CN113163102A

CN113163102A - Rear focus adjusting device and camera

Info

Publication number: CN113163102A
Application number: CN202010074219.1A
Authority: CN
Inventors: 秦玉良; 李增强
Original assignee: Zhejiang Uniview Technologies Co Ltd
Current assignee: Zhejiang Uniview Technologies Co Ltd
Priority date: 2020-01-22
Filing date: 2020-01-22
Publication date: 2021-07-23
Anticipated expiration: 2040-01-22
Also published as: CN113163102B

Abstract

The invention relates to the technical field of focal length adjustment, and discloses a back focus adjusting device and a camera. The back focus adjusting device comprises a driving assembly, and the driving assembly comprises an output gear; the transmission assembly comprises a rack and a push rod connected to the rack, and the output gear is in meshing transmission with the rack; the fixed plate is provided with a first guide hole for guiding the push rod, the push rod penetrates through the first guide hole, and the rack drives the push rod to reciprocate along the axial direction of the first guide hole; the Sensor plate is arranged on the mounting plate, the mounting plate is positioned on one side of the fixed plate, and the transmission assembly is positioned on the other side of the fixed plate; the push rod passes through first guiding hole and promotes mounting panel and Sensor board along the synchronous reciprocating motion of the axial of first guiding hole to guarantee the plane degree in the Sensor board motion process. The back focus adjusting device realizes automatic adjustment of the back focus of the camera on the basis of ensuring the flatness of the sensor plate, and has the advantages of simple structure, accurate adjustment and low cost.

Description

Rear focus adjusting device and camera

Technical Field

The invention relates to the technical field of focal length adjustment, in particular to a back focus adjusting device and a camera.

Background

In order to ensure the shooting performance of the camera, a standard lens is usually configured for the camera at the time of factory shipment. Since the application scene of the camera mainly depends on the parameters of the shot, once the shot is determined, the application scene of the camera is greatly limited. Different application scenes need to purchase different models of cameras.

At present, a mode of adjusting a back focus (a distance between a mechanical back end surface of a lens and an image surface) is mostly adopted, so that the same camera is adaptive to various lenses, and the application range of the camera is expanded. The automatic degree of focusing of the camera can be divided into manual focusing and automatic focusing.

And manual focusing, namely, in the field installation and debugging process, a single person carries a notebook computer as a client, and the focusing of the lens is carried out while watching the video of the client. In the security industry, in most cases, a camera is installed at a high place, a notebook computer is inconvenient to carry during high-altitude operation, two persons are often adopted for cooperation, one person watches video images through the notebook computer on the ground, the other person manually adjusts the video images at high altitude, and the person on the ground sends an adjusting instruction to be executed by the high-altitude operation person. This method is relatively low in implementation cost, but is inconvenient to operate and long in adjustment time, and the adjustment result is difficult to achieve the optimal matching state.

The automatic focusing, also called as ABF (auto Back focus), controls the action of a focusing device carried by the camera by triggering an ABF key of the camera or a remote Web interface button, automatically completes the Back focus adjustment, and is beneficial to simplifying the process of engineering installation and background maintenance. However, at present, the camera with the automatic back focus adjusting function has a complex structure and higher cost.

Disclosure of Invention

The invention aims to provide a back focus adjusting device, which realizes back focus adjustment of a camera in a novel structural form, realizes automatic adjustment of the back focus of the camera on the basis of ensuring the flatness of a sensor plate, and has the advantages of simple structure, accurate adjustment and low cost.

