Zoom projection lens

Abstract

The utility model discloses a zoom projection lens, which is used in the technical field of optical equipment, and comprises a shell, a pair of lens groups, an induction part, an adjusting structure and a control module, the shell comprises a rotating part and a fixed part, the rotating part can rotate by taking a first direction as an axis, and the fixed part can rotate by taking a second direction as an axis. A pair of lens groups are arranged on the fixing part of the shell at intervals in the first direction, the sensing part is arranged above the lens groups corresponding to the lens groups and is used for sensing the positions of the lens groups, the adjusting structure is used for adjusting the positions of the lens groups, and the adjusting structure is used for adjusting the positions of the lens groups. The control module is arranged on the fixing part of the shell and is electrically connected with the sensing part and the adjusting structure, the first direction is the direction of the optical axis, and therefore the zoom projection lens controlled in a closed-loop feedback mode is provided, and a projection picture is clearer.

Description

Technical Field

[0001] The utility model relates to the technical field of optical equipment, in particular to a zoom projection lens. Background Art

[0002] With the continuous development and progress of the times, projection display products have gradually replaced traditional televisions and entered people's daily lives. Among them, the projection lens, as an important component of the projector, is crucial to ensure the clarity of the display image and the smoothness and accuracy of the focus. However, in order to achieve the focus of different projection distances and projection screen sizes, the projection lens in the existing projection display products mainly adopts stepper motors and optical coupling to realize the focusing function of the projection lens; but this control system is an open-loop system, and the optical coupling switch is used as the initial position and end position sensor. When the two sensors are driven between them, it can only be guaranteed by the assembly accuracy of each component. If the stepper motor loses step during the process or the assembly gap between the transmission components is too large, the projection lens will be because the moving lens group cannot accurately reach the corresponding position and the projection screen will be blurred; the existing position feedback system cannot achieve accurate closed-loop control of the displacement of the moving lens group.

[0003] In order to achieve focusing at different projection distances and projection screen sizes, the projection lenses in current projection display products mainly use stepper motors and optical coupling to realize the focusing function of the projection lens. However, this control system is an open-loop system, and the optical coupling switch is used as the initial position and end position sensor. When driven between the two sensors, it can only be guaranteed by the assembly accuracy of each component. If the stepper motor loses step during the process or the assembly gap between the transmission components is too large, the projection lens will be unable to accurately reach the corresponding position due to the inability of the moving lens group to accurately reach the corresponding position, resulting in a blurred projection screen. Utility Model Content

[0004] The main purpose of the utility model is to provide a zoom projection lens, aiming to provide a zoom projection lens with closed-loop feedback control, so that the projection picture is clearer.

[0005] To achieve the above-mentioned object, the utility model provides a zoom projection lens, comprising: a housing, comprising a rotating part and a fixed part, wherein the rotating part can rotate with a first direction as an axis;

[0006] a pair of lens groups, spaced apart in the first direction and mounted on the fixing portion of the housing;

[0007] A sensing part, mounted above the lens group corresponding to the lens group, and used for sensing the position of the lens group;

[0008] an adjusting structure for adjusting the position of the lens group; and

[0009] A control module, disposed on the fixed portion of the housing and electrically connected to the sensing portion and the regulating structure;

[0010] Wherein, the first direction is the optical axis direction.

[0011] In one embodiment, the sensing unit includes:

[0012] The induction magnetic part is arranged above the lens group;

[0013] The displacement sensor is located just above the inductive magnetic part and is installed on the shell.

[0014] In one embodiment, the inductive magnetic part includes a positioning magnetic block.

[0015] In one embodiment, the inductive magnetic part includes a positioning magnetic strip, and the positioning magnetic strip includes a plurality of magnetic signal grid strips with equal spacing and alternating positive and negative polarities.

[0016] In one embodiment, the distance between the positioning magnetic strip and the displacement sensor in the up and down directions is 0.2 to 0.3 mm.

