CN114721120B

CN114721120B - Zoom device without zero detection sensor and control method thereof

Info

Publication number: CN114721120B
Application number: CN202210229163.1A
Authority: CN
Inventors: 王健; 赵华鹤; 孙金霞
Original assignee: Suzhou Oriental Croto Photoelectric Technology Co ltd
Current assignee: Suzhou Oriental Croto Photoelectric Technology Co ltd
Priority date: 2022-03-10
Filing date: 2022-03-10
Publication date: 2024-04-09
Anticipated expiration: 2042-03-10
Also published as: CN114721120A

Abstract

The invention relates to a zoom device without zero detection sensor and its control method, the cam in the zoom device is sleeved on the lens barrel, the cam has spiral cam groove; the motor is connected with the cam through a transmission mechanism; the sliding frame component is arranged in the lens barrel, a driving guide pin is fixed on the sliding frame component, and the driving guide pin is positioned in the cam groove; the controller is electrically connected with the motor and the encoder thereof; the control method of the zoom device is as follows: the controller drives the cam to rotate through the motor, and the sliding frame component and the lens move forward under the combined action of the driving guide pin and the cam groove until the motor is blocked; the motor drives the cam to reversely rotate to reversely move the carriage assembly and the lens until the motor is blocked, and the number Y of pulses output by the encoder is recorded; if Y is equal to the total number of pulses W of the full stroke, the zero position is marked. The invention does not need a position sensor for detecting zero position, and has the advantages of simple structure, low cost, small volume and the like.

Description

Zoom device without zero detection sensor and control method thereof

Technical Field

The invention belongs to the technical field of optical imaging automatic zoom lenses, and relates to a zoom device without a zero detection sensor and a control method thereof.

Background

At present, many optical instruments require that the magnification of an optical system can be changed, so that the same instrument can see the whole with a large field of view and a low magnification, and can carefully observe the part with a small field of view and a high magnification, and the lens is replaced by a common method, such as a microscope objective, however, the intermittent zooming method of the lens is replaced to make the imaging size suddenly change. In order to continuously change the imaging size, a zoom lens has been developed. In recent years, the technology of a zoom lens is rapidly developed, and the zoom lens is greatly broken through in the aspects of imaging quality, a zoom ratio range, an external dimension, a field of view range and the like, so that the application field of the zoom lens is more and more wide, and the zoom lens plays an important role in daily life, art and work from a camera instrument to a camera, a telescope, a microscope, a monitoring system and a machine vision to a camera phone, and gradually develops towards a large-field-of-view zoom ratio direction, and also places higher requirements on lens positioning accuracy in a zoom focusing process. The current optical imaging zoom lens adopts a direct current gear motor to drive a zoom group, a compensation group and a focusing group lens to axially move so as to achieve the purpose of zoom focusing of the lens, so that the zero position detection of the lens and whether a moving part in a detection system moves normally are involved at the beginning of power-on of an imaging system, and the current zoom lens adopts one or more position detection sensors such as a photoelectric switch, a touch switch and a potentiometer to determine the zero position of the lens, so that the method can really solve the problems of zero position detection and whether the moving part of the system is blocked or not, but has the following defects: 1. the photoelectric switch is used for zero position detection, the photoelectric switch is matched with the photoelectric switch to use the photoelectric switch, the photoelectric switch is required to accurately position the photoelectric switch in the initial stage of lens assembly and adjustment, so that the lens can find a correct zero position, but the photoelectric switch is very complicated to operate in the actual production process, the photoelectric switch is required to repeatedly adjust the position of the photoelectric switch, the expected effect can be achieved, and the efficiency is low. 2. The use of the touch switch has similar problems with the structure of the photoelectric switch, namely the repeated position adjustment is low in efficiency, and the long-term repeated contact is easy to cause loosening of structural member screws such as the structure touch switch because the touch switch is in mechanical contact detection, so that the zero position positioning precision is reduced. 3. The potentiometer structure is used, and because the potentiometer inner structure principle is the same as that of the slide rheostat, the resistance is changed by changing the contact position, the defect of low service life is naturally brought, and the output precision is easily reduced due to long-term repeated movement, so that the positioning precision of a lens reset point is influenced.

