Large-stroke TMR focusing projection lens

Abstract

The utility model relates to a large-stroke TMR focusing projection lens. The large-stroke TMR focusing projection lens comprises a lens, a focusing ring, a lens base, a driving assembly and a magnetic position sensor module. The lens, the lens base and the focusing ring are sequentially sleeved from inside to outside, the focusing ring drives the lens to do telescopic motion relative to the lens base in the rotating process, and the motion direction is parallel to an optical axis; the magnetic position sensor module mainly comprises a TMR angle sensor chip and a strip-shaped magnet, the TMR angle sensor chip is arranged on the lens base, a strip-shaped groove is formed in the outer side wall of the lens, and the strip-shaped magnet is arranged in the strip-shaped groove; the driving assembly is assembled on the lens base and used for driving the focusing ring to rotate, at the moment, the lens and the lens base generate relative displacement, focusing is achieved, meanwhile, the TMR angle sensor chip can sense position information of the strip-shaped magnet, accurate control over the position of the lens is achieved, and the problem that when the projection lens carries out projection, the focusing effect is poor is solved. And the problems of small focusing range and insufficient accuracy are solved.

Description

Technical Field

[0001] This application relates to the technical field of projectors, and particularly to a TMR focusing projection lens with a large stroke. Background Art

[0002] In recent years, with the continuous development and popularization of projection technology, projection devices have been widely used in fields such as education, commercial display, and home entertainment. As a key component of projection devices, the performance of projection lenses directly affects the quality of projection effects. To meet the requirements of different scenarios and applications, the focusing accuracy and focusing range of projection lenses have become the focus of the industry.

[0003] In related technical means, the automatic focusing technology of projectors requires the use of a stepper motor to achieve focusing. The stepper motor drives the lens to adjust to a specified position, achieving automatic focusing and effectively solving the problem of inaccurate focusing caused by the traditional optoelectronic switch or mechanical limit switch structure.

[0004] For the above technical solution, although automatic focusing can be achieved through TMR focusing technology, when the projection lens projects, there are problems of a small focusing range and insufficient accuracy. Summary of the Utility Model

[0005] In order to improve the problems of a small focusing range and insufficient accuracy when the projection lens projects, this application provides a TMR focusing projection lens with a large stroke.

[0006] A TMR focusing projection lens with a large stroke provided by this application includes a lens, a focusing ring, a lens mount, a driving component, and a magnetic position sensor module. The lens is telescopically disposed through the inner wall of the focusing ring along the movement direction, and the focusing ring is rotatably sleeved on the outer peripheral wall of the lens mount along the movement direction; the driving component is disposed on the side of the focusing ring, and the driving component is used to drive the focusing ring to rotate; the magnetic position sensor module includes a TMR angle sensor chip and a bar magnet. A bar-shaped groove is formed in the side wall of the lens along the movement direction, the bar magnet is disposed in the bar-shaped groove, the TMR angle sensor chip is disposed on the lens mount, and the TMR angle sensor chip is used to sense the relative displacement of the bar magnet.

[0007] As a preferred solution, an inclined guiding groove and an installation groove are provided on the inner side wall of the focusing ring, and the installation groove communicates with the inclined guiding groove; a detachable guide post is further provided on the side of the lens, a straight guiding groove is formed in the side wall of the lens mount along the movement direction, the guide post is disposed through the straight guiding groove, and the guide post passes through the installation groove and slides in the inclined guiding groove.

[0008] As a preferred solution, an installation part is provided on the lens base, and the magnetic position sensor module is connected to the installation part by screws.

[0009] As a preferred solution, the magnetic position sensor module includes a TMR angle sensor chip and a circuit board. The TMR angle sensor chip is soldered on the circuit board, and the circuit board is connected to the installation part by screws.

[0010] As a preferred solution, a driven gear is provided on the outer peripheral wall of the focusing ring. The driving assembly includes a driving motor and a transmission gear. The driving motor is arranged on the lens base, the transmission gear is arranged at the output end of the driving motor, and the transmission gear meshes with the driven gear.

