projector

Abstract

The application provides a projector. The projector comprises a light combination module and a zoom lens, the zoom lens is located on the light exit side of the light combination module, the zoom lens comprises a first lens group with positive refractive power, a second lens group with negative refractive power and a third lens group with positive refractive power from the first side to the second side in sequence, the first lens group comprises a first lens with positive refractive power and a second lens with positive refractive power from the first side to the second side in sequence; the second lens group comprises a third lens with positive refractive power, a fourth lens with negative refractive power and a fifth lens with negative refractive power from the first side to the second side in sequence; the third lens group comprises a sixth lens with positive refractive power and a seventh lens with positive refractive power from the first side to the second side in sequence; the fourth lens and the fifth lens are movably arranged on the optical axis. The application solves the problem that the zoom lens of the projector in the prior art is difficult to realize miniaturization.

Description

Technical Field

[0001] This invention relates to the field of optical imaging equipment technology, and more specifically, to a projector. Background Technology

[0002] Currently, zoom lenses are experiencing rapid development. Due to their unique zoom capabilities and rich shooting functions, the demand for zoom lenses is increasing, especially in projectors. In projectors, the beam combining module combines the light from a light source for output. Typically, an illumination system collects the light to form a uniform illumination beam, which is then transmitted to the imaging system for projection. The illumination system plays a crucial role in projectors, and zoom lenses are commonly used to control the beam emitted from the beam combining module. Existing zoom lenses, in order to meet the demands of high magnification, usually employ numerous lenses, leading to an increase in overall length and size, making them difficult to apply in miniaturized devices.

[0003] In other words, existing projector zoom lenses face the challenge of miniaturization. Summary of the Invention

[0004] The main objective of this invention is to provide a zoom lens to solve the problem that zoom lenses in existing projectors are difficult to miniaturize.

[0005] To achieve the above objectives, the present invention provides a projector including a light combining module and a zoom lens. The zoom lens is located on the light-emitting side of the light combining module. From the first side to the second side, the zoom lens sequentially includes a first lens group with positive optical power, a second lens group with negative optical power, and a third lens group with positive optical power. The first lens group sequentially includes a first lens with positive optical power and a second lens with positive optical power from the first side to the second side. The second lens group sequentially includes a third lens with positive optical power, a fourth lens with negative optical power, and a fifth lens with negative optical power from the first side to the second side. The third lens group sequentially includes a sixth lens with positive optical power and a seventh lens with positive optical power from the first side to the second side. The fourth and fifth lenses are movably arranged on the optical axis. The light beam emitted from the zoom lens enters a light modulator, and the field of view (FOV) of the light beam output by the zoom lens satisfies: FOV < 0.7°.

[0006] Furthermore, the zoom lens also includes an aperture stop, which is located between the second lens group and the third lens group or in the third lens group; and / or, the aperture stop is an adjustable aperture stop.

[0007] Furthermore, the distance L from the aperture stop to the imaging plane of the zoom lens on the optical axis satisfies the following relationship with the total optical length TTL of the zoom lens: 0.03 < L / TTL < 0.37.

[0008] Furthermore, when the zoom lens is at the wide-angle end, the focal length fw of the zoom lens and the focal length f1 of the first lens group satisfy: 0.015 < fw / f1 < 0.09; or, when the zoom lens is at the wide-angle end, the focal length fw of the zoom lens and the focal length f2 of the second lens group satisfy: -4.05 < fw / f2 < -1.41; or, when the zoom lens is at the wide-angle end, the focal length fw of the zoom lens and the focal length f3 of the third lens group satisfy: 0.82 < fw / f3 < 2.07.

[0009] Furthermore, when the zoom lens is at the telephoto end, the focal length ft of the zoom lens and the focal length f1 of the first lens group satisfy: 0.31 < ft / f1 < 1.81; or, when the zoom lens is at the telephoto end, the focal length ft of the zoom lens and the focal length f2 of the second lens group satisfy: -81.2 < ft / f2 < -28.3; or, when the zoom lens is at the telephoto end, the focal length ft of the zoom lens and the focal length f3 of the third lens group satisfy: 16.39 < ft / f3 < 41.41.