[0017] In one embodiment, the regulating structure comprises:

[0018] A first gear meshing portion formed on the lens group;

[0019] A focus ring, comprising a second gear meshing portion, arranged corresponding to the lens group, wherein the first gear meshing portion meshes with the second gear meshing portion;

[0020] The driving motor is drivingly connected to the focusing ring, and the control module is electrically connected to the driving motor.

[0021] In one embodiment, the zoom projection lens further includes:

[0022] An optical coupling sensor is arranged on the fixing portion.

[0023] A positioning baffle, arranged on the rotating part;

[0024] When the rotating part rotates, the optical coupling sensor is located on the path of the positioning baffle.

[0025] In one embodiment, the zoom projection lens further includes a signal amplifier mounted on the fixing portion and electrically connected to the displacement sensor.

[0026] In the technical solution of the utility model, a zoom projection lens is proposed, including a shell, a pair of lens groups, a sensing part, an adjustment structure and a control module. Based on the shell, the shell includes a rotating part and a fixed part, the rotating part can rotate with a first direction as an axis, a pair of the lens groups are installed on the fixed part of the shell at intervals in the first direction, the sensing part is installed above the lens group corresponding to the lens group for sensing the position of the lens group, the adjustment structure is used to adjust the position of the lens group, the control module is arranged on the fixed part of the shell, and is electrically connected to the sensing part and the adjustment structure, wherein the first direction is the direction of the optical axis. The position of the lens group is accurately sensed by the sensing part and fed back to the control module, and the control module controls the adjustment structure to adjust the position of the lens group according to the sensed information, thereby providing a zoom projection lens with closed-loop feedback control, so that the projection picture is clearer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0028] Figure 1 A schematic structural diagram of an embodiment of a zoom projection lens provided by the utility model;

[0029] Figure 2 for Figure 1 A schematic diagram of a three-dimensional structure in which a lens group, a displacement sensor, and a sensing part of a zoom projection lens are assembled together;

[0030] Figure 3 for Figure 2 Explosion diagram of each component;

[0031] Figure 4 for Figure 1 A schematic diagram of a three-dimensional structure in which the rotating part of the middle shell rotates a certain angle until the positioning stopper and the optical coupling sensor abut against each other.

[0032] Description of Figure Numbers:

[0033] Label name Label name 100 Zoom projection lens 6 Drive motor 1 Control Module 7 Displacement Sensors 2 case 81 Positioning magnet 3 Signal amplifier 82 Positioning magnetic stripe 4 Optocoupler Sensor 9 Focus ring 5 Positioning baffle 10 Lens Group

[0034] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0036] It should be noted that if a directional indication is involved in the embodiments of the present invention, the directional indication is only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0037] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0038] With the continuous development and progress of the times, projection display products have gradually replaced traditional televisions and entered people's daily lives. Among them, the projection lens, as an important component of the projector, is crucial to ensure the clarity of the display image and the smoothness and accuracy of the focus. However, in order to achieve the focus of different projection distances and projection screen sizes, the projection lens in the existing projection display products mainly adopts stepper motors and optical coupling to realize the focusing function of the projection lens; but this control system is an open-loop system, and the optical coupling switch is used as the initial position and end position sensor. When the two sensors are driven between them, it can only be guaranteed by the assembly accuracy of each component. If the stepper motor loses step during the process or the assembly gap between the transmission components is too large, the projection lens will be because the moving lens group cannot accurately reach the corresponding position and the projection screen will be blurred; the existing position feedback system cannot achieve accurate closed-loop control of the displacement of the moving lens group.

[0039] In order to achieve focusing at different projection distances and projection screen sizes, the projection lenses in current projection display products mainly use stepper motors and optical coupling to realize the focusing function of the projection lens. However, this control system is an open-loop system, and the optical coupling switch is used as the initial position and end position sensor. When driven between the two sensors, it can only be guaranteed by the assembly accuracy of each component. If the stepper motor loses step during the process or the assembly gap between the transmission components is too large, the projection lens will be unable to accurately reach the corresponding position due to the inability of the moving lens group to accurately reach the corresponding position, resulting in a blurred projection screen.