[0011] As a preferred solution, an assembly part is provided on the side of the lens base, and the driving motor is fixed on the assembly part.

[0012] As a preferred solution, the driving motor is a stepping motor.

[0013] As a preferred solution, reinforcing ribs are arranged around the outer peripheral wall of the lens base, and one end face of the focusing ring abuts against the reinforcing ribs and rotates.

[0014] Compared with the prior art, the present application has the following beneficial effects: large focusing range and high accuracy. By cooperating the lens, the focusing ring and the lens base with each other, the lens can be telescoped in the moving direction, providing a basic focusing function; the magnetic position sensor module mainly includes a TMR chip and a bar magnet. The TMR chip is arranged on the lens base, a bar-shaped groove is formed on the outer side wall of the lens, and the bar magnet is arranged in the bar-shaped groove; the driving assembly is arranged on the side of the focusing ring and is used to drive the focusing ring to rotate. When the driving assembly drives the focusing ring to rotate, a relative displacement occurs between the lens and the lens base to achieve focusing. At the same time, the TMR chip can sense the position information of the bar magnet to achieve precise control of the lens position, and improve the problems of small focusing range and insufficient accuracy existing when the projection lens projects. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] The structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present utility model. Therefore, they do not have substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present utility model.

[0017] Figure 1 It is a schematic diagram of the overall structure of a large-stroke TMR focusing projection lens in an embodiment of the present application;

[0018] Figure 2 It is an exploded view of the structure of a large-stroke TMR focusing projection lens in an embodiment of the present application;

[0019] Figure 3 It is a schematic diagram of the structure of a focusing ring in an embodiment of the present application;

[0020] Figure 4 It is a schematic diagram of the working process of a TMR angle sensor in an embodiment of the present application;

[0021] Figure 5 It is a logic diagram of the working process of a large-stroke TMR focusing projection lens in an embodiment of the present application.

[0022] Explanation of reference numerals:

[0023] 1. Lens; 11. Strip-shaped groove; 111. Strip-shaped magnet; 12. Guide post; 2. Focusing ring; 21. Oblique guide groove; 22. Installation groove; 23. Driven gear; 3. Lens base; 31. Straight guide groove; 32. Installation part; 33. Assembly part; 34. Reinforcing rib; 4. Driving assembly; 41. Driving motor; 42. Transmission gear; 5. Magnetic position sensor module; 51. TMR angle sensor chip; 52. Circuit board. Detailed implementation manners

[0024] To make the utility model purpose, features, and advantages of the present utility model more obvious and understandable, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the present utility model. Obviously, the embodiments described below are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts belong to the scope of protection of the present utility model.

[0025] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component present at the same time.

[0026] The technical solution of the present utility model will be further described below in conjunction with the drawings and through specific embodiments.

[0027] Embodiment 1:

[0028] As Figures 1 to 3 shown, a TMR focusing projection lens with a large stroke includes a lens 1, a focusing ring 2, a lens mount 3, a driving component 4, and a magnetic position sensor module 5. The lens 1 is telescopically inserted into the inner wall of the focusing ring 2 along the moving direction, and the focusing ring 2 is rotatably sleeved on the outer peripheral wall of the lens mount 3 along the moving direction.

[0029] The driving component 4 is arranged on the side of the focusing ring 2, and the driving component 4 is used to drive the focusing ring 2 to rotate.

[0030] Through the mutual cooperation of the lens 1, the focusing ring 2, and the lens mount 3, when the driving component 4 drives the focusing ring 2 to rotate, at this time, the lens 1 makes a linear motion along the moving direction, so that the lens 1 can be telescoped, realizing the focusing operation, ensuring that the lens 1 can achieve large-stroke focusing in the moving direction; and on the premise of ensuring that the mutual activities of the lens, the lens mount, and the focusing ring are not affected, the fitting gaps between them are as tightly fitted as possible to ensure the stability of the picture during the focusing process.