[0010] Furthermore, the focal length f1 of the first lens group and the focal length f11 of the first lens satisfy: 0.17 < f1 / f11 < 0.94; and / or, the focal length f1 of the first lens group and the focal length f12 of the second lens satisfy: 0.32 < f1 / f12 < 0.87.

[0011] Furthermore, the zoom lens satisfies at least one of the following three items: the focal length f2 of the second lens group and the focal length f21 of the third lens satisfy: -0.37 < f2 / f21 < -0.025; the focal length f2 of the second lens group and the focal length f22 of the fourth lens satisfy: 0.07 < f2 / f22 < 0.68; the focal length f2 of the second lens group and the focal length f23 of the fifth lens satisfy: 0.37 < f2 / f23 < 0.86.

[0012] Furthermore, the focal length f3 of the third lens group and the focal length f31 of the sixth lens satisfy: 0.36 < f3 / f31 < 0.74; and / or, the focal length f3 of the third lens group and the focal length f32 of the seventh lens satisfy: 0.13 < f3 / f32 < 0.68.

[0013] Furthermore, the first side of the first lens is convex, and the second side is convex; the first side of the second lens is convex, and the second side is concave; the first side of the third lens is convex, and the second side is concave; the first side of the fourth lens is convex, and the second side is concave; the first side of the fifth lens is concave, and the second side is concave; the first side of the sixth lens is convex, and the second side is convex; the first side of the seventh lens is convex, and the second side is concave.

[0014] Furthermore, the focal length fw of the zoom lens at the wide-angle end and the focal length ft of the zoom lens at the telephoto end satisfy the following condition: 1≤ft / fw≤20.

[0015] According to the technical solution of this invention, the projector includes a light combining module and a zoom lens. The zoom lens is located on the light emitting side of the light combining module. The zoom lens sequentially includes, from the first side to the second side, a first lens group with positive optical power, a second lens group with negative optical power, and a third lens group with positive optical power. The first lens group sequentially includes, from the first side to the second side, a first lens with positive optical power and a second lens with positive optical power. The second lens group sequentially includes, from the first side to the second side, a third lens with positive optical power, a fourth lens with negative optical power, and a fifth lens with negative optical power. The third lens group sequentially includes, from the first side to the second side, a sixth lens with positive optical power and a seventh lens with positive optical power. The fourth and fifth lenses are movably arranged on the optical axis. The light beam emitted from the zoom lens enters the light modulator, and the field of view (FOV) of the light beam output by the zoom lens satisfies: FOV < 0.7°.

[0016] By setting the first lens group to have positive optical power, the second lens group to have negative optical power, and the third lens group to have positive optical power, it is beneficial to rationally allocate the optical power of each lens group, and consequently, the optical power of the lenses within each lens group. This facilitates the deflection and transmission of light and a smooth transition, rationally planning the optical path and ensuring imaging reliability. Simultaneously, it allows the zoom lens to collect light from the first side, ensuring sufficient light transmission and further guaranteeing the image sharpness and brightness of the zoom lens. Furthermore, the fact that both the first lens group and the first lens have positive optical power helps to reduce the entry of large-angle light rays into the zoom lens, compressing the optical path length. The rational allocation of optical power from the second to the seventh lens further helps to compress the overall optical length of the zoom lens, ensuring miniaturization. The fourth and fifth lenses are movable on the optical axis. By adjusting the positions of the fourth and fifth lenses on the optical axis, the distance between the third and fourth lenses, and the distance between the fifth and sixth lenses, is changed, thus enabling the zoom lens to fulfill its zoom function. The light beam emitted from the zoom lens enters the light modulator, and the field of view (FOV) of the light beam output by the zoom lens satisfies: FOV < 0.7°. This setting enables the zoom lens of this application to still achieve a good collimation effect at the wide-angle end. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1A schematic diagram of a projector with its zoom lens at the wide-angle end, according to an optional embodiment of the present invention, is shown.

[0019] Figure 2 A schematic diagram of a projector with its zoom lens at the middle end, according to an optional embodiment of the present invention, is shown.