Disclosure of Invention

The invention aims to solve the technical problem of providing a zoom device without a zero detection sensor, which can reduce the system cost and improve the stability of the system while reducing the volume and the weight of the system.

In order to solve the technical problem, the zooming device without a zero detection sensor comprises a rotary driving device, a cam and a carriage assembly, and a controller; the rotary driving device adopts a motor integrated with an encoder, and the motor is arranged on the lens barrel; the cam is sleeved on the lens barrel and is provided with a spiral cam groove; the motor is connected with the cam through a transmission mechanism; the sliding frame component is arranged in the lens barrel, the lens is fixed on the sliding frame component, the driving guide nail is fixed on the sliding frame component, and the driving guide nail is positioned in the cam groove; the controller is electrically connected with the motor and the encoder; when the motor drives the cam to rotate, the driving guide nail moves along the axial direction of the lens barrel under the action of the cam groove, so that the carriage assembly and the lens are driven to move.

The motor is connected with the cam through a gear transmission mechanism.

Further, the present invention also includes a guide roller mounted on the drive guide.

The controller is integrated on a control board which is fixed on the lens cone.

The motor adopts a Ful Ha Bei 1331T0124r246:1_IE2-50 direct-current speed reduction motor.

Further, the invention also comprises an anti-backlash structure; the gap eliminating structure comprises a supporting plate and 3 eccentric shaft assemblies with the same structure; the 3 eccentric shaft assemblies and the driving guide nails are arranged on the assembly supporting plate; the eccentric shaft assembly comprises an eccentric shaft seat, an eccentric shaft and a guide groove bearing; the eccentric shaft is fixed on the eccentric shaft seat, the axis of the eccentric shaft is deviated from the axis of the eccentric shaft seat, and the guide groove bearing is arranged on the eccentric shaft; the eccentric shaft seat can drive the guide groove bearing to rotate around the axis of the eccentric shaft seat and be fixed; the lens barrel is provided with a linear guide groove extending along the axial direction, the assembly supporting plate is fixed on the outer circumferential surface of the carriage assembly, and the guide groove bearings of the eccentric shaft assemblies are positioned in the linear guide groove.

The control method of the zoom device without the zero detection sensor is as follows:

step one, a controller controls a motor to operate and drives a cam to rotate, so that a driving guide pin moves forwards along the axial direction of a lens barrel under the action of a cam groove, and a sliding frame component and a lens are driven to move until the driving guide pin reaches the C end point of the front end and contacts with the B end point of the cam groove to cause the motor to stop rotating; setting the number of pulses output to the controller by the encoder in the process of driving the guide nail to move from the starting point to the end point C as X;

judging the pulse number X output by the encoder to be compared with the total pulse number W of the whole stroke of the driving guide nail moving in the cam groove, reporting alarm information if X is larger than or equal to W, controlling the motor to reversely run and driving the cam to reversely rotate by the controller if X is smaller than or equal to W, driving the guide nail to move towards the rear end along the axis of the lens barrel under the action of the cam groove, and driving the sliding frame component and the lens to reversely move until the driving guide nail reaches the D end point of the rear end to be in contact with the A end point of the cam groove so as to cause the motor to stop rotating; setting the number of pulses output by the encoder to the controller in the process of driving the guide pin to move from the end point C to the end point D as Y;

and thirdly, comparing the pulse number Y output by the encoder with the total pulse number W of the full stroke, reporting alarm information if Y is not equal to W, and marking zero position if Y=W, indicating that the driving guide nail reaches the end point D at the moment.