Another object of the present invention is to provide a camera, when the camera is used, the back focus adjusting device is used to quickly adjust the back focus parameters of the camera to obtain a clear image, so as to enhance the experience of the user and reduce the production cost of the camera.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a back focus adjusting device, which comprises:

a drive assembly including an output gear;

the transmission assembly comprises a rack and a push rod connected to the rack, and the output gear is in meshed transmission with the rack;

the fixed plate is provided with a first guide hole for guiding the push rod, the push rod penetrates through the first guide hole, and the rack drives the push rod to reciprocate along the axial direction of the first guide hole;

the Sensor plate is arranged on the mounting plate, the mounting plate is positioned on one side of the fixed plate, and the transmission assembly is positioned on the other side of the fixed plate;

the push rod penetrates through the first guide hole to push the mounting plate and the Sensor plate to synchronously reciprocate along the axial direction of the first guide hole, so that the flatness of the Sensor plate in the motion process is guaranteed.

Preferably, the back focus adjusting device further comprises:

one end of the guide post is connected to the mounting plate, the other end of the guide post penetrates through the fixing plate, and the guide post can reciprocate relative to the fixing plate along the axial direction of the first guide hole;

the guide post penetrates through one end of the fixing plate and is connected to the fastener;

the elastic piece is sleeved on the guide post and is positioned between the fixing plate and the fastening piece.

Preferably, the fixing plate is provided with a second guide hole for guiding the guide post.

Preferably, in the initial state, the elastic member is in a pre-compressed state.

Preferably, the push rod penetrates through the fixing plate and is pressed against the mounting plate; or the push rod penetrates through the fixing plate and is fixedly connected with the mounting plate.

Preferably, the drive assembly comprises a motor assembly and a gearbox assembly;

the motor assembly includes:

a stepping motor;

and the driving gear is connected to an output shaft of the stepping motor and meshed with an input gear of the gearbox assembly.

Preferably, the motor assembly further includes:

the PCB is fixed on the stepping motor, and the optical sensor and the stepping motor are both electrically connected with the PCB;

the blocking piece is arranged on the transmission assembly, and the optical sensor is matched with the blocking piece so as to determine the initial reference position of the movement of the stepping motor.

Preferably, the number of the push rods is at least three, the at least three push rods are arranged in parallel, and the push rods are equal in height.

Preferably, the back focus adjusting device further comprises at least three guide columns.

The invention also provides a camera which comprises the back focus adjusting device, and the back focus adjusting device is used for adjusting the back focus of the camera. The invention has the beneficial effects that: in the invention, the transmission assembly and the output gear of the driving assembly form a gear-rack transmission structure, and the rotary motion of the driving assembly is converted into linear motion along the central axis (front and back) of the first guide hole. When the transmission assembly moves forwards, the mounting plate and the Sensor plate are pushed to move towards the direction far away from the fixed plate so as to adjust the back focus to be small. When the transmission assembly moves backwards, the mounting plate and the Sensor plate are driven to move towards the direction close to the fixed plate together, so that the back focus is enlarged.

According to the invention, the first guide hole is matched with the push rod and guides the push rod, so that the shaking amount between the push rod and the first guide hole is effectively reduced. When the push rod promoted the mounting panel, the terminal surface of push rod passed through face contact with the mounting panel, and consequently, the push rod was exerted the power of installing in the mounting panel and is the relatively even power, and this power is face thrust, and face thrust is exerted to the mounting panel and has been avoided the mounting panel to lead to rocking or blocking because of the atress is uneven. Through the design optimization, the output gear, the rack, the push rod and the first guide hole only need to guarantee general machining precision, and the requirement for the flatness of the Sensor plate in the motion process can be met. The rear coke adjusting device is simple in overall structure, low in production cost, convenient to install each structural part and easy to assemble, disassemble and maintain.

Drawings

Fig. 1 is an exploded view of a gun type camera according to the present invention;

fig. 2 is a front view of the gun camera of fig. 1;

FIG. 3 is a schematic diagram illustrating a back focus adjustment process of a gun camera according to the present invention;

FIG. 4 is a schematic diagram of an exploded view of a back focus adjustment mechanism provided by the present invention;

FIG. 5 is a schematic top view of the back focus adjustment assembly of FIG. 4;

fig. 6 is a side view schematically showing the back focus adjusting device of fig. 4.

