Projection lens and projector

Abstract

A projection lens (1), characterized in that it comprises: a lens tube (10); a lens optics group (20) located in the lens tube (10); wherein the lens optics group (20) has a first optical axis (H) and comprises a zoom lens group (22); the zoom lens group (22) is able to move relative to the lens tube (10) along the extension direction of the first optical axis (H); and a zoom detection component (40) comprising a zoom movement part and a zoom detection part; wherein one of the zoom movement part and the zoom detection part is connected to the zoom lens group (22) to move with the zoom lens group (22) to change the zoom, and the other of the zoom movement part and the zoom detection part is fixed relative to the lens tube (10); wherein the zoom detection part serves to cooperate with the zoom movement part to detect the displacement distance of the zoom lens group (22) relative to the lens tube (10).

Description

Technical field

[0001] The present application concerns the field of projection technology and relates in particular to a projection lens and a projector. State of the art

[0002] A projector can be used as office equipment. Projectors can be used not only for meetings, technical presentations, in network centers, command and control centers, but also connected to computers, workstations, or to video recorders, televisions, DVD players, and document cameras. It can be said that it is a versatile large-screen device. However, in the relevant technology, it is difficult to improve the accuracy of the fixed focal length or zoom function of projection devices. Content of the present application

[0003] The embodiments of the present application provide a projection lens and a projector which can improve the accuracy of the focusing and / or zooming of the projection lens.

[0004] In a first aspect, the present application provides a projection lens, comprising: a lens tube; a lens optical group located in the lens tube; wherein the lens optical group has a first optical axis and includes a zoom lens group; the zoom lens group can move relative to the lens tube along the extension direction of the first optical axis; and A zoom sensing component comprising a zoom movement part and a zoom sensing part; wherein one of the zoom movement part and the zoom sensing part is connected to the zoom lens group to move with the zoom lens group to change the zoom, and the other of the zoom movement part and the zoom sensing part is fixed relative to the lens tube; wherein the zoom sensing part serves to cooperate with the zoom movement part to sensing the displacement distance of the zoom lens group relative to the lens tube.

[0005] In a second aspect, the present application provides a projection lens, comprising: a lens tube; a lens optical group located in the lens tube; wherein the lens optical group has a first optical axis and comprises a zoom lens group and a focusing lens group arranged along the extension direction of the first optical axis; wherein both the zoom lens group and the focusing lens group are able to slide relative to the lens tube along the extension direction of the first optical axis; a zoom sensing component comprising a zoom movement part and a zoom sensing part; wherein one of the zoom movement part and the zoom sensing part is connected to the zoom lens group to move with the zoom lens group to change the zoom, and the other of the zoom movement part and the zoom sensing part is fixed relative to the lens tube; wherein the zoom sensing part serves to interact with the zoom movement part to sensing the displacement distance of the zoom lens group relative to the lens tube; and A focus detection component comprising a focus movement part and a focus detection part; wherein one of the focus movement part and the focus detection part is connected to the focusing lens group to move with the focusing lens group to focus adjustment, and the other of the focus movement part and the focus detection part is fixed relative to the lens tube; wherein the focus detection part serves to cooperate with the focus movement part to detect the displacement distance of the focusing lens group relative to the lens tube.

[0006] In a third aspect, the present application further provides a projector. The projector comprises a light motor and the projection lens according to one of the embodiments mentioned above; wherein the projection lens is connected to the light motor, and the light source of the light motor is configured to be projected through the projection lens onto an external projection plane.

[0007] Based on the projection lens and the projector in the embodiment of the present application, either the zoom movement part or the zoom detection part is attached to the zoom lens group and the other to the fixed lens group. Furthermore, either the focus movement part or the focus detection part is attached to the focusing lens group and the other to the fixed lens group. When the projection lens performs a focus and / or zoom operation, the zoom detection part can be used to detect the displacement distance required to focus the projection lens by cooperating with the zoom movement part, and the displacement distance required to zoom the projection lens can be detected by cooperating with the focus detection part.This allows the zoom lens group and the focusing lens group to be moved directly to the required adjustment positions, thus realizing the focus and zoom functions of the projection lens. By arranging the zoom detection component and the focus detection component on different lens groups, the present application can reduce the time required for the focus and / or zoom operation of the projection lens and improve the accuracy of the focusing and / or zooming of the projection lens. Brief description of the drawing

[0008] To clarify the technical solutions in the embodiments of the present application or in the prior art, the drawings required in the descriptions of the embodiments or the prior art are briefly presented below. It is understood that the drawings in the following descriptions represent only some embodiments of the present application. A person skilled in the art can derive further drawings from these drawings without any creative effort. Fig. Figure 1 is a schematic structure diagram of a lens according to some embodiments of the present application. Fig. Figure 2 is a schematic structure diagram of a lens optics group according to some embodiments of the present application. Reference symbol:

[0009] 1. Projection lens; 10, lens barrel; 11, curve groove; 20, lens optical group; 21, focusing lens group; 22, zoom lens group; 221, first lens group; 222, second lens group; 223, third lens group; 224, fourth lens group; L1, first lens; L2, second lens; L3, third lens; L4, fourth lens; L5, fifth lens; L6, sixth lens; L7, seventh lens; STO, aperture; 23, fixed lens group; 30, focus detection component; 40, Zoom capture component; 51, first transmission element; 52, second transmission element; H, first optical axis. Detailed description of the embodiments

[0010] To clarify the technical solutions in the embodiments of the present application or in related technologies, the embodiments of the present application are described below with reference to the accompanying drawings. Obviously, the described embodiments represent only a subset of the embodiments of the present application and not all embodiments. Based on the embodiments of the present application, all other embodiments that a person skilled in the art in this field obtains without inventive work fall within the scope of protection of the present application.

[0011] In current technology, projector lenses typically incorporate position sensors. These sensors move along the optical axis with the projection lens to detect its forward and backward movement, thus enabling the lens's focusing and zooming functions. However, because the projection lens's travel distance within the projector is small, minimizing errors during focusing and zooming is crucial.

[0012] To address the aforementioned situation, the present application proposes, in a first aspect, with reference to Fig. 1 to Fig. 2, a projection lens 1 comprising a lens tube 10, a lens optics group 20, and a zoom detection component 40.

[0013] The lens optical group 20 is located in the lens tube 10. The lens optical group 20 has a first optical axis H, and the lens optical group 20 includes a zoom lens group 22. The zoom lens group 22 can displace relative to the lens tube 10 along the direction of extension of the first optical axis H. The zoom sensing component 40 comprises a zoom movement part and a zoom sensing part (not shown). One part of the zoom movement part and the zoom sensing part is connected to the zoom lens group 22 to move with the zoom lens group 22 to change the zoom, while the other part of the zoom movement part and the zoom sensing part is fixed relative to the lens tube 10. The zoom sensing part serves to interact with the zoom movement part to detect the displacement distance of the zoom lens group 22 relative to the lens tube 10.

[0014] Specifically, the lens tube 10 provides installation space for the lens optics group 20. The zoom lens group 22 can comprise a lens carrier and one or more lenses. The lens(es) is / are attached to the lens carrier, and the lens carrier is slidably connected to the lens tube 10 along the direction of extension of the first optical axis H, thereby displacing the lens(es) along the direction of extension of the first optical axis H. The lens tube 10 has a front and a rear side, with the distance from the front side of the lens tube 10 to the object being imaged being smaller and the distance from the rear side of the lens tube 10 to the object being imaged being larger. The zoom lens group 22 can serve as the zoom group of the projection lens 1, which is located in the center of the lens tube 10.The movement of the zoom lens group 22 changes the focal length of the projection lens 1, which leads to a change in the angle of view or image size and achieves a zoom-in or zoom-out effect.

[0015] It should be noted that in these embodiments of the present application, either the zoom movement part or the zoom detection part is attached to the zoom lens group 22, and the other part of the zoom movement part and the zoom detection part is fixedly attached to the lens tube 10. During the zooming process of the projection lens 1, the interaction of the zoom movement part and the zoom detection part allows the displacement distance required for zooming the projection lens 1 to be detected, thereby enabling the zoom lens group 22 to be moved directly to the position to be set, thus realizing the zoom function of the projection lens 1. By arranging the zoom detection component 40 on different optical components, these embodiments shorten the time required for zooming the projection lens 1 and increase the accuracy of the zoom of the projection lens 1.

[0016] With reference to Fig. In some embodiments of the present application, the lens optics group 20 further comprises a fixed lens group 23, which is attached to the lens tube 10. The fixed lens group 23 and the zoom lens group 22 are arranged along the direction of extension of the first optical axis H. One of the zoom movement part and the zoom detection part is connected to the zoom lens group 22, the other is connected to the fixed lens group 23. The zoom detection part serves to cooperate with the zoom movement part to detect the distance between the zoom lens group 22 and the fixed lens group 23.

[0017] Specifically, the fixed lens group 23 can provide a mounting base for one of the zoom movement parts and the zoom detection part. The fixed lens group 23 is located at the rear of the lens tube 10, provides the lens optics group 20 with basic optical performance (refractive power), and remains stationary. The fixed lens group 23 can also serve as a reference point for the movement of the zoom lens group 22.

[0018] In some embodiments of the present application, the zoom detection part is a first magnet, and the zoom movement part is a first sensor. The first sensor serves to detect the magnetic signal of the first magnet in order to detect the distance between the zoom lens group 22 and the fixed lens group 23.