[0020] Figure 3 A schematic diagram of a projector with its zoom lens at the telephoto end, according to an optional embodiment of the present invention, is shown.

[0021] Figure 4 A schematic diagram of the beam angle distribution output through a zoom lens according to an optional embodiment of the present invention is shown.

[0022] The above figures include the following reference numerals:

[0023] G1, First lens; G2, Second lens; G3, Third lens; G4, Fourth lens; G5, Fifth lens; 10, Aperture stop; G6, Sixth lens; G7, Seventh lens; 20, Imaging plane. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0026] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0027] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features.

[0028] In this paper, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the first side is called the first side surface of the lens, and the surface of each lens closest to the second side is called the second side surface of the lens. The surface shape in the paraxial region can be determined according to the judgment method commonly known in the field, using the R value (R refers to the radius of curvature of the paraxial region, usually the R value in the lens database of optical software) to determine concavity or convexity. For the first side surface, when the R value is positive, it is determined to be convex, and when the R value is negative, it is determined to be concave; for the second side surface, when the R value is positive, it is determined to be concave, and when the R value is negative, it is determined to be convex.

[0029] In this application, the left side of the zoom lens is the first side, and the right side is the second side.

[0030] The main objective of this invention is to provide a projector that solves the problem of miniaturization of zoom lenses in existing projectors.

[0031] like Figures 1 to 4 As shown, the projector includes a light combining module and a zoom lens. The zoom lens is located on the light-emitting side of the light combining module. From the first side to the second side, the zoom lens sequentially includes a first lens group with positive optical power, a second lens group with negative optical power, and a third lens group with positive optical power. The first lens group sequentially includes a first lens with positive optical power and a second lens with positive optical power from the first side to the second side. The second lens group sequentially includes a third lens with positive optical power, a fourth lens with negative optical power, and a fifth lens with negative optical power from the first side to the second side. The third lens group sequentially includes a sixth lens with positive optical power and a seventh lens with positive optical power from the first side to the second side. The fourth and fifth lenses are movable on the optical axis. The light beam emitted from the zoom lens enters the light modulator, and the field of view (FOV) of the light beam output by the zoom lens satisfies: FOV < 0.7°.

[0032] By setting the first lens group to have positive optical power, the second lens group to have negative optical power, and the third lens group to have positive optical power, it is beneficial to rationally allocate the optical power of each lens group, and consequently, the optical power of the lenses within each lens group. This facilitates the deflection and transmission of light and a smooth transition, rationally planning the optical path and ensuring imaging reliability. Simultaneously, it allows the zoom lens to collect light from the first side, ensuring sufficient light transmission and further guaranteeing the image sharpness and brightness of the zoom lens. Furthermore, the fact that both the first lens group and the first lens have positive optical power helps to reduce the entry of large-angle light rays into the zoom lens, compressing the optical path length. The rational allocation of optical power from the second to the seventh lens further helps to compress the overall optical length of the zoom lens, ensuring miniaturization. The fourth and fifth lenses are movable on the optical axis. By adjusting the positions of the fourth and fifth lenses on the optical axis, the distance between the third and fourth lenses, and the distance between the fifth and sixth lenses, can be changed, thus enabling the zoom lens to fulfill its zoom function. The light beam emitted from the zoom lens enters the light modulator, and the field of view (FOV) of the light beam output by the zoom lens satisfies: FOV < 0.7°. This setting enables the zoom lens of this application to still achieve a good collimation effect at the wide-angle end.

[0033] It should be noted that the fourth and fifth lenses move synchronously, meaning that the distance between them remains constant. The on-axis distance D1 between the third and fourth lenses, and the on-axis distance D2 between the fifth and sixth lenses, are adjustable. By adjusting D1 and D2, the zoom lens can fulfill its zoom function.