In the figure:

1. a front housing; 2. a filter element adjustment assembly;

3. a back focus adjusting device; 31. a set screw; 32. a Sensor board; 33. mounting a plate; 331. a guide post; 34. an elastic member; 35. a fastener; 36. a fixing plate; 361. a first guide hole; 362. a second guide hole; 37. a transmission assembly; 371. a push rod; 372. a rack; 373. a baffle plate; 38. a gearbox assembly; 381. a transmission housing; 382. a reduction gear; 39. a motor assembly; 391. a driving gear; 392. a light sensor; 393. a PCB board;

4. a lower cover; 5. a master control assembly; 51. an optical module interface; 52. ABF adjust the key set; 53. a network port; 6. an upper cover; 7. and (7) a rear cover.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that are conventionally placed when the products of the present invention are used, and are used only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements to be referred to must have specific orientations, be constructed in specific orientations, and operate, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; either mechanically or electrically. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

The invention provides a camera, which is characterized in that an interface of a lens is reserved, and a client can select the type of the lens and install the lens in a matching way. In addition, for some large-aperture lenses, the lenses cannot be installed inside a camera due to their large external dimensions, and can only be used in cooperation with the camera, so that after the lenses are installed, the back focus of the camera (the distance between the mechanical back end surface of the lens and the image plane) needs to be adjusted to obtain a clear image.

For the current security industry, most of cameras with back focus adjusting functions are gun-type cameras, and the following scheme mainly aims to adjust the back focus of the camera in another structural form, so that the embodiment of the invention is described in detail by taking the gun-type camera as an example.

Fig. 1 is an exploded view of a gun type camera according to the present invention, and fig. 2 is a front view of the gun type camera shown in fig. 1, which is combined with fig. 1 and 2, and includes a front case 1, a filter adjustment assembly 2, a back focus adjustment device 3, a lower cover 4, a main control assembly 5, an upper cover 6, and a rear cover 7. Wherein, the middle part of the front shell 1 is provided with a threaded hole which can be adapted to the lenses with various specifications. The filter lens adjusting component 2 can select an integral ICR, can also design a filter frame by oneself, and can be dragged by a motor to realize the switching of the filter lens.

The main control assembly 5 is composed of a plurality of single boards and is responsible for operation and signal processing of the whole machine. The external interface of the whole machine is directly led out from the main control assembly 5, wherein the external interface comprises an optical module interface 51, a network interface 53 and an ABF adjusting key 52. After the external lens assembly and the power-on of the whole machine are completed, the ABF adjusting key 52 can be directly pressed, and the back focus adjusting device 3 executes the back focus automatic adjusting process after receiving the back focus adjusting command. When the gun-type camera is used, an ABF adjustment option box can be found in a remote Web interface when image blurring or other abnormalities occur, and automatic adjustment of the back focus is remotely controlled.

Specifically, the back focus adjustment process of the gun camera is as shown in fig. 3, and a back focus adjustment command is issued through the ABF adjustment button 52 or a remote Web interface. The main control module 5 processes the command and transmits the command to the back focus adjusting device 3, and the back focus adjusting device 3 moves back and forth (the direction "front" means one end for mounting the lens) and transmits the image to the main control module 5. The main control component 5 obtains the resolution of the image, when the resolution is within a preset range, the image is judged to be clear, and when the clear image is obtained, the main control component 5 sends a stop command to the back focus adjusting device 3 to complete back focus adjustment. The preset range of the resolution may be set according to the precision of the device or the image requirement, and is not limited herein.

The specific method for the back focus adjusting device 3 to obtain the clear image is that, in the process of adjusting the back focus of the gun-type camera, the resolution of the image obtained by the main control assembly 5 gradually changes along with the change of the adjusting distance, when the resolution of the image obtained by the main control assembly 5 is within the preset range, the current image is considered to be the clear image, and the main control assembly 5 sends a stop command to stop the back focus adjusting device 3 from adjusting.

The back focus adjusting device 3 is applied to a gun-type camera, and realizes back focus adjustment of the gun-type camera in a novel structural form.