[0019] Specifically, the first sensor can detect the magnetic field strength of the first magnet. According to the principle of magnetic field attenuation with distance, the magnetic field strength of the first magnet detected by the first sensor differs depending on whether the first magnet and the first sensor are in different relative positions. One of the first magnet and first sensor moves with the zoom lens group 22 along the direction of extension of the first optical axis H, while the other of the first magnet and first sensor is fixed at the position of the fixed lens group 23. Thus, a mapping relationship can be established between the position of the fixed lens group 23 and the magnetic field strength detected by the first sensor.

[0020] For example, if the position of the first magnet changes, its magnetic field moves with the magnet, and the magnetic field strength detected by the first sensor changes. Then, in the projection lens 1, the zoom lens group 22 can be moved directly to the position where the first sensor detects a preset magnetic field strength, thus completing the zoom operation of the projection lens 1 and capturing a clear image. Preferably, the first sensor is a tunnel magnetoresistance (TMR) sensor. TMR sensors exhibit good temperature stability, higher sensitivity, lower power consumption, and better linearity; therefore, the use of a TMR sensor further optimizes the zoom performance of the projection lens 1.

[0021] Furthermore, in some embodiments, the first magnet is a magnetic strip, i.e., the first magnet consists of several magnetic segments arranged in a row. The first magnet has several north poles and several south poles, with the multiple north poles and the multiple south poles of the first magnet being arranged alternately along the direction of extension of the first optical axis H. This causes the first magnet to generate a magnetic field in the form of a periodic sine wave. By detecting this periodically changing magnetic field, the first sensor can measure the distance between the zoom lens group 22 and the fixed lens group 23 more precisely and, moreover, effectively reduce external interference, thereby improving the precision and stability of the zoom of the projection lens 1.This magnetic field in the form of a periodic sine wave allows the first sensor not only to accurately measure the distance and thus ensure stability and accuracy during the zoom process, but also enables the first magnet to maintain high sensitivity under complex environmental conditions, reduce errors, and allow the projection lens 1 to deliver clear images at different focal lengths, significantly increasing the image quality of the projection lens 1.

[0022] In some embodiments of the present application, as in Fig. As shown in Figure 1, the projection lens 1 further comprises a first transmission element 51. The first transmission element 51 is movably connected to the lens tube 10 and force-fitted to the zoom lens group 22. The first transmission element 51 serves to allow the zoom lens group 22 to slide along the direction of extension of the first optical axis H.

[0023] In some embodiments, the first transmission element 51 can be a stepper motor that enables fine zooming of the zoom lens group 22. For example, the first transmission element 51 is a zoom tube. The zoom tube is rotatably connected to the lens tube 10 and, by rotation, can cause the zoom lens group 22 to slide along the direction of extension of the first optical axis H, thereby achieving independent control of the zoom of the projection lens 1.

[0024] Furthermore, in some embodiments of the present application, the projection lens 1 also comprises a drive component (not shown) attached to the lens tube 10. The drive component is electrically connected to the first sensor and serves to receive the detection signal of the first sensor and to drive the first transmission element 51 so that it causes the zoom lens group 22 to slide along the direction of extension of the first optical axis H.

[0025] Specifically, a microprocessor is integrated into the drive component. This microprocessor processes the acquisition data from the first sensor in real time, thereby optimizing the movement path of the zoom lens group 22 and ensuring its precise positioning. This improves the image quality of the projection lens 1. The interaction of the drive component and the first sensor enables the automatic zooming of the projection lens 1, ensuring that it can react quickly and capture clear images in various shooting situations, thus meeting the requirements of high-dynamic-range photography.

[0026] With reference to Fig. In some embodiments of the present application, the zoom movement element is connected to the zoom lens group 22, and the zoom detection element is fixedly attached relative to the lens tube 10. A curved groove 11 is formed on the lens tube 10, in which the zoom movement element slides along the direction of extension of the first optical axis H. It is readily apparent that the curved groove 11 can provide guidance for the zoom movement element, which helps to ensure that the zoom movement element is guided precisely along a predetermined curved path in the curved groove 11, thus ensuring that the image quality of the projection lens 1 is not impaired during the zooming process.

[0027] In some embodiments of the present application, the maximum sliding distance of the zoom lens group 22 along the extension direction of the first optical axis H is greater than 30 mm.

