Lens focusing mechanism based on crank focusing

Abstract

The invention relates to the technical field of optical lens focusing, in particular to a crank focusing lens focusing mechanism, which comprises a detector, a focusing lens barrel, a focusing lens, a focusing lens seat, a crank driving motor and a crank sliding block mechanism, the crank driving motor, the detector and the focusing lens cone are fixedly connected in sequence; and an output shaft of the crank driving motor is connected with a focusing lens to be focused through a crank sliding block mechanism, so that the focusing lens moves in the focusing lens barrel. The characteristics of the slider-crank mechanism are utilized and improved, the defects of the slider-crank mechanism applied to the field of lens focusing are overcome, the slider-crank mechanism can adapt to the field of lens focusing, and the defects existing in other traditional focusing technologies are overcome.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical lens focusing, in particular to a lens focusing mechanism of crank focusing. BACKGROUND

[0002] In the existing focusing technology of all fields, it is usually divided into cam focusing, screw rod focusing, worm and gear focusing and crank slider focusing. However, in the precise optical system, only the following several kinds of focusing mechanisms are commonly used for focusing and focusing work, and the crank slider focusing is not included: 1) cam focusing mechanism, defects: cam cannot realize continuous rotation, there is return error when cam reverses, and the focusing speed is slightly slow. 2) screw rod focusing mechanism, defects: screw rod focusing mechanism needs to rely on motor to frequently reverse to realize full-range adjustment, which not only increases the control complexity, but also reduces the response speed and system reliability; and the ordinary screw rod guide rail does not have self-locking function, and needs additional brake device to prevent load movement after power failure. 3) worm and gear focusing mechanism, defects: worm and gear focusing mechanism has large transmission friction, low efficiency, is easy to appear heating and wear and low temperature card stagnation phenomenon, and long-term use may cause focusing precision degradation, and even affect the imaging performance of optical components.

[0003] Therefore, the technical personnel in the art urgently need to put forward a new kind of lens focusing mechanism using crank slider focusing to comprehensively improve the technical problems existing in the above-mentioned prior art. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the defects existing in the above-mentioned prior art, so as to provide a lens focusing mechanism of crank focusing.

[0005] A lens focusing mechanism of crank focusing, comprising a detector, a focusing lens barrel and a focusing lens, further comprising: a crank driving motor and a crank slider mechanism. The crank driving motor, the detector and the focusing lens barrel are sequentially fixedly connected. The output shaft of the crank driving motor is connected with the focusing lens to be focused through the crank slider mechanism, so that the focusing lens moves in the focusing lens barrel.

[0006] Preferably, the crank slider mechanism is composed of a focusing crank and a focusing connecting rod which are sequentially connected. A groove is formed at one end of the focusing crank, and a key sleeve is formed on the output shaft perpendicular to the one end of the focusing crank, and the groove and the key sleeve are engaged with each other. The other end of the focusing crank is hinged with the focusing connecting rod.

[0007] Preferably, it further comprises a focusing guide column. A straight sliding groove coaxial with the output shaft is formed on the focusing lens barrel. The focusing guide column arranged in the linear sliding groove is rotatably connected with the focusing connecting rod at one end and is connected with the focusing mirror arranged in the focusing lens barrel at the other end.

[0008] Preferably, inside the focusing lens barrel: The focusing mirror seat is slidably connected with the focusing lens barrel. The focusing mirror is mounted on the focusing mirror seat. The focusing guide column is indirectly connected with the focusing mirror through the focusing mirror seat.

[0009] Preferably, the relationship between the displacement of the focusing guide column and the rotation angle of the focusing crank is expressed as: ; In the formula: represents the displacement of the focusing guide column; is the length of the focusing crank; is the length of the focusing connecting rod; is the rotation angle of the focusing crank; is the eccentricity between the linear sliding groove of the focusing lens barrel and the output shaft; The stroke of the linear sliding groove is greater than or equal to the displacement of the focusing guide column.

[0010] The technical scheme of the present application has the following advantages: The present application adopts a crank slider structure as a transmission system, has a quick return motion characteristic, can drive the focusing lens group to quickly and accurately complete the focusing process, and is especially suitable for operating scenes of high-speed lenses, thereby significantly improving the focusing efficiency. Supports two focusing modes of coarse adjustment and fine adjustment, can work by driving the crank driving motor according to actual needs, flexibly selects the rotation angle of the focusing crank, satisfies rapid large-range focusing, supports fine precision adjustment, and is suitable for a wide range of scenes.