Specifically, fig. 4 is an exploded schematic view of a back focus adjusting device provided by the present invention, fig. 5 is a schematic view of a back focus adjusting device in fig. 4, and fig. 6 is a schematic view of a back focus adjusting device in fig. 4. The specific structure of the back focus adjusting device 3 will be described in detail with reference to fig. 4 to 6.

The back focus adjusting device 3 comprises a driving assembly, a transmission assembly 37, a guiding assembly and a Sensor plate 32, in the gun type camera, the guiding assembly comprises a fixing plate 36, the fixing plate 36 is used as a core fixing structure of the back focus adjusting device 3, the rest parts are directly or indirectly arranged on the fixing plate 36, the fixing plate 36 is arranged on the front shell 1 in fig. 1, and the position is fixed, so that a complete and independent back focus adjusting device 3 is formed.

The driving assembly comprises an output gear, the transmission assembly 37 comprises a rack 372 and a push rod 371 connected to the rack 372, specifically, the transmission assembly 37 further comprises a connecting plate, the rack 372 is connected to one side of the connecting plate and is in meshed transmission with the output gear, the push rod 371 is connected to the other side of the connecting plate, and the push rod 371 is cylindrical.

The guide assembly further comprises a mounting plate 33, wherein the mounting plate 33 is located on one side of the fixed plate 36 and the transmission assembly 37 and the driving assembly are located on the other side of the fixed plate 36. The Sensor plate 32 is mounted on the fixing plate 36, and specifically, the Sensor plate 32 and the mounting plate 33 are similar to a flat plate structure, and the Sensor plate 32 is fastened to the mounting plate 33 by the fixing screw 31, and after fastening, the Sensor plate 32 is parallel to the mounting plate 33.

The fixed plate 36 is provided with a first guide hole 361 for guiding the push rod 371, the output gear drives the rack to move along the axial reciprocating motion process of the first guide hole 361, the rack 372 drives the push rod 371 to move, the push rod 371 can penetrate through the first guide hole 361, and the mounting plate 33 and the Sensor plate 32 are pushed to synchronously reciprocate along the axial direction of the first guide hole 361, so that the flatness of the Sensor plate 32 in the motion process is guaranteed.

In this embodiment, the transmission assembly 37 and the output gear of the driving assembly form a gear-rack transmission assembly, which converts the rotation of the driving assembly into a linear motion along the central axis (back and forth) of the first guiding hole 361. When the transmission assembly 37 moves forward, the mounting plate 33 and the Sensor plate 32 are pushed to move away from the fixing plate 36, so that the back focus is adjusted to be small. When the transmission assembly 37 moves backward, the mounting plate 33 and the Sensor plate 32 are driven to move together in a direction close to the fixing plate 36, so as to adjust the back focus.

The first guiding hole 361 of the present embodiment is matched with the push rod 317 and guides the push rod 371, thereby effectively reducing the shaking amount between the push rod 371 and the first guiding hole 361. When the push rod 37 pushes the mounting plate 33, the end face of the push rod 37 is in surface contact with the mounting plate 33, and acting force between the end face of the push rod 37 and the mounting plate 33 is uniformly distributed on the whole contact surface, so that the force applied to the mounting plate 33 by the push rod 37 is relatively uniform, the force is surface thrust, and the surface thrust applied to the mounting plate 33 avoids shaking or blocking of the mounting plate 33 due to uneven stress. Through the design optimization, the flatness requirement of the Sensor plate 32 in the motion process can be met only by ensuring the general machining precision of the output gear and the rack 372, and the push rod 371 and the first guide hole 361 (as the precision requirement of the flatness of the Sensor plate 32 in the embodiment is 0.16 mm). The rear coke adjusting device is simple in overall structure, low in production cost, convenient to install each structural part and easy to assemble, disassemble and maintain.