[0028] Specifically, during the sliding zoom process of the zoom lens group 22, the data required for zooming the projection lens 1 can be fed back in real time by detecting the change in position of the zoom lens group 22 by the zoom movement unit and the zoom sensing unit. For example, the zoom movement unit is attached to the zoom lens group 22 and the zoom sensing unit to the fixed lens group 23. During the zoom process of the projection lens 1, the travel distance of the zoom movement unit is correspondingly larger because the range of the maximum sliding distance of the zoom lens group 22 is relatively large. This reduces the error that occurs when the zoom sensing unit detects the travel distance of the zoom movement unit, ensures data accuracy, thus optimizing zoom precision, improving image quality, and meeting high demands in complex shooting situations.

[0029] It should be noted that in some embodiments, such as in Fig. Figure 2 shows that the zoom lens group 22 is arranged successively along the extension direction of the first optical axis H and comprises a first lens group 221, a second lens group 222, a third lens group 223, and a fourth lens group 224. The first lens group 221, the second lens group 222, the third lens group 223, and the fourth lens group 224 are all slidably connected to the lens tube 10, and the sliding distances between the four lens groups can each be different.

[0030] Specifically, the zoom lens group 22 can serve as the zoom group of the projection lens 1. This zoom group utilizes a four-group cooperative design solution. By fine-tuning the distances and positions of the first lens group 221 to the fourth lens group 224, the light refraction path is precisely controlled to enable multi-stage zooming and thus optimize optical performance at different focal lengths. The four lens groups work together to correct primary and higher aberrations, reduce chromatic aberration and distortion, ensure a detailed image, and further improve the overall image quality of the projection lens 1. Furthermore, the coordinated optimization of the four lens groups allows for a change in the projection ratio and miniaturization of the projection lens 1.

[0031] Furthermore, as in Fig. Figure 2 shows the fourth lens group 224, comprising seven lenses with optical power (refractive power). The seven lenses are arranged successively along the direction of extension of the first optical axis H as follows: first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, and seventh lens L7. The first lens L1 and the second lens L2 are bonded together, as are the fourth lens L4, the fifth lens L5, and the sixth lens L6. It is readily apparent that the seven lenses in the fourth lens group 224 are arranged successively in a 2:1:3:1 configuration, which serves to correct chromatic aberration.

[0032] The material of the first to seventh lenses, L1 to L7, can be either plastic or glass. For example, lenses L1 to L7 can be plastic lenses. Using plastic lenses can not only effectively reduce the aberrations of the zoom lens group 22 and decrease its length, but also make the overall weight of the zoom lens group 22 lighter. For example, the material of at least one lens in the lens group 20 can be plastic (PC), where plastic materials can be polycarbonate, synthetic resin, etc.; or the material of at least one lens in the lens group 20 can be glass (GL); or lenses of different materials can be used in the lens group 20, i.e., a combined design of glass and plastic lenses is possible.Lenses made of plastic can reduce the production costs of lens optics group 20, while glass lenses withstand higher or lower temperatures and offer excellent optical performance and better stability. The specific configuration relationship of lenses made of different materials can be determined according to actual requirements and is not exhaustively listed here.

[0033] Furthermore, in some embodiments of the present application, the maximum sliding distance of the first lens group 221 along the direction of extension of the first optical axis H is greater than 5 mm; the maximum sliding distance of the second lens group 222 along the direction of extension of the first optical axis H is greater than 5 mm; the maximum sliding distance of the third lens group 223 along the direction of extension of the first optical axis H is greater than 30 mm; and the maximum sliding distance of the fourth lens group 224 along the direction of extension of the first optical axis H is greater than 10 mm. Specifying the maximum sliding distance for each lens group contributes to the precise adjustment of the sliding distance of each group, improves the smoothness of the projection lens 1 during the zoom process, and ensures the stable performance of the projection lens 1 at different focal lengths.

[0034] Furthermore, one of the zoom movement part and the zoom detection part is attached to the third lens group 223, while the other of the zoom movement part and the zoom detection part is fixed relative to the lens tube 10. It is readily apparent that if the maximum sliding distance of the third lens group 223 along the direction of extension of the first optical axis H is greater than 30 mm, the movement distance detected by the zoom detection component 40 will also be greater than 30 mm.

[0035] Specifically, during the sliding zoom process of the zoom lens group 22, the data required for zooming the projection lens 1 can be fed back in real time by detecting the change in position of the third lens group 223 by the zoom movement unit and the zoom sensing unit. For example, the zoom movement unit is attached to the third lens group 223 and the zoom sensing unit to the fixed lens group 23. During the zoom process of the projection lens 1, the travel distance of the zoom movement unit is correspondingly larger because the range of the maximum sliding distance of the third lens group 223 is relatively large. This reduces the error that occurs when the zoom sensing unit detects the travel distance of the zoom movement unit, ensures data accuracy, thus optimizing zoom precision, improving image quality, and meeting high demands in complex shooting situations.

[0036] Furthermore, as in Fig. Figure 2 shows the zoom lens group 22 with an aperture STO. The aperture STO is attached to the third lens group 223 to control the amount of light and the depth of field, to correct off-axis aberrations (such as coma, astigmatism, etc.) and thus to improve image quality.