[0011] The present application adopts a crank slider structure as a transmission system, which can effectively improve the stability of the focusing lens, has a self-locking function, can automatically lock the position after focusing, prevents the lens from being deviated due to external force or vibration, and ensures the imaging stability. The linear sliding groove guide structure of the focusing lens barrel strictly limits the degree of freedom of movement, eliminates the possible rotation phenomenon in the focusing process, and ensures that the lens moves smoothly along the axial direction. DETAILED DESCRIPTION

[0012] In order to more clearly illustrate the specific embodiments of the present application or the technical scheme in the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0013] Figure 1 It is a schematic diagram of the overall structure of the present application; Figure 2 It is a schematic diagram of the connection relationship between the focusing guide column and the focusing mirror.

[0014] Explanation of reference signs: 1 - driving motor, 2 - detector, 3 - focusing lens barrel, 4 - focusing crank, 5 - focusing connecting rod, 6 - focusing guide column, 7 - focusing mirror seat, 8 - focusing mirror, 9 - output shaft. DETAILED DESCRIPTION

[0015] The technical solutions of the present application will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0016] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0017] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0018] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0019] Example 1 Due to the characteristics of the crank slider mechanism: a mechanism for converting rotary motion into long-stroke linear motion, poor space compactness and motion stability; while the demand for lens focusing is short-stroke, high-precision, high-stability, ultra-compact. Therefore, the thread focusing and cam focusing have absolute advantages in precision, feel, space utilization and reliability, and become the preferred structure of the technical personnel in the field of optical focusing. Therefore, the technical personnel will have inherent thinking from the performance principle: the crank slider mechanism is not suitable for application to the lens focusing.

[0020] But in this embodiment, it is through the use of the characteristics of the crank slider mechanism and improvement, to improve the defects of the crank slider mechanism applied to the field of lens focusing, so that the crank slider mechanism can be adapted to the field of lens focusing.

[0021] The embodiment specifically discloses a kind of crank focusing lens focusing mechanism, including detector 2, focusing lens barrel 3, focusing mirror 8, focusing mirror seat 7, crank drive motor 1 and crank slider mechanism; Crank drive motor 1, detector 2 and focusing lens barrel 3 are sequentially fixedly connected;Specifically, crank drive motor 1 is fixed to the side of detector 2 away from focusing lens barrel 3 by screw; The output shaft 9 of crank drive motor 1 is connected with the focusing mirror 8 to be focused by the crank slider mechanism, so that the focusing mirror 8 moves in the focusing lens barrel 3.

[0022] Crank slider mechanism specifically adopts eccentric crank slider mechanism.

[0023] Crank slider mechanism is composed of focusing crank 4 and focusing connecting rod 5 connected in sequence; The groove opened in one end of focusing crank 4 and the key sleeve on the output shaft 9 perpendicular to one end of focusing crank 4 are connected and meshed with each other; The other end of focusing crank 4 is hinged with focusing connecting rod 5.

[0024] Specifically: It should be noted that in order to overcome the above inherent thinking, therefore, in this embodiment, crank drive motor is arranged at the other end of detector 2 away from focusing lens barrel 3, the size of detector 2 is utilized, and the size of focusing crank 4 is selected according to the actual size of detector 2 to improve the application defects of the above-mentioned crank slider mechanism. And by adopting the setting that crank drive motor 1 drives crank slider mechanism to work, the crank slider mechanism originally without self-locking function has self-locking property, and focusing is more flexible.

[0025] And, further in this embodiment, the crank slider mechanism adopts eccentric design, which makes the overall crank slider mechanism have quick-return characteristics, so that the focusing mirror 8 can quickly respond to the accurate positioning of focusing demand, and adapt to high-speed lens that needs fast focusing. In the embodiment, the focusing mechanism of the lens focusing mechanism further comprises a focusing guide column 6; A linear sliding groove coaxial with the output shaft 9 is formed on the focusing lens barrel 3. One end of the focusing guide column 6 is rotatably connected with the focusing connecting rod 5, and the other end is connected with the focusing lens 8 in the focusing lens barrel 3. Specifically, one end of the focusing guide column 6 is connected with the focusing connecting rod 5 through a pin. One end of the focusing guide column 6 is provided with a bearing and is connected with the focusing connecting rod 5 through the focusing connecting rod 5.

