaphragm 3 and the compensating lens group 4 move synchronously and in the opposite direction to the movement direction of the zoom lens group 2, which is beneficial to improving the stability of the image plane illuminance of the zoom projection lamp lens and clearly projecting the pattern on the basis of realizing the flexible adjustment of the light-emitting field angle of the lens. At the same time, the optical powers of the front fixed lens group 1, the zoom lens group 2, and the compensating lens group 4 are controlled specifically to satisfy: -3 < F(1) / F(2) < -2; -1 < F(4) / F(2) < -0.3; this is beneficial to realizing a certain zoom ratio and not increasing the aperture and total length of the lens due to the too long moving distance of the lens group, making the lens have the advantages of compact structure, small volume, light weight, and low cost.

[0042] The following Table 1 lists the actual parameters of each lens in this embodiment that meet the above mathematical relationship:

[0043]

[0044]

[0045] Table 1

[0046] In Table 1, S1 is the side surface of the first lens LI facing the image plane side, S2 is the side surface of the first lens LI facing away from the image plane side; S3 is the side surface of the second lens L2 facing the image plane side, S4 is the side surface of the second lens L2 facing away from the image plane side; S5 is the diaphragm; S6 is the side surface of the third lens L3 facing the image plane side, S7 is the side surface of the third lens L3 facing away from the image plane side; S8 is the side surface of the fourth lens L4 facing the image plane side, S9 is the side surface of the fourth lens L4 facing away from the image plane side; S10 is the side surface of the fifth lens L5 facing the image plane side, S11 is the side surface of the fifth lens L5 facing away from the image plane side; S12 is the side surface of the sixth lens L6 facing the image plane side, S13 is the side surface of the sixth lens L6 facing away from the image plane side; S14 is the side surface of the seventh lens L7 facing the image plane side, S15 is the side surface of the seventh lens L7 facing away from the image plane side.

[0047] When the zoom projection lamp lens zooms from a field angle of 18° to a field angle of 36°, the air interval parameters change as shown in Table 2 below:

[0048] Thickness (mm) 18° configuration 36° configuration D(2) 41.98 2.18 D(4) 8.50 81.20 D(13) 35.38 2.49

[0049] Table 2

[0050] In Table 2, D(2) is the central air gap between the first lens L1 and the second lens L2 in the optical axis direction; D(4) is the central air gap between the second lens L2 and the third lens L3 in the optical axis direction; D(13) is the central air gap between the sixth lens L6 and the seventh lens L7 in the optical axis direction.

[0051] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A variable magnification projection lamp lens, characterized in that, it includes a front fixed lens group (1) with positive optical power, a variable magnification lens group (2) with negative optical power, a diaphragm (3), a compensating lens group (4), and a rear fixed lens group (5) with positive optical power, which are sequentially arranged from the image plane side to the projection side along the optical axis; the focal lengths of the front fixed lens group (1), the variable magnification lens group (2), and the compensating lens group (4) satisfy the following conditional expressions: -3 < F(1) / F(2) < -2; -1 < F(4) / F(2) < -0.3; wherein, F(1) is the focal length of the front fixed lens group (1), F(2) is the focal length of the variable magnification lens group (2), and F(4) is the focal length of the compensating lens group (4); the variable magnification lens group (2) and the compensating lens group (4) approach or move away from each other along the optical axis to adjust the focal length of the variable magnification projection lamp lens, and further adjust the range of the light-emitting field angle of the variable magnification projection lamp lens.

2. The variable magnification projection lamp lens according to claim 1, characterized in that, the diaphragm (3) and the compensating lens group (4) can move synchronously along the optical axis and maintain a fixed relative position.

3. The variable magnification projection lamp lens according to claim 2, characterized in that, when the variable magnification lens group (2) moves along the optical axis, the compensating lens group (4) and the diaphragm (3) both move in the opposite direction along the optical axis to offset the image plane movement caused by the movement of the variable magnification lens group (2).

4. The variable magnification projection lamp lens according to claim 1, characterized in that, the front fixed lens group (1) includes a first lens (L1) with positive optical power; the variable magnification lens group (2) includes a second lens (L2) with negative optical power; the compensating lens group (4) includes a third lens (L3) with positive optical power, a fourth lens (L4) with negative optical power, a fifth lens (L5) with negative optical power, and a sixth lens (L6) with positive optical power, which are sequentially arranged from the image plane side to the projection side along the optical axis; the rear fixed lens group (5) includes a seventh lens (L7) with positive optical power.

5. The variable magnification projection lamp lens according to claim 1, characterized in that, the adjustable range of the light-emitting field angle of the variable magnification projection lamp lens is 18° - 36°.

6. The variable magnification projection lamp lens according to claim 1, characterized in that, a projection object (6), a collimating component (7), and a light source (8) are sequentially arranged along the optical axis on one side of the rear fixed lens group (5); the collimating component (7) is used to convert the light emitted by the light source (8) into parallel light and then emit it onto the projection object (6).

7. The variable magnification projection lamp lens according to claim 6, characterized in that, the distance between the projection object (6) and the rear fixed lens group (5) along the optical axis is adjustable.

8. The variable magnification projection lamp lens according to claim 6, characterized in that, the maximum clear aperture diameter of the projection object (6) is 50 - 60 mm.

9. The variable magnification projection lamp lens according to claim 6, characterized in that, The maximum aperture of the zoom projection lamp lens does not exceed 117 mm, and the length of the zoom projection lamp lens does not exceed 340 mm.

10. The zoom projection lamp lens according to claim 6, characterized in that the total weight of other parts of the zoom projection lamp lens except the light source (8) does not exceed 1400 g.

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