[0037] In a second aspect, the present application proposes, with reference to Fig. 1 to Fig. 2, a projection lens 1 comprising a lens tube 10, a lens optics group 20, a focus detection component 30, and a zoom detection component 40.

[0038] The lens optical group 20 is located in the lens tube 10. The lens optical group 20 has a first optical axis H and comprises a focusing lens group 21 and a zoom lens group 22, which are arranged sequentially along the direction of extension of the first optical axis H. Both the focusing lens group 21 and the zoom lens group 22 can move relative to the lens tube 10 along the direction of extension of the first optical axis H. The zoom sensing component 40 comprises a zoom movement part and a zoom sensing part (not shown). One part of the zoom movement part and the zoom sensing part is attached to the zoom lens group 22, while the other part of the zoom movement part and the zoom sensing part is fixed relative to the lens tube 10. The zoom sensing part serves to interact with the zoom movement part to detect the displacement distance of the zoom lens group 22 relative to the lens tube 10.The focus detection component 30 comprises a focus movement part and a focus detection part (not shown). One of the focus movement part and focus detection part is attached to the focusing lens group 21, while the other of the focus movement part and focus detection part is fixed relative to the lens tube 10. The focus detection part serves to interact with the focus movement part to detect the displacement distance of the focusing lens group 21 relative to the lens tube 10.

[0039] Specifically, the lens tube 10 provides an installation space for the lens optics group 20. Both the focusing lens group 21 and the zoom lens group 22 can each comprise a lens carrier and one or more lenses. The lens(es) is / are attached to the lens carrier, and the lens carrier is slidably connected to the lens tube 10 along the direction of extension of the first optical axis H, thereby displacing the lens(es) along the direction of extension of the first optical axis H. The lens tube 10 has a front and a rear side, with the distance from the front side of the lens tube 10 to the object being imaged being smaller and the distance from the rear side of the lens tube 10 to the object being imaged being larger.The focusing lens group 21 can serve as the focus group of the projection lens 1, located at the front of the lens tube 10, to allow adjustments of the forward / backward position according to the object distance and thus produce a sharper image. Furthermore, the focusing lens group 21 can also be used to correct distortions to improve the image quality of the projected image. The zoom lens group 22 can serve as the zoom group of the projection lens 1, located between the focusing lens group 21 and the fixed lens group 23, i.e., in the middle of the lens tube 10. Moving the zoom lens group 22 changes the focal length of the projection lens 1, resulting in a change in the angle of view or image size, producing a zoom-in or zoom-out effect.

[0040] It should be noted that in these embodiments of the present application, either the zoom movement part or the zoom detection part is attached to the zoom lens group 22, and the other part of the zoom movement part and the zoom detection part is fixedly attached relative to the lens tube 10. Either the focus movement part or the focus detection part is attached to the focusing lens group 21, and the other part of the focus movement part or the focus detection part is fixedly attached relative to the lens tube 10. During the focusing and zooming process of the projection lens 1, the displacement distance required for focusing the projection lens 1 can be detected by the interaction of the focus movement part and the focus detection part, and the displacement distance required for zooming the projection lens 1 can be detected by the interaction of the zoom movement part and the zoom detection part.This allows the focusing lens group 21 and the zoom lens group 22 to be moved directly to the positions to be set, thus enabling the focus and zoom functions of the projection lens 1. By arranging the focus detection component 30 and the zoom detection component 40 on different optical components, these embodiments reduce the time required for the focus and zoom operation of the projection lens 1 and increase the accuracy of the focusing and zooming of the projection lens 1.

[0041] With reference to Fig. In some embodiments of the present application, the lens optics group 20 further comprises a fixed lens group 23, which is attached to the lens tube 10. The focusing lens group 21, the zoom lens group 22, and the fixed lens group 23 are arranged sequentially along the direction of extension of the first optical axis H. One of the zoom movement part and the zoom detection part is connected to the zoom lens group 22, and the other is connected to the fixed lens group 23. The zoom detection part serves to cooperate with the zoom movement part to detect the distance between the zoom lens group 22 and the fixed lens group 23. One of the focus movement part and the focus detection part is connected to the focusing lens group 21, and the other is connected to the fixed lens group 23.The focus detection part is designed to work in conjunction with the focus movement part to detect the distance between the focusing lens group 21 and the fixed lens group 23.

[0042] Specifically, the fixed lens group 23 can provide a mounting base for part of the zoom detection component 40 and part of the focus detection component 30. The fixed lens group 23 is located at the rear of the lens tube 10, provides the lens optics group 20 with basic optical performance (refractive power), and remains stationary. The fixed lens group 23 can also serve as a reference point for the movement of the zoom lens group 22 and the focusing lens group 21.