[0034] It's important to note that the changes in D1 and D2 are actually achieved by adjusting the movable settings of the fourth and fifth lenses along the optical axis. Specifically, both the on-axis distance D1 between the third and fourth lenses and the on-axis distance D2 between the fifth and sixth lenses are adjustable. In other words, the fourth and fifth lenses are movable along the optical axis. By changing the distances between the third and fourth lenses, and between the fifth and sixth lenses, the zoom function is achieved, allowing the zoom lens to switch between at least the wide-angle, intermediate, and telephoto ends. Specifically, the distance between the fifth and sixth lenses is also the distance between the second and third lens groups. By adjusting the movement of the third lens group along the optical axis, the zoom lens's focusing is achieved.

[0035] Furthermore, as the zoom lens zooms from the telephoto end to the wide-angle end, the field of view (FOV) of the light beam gradually increases. The light beam emitted from the zoom lens enters the light modulator, and after collimation and beam expansion by the zoom lens, the FOV of the output light beam satisfies: FOV < 0.7°. Specifically, when the zoom lens is at the wide-angle end, the FOV of the light beam output by the zoom lens satisfies: FOV < 0.7°. This setting allows this application to achieve good collimation effects even at the wide-angle end. Figure 4 The diagram shows the angular distribution of the light beam output by the zoom lens when it is at the telephoto end. As can be seen from the diagram, the field of view of the light beam output by the zoom lens at the telephoto end is smaller, approximately 0.035°. Preferably, 0° ≤ FOV < 0.7°.

[0036] In this application, the projector includes a light combining module, a zoom lens, and an imaging module. The light combining module is an optical system that combines multiple color light sources, emitting light from multiple different colors of light. The zoom lens is located on the light-emitting side of the light combining module, specifically between the imaging module and the light combining module. The zoom lens receives the light beam emitted from the light combining module and outputs a collimated beam to the imaging module. Therefore, the zoom lens in this application is mainly used in the illumination section of the projector.

[0037] Specifically, zoom lenses also include an aperture stop, which is located between the second and third lens groups, or within the third lens group. In this case, the aperture stop moves as the third lens group moves along the optical axis. By properly setting the position of the aperture stop, it is beneficial to properly converge the light rays, to plan the light path, and to ensure the rationality and stability of light transmission.

[0038] In a specific embodiment of this application, the aperture stop is an adjustable aperture stop. Specifically, the aperture stop is an aperture stop of variable size, which can adjust the size of the aperture. The aperture stop is used to limit the beam diameter, and the power of the emitted light can be changed by adjusting the aperture stop.

[0039] Specifically, the distance L from the aperture stop to the imaging plane of the zoom lens on the optical axis satisfies the following condition with respect to the total optical length TTL of the zoom lens: 0.03 < L / TTL < 0.37. The total optical length TTL of the zoom lens is specifically the axial distance from the first side surface of the first lens to the imaging plane. In a preferred embodiment of this application, the aperture stop is positioned between the second and third lens groups, satisfying: 0.15 < L / TTL < 0.30. This arrangement is beneficial for compressing the total optical length of the zoom lens, thus facilitating miniaturization. In different embodiments of this application, L / TTL = 0.03, 0.08, 0.15, 0.21, 0.27, 0.30, and 0.37.

[0040] Specifically, when the zoom lens is at the wide-angle end, the focal length fw of the zoom lens and the focal length f1 of the first lens group satisfy: 0.015 < fw / f1 < 0.09. Such a setting is beneficial to the reasonable distribution of the focal length of the first lens group when the zoom lens is at the wide-angle end, ensuring the rationality of the proportion of the focal length of the first lens group and facilitating the stability of the zoom lens at the wide-angle end. In different embodiments of the present application, fw / f1 = 0.015, 0.07, 0.09.

[0041] Specifically, when the zoom lens is at the wide-angle end, the focal length fw of the zoom lens and the focal length f2 of the second lens group satisfy: -4.05 < fw / f2 < -1.41. Such a setting is beneficial to the reasonable distribution of the focal length of the second lens group when the zoom lens is at the wide-angle end, ensuring the rationality of the proportion of the focal length of the second lens group and facilitating the stability of the zoom lens at the wide-angle end. In different embodiments of the present application, fw / f2 = -4.05, -3.20, -2.96, -1.70, -1.41.