The invention has the beneficial effects that:

according to the invention, the forward rotation and the reverse rotation of the motor are controlled to drive the lens to move forwards and backwards, so that the zero detection of the system is completed by matching with the locked rotation detection of the motor and reasonable control logic. The device does not need a position sensor for detecting zero position, so the device has the advantages of simple structure, low cost, small volume and the like. The invention marks zero position not simply through the unidirectional motor movement locked rotation, but detects the system problem and adds the function of reporting alarm information when completing zero position detection through the control logic, thereby having the advantages of stability and reliability.

Drawings

The invention is described in further detail below with reference to the drawings and the detailed description.

FIG. 1 is a perspective view of a zoom apparatus of the present invention that does not require a zero detection sensor.

FIG. 2 is a top view of a zoom apparatus of the present invention that does not require a zero detection sensor.

FIG. 3 is a cross-sectional view of a zoom apparatus of the present invention that does not require a zero detection sensor.

Fig. 4 is a cross-sectional view of a zoom apparatus with an anti-backlash structure.

Fig. 5 is a perspective view of a carriage assembly with an anti-backlash structure.

Fig. 6 is a perspective view of an anti-backlash structure.

Fig. 7 is an exploded view of the eccentric shaft assembly.

Fig. 8 is a perspective view of the anti-backlash mechanism mated with the linear guide slot.

Fig. 9 is a flow chart of a control method of the present invention.

In the figure: 1. a lens barrel; 11. a straight guide groove; 21. a motor; 22. a drive gear set; 31. a cam; 311. cam grooves; 312. a protrusion; 32. a driven gear; 4. driving the guide nails; 5. a carriage assembly; 6. a lens; 7. a control board; 81. support plates 82, 83, 84; 821. a eccentric shaft seat; 8211. a central shaft; 822. an eccentric shaft; 823. a guide groove bearing; 824. pressing nails by a bearing; 825. a bearing pressing washer; 833. a guide groove bearing; 843. a guide groove bearing; 85. shaft seat nails; 86. a screw; 9. a guide roller.

Detailed Description

The present invention will now be described in further detail with reference to the drawings and examples, it being understood that the specific examples described herein are intended to illustrate the invention only and are not intended to be limiting. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present invention are shown in the drawings.

In the description of the present invention, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements or interaction relationship between the two elements. The specific meaning of the above terms in the present invention can be understood in detail by those skilled in the art.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below", "beneath" the second feature includes the first feature being "directly under" and obliquely below "the second feature, or simply indicating that the first feature is less level than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are orientation or positional relationships based on those shown in the drawings, for convenience of description and simplicity of operation, and are not meant to indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," and the like, are used merely for distinguishing between descriptions and not for distinguishing between them.

As shown in fig. 1-3, the zoom apparatus of the present invention without zero detection sensor comprises a rotary drive device, a cam, a carriage assembly 5, a control board 7; the rotary driving device adopts a motor 21 integrated with an encoder, and the motor 21 is fixedly connected with the lens barrel 1 of the zoom lens; the cam 31 is sleeved on the lens barrel 1 and is provided with a spiral cam groove 311; the driving shaft of the motor 21 is connected with the cam 31 through the driving gear set 22 and the driven gear; the driven gear 32 is sleeved on the cam 31, and the driven gear 32 and the cam are clamped with a notch on the inner side of the driven gear through a bulge 312 on the outer side of the cam; the sliding frame component 5 is arranged in the lens barrel 1, and the lens 6 is fixed on the sliding frame component 5 and can move along the axial direction of the lens barrel along with the sliding frame component 5; the driving guide nail 4 is fixed on the carriage assembly, and the driving guide nail 4 is positioned in the cam groove 311; the control board 7 is fixed on the lens barrel and a controller thereon is electrically connected with the motor and the encoder.

The motor adopts a Fuer Ha Bei 1331T012SR_246:1_IE2-50 direct-current gear motor, a fifty-line incremental encoder is integrated at the tail part of the motor, zero detection of the zooming device is completed through the locked rotor detection function of the encoder and a control board in combination with reasonable control logic, and the motor has a power-on self-detection function for detecting whether a moving part moves normally or not.