[0043] In some embodiments of the present application, the zoom detection part is a first magnet, and the zoom movement part is a first sensor. The first sensor serves to detect the magnetic signal of the first magnet in order to detect the distance between the zoom lens group 22 and the fixed lens group 23. The first magnet can be a magnetic strip.

[0044] Specifically, when the position of the first magnet changes, its magnetic field moves with the first magnet, and the magnetic field strength detected by the first sensor changes. Then, in the projection lens 1, the zoom lens group 22 can be moved directly to the position where the first sensor detects a preset magnetic field strength, thus completing the zoom operation of the projection lens 1 and capturing a clear image.

[0045] Accordingly, in some embodiments of the present application, the focus detection part is a second magnet, and the focus movement part is a second sensor. The second sensor serves to detect the magnetic signal of the second magnet in order to detect the distance between the focusing lens group 21 and the fixed lens group 23.

[0046] For example, if the position of the second magnet changes, its magnetic field moves with the second magnet, and the magnetic field strength detected by the second sensor changes. Then, in the projection lens 1, the focusing lens group 21 can be moved directly to the position where the second sensor detects a preset magnetic field strength, thus completing the focusing process of the projection lens 1. Preferably, both the first and second sensors are tunnel magnetoresistive (TMR) sensors. TMR sensors exhibit good temperature stability, higher sensitivity, lower energy consumption, and better linearity; therefore, the use of TMR sensors further optimizes the focus and zoom performance of the projection lens 1.

[0047] With reference to Fig.In some embodiments of the present application, the projection lens 1 further comprises a first transmission element 51 and a second transmission element 52. The first transmission element 51 is movably connected to the lens tube 10 and force-fit connected to the zoom lens group 22. The first transmission element 51 serves to allow the zoom lens group 22 to slide along the direction of extension of the first optical axis H. The second transmission element 52 is movably connected to the lens tube 10 and force-fit connected to the focusing lens group 21. The second transmission element 52 serves to allow the focusing lens group 21 to slide along the direction of extension of the first optical axis H.

[0048] In some embodiments, the second transmission element 52 can be driven by a motor to precisely control the movement of the focusing lens group 21 and ensure focus accuracy. The first transmission element 51 can be a stepper motor to achieve fine zoom of the zoom lens group 22. Both the first transmission element 51 and the second transmission element 52 work together to enhance the overall performance of the projection lens 1. By way of example, the second transmission element 52 is a focus ring, and the first transmission element 51 is a zoom tube. Both the focus ring and the zoom tube are rotatably connected to the lens tube 10.The focus ring can, by rotation, allow the focusing lens group 21 in the lens tube 10 to slide along the direction of extension of the first optical axis H, and the zoom tube can, by rotation, allow the zoom lens group 22 to slide along the direction of extension of the first optical axis H, thereby realizing independent control of focus and zoom of the projection lens 1.

[0049] Furthermore, in some embodiments of the present application, the projection lens 1 also comprises a drive component (not shown) attached to the lens tube 10. The drive component is electrically connected to both the first and the second sensor. The drive component serves to receive the detection signal of the first sensor and to drive the first transmission element 51 so that it slides the zoom lens group 22 along the direction of extension of the first optical axis H, and it also serves to receive the detection signal of the second sensor and to drive the second transmission element 52 so that it slides the focusing lens group 21 along the direction of extension of the first optical axis H.

[0050] Specifically, a microprocessor is integrated into the drive component. This microprocessor processes the acquisition data from the first and second sensors in real time, thereby optimizing the movement paths of the focusing lens group 21 and the zoom lens group 22 and ensuring their precise positioning. This improves the image quality of the projection lens 1. The interaction of the drive component and sensors enables the automatic focusing and zooming of the projection lens 1, ensuring that it can react quickly and capture clear images in various shooting situations, thus meeting the demands of high-dynamic-range photography.

[0051] In some embodiments of the present application, the maximum sliding distance of the focusing lens group 21 along the direction of extension of the first optical axis H is less than 5 mm. The focusing lens group 21 can then serve as a focus group. Its relatively small maximum sliding distance enables efficient operation in confined spaces and a high focusing speed. Furthermore, because the maximum sliding distance of the focusing lens group 21 is small, a permanent magnet can be used for the second magnet, thus reducing production costs.

[0052] In a third embodiment, the present application further provides a projector (not shown). The projector comprises a light motor and a projection lens 1 according to one of the embodiments described above. The projection lens 1 is connected to the light motor. The light source of the light motor is projected by the projection lens 1 onto an external projection plane.