[0031] Among them, the magnetic position sensor module 5 includes a TMR angle sensor chip 51 and a bar magnet 111. A bar-shaped groove 11 is formed in the side wall of the lens 1 along the moving direction, the bar magnet 111 is arranged in the bar-shaped groove 11, the TMR angle sensor chip 51 is arranged on the lens mount 3, and the TMR angle sensor chip 51 is used to sense the relative displacement of the bar magnet 111 with respect to the TMR angle sensor chip 51, that is, the relative displacement of the lens 1 with respect to the lens mount 3.

[0032] Through the strip-shaped groove 11 and the strip-shaped magnet 111 on the side wall of the lens 1, and the TMR angle sensor chip 51 arranged on the lens holder 3, the induction of the position change of the strip-shaped magnet 111 is realized, so as to feedback the position information to the control system to ensure the precise control and focusing of the position of the lens 1; among them, the TMR (Tunneling Magneto Resistance) angle sensor 51 is a magnetic sensor based on the tunneling magnetoresistance effect, which is used to detect the direction of the magnetic field of the magnet; as Figure 4 shown, when the strip-shaped magnet 111 changes in position through the induction of the TMR angle sensor chip 51, the change in the magnetic field angle of the strip-shaped magnet 111 on the induction area of the TMR angle sensor chip 51 is sensed, and the corresponding sine and cosine voltage signals are output. The period of this signal is that the magnetic field direction rotates 360° in the induction plane, which can measure a large range, and there are no additional requirements for the placement of the strip-shaped magnet 111; after being calculated by the main board, the voltage signal outputs the real-time information of the position of the strip-shaped magnet 111 relative to the TMR angle sensor chip 51, that is, the position of the lens 1 relative to the TMR angle sensor chip 51. The accuracy of this position information is relatively high, and there is no need to find the zero position additionally.

[0033] In this embodiment, the driving assembly 4 is arranged on the side of the focusing ring 2, and the focusing ring 2 is driven to rotate through the driving assembly 4, so as to drive the lens 1 to expand and contract along the moving direction. A strip-shaped groove 11 is opened on the side wall of the lens 1 along the moving direction. The magnetic position sensor module 5 includes a TMR angle sensor chip 51 and a strip-shaped magnet 111. The strip-shaped magnet 111 is arranged on the strip-shaped groove 11, and the TMR angle sensor chip 51 is arranged on the lens holder 3. When the lens 1 is focused under the drive of the focusing ring 2, the position of the strip-shaped magnet 111 changes accordingly. At this time, the TMR angle sensor chip 51 senses the position information of the strip-shaped magnet 111 and feeds this information back to the control system, so as to realize the precise control and focusing of the position of the lens 1.

[0034] Through the mutual cooperation of the driving assembly 4, the TMR angle sensor chip 51 and the strip-shaped magnet 111, automatic focusing with a large stroke and high precision is realized, significantly expanding the focusing range of the projection lens, and solving the problems of small focusing range and insufficient projection range in the prior art.

[0035] Embodiment 2:

[0036] As Figures 1 to 3 shown, an inclined guide groove 21 and an installation groove 22 are arranged on the inner side wall of the focusing ring 2, and the installation groove 22 is communicated with the inclined guide groove 21.

[0037] By providing an inclined guiding groove 21 and a mounting groove 22 on the inner sidewall of the focusing ring 2 and connecting them, when the lens 1 rotates and extends, it can move smoothly along the guidance of the inclined guiding groove 21 and the mounting groove 22, thereby improving the stability and accuracy of focusing.

[0038] A detachable guide post 12 is also provided on the side of the lens 1. A straight guiding groove 31 is formed on the sidewall of the lens mount 3 along the moving direction. The guide post 12 is inserted into the straight guiding groove 31, and the guide post 12 passes through the mounting groove 22 and slides in the inclined guiding groove 21.

[0039] By providing the detachable guide post 12 on the side of the lens 1 and the straight guiding groove 31 on the sidewall of the lens mount 3, and making the guide post 12 pass through and slide in the straight guiding groove 31 and the mounting groove 22, precise guidance of the lens 1 during the focusing process is achieved, ensuring the stability of the lens 1 and the accuracy of focusing.