[0042] Specifically, when the zoom lens is at the wide-angle end, the focal length fw of the zoom lens and the focal length f3 of the third lens group satisfy: 0.82 < fw / f3 < 2.07. Such a setting is beneficial to the reasonable distribution of the focal length of the third lens group when the zoom lens is at the wide-angle end, ensuring the rationality of the proportion of the focal length of the third lens group and facilitating the stability of the zoom lens at the wide-angle end. In different embodiments of the present application, fw / f3 = 0.82, 1.33, 1.84, 2.07.

[0043] Specifically, when the zoom lens is at the telephoto end, the focal length ft of the zoom lens and the focal length f1 of the first lens group satisfy: 0.31 < ft / f1 < 1.81; such a setting is beneficial to the reasonable distribution of the focal length of the first lens group when the zoom lens is at the telephoto end, ensuring the rationality of the proportion of the focal length of the first lens group and facilitating the stability of the zoom lens at the telephoto end. In different embodiments of the present application, ft / f1 = 0.31, 0.87, 1.22, 1.81.

[0044] Specifically, when the zoom lens is at the telephoto end, the focal length ft of the zoom lens and the focal length f2 of the second lens group satisfy: -81.2 < ft / f2 < -28.3; such a setting is beneficial to the reasonable distribution of the focal length of the second lens group when the zoom lens is at the telephoto end, ensuring the rationality of the proportion of the focal length of the second lens group and facilitating the stability of the zoom lens at the telephoto end. In different embodiments of the present application, ft / f2 = -81.2, -66.3, -51.5, -38.1, -28.3.

[0045] Specifically, the focal length ft of the zoom lens at the telephoto end and the focal length f3 of the third lens group satisfy the following relationship: 16.39 < ft / f3 < 41.41. This setting facilitates the reasonable allocation of the focal length of the third lens group when the zoom lens is at the telephoto end, ensuring a reasonable proportion of the focal length of the third lens group and contributing to the stability of the zoom lens at the telephoto end. In different embodiments of this application, ft / f3 = 16.39, 18.2, 22.5, 35.7, and 41.41.

[0046] Specifically, the focal length f1 of the first lens group and the focal length f11 of the first lens satisfy the following relationship: 0.17 < f1 / f11 < 0.94; the focal length f1 of the first lens group and the focal length f12 of the second lens satisfy the following relationship: 0.32 < f1 / f12 < 0.87. This arrangement facilitates the rational allocation of the focal lengths of the first and second lenses, ensures the stability of the light rays at the transition front end between the first and second lenses, and helps to guarantee the amount of light transmitted. In different embodiments of this application, f1 / f11 = 0.17, 0.44, 0.68, 0.94. In different embodiments of this application, f1 / f12 = 0.32, 0.43, 0.56, 0.87.

[0047] Specifically, the focal length f2 of the second lens group and the focal length f21 of the third lens satisfy the following relationship: -0.37 < f2 / f21 < -0.025; the focal length f2 of the second lens group and the focal length f22 of the fourth lens satisfy the following relationship: 0.07 < f2 / f22 < 0.68; the focal length f2 of the second lens group and the focal length f23 of the fifth lens satisfy the following relationship: 0.37 < f2 / f23 < 0.86. This arrangement facilitates the rational allocation of the focal lengths of the third, fourth, and fifth lenses, ensuring that the three lenses of the second lens group can stably receive the light from the first lens group, ensuring a smooth light transition and guaranteeing light transmission efficiency. Simultaneously, the combination of positive and negative lenses helps eliminate aberrations in the first lens group, ensuring image quality. In different embodiments of this application, f2 / f21 = -0.37, -0.28, -0.17, -0.04, and -0.025. In different embodiments of this application, f2 / f22 = 0.07, 0.20, 0.37, 0.55, 0.68. In different embodiments of this application, f2 / f23 = 0.37, 0.46, 0.73, 0.86.

[0048] Specifically, the focal length f3 of the third lens group and the focal length f31 of the sixth lens satisfy the following relationship: 0.36 < f3 / f31 < 0.74; the focal length f3 of the third lens group and the focal length f32 of the seventh lens satisfy the following relationship: 0.13 < f3 / f32 < 0.68. This arrangement facilitates a reasonable allocation of the focal lengths of the fifth and sixth lenses, allows the third lens group to receive the light transmitted from the second lens group, ensures stable imaging, avoids light loss, and guarantees image quality. In different embodiments of this application, f3 / f31 = 0.36, 0.49, 0.62, 0.74. In different embodiments of this application, f3 / f32 = 0.13, 0.25, 0.41, 0.53, 0.68.