[0053] Specifically, the light motor in the projector can convert an input signal into an optical image and project it onto an external projection surface (e.g., a screen or wall) via the projection lens 1. The projection lens 1 can implement its focus and zoom functions by adjusting the position of the zoom lens group 22 and / or the focusing lens group 21 relative to the fixed lens group 23, thereby improving the image sharpness of the image projected by the projector.

[0054] In the drawings of these embodiments, identical or similar reference numerals correspond to identical or similar components. In the description of this application, terms such as "top," "bottom," "left," "right," etc., are to be understood as indicating the orientation or positional relationship based on the drawings, solely to facilitate and simplify the description of this application, and not to indicate or imply that the component or element in question must have a specific orientation, be constructed in a specific orientation, or be operated in a specific orientation. Therefore, the terms used in the drawings to describe positional relationships serve only as illustrative examples and cannot be understood as limiting the present application. For a person skilled in the art, the specific meaning of the aforementioned terms can be understood depending on the specific situation.

[0055] The embodiments mentioned above are only the preferred embodiments of the present application and are not intended to limit the present application. All amendments, equivalent replacements, and improvements made in the spirit and principle of the present application should be included within the scope of protection of the present application.

Claims

[1] A projection lens (1), characterized by , that it includes: a lens tube (10); a lens optics group (20) located in the lens tube (10); wherein the lens optics group (20) has a first optical axis (H) and comprises a zoom lens group (22); the zoom lens group (22) is able to move relative to the lens tube (10) along the extension direction of the first optical axis (H); and a zoom detection component (40) comprising a zoom movement part and a zoom detection part; wherein one of the zoom movement part and the zoom detection part is connected to the zoom lens group (22) to move with the zoom lens group (22) to change the zoom, and the other of the zoom movement part and the zoom detection part is fixed relative to the lens tube (10); wherein the zoom detection part serves to cooperate with the zoom movement part to detect the displacement distance of the zoom lens group (22) relative to the lens tube (10). [2] The projection lens (1) according to claim 1, wherein the lens optics group (20) further comprises a fixed lens group (23) attached to the lens tube (10); the fixed lens group (23) and the zoom lens group (22) are arranged along the extension direction of the first optical axis (H); one of the zoom movement part and the zoom sensing part is connected to the zoom lens group (22), and the other of the zoom movement part and the zoom sensing part is connected to the fixed lens group (23); the zoom sensing part serves to cooperate with the zoom movement part to sensing the distance between the zoom lens group (22) and the fixed lens group (23). [3] The projection lens (1) according to claim 1, wherein the zoom detection part is a first magnet and the zoom movement part is a first sensor; the first sensor serves to detect the magnetic signal of the first magnet in order to detect the displacement distance of the zoom lens group (22) relative to the lens tube (10). [4] The projection lens (1) according to claim 3, wherein the zoom lens group (22) is arranged in a center of the lens tube (10) and is configured to change a focal length of the projection lens (1) by movement; and a zoom operation is completed as soon as the zoom lens group (22) is moved to a position at which the first sensor detects a preset magnetic field strength. [5] The projection lens (1) according to claim 3, further comprising a first transmission element (51) which is movably or rotatably connected to the lens tube (10) and is connected to the zoom lens group (22) for drive purposes, as well as a drive component and a microprocessor arranged in the drive component; wherein the first transmission element (51) is a zoom tube and is configured to drive the zoom lens group (22) to slide along the extension direction of the first optical axis (H); and the microprocessor is configured to process acquisition data from the first sensor in real time. [6] The projection lens (1) according to claim 3, wherein the first magnet consists of several magnetic segments arranged in series, and several north poles and several south poles of the first magnet are arranged alternately along the extension direction of the first optical axis (H). [7] The projection lens (1) according to claim 1, wherein the maximum sliding distance of the zoom lens group (22) along the extension direction of the first optical axis (H) is greater than 30 mm. [8] The projection lens (1) according to claim 1, wherein the zoom movement part is connected to the zoom lens group (22), and the zoom detection part is fixedly attached relative to the lens tube (10); wherein the lens tube (10) is provided with a curved groove (11), and the zoom movement part can slide along the extension direction of the first optical axis (H) in the curved groove (11). [9] The projection lens (1) according to claim 1, wherein the zoom lens group (22) comprises a lens carrier and at least one lens; the at least one lens is attached to the lens carrier; the lens carrier is slidably connected to the lens tube (10) along the extension direction of the first optical axis (H) in order to drive the at least one lens to slide along the extension direction of the first optical axis (H). [10] The projection lens (1) according to claim 9, wherein the zoom lens group (22) further comprises a first lens group (221), a second lens group (222), a third lens group (223), and a fourth lens group (224) arranged in this order along the extension direction of the first optical axis (H); the first lens group (221), the second lens group (222), the third lens group (223), and