[0040] As Figures 1 to 3 shown, a mounting portion 32 is provided on the lens mount 3, and the magnetic position sensor module 5 is screw-connected to the mounting portion 32.

[0041] By providing the mounting portion 32 on the lens mount 3 and fixing the magnetic position sensor module 5 to the mounting portion 32 by screws, stable installation of the magnetic position sensor module 5 is achieved, thus ensuring the accuracy and reliability of position detection.

[0042] Among them, the magnetic position sensor module 5 further includes a circuit board 52. The TMR angle sensor chip 51 is soldered on the circuit board 52, and the circuit board 52 is screw-connected to the mounting portion 32.

[0043] By soldering the TMR angle sensor chip 51 on the circuit board 52 and fixing the circuit board 52 to the mounting portion 32 by screws, stable installation and reliable connection of the TMR angle sensor chip 51 are achieved; the magnetic position sensor module 5 uses a high-precision TMR angle sensor chip 51. Compared with traditional TMR position sensor chips, the TMR angle sensor chip 51 has good temperature characteristics, allows a larger measurement gap, and can cover a larger measurement range; coupled with the design for the magnet, the entire lens 1 module has a larger focusing range, and the TMR angle sensor chip 51 has high accuracy and strong anti-magnetic shock ability, improving the accuracy of position detection and the stability of the system.

[0044] As Figures 1 to 3 shown, a driven gear 23 is provided on the outer peripheral wall of the focusing ring 2. The driving assembly 4 includes a driving motor 41 and a transmission gear 42. The driving motor 41 is provided on the lens mount 3, the transmission gear 42 is provided at the output end of the driving motor 41, and the transmission gear 42 meshes with the driven gear 23.

[0045] By providing a driven gear 23 on the outer peripheral wall of the focusing ring 2 and including a drive motor 41 and a transmission gear 42 in the drive assembly 4, and meshing the transmission gear 42 with the driven gear 23, the drive motor 41 drives the transmission gear 42, thereby driving the driven gear 23 and the focusing ring 2 to rotate, so as to realize the rotational telescopic focusing of the lens 1.

[0046] As Figures 1 to 3 shown, the lens mount 3 is provided with an assembly portion 33 on one side of the focusing ring 2, and the drive motor 41 is fixed to the assembly portion 33.

[0047] By providing an assembly portion 33 on one side of the lens mount 3 and fixing the drive motor 41 to the assembly portion 33, the stable installation of the drive motor 41 is realized, thereby ensuring the stability of the drive system and the accuracy of drive transmission.

[0048] Among them, the drive motor 41 is a stepper motor. And a reinforcing rib 34 is provided around the outer peripheral wall of the lens mount 3, and one end face of the focusing ring 2 abuts against the reinforcing rib 34 and rotates.

[0049] By selecting the drive motor 41 as a stepper motor and providing a reinforcing rib 34 around the outer peripheral wall of the lens mount 3, and making one end face of the focusing ring 2 abut against the reinforcing rib 34 and rotate, the precise control of the drive motor 41 and the stable rotation of the focusing ring 2 are realized, thereby improving the accuracy and stability of the focusing of the lens 1.

[0050] In practical applications, the logic that the projector lens 1 needs to go through for focusing is as Figure 5 shown: The distance sensor measures the distance between the projector and the projection plane and transmits it to the main board; the TMR angle sensor chip 51 measures the position of the lens 1 and transmits it to the circuit board 52; the circuit board 52 calculates the distance that the lens 1 still needs to be focused and the corresponding number of steps of the stepper motor, and sends an instruction to the stepper motor; the stepper motor drives the lens 1 to focus to the specified position; during the focusing process, the TMR angle sensor chip 51 still detects and feedbacks the position of the lens 1 in real time to ensure that the lens 1 is adjusted to the target position.