[0049] Specifically, the focal length fw of the zoom lens at the wide-angle end and the focal length ft of the zoom lens at the telephoto end satisfy the following condition: 1 ≤ ft / fw ≤ 20. This setting enables the zoom lens of this application to achieve arbitrary zoom from 1x to 20x, thus fulfilling the zoom function.

[0050] It should be noted that the zoom lens of this application is mainly used in the field of laser lighting, specifically a laser lighting zoom lens, applicable to the visible light wavelength range.

[0051] The zoom lens of the projector of this application will now be described with reference to the accompanying drawings and specific embodiments.

[0052] like Figures 1 to 3 The zoom lens of this application is shown in the figure. Figure 1 A schematic diagram of the zoom lens at the wide-angle end is shown. Figure 2 A schematic diagram of the structure with the zoom lens at the middle end is shown. Figure 3 A schematic diagram of the zoom lens at the telephoto end is shown.

[0053] like Figures 1 to 3 As shown, the zoom lens, from the first side to the second side, includes, in sequence, a first lens G1, a second lens G2, a third lens G3, a fourth lens G4, a fifth lens G5, an aperture stop 10, a sixth lens G6, a seventh lens G7, and an imaging plane 20. The first lens G1 and the second lens G2 form the first lens group. The third lens G3, the fourth lens G4, and the fifth lens G5 form the second lens group. The sixth lens G6 and the seventh lens G7 form the third lens group.

[0054] In this embodiment, the first lens G1 has a convex first side and a convex second side; the second lens G2 has a convex first side and a concave second side; the third lens G3 has a convex first side and a concave second side; the fourth lens G4 has a convex first side and a concave second side; the fifth lens G5 has a concave first side and a concave second side; the sixth lens G6 has a convex first side and a convex second side; and the seventh lens G7 has a convex first side and a concave second side.

[0055] In this embodiment, the optical power of the first lens G1 is 158.1. The optical power of the second lens G2 is 126.2. The optical power of the third lens G3 is 41.3. The optical power of the fourth lens G4 is -17.6. The optical power of the fifth lens G5 is -2.3. The optical power of the sixth lens G6 is 5.5. The optical power of the seventh lens G7 is 5.2.

[0056] In this embodiment, fw / f1 = 0.07, fw / f2 = -2.96, fw / f3 = 1.84, f1 / f11 = 0.44, f1 / f12 = 0.56, f2 / f21 = -0.04, f2 / f22 = 0.20, f2 / f23 = 0.73, f3 / f31 = 0.49, and f3 / f32 = 0.53.

[0057] In this embodiment, the focal length of the zoom lens can be switched and changed within a range of greater than or equal to 5mm and less than or equal to 100mm. The on-axis distance D1 between the third and fourth lenses varies within a range of greater than or equal to 1mm and less than or equal to 3.74mm. The on-axis distance D2 between the fifth and sixth lenses varies within a range of greater than or equal to 0.16mm and less than or equal to 6.48mm. The total optical length (TTL) of the zoom lens is less than or equal to 79.7mm.

[0058] Table 1 below shows the basic structural parameters of the zoom lens in this embodiment.

[0059]

[0060]

[0061] Table 1

[0062] Table 2 below shows detailed parameters of the zoom lens, including focal length f, F-number, field of view (FOV), and total optical length (TTL), when the zoom lens is at the wide-angle, intermediate, and telephoto ends.