the fourth lens group (224) are each slidably connected to the lens tube (10); and the distances and positions of the first lens group (221) to the fourth lens group (224) are adjustable to control a light refraction path. [11] The projection lens (1) according to claim 10, wherein the fourth lens group (224) comprises a first lens (L1), a second lens (L2), a third lens (L3), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), and a seventh lens (L7) arranged in this order along the extension direction of the first optical axis (H); the first lens (L1) and the second lens (L2) are bonded together; and the fourth lens (L4), the fifth lens (L5), and the sixth lens (L6) are bonded together successively. [12] The projection lens (1) according to claim 11, wherein the maximum sliding distance of the first lens group (221) along the extension direction of the first optical axis (H) is greater than 5 mm; the maximum sliding distance of the second lens group (222) along the extension direction of the first optical axis (H) is greater than 5 mm; the maximum sliding distance of the third lens group (223) along the extension direction of the first optical axis (H) is greater than 30 mm; and the maximum sliding distance of the fourth lens group (224) along the extension direction of the first optical axis (H) is greater than 10 mm. [13] The projection lens (1) according to claim 1, wherein the lens optics group (20) further comprises a focusing lens group (21), and the zoom lens group (22) and the focusing lens group (21) are arranged along the extension direction of the first optical axis (H); wherein both the zoom lens group (22) and the focusing lens group (21) are able to slide relative to the lens tube (10) along the extension direction of the first optical axis (H); wherein the projection lens (1) further comprises: a focus detection component (30) comprising a focus movement part and a focus detection part; wherein one of the focus movement part and the focus detection part is connected to the focusing lens group (21) to move with the focusing lens group (21) to focus adjustment, and the other of the focus movement part and the focus detection part is fixed relative to the lens tube (10); wherein the focus detection part serves to cooperate with the focus movement part to detect the displacement distance of the focusing lens group (21) relative to the lens tube (10). [14] The projection lens (1) according to claim 13, wherein the lens optics group (20) further comprises a fixed lens group (23) attached to the lens tube (10); the focusing lens group (21), the zoom lens group (22), and the fixed lens group (23) are arranged successively along the extension direction of the first optical axis (H); wherein one of the zoom movement part and the zoom sensing part is connected to the zoom lens group (22), and the other of the zoom movement part and the zoom sensing part is connected to the fixed lens group (23); the zoom sensing part serves to cooperate with the zoom movement part to sensing the distance between the zoom lens group (22) and the fixed lens group (23); wherein one of the focusing movement part and the focusing detection part is connected to the focusing lens group (21), and the other of the focusing movement part and the focusing detection part is connected to the fixed lens group (23); the focusing detection part serves to cooperate with the focusing movement part to detect the distance between the focusing lens group (21) and the fixed lens group (23). [15] The projection lens (1) according to claim 13, wherein the zoom detection part is a first magnet, and the zoom movement part is a first sensor; the first sensor serves to detect the magnetic signal of the first magnet in order to detect the displacement distance of the zoom lens group (22) relative to the lens tube (10); wherein the focus detection part is a second magnet, and the focus movement part is a second sensor; the second sensor serves to detect the magnetic signal of the second magnet in order to detect the displacement distance of the focus lens group (21) relative to the lens tube (10). [16] The projection lens (1) according to claim 15, further comprising a first transmission element (51) and a second transmission element (52), wherein: the first transmission element (51) is a zoom tube; the second transmission element (52) is a focusing ring; the first transmission element (51) is movably connected to the lens tube (10) and is connected to the zoom lens group (22) for drive purposes; the second transmission element (52) is movably connected to the lens tube (10) and is connected to the focusing lens group (21) for drive purposes; the first transmission element (51) is configured to drive the zoom lens group (22) to slide along the extension direction of the first optical axis (H); and the second transmission element (52) is configured to drive the focusing lens group (21) to slide along the extension direction of the first optical axis (H). [17] The projection lens (1) according to claim 16, further comprising a drive component arranged in the lens tube (10), wherein: the drive component is electrically connected to the first sensor and the second sensor; the drive component is configured to receive a detection signal from the first sensor and to drive the first transmission element (51) to drive the zoom lens group (22) to slide along the extension direction of the first optical axis (H); and the drive component is configured to receive a detection signal from the second sensor and to drive the second transmission element (52) to drive the focusing lens group (21) to slide along the extension direction of the first optical axis (H). [18] The projection lens (1) according to claim 13, wherein the maximum sliding distance of the focusing lens group (21) along the extension direction of the first optical axis (H) is less than 5 mm. [19] A projector comprising: a light motor and the projection lens (1) according to any one of claims 1 to 18; wherein the projection lens (1) is connected to the light motor, and the light source of the light motor is configured to be projected through the projection lens (1) onto an external projection plane.

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