Specifically, with reference to fig. 4 and 5, the driving assembly includes a motor assembly 39 and a transmission assembly 38 connected to the fixing plate 36, in this embodiment, the transmission assembly 38 is indirectly fastened to the fixing plate 36 through a mounting member, and the transmission assembly 38 can also be fixed to other structural members inside the gun-type camera. The motor assembly 39 includes a stepper motor and a pinion gear 391, wherein the pinion gear 391 is coupled to an output shaft of the stepper motor, the pinion gear 391 engages an input gear of the transmission assembly 38, and an output gear of the transmission assembly 38 engages the rack 372. The stepper motor drives the gearbox assembly 38 to transfer torque, which reduces rotational speed through the gearbox assembly 38 and increases torque.

The driving gear 391 is engaged with the input gear of the transmission case assembly 38 as the output gear of the motor assembly 39, the motor assembly 39 is located on one side of the transmission case assembly 38, and the two are arranged side by side. Referring to fig. 5, the gearbox assembly 38 includes a gearbox housing 381 and a plurality of reduction gears 382 fixed inside the gearbox housing 381, a first stage gear of the reduction gears 382 is used as an input gear to engage with the driving gear 391, a last stage gear is used as an output gear to engage with the rack 372, and the reduction gears 382 realize speed reduction and torque increase through multi-stage transmission.

Referring to fig. 1, 4 and 5, the motor assembly 39 further includes a PCB 393, a photo sensor 392 and a blocking piece 373, wherein the PCB 393 is fixed to the stepping motor, and the photo sensor 392 and the stepping motor are electrically connected to the PCB 393. Specifically, the PCB 393 is a flexible PCB and is fixedly mounted on the housing of the stepping motor, the PCB 393 is electrically connected to the main control module 5, the blocking piece 373 is disposed on the transmission module 37, and the optical sensor 392 is engaged with the blocking piece 373 to determine the initial reference position of the stepping motor.

Specifically, a high level is output when the shutter 373 is not shielded, and a low level is output when the shutter is shielded. After the gun-type camera is initialized at power-on, in the forward or backward movement process of the transmission assembly 37, the blocking sheet 373 on the transmission assembly 37 can cause the level signal of the optical Sensor 392 to jump or block or leave the optical Sensor 392, the jumping point is used as the reference point of the front and back positions of the transmission assembly 37, the acquired reference point is used as the initial reference position of the movement of the stepping motor, when the camera needs to adjust the back focal length of the gun-type camera according to the specific application scene requirements, the focusing command is transmitted to the stepping motor through the main control assembly 5, the stepping motor is started, the stepping motor is decelerated and increased through the multi-stage reduction gear 382 to drive the transmission assembly 37 to transmit, the push rod 371 is precisely matched with the first guide hole 361, and the push rod 371 can be ensured to do linear movement along the front and back direction, so as to meet the requirement of the flatness of the Sensor plate 32 in the movement process.

In addition, when the stepping motor works, two modes of controlling the rotating step number of the stepping motor are provided, one mode is to directly detect the rotating step number of the stepping motor through the main control assembly 5 so as to control the rotating step number of the stepping motor, the other mode is to detect the number of pulses sent to the stepping motor through the main control assembly 5 so as to control the rotating step number of the stepping motor, the forward or backward movement distance of the rack 372 can be accurately controlled through the two modes, so as to control the forward and backward movement length of the Sensor plate 32, and therefore the back focus adjustment of the gun type camera is realized.

With reference to the above-mentioned push rods 371, with continuing reference to fig. 4 and 5, preferably, there are at least three push rods 371, at least three push rods 371 are all disposed in parallel, and the push rods 371 are all equal in height. Correspondingly, the push rods 371 and the first guide holes 361 correspond to each other one by one, a plurality of push rods 371 can simultaneously apply surface thrust to the mounting plate 33, and the push rods 371 and the mounting plate 33 are in multipoint contact, so that the thrust acting on the mounting plate 33 is more uniform. The guide design of a plurality of push rods 371 and a plurality of first guide holes 361 is adopted, the shaking amount between the push rods 371 and the first guide holes 361 is further effectively reduced, the mounting plate 33 and the Sensor plate 32 are guaranteed to be more stable in the front-back movement process, the flatness error of the Sensor plate 32 is kept in a preset error range, and the flatness requirement of the Sensor plate 32 is guaranteed.