[0026] Inside the focusing lens barrel 3: The focusing lens seat 7 is slidably connected with the focusing lens barrel 3. The focusing lens 8 is installed on the focusing lens seat 7. The focusing guide column 6 is indirectly connected with the focusing lens 8 through the focusing lens seat 7.

[0027] The relationship between the displacement of the focusing guide column 6 and the rotation angle of the focusing crank 4 is expressed as: ; In the formula: represents the displacement of the focusing guide column 6; is the length of the focusing crank 4; is the length of the focusing connecting rod 5; is the rotation angle of the focusing crank 4; is the eccentricity of the linear sliding groove of the focusing lens barrel 3 and the output shaft 9; The stroke of the linear sliding groove is greater than or equal to the displacement of the focusing guide column 6.

[0028] Embodiment 2 Based on embodiment 1, the following specific workflow is further disclosed in this embodiment: Start the crank driving motor 1 to drive the focusing crank 4 to rotate around the output shaft 9. The other end of the focusing crank 4 is connected with one end of the focusing connecting rod 5 through a pin, and the rotation of the focusing crank 4 drives the focusing connecting rod 5 to swing and further drives the focusing connecting rod 5 to swing around the focusing guide column 6.

[0029] The swinging of the focusing connecting rod 5 drives the focusing guide column 6 to reciprocate in the linear sliding groove. The linear sliding groove plays a role of auxiliary guide in the focusing process, and the linear sliding groove converts the swinging of the focusing connecting rod 5 into the linear motion of the focusing lens seat 7 through the focusing guide column 6. In addition, since the focusing crank 4 can continuously rotate, the difficulty of servo control can be reduced, and the crank driving motor 1 will not appear the phenomenon of locked rotor, which can effectively reduce the failure rate.

[0030] Obviously, the above embodiments are merely example for clearly illustrating but not limitation to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments need not and can not be enumerated. The obvious changes or variations derived from the above description are still within the protection scope of the present application.

Claims

1. A focusing mechanism of a lens with a crank focusing, comprising a detector (2), a focusing lens barrel (3) and a focusing mirror (8), characterized in that, Also include: Crank drive motor (1) and crank slider mechanism; Crank drive motor (1), detector (2) and focusing lens barrel (3) are sequentially fixedly connected; The output shaft (9) of the crank drive motor (1) is connected with the focusing lens (8) to be focused through the crank slider mechanism, so that the focusing lens (8) moves in the focusing lens barrel (3).

2. A crank focusing lens focusing mechanism according to claim 1, wherein The crank slider mechanism is composed of focusing crank (4) and focusing connecting rod (5) connected in sequence; The groove opened at one end of the focusing crank (4) and the key sleeve on the output shaft (9) perpendicular to one end of the focusing crank (4) are sleeved and meshed with each other; The other end of the focusing crank (4) is hinged with the focusing connecting rod (5).

3. A crank focusing lens focusing mechanism according to claim 2, wherein Also include focusing guide column (6); A straight line sliding groove coaxial with the output shaft (9) is opened on the focusing lens barrel (3); The focusing guide column (6) is rotatably connected with the focusing connecting rod (5) at one end and connected with the focusing lens (8) in the focusing lens barrel (3) at the other end.

4. The crank focusing lens focusing mechanism according to claim 3, wherein Inside the focusing lens barrel (3): The focusing lens seat (7) is slidably connected with the focusing lens barrel (3); The focusing lens (8) is installed on the focusing lens seat (7); The focusing guide column (6) is indirectly connected with the focusing lens (8) through the focusing lens seat (7).

5. A crank focusing lens focusing mechanism according to claim 4, wherein The relationship expression between the displacement of the focusing guide column (6) and the rotation angle of the focusing crank (4) is: ； In the formula: represents the displacement amount of the focusing guide column (6); is the length of the focusing crank (4); is the length of the focusing connecting rod (5); is the rotation angle of the focusing crank (4); is the eccentricity of the linear sliding slot of the focusing lens barrel (3) and the output shaft (9); The stroke of the straight line sliding groove is greater than or equal to the displacement of the focusing guide column (6).

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