[0051] In this embodiment, by providing an inclined guide groove 21 and a mounting groove 22 on the inner side wall of the focusing ring 2, the smooth movement of the lens 1 during rotational telescoping is ensured; by providing a detachable guide post 12 on the side of the lens 1 and a straight guide groove 31 on the side wall of the lens mount 3, accurate guiding during the focusing process of the lens 1 is achieved; by providing a mounting portion 32 on the lens mount 3 and stably mounting the magnetic position sensor module 5, the accuracy and reliability of position detection are achieved; by soldering the TMR angle sensor chip 51 onto the circuit board 52 and fixing it to the mounting portion 32 with screws, the stability of the detection system is ensured; by providing a driven gear 23 on the outer peripheral wall of the focusing ring 2 and including a drive motor 41 and a transmission gear 42 in the drive assembly 4, accurate transmission of rotational drive is achieved; by providing an assembly portion 33 on one side of the lens mount 3 to fix the drive motor 41, the stability of the drive system is ensured; by selecting a stepper motor as the drive motor 41 and providing reinforcing ribs 34 on the outer peripheral wall of the lens mount 3, accurate control of the drive and stable rotation of the focusing ring 2 are achieved.

[0052] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A TMR focusing projection lens with a large stroke, characterized in that It includes a lens (1), a focusing ring (2), a lens mount (3), a driving component (4) and a magnetic position sensor module (5). The lens (1) is telescopically inserted into the inner wall of the focusing ring (2) along the movement direction, and the focusing ring (2) is rotatably sleeved on the outer peripheral wall of the lens mount (3) along the movement direction; The driving component (4) is arranged on the side of the focusing ring (2), and the driving component (4) is used to drive the focusing ring (2) to rotate; The magnetic position sensor module (5) includes a TMR angle sensor chip (51) and a bar magnet (111). A bar-shaped groove (11) is formed in the side wall of the lens (1) along the movement direction. The bar magnet (111) is arranged in the bar-shaped groove (11). The TMR angle sensor chip (51) is arranged on the lens mount (3), and the TMR angle sensor chip (51) is used to sense the relative displacement of the bar magnet (111).

2. The TMR focusing projection lens with a large stroke according to claim 1, characterized in that, An inclined guiding groove (21) and a mounting groove (22) are arranged on the inner side wall of the focusing ring (2), and the mounting groove (22) is communicated with the inclined guiding groove (21); A detachable guide post (12) is further arranged on the side of the lens (1). A straight guiding groove (31) is formed in the side wall of the lens mount (3) along the movement direction. The guide post (12) is inserted into the straight guiding groove (31), and the guide post (12) passes through the mounting groove (22) and slides in the inclined guiding groove (21).

3. The TMR focusing projection lens with a large stroke according to claim 1, characterized in that, A mounting portion (32) is arranged on the lens mount (3), and the magnetic position sensor module (5) is connected to the mounting portion (32) by screws.

4. A TMR focusing projection lens with a large stroke according to claim 3, characterized in that The magnetic position sensor module (5) further includes a circuit board (52). The TMR angle sensor chip (51) is welded on the circuit board (52), and the circuit board (52) is connected to the mounting portion (32) by screws.

5. A TMR focusing projection lens with a large stroke according to claim 1, characterized in that, A driven gear (23) is arranged on the outer peripheral wall of the focusing ring (2). The driving component (4) includes a driving motor (41) and a transmission gear (42). The driving motor (41) is arranged on the lens mount (3), the transmission gear (42) is arranged at the output end of the driving motor (41), and the transmission gear (42) meshes with the driven gear (23).

6. The large-stroke TMR focusing projection lens according to claim 5, characterized in that An assembling portion (33) is arranged on the side wall of the lens mount (3), and the driving motor (41) is fixed on the assembling portion (33).

7. A TMR focusing projection lens with a large stroke according to claim 6, characterized in that, The driving motor (41) is a stepping motor.

8. A TMR focusing projection lens with a large stroke according to claim 1, characterized in that, Reinforcing ribs (34) are arranged around the outer peripheral wall of the lens mount (3), and one end face of the focusing ring (2) abuts against the reinforcing ribs (34) and rotates.

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