More specifically, in the present embodiment, there are three push rods 371, and the three push rods 371 are arranged in a triangle. By the arrangement, the surface thrust of the mounting plate 33 can be ensured to be uniform, the structural design can be simplified as much as possible, structural parts are reduced, and the production cost is reduced.

In order to further ensure that the surface thrust of the mounting plate 33 by the three push rods 371 is basically consistent, the accuracy error of the end surfaces of the three push rods 371 contacting with the mounting plate 33 is within a certain range, namely, the accuracy of the end surfaces of the three push rods 371 is basically consistent.

Referring to fig. 4-6, the guiding assembly further includes a guiding post 331, a fastening member 35 and an elastic member 34, wherein one end of the guiding post 331 is connected to the mounting plate 33, and the other end thereof is inserted into the fixing plate 36, specifically, the other end of the guiding post 331 is inserted into the fixing plate 36, where the insertion means that the guiding post 33 can pass through the fixing plate 36 and reciprocate relative to the fixing plate 36. In this embodiment, the fixing plate 36 is provided with a second guide hole 362 for guiding the guide post 331, the guide post 33 is inserted into the fixing plate 36 through the second guide hole 362, the guide post 331 can reciprocate relative to the fixing plate 36 in the axial direction of the second guide hole 362, and the central axes of the first guide hole 361 and the second guide hole 362 are parallel. In other embodiments, a guide sleeve may be further provided on the fixing plate 36, and an inner hole of the guide sleeve may serve as a second guide hole for guiding the guide post 33.

The guiding post 331 passes through one end of the fixing plate 36 and is connected to the fastening member 35, and the elastic member 34 is sleeved on the guiding post 331 and is located between the fixing plate 36 and the fastening member 35. Under initial condition, elastic component 34 is in the precompression state, and elastic component 34 provides the pretightning force for mounting panel 33, guarantees that mounting panel 33 in the front and back motion process, and mounting panel 33 can closely cooperate all the time with push rod 371, does not have and rocks. The pre-compression state means that the elastic member 34 is in a compression state after the installation of the back focus adjusting device is completed, and the compression amount can be adjusted according to actual needs.

When the push rod 371 is in the process of pushing the mounting plate 33 and the Sensor plate 32 to move back and forth, after the push rod 371 is guided through the first guide hole 361, if the Sensor plate still inclines by a certain amount, the flatness of the Sensor plate 32 cannot meet the requirement, the elastic piece 34 and the second guide hole 362 are matched to compensate the flatness deviation of the Sensor plate 32 to a certain degree, and the flatness of the Sensor plate 32 meets the use requirement. Preferably, the elastic member 34 in this embodiment is a spring.

The number of the guide posts 331 is at least three, the guide posts 331 are arranged in parallel, and the guide posts 331 are equal in height. Correspondingly, there are at least three second guide holes 362, and the guide posts 331 are in one-to-one correspondence with the second guide holes 362. Through setting up a plurality of second guiding holes 362 and a plurality of guide post 331, both cooperate the direction, have further reduced the volume of rocking between second guiding hole 362 and the guide post 331, further guarantee the stability of mounting panel 33 and Sensor board 32 fore-and-aft movement in-process, make the flatness error of the Sensor board 32 in the motion process littleer, further guarantee the flatness of Sensor board 32 promptly.

In this embodiment, there are three guide posts 331 and correspondingly three second guide holes 362, and the second guide holes 362 are arranged in a triangular shape and located on the outer periphery of the first guide holes 361.