[0040] In view of this, the utility model provides a zoom projection lens. Figures 1 to 4 An embodiment of a zoom projection lens provided by the utility model; Figure 1 A schematic structural diagram of an embodiment of a zoom projection lens provided by the utility model; Figure 2 for Figure 1 A schematic diagram of a three-dimensional structure in which a lens group 10, a displacement sensor 7, and a sensing part of a zoom projection lens are assembled together; Figure 3 for Figure 2 Explosion diagram of each component;

[0041] Figure 4 for Figure 1 A schematic diagram of a three-dimensional structure in which the rotating part of the middle shell rotates a certain angle until the positioning stopper and the optical coupling sensor abut against each other.

[0042] In this embodiment, the sensing part includes an inductive magnetic part and a displacement sensor 7. The inductive magnetic part is arranged above the lens group 10, and the displacement sensor 7 is installed on the housing 2 just above the inductive magnetic part. The inductive magnetic part is arranged above the lens group 10 to move with the lens group 10 and sense the position of the lens group 10. The displacement sensor 7 determines the position of the lens group 10 by sensing the change of the magnetic field caused by the movement of the inductive magnetic part.

[0043] In another embodiment, the inductive magnetic part includes a positioning magnetic strip 82, and the positioning magnetic strip 82 includes a plurality of magnetic signal bars with equal spacing and alternating positive and negative polarities. The N and S poles of the positioning magnetic block 81 are relatively short, which is suitable for short-stroke measurement. In order to adapt to the measurement of long strokes, the positioning magnetic strip 82 is made of magnetic signal bars with equal spacing and alternating positive and negative polarities. When the displacement sensor 7 and the positioning magnetic strip 82 produce relative displacement, the magnetic field intensity directly below the positioning magnetic strip 82 and in the moving direction of the lens group 10 can be detected during the movement of the displacement sensor 7, thereby obtaining the position of the lens group 10.

[0044] Furthermore, the inductive magnetic part includes a positioning magnetic block 81. The positioning magnetic block 81 has N and S poles, and the positioning magnetic block 81 is light in weight and low in cost and is easily available on the market. When the positioning magnetic block 81 generates a displacement offset in the N and S pole directions, the displacement sensor 7 above the positioning magnetic block 81 will obtain the position of the lens group 10.

[0045] Further, the distance between the positioning magnetic strip 82 and the displacement sensor 7 in the up and down directions includes 0.2 to 0.3 mm. At this distance, the displacement sensor 7 can sensitively and accurately sense the positioning magnetic strip 82. If the distance is too far, the induction between the displacement sensor 7 and the positioning magnetic strip 82 is not sensitive. If the distance is too small, the magnetism is too strong and the transmission effect is not good. Being close to the positioning magnetic strip 82 will cause magnetic field interference, resulting in distortion or instability of the signal output by the sensor. This will affect the accuracy and reliability of the displacement sensor 7. If the magnetic field strength of the positioning magnetic strip 82 is too large, the displacement sensor 7 may be affected by the saturation effect. In this case, the output of the displacement sensor 7 will no longer be proportional to the actual change in displacement, but a nonlinear response will occur. If the displacement sensor 7 is too close to the positioning magnetic strip 82, it may cause a collision or magnetic attraction between them, thereby causing mechanical damage or failure of the sensor.

[0046] In addition, after the sensing part senses the displacement change, the position of the lens group 10 can be adjusted by using an adjustment structure, the adjustment structure includes a first gear meshing part, a focus ring 9 and a drive motor 6, the first gear meshing part is formed on the lens group 10, the focus ring 9 includes a second gear meshing part, which is arranged corresponding to the lens group 10, the first gear meshing part is meshed with the second gear meshing part, the drive motor 6 is drivingly connected to the focus ring 9, and the control module 1 is electrically connected to the drive motor 6. Through gear meshing transmission, the transmission is more stable and reliable, and the gear transmission can transmit high torque, making it suitable for applications requiring high power output, such as automotive transmission systems, industrial machinery, etc. Compared with other transmission methods, such as belt drive or chain drive, the efficiency of gear transmission is usually higher, because the mechanical connection between the gears is more direct, and the meshing between the gears provides a smooth power transmission, reducing vibration and noise, making it suitable for applications requiring high precision and low noise, and can be used in various working environments, including high temperature, high pressure, high speed and other conditions, with strong adaptability.