[0063] Parameters / Status Wide-angle end middle end telephoto end f(mm) 5 25 100 F-number 2.27 2.27 2.27 FOV 0.7 0.14 0.035 TTL(mm) 78.7 79.7 75.2 D1(mm) 1.0 3.3 3.74 D2 (mm) 6.48 5.14 0.16

[0064] Table 2

[0065] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0066] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0067] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A projector, characterized in that, It includes a light-combining module and a zoom lens. The zoom lens is located on the light-emitting side of the light-combining module. The zoom lens sequentially includes a first lens group with positive optical power, a second lens group with negative optical power, and a third lens group with positive optical power from the first side to the second side. The first lens group sequentially includes a first lens with positive optical power and a second lens with positive optical power from the first side to the second side. The second lens group sequentially includes a third lens with positive optical power, a fourth lens with negative optical power, and a fifth lens with negative optical power from the first side to the second side. The third lens group sequentially includes a sixth lens with positive optical power and a seventh lens with positive optical power from the first side to the second side. The fourth lens and the fifth lens are movably arranged on the optical axis. The light beam emitted by the zoom lens enters the optical modulator. The full field of view FOV of the light beam output by the zoom lens satisfies: FOV < 0.7°.

2. The projector according to claim 1, characterized in that, The zoom lens further includes an aperture stop. The aperture stop is located between the second lens group and the third lens group or within the third lens group; and / or, The aperture stop is an adjustable aperture stop.

3. The projector according to claim 1, characterized in that, The distance L between the aperture stop and the imaging plane of the zoom lens on the optical axis and the total optical length TTL of the zoom lens satisfy: 0.03 < L / TTL < 0.

37.

4. The projector according to claim 1, wherein The focal length fw of the zoom lens at the wide-angle end and the focal length f1 of the first lens group satisfy: 0.015 < fw / f1 < 0.09; or, The focal length fw of the zoom lens at the wide-angle end and the focal length f2 of the second lens group satisfy: -4.05 < fw / f2 < -1.41; or, The focal length fw of the zoom lens at the wide-angle end and the focal length f3 of the third lens group satisfy: 0.82 < fw / f3 < 2.

07.

5. The projector according to claim 1, wherein The focal length ft of the zoom lens at the telephoto end and the focal length f1 of the first lens group satisfy: 0.31 < ft / f1 < 1.81; or, The focal length ft of the zoom lens at the telephoto end and the focal length f2 of the second lens group satisfy: -81.2 < ft / f2 < -28.3; or, The focal length ft of the zoom lens at the telephoto end and the focal length f3 of the third lens group satisfy: 16.39 < ft / f3 < 41.

41.

6. The projector according to any one of claims 1 to 5, characterized in that, The focal length f1 of the first lens group and the focal length f11 of the first lens satisfy: 0.17 < f1 / f11 < 0.94; and / or, the focal length f1 of the first lens group and the focal length f12 of the second lens satisfy: 0.32 < f1 / f12 < 0.

87.

7. The projector according to any one of claims 1 to 5, characterized in that, The zoom lens satisfies at least one of the following three items: The focal length f2 of the second lens group and the focal length f21 of the third lens satisfy: -0.37 < f2 / f21 < -0.025; The focal length f2 of the second lens group and the focal length f22 of the fourth lens satisfy the following condition: 0.07 < f2 / f22 < 0.68; The focal length f2 of the second lens group and the focal length f23 of the fifth lens satisfy the following condition: 0.37 < f2 / f23 < 0.

86.

8. The projector according to any one of claims 1 to 5, characterized in that, The focal length f3 of the third lens group and the focal length f31 of the sixth lens satisfy the following condition: 0.36 < f3 / f31 < 0.74; and / or, The focal length f3 of the third lens group and the focal length f32 of the seventh lens satisfy the following condition: 0.13 < f3 / f32 < 0.

68.

9. The projector according to any one of claims 1 to 5, characterized in that, The first lens has a convex first side and a convex second side; the second lens has a convex first side and a concave second side; the third lens has a convex first side and a concave second side; the fourth lens has a convex first side and a concave second side; the fifth lens has a concave first side and a concave second side; the sixth lens has a convex first side and a convex second side; and the seventh lens has a convex first side and a concave second side.

10. The projector according to any one of claims 1 to 5, characterized in that, The focal length fw of the zoom lens at the wide-angle end and the focal length ft of the zoom lens at the telephoto end satisfy the following condition: 1 ≤ ft / fw ≤ 20.

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