In this embodiment, by providing the plurality of sets of first guide holes 361 and the push rods 371, and the plurality of sets of second guide holes 362 and the guide posts 331, the amount of shaking between the shaft and the holes is effectively reduced, and simultaneously, the push rods 371 apply relatively uniform surface thrust to the mounting plate 33 in a multi-point contact manner, thereby further avoiding shaking or jamming of the mounting plate 33 caused by uneven stress. Through the above optimization design, the output gear and the rack 372, the first guide hole 361 and the push rod 371, and the second guide hole 362 and the guide column 331 all only need to guarantee general machining precision, and then the Sensor plate 32 can be guaranteed to realize higher flatness on the basis of meeting the requirement of flatness.

In other embodiments, the end of the push rod 371 can also be fixedly connected to the mounting plate 33, in this technical solution, during the back and forth reciprocating motion of the push rod 371, the mounting plate 33 and the Sensor plate 32 are connected into an integral structure, and synchronously reciprocate.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A back focus adjustment device, comprising:

a drive assembly including an output gear;

a transmission assembly (37), wherein the transmission assembly (37) comprises a rack (372) and a push rod (371) connected to the rack (372), and the output gear is in meshing transmission with the rack (372);

the fixing plate (36) is provided with a first guide hole (361) for guiding the push rod (371), the push rod (371) penetrates through the first guide hole (361), and the rack (372) drives the push rod (371) to reciprocate along the axial direction of the first guide hole (361);

the mounting plate (33), the Sensor plate (32) is mounted on the mounting plate (33), the mounting plate (33) is positioned on one side of the fixing plate (36), and the transmission assembly (37) is positioned on the other side of the fixing plate (36);

the push rod (371) penetrates through the first guide hole (361) to push the mounting plate (33) and the Sensor plate (32) to synchronously reciprocate along the axial direction of the first guide hole (361) so as to ensure the flatness of the Sensor plate (32) in the moving process.

2. The back focus adjustment device of claim 1, further comprising:

a guide post (331) having one end connected to the mounting plate (33) and the other end penetrating the fixing plate (36), the guide post (331) being capable of reciprocating relative to the fixing plate (36) in the axial direction of the first guide hole (361);

a fastener (35), wherein the guide column (331) passes through one end of the fixing plate (36) and is connected to the fastener (35);

and the elastic piece (34) is sleeved on the guide post (331) and is positioned between the fixing plate (36) and the fastener (35).

3. The back focus adjusting apparatus according to claim 2, wherein the fixing plate (36) is provided with a second guide hole (362) that guides the guide post (331).

4. A back focus adjustment device according to claim 3, wherein in an initial state the resilient member (34) is in a pre-compressed state.

5. The back focus adjustment device according to claim 4, wherein the push rod (371) passes through the fixing plate (36) and presses against the mounting plate (33); or the push rod (371) penetrates through the fixing plate (36) to be fixedly connected with the mounting plate (33).

6. The back focus adjustment device according to claim 1, wherein the drive assembly comprises a motor assembly (39) and a gearbox assembly (38);

the motor assembly (39) includes:

a stepping motor;

and the driving gear (391) is connected to an output shaft of the stepping motor, and the driving gear (391) is meshed with an input gear of the gearbox assembly (38).

7. The back focus adjustment device according to claim 6, wherein the motor assembly (39) further comprises:

the PCB (393) and the optical sensor (392), the PCB (393) is fixed on the stepping motor, and the optical sensor (392) and the stepping motor are both electrically connected with the PCB (393);

the blocking piece (373) is arranged on the transmission component (37), and the optical sensor (392) is matched with the blocking piece (373) to determine an initial reference position of the movement of the stepping motor.

8. The back focus adjusting device according to any one of claims 1-7, wherein the number of the push rods (371) is at least three, at least three push rods (371) are arranged in parallel with each other, and the push rods (371) are all equal in height.

9. The back focus adjustment device according to any one of claims 1-7, further comprising guide posts (331), the guide posts (331) being at least three.

10. A camera comprising a back focus adjustment device as claimed in any one of claims 1 to 9 for adjusting the back focus of the camera.