[0047] In addition, the zoom projection lens 100 further includes an optical coupling sensor 4 and a positioning baffle 5, wherein the optical coupling sensor 4 is disposed on the fixed portion, and the positioning baffle 5 is disposed on the rotating portion, wherein when the rotating portion rotates, the optical coupling sensor 4 is located on the path of the positioning baffle 5. The optical coupling sensor 4 interacts with the positioning baffle 5, and when the positioning baffle 5 rotates into the optical coupling sensor 4 following the rotating portion of the housing 2, the infrared rays in the optical coupling sensor 4 are blocked by the baffle, which is defined as the initial position of the lens group 10, and can detect the periodic changes in the magnetic field intensity directly below the positioning magnetic strip 82 and in the moving direction of the lens group 10 during the movement of the displacement sensor 7.

[0048] In addition, the zoom projection lens 100 further includes a signal amplifier 3, which is mounted on the fixed portion and electrically connected to the displacement sensor 7. The signal amplifier 3 is mounted on the fixed portion of the housing 2 and electrically connected to the displacement sensor 7. The signal amplifier 3 is used to enhance the amplitude, voltage or power of the input signal. The signal amplifier 3 uses an OPA operational amplifier circuit, which can accurately amplify the detection signal of the displacement sensor 7 and provide the closed-loop feedback system with more accurate position information of the lens group 10.

[0049] The above description is only a preferred embodiment of the utility model, and does not limit the patent scope of the utility model. All equivalent structural changes made by using the contents of the utility model specification and drawings under the concept of the utility model, or directly / indirectly used in other related technical fields are included in the patent protection scope of the utility model.

Claims

1. A zoom projection lens, characterized in that: include: The housing comprises a rotating part and a fixed part, wherein the rotating part can rotate with a first direction as an axis; a pair of lens groups, spaced apart in the first direction and mounted on the fixing portion of the housing; A sensing part, mounted above the lens group corresponding to the lens group, and used for sensing the position of the lens group; an adjusting structure for adjusting the position of the lens group; and A control module, disposed on the fixed portion of the housing and electrically connected to the sensing portion and the regulating structure; Wherein, the first direction is the optical axis direction.

2. The zoom projection lens according to claim 1, wherein: The sensing unit comprises: The induction magnetic part is arranged above the lens group; The displacement sensor is located just above the inductive magnetic part and is installed on the shell.

3. The zoom projection lens according to claim 2, wherein: The inductive magnetic part includes a positioning magnetic block.

4. The zoom projection lens according to claim 2, wherein: The inductive magnetic part includes a positioning magnetic strip, and the positioning magnetic strip includes a plurality of magnetic signal grid strips with equal spacing and alternating positive and negative polarities.

5. The zoom projection lens according to claim 4, wherein: The distance between the positioning magnetic strip and the displacement sensor in the up and down directions is comprised between 0.2 and 0.3 mm.

6. The zoom projection lens according to claim 1, wherein: The regulatory structure comprises: A first gear meshing portion formed on the lens group; A focus ring, comprising a second gear meshing portion, arranged corresponding to the lens group, wherein the first gear meshing portion meshes with the second gear meshing portion; The driving motor is drivingly connected to the focusing ring, and the control module is electrically connected to the driving motor.

7. The zoom projection lens according to claim 1, wherein: The zoom projection lens also includes: An optical coupling sensor is arranged on the fixing portion. A positioning baffle, arranged on the rotating part; When the rotating part rotates, the optical coupling sensor is located on the path of the positioning baffle.

8. The zoom projection lens according to claim 2, wherein: The zoom projection lens also includes a signal amplifier, which is installed on the fixing part and is electrically connected to the displacement sensor.

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