As shown in fig. 4-6, the zoom device may further comprise a guide roller 9 mounted on the driving guide 4.

The zoom device can also comprise an anti-backlash structure; the gap eliminating structure comprises a support plate 81,3 eccentric shaft assemblies 82, 83 and 84 with the same structure; the 3 eccentric shaft assemblies are sequentially mounted on the assembly support plate 81, and the driving guide pin 4 is mounted on the assembly support plate 81 between the eccentric shaft assembly 83 and the eccentric shaft assembly 84.

As shown in fig. 7, taking an eccentric shaft assembly 82 as an example, the eccentric shaft assembly includes an eccentric shaft seat 821, an eccentric shaft 822, a guide slot bearing 823, a bearing pressing nail 824 and a bearing pressing washer 825; a central shaft 8211 at the lower part of the eccentric shaft base 821 is arranged in a matching hole of the component supporting plate 81, can rotate around the axis of the matching hole and is fixed by a corresponding shaft seat nail 85; the eccentric shaft 822 is fixed on the eccentric shaft seat 821 and the axis of the eccentric shaft seat 821 is deviated from the axis of the eccentric shaft seat 821; the channel bearing 823 is mounted on the eccentric shaft 822 and is fixed by bearing compression pins 824 and bearing compression washers 825.

The lens barrel 1 is provided with a linear guide groove 11 extending along the axial direction, an assembly supporting plate 81 is fixed on the outer circumferential surface of the carriage assembly 5 through 2 screws 86, and guide groove bearings of each eccentric shaft assembly are positioned in the linear guide groove 11; as shown in fig. 8, the angles of the eccentric shaft seats are adjusted during installation so that the guide groove bearing 833 and the guide groove bearing 843 are in close contact with the lower vertical surface of the linear guide groove 11, the guide groove bearing 823 is in close contact with the upper vertical surface of the linear guide groove 11, and the shaft seat nails 85 are respectively locked. At this time, the carriage assembly 5 cannot rotate around the axis of the lens barrel 1, when the cam 31 drives the carriage assembly 5 to move by the guide roller 9. The carriage assembly 5 generates only a linear motion in the direction of the barrel axis. Therefore, the phenomenon of backlash in the zooming process of the lens can be eliminated, and the repeated positioning precision is improved.

As shown in fig. 9, the control method of the zoom apparatus without zero detection sensor of the present invention is specifically as follows:

step one, the control panel is electrified, a controller on the control panel controls the motor to operate, and the driving gear and the driven gear drive the cam to rotate, so that the driving guide nail moves forwards along the axial direction of the lens barrel under the action of the cam groove, and the carriage assembly and the lens are driven to move until the driving guide nail reaches the C end point of the front end and contacts with the B end point of the cam groove to stop the motor; setting the number of pulses output to the controller by the encoder in the process of driving the guide nail to move from the starting point to the end point C as X;

judging that the pulse number X output by the encoder is compared with the total pulse number W of the full stroke of the driving guide nail moving in the cam groove, if X > W, indicating that the zoom device has a problem and alarm information is required to be reported (possibly the problem occurs in a transmission system), if X is less than or equal to W, controlling a motor to reversely run by a controller, driving a cam to reversely rotate through a driving gear and a driven gear, and driving the guide nail to move towards the rear end along the axis of the lens barrel under the action of the cam groove, so as to drive a sliding frame assembly and a lens to reversely move until a D end point of the driving guide nail reaches the rear end to be contacted with an A end point of the cam groove to cause the motor to stop rotating; setting the number of pulses output by the encoder to the controller in the process of driving the guide pin to move from the end point C to the end point D as Y;

and thirdly, comparing the pulse number Y output by the encoder with the total pulse number W of the full stroke, if Y is not equal to W, indicating that the zoom device has a problem and alarm information needs to be reported (possibly the control board is blocked due to faults), and if Y=W, indicating that the driving guide nail reaches the end point D at the moment, namely, the zoom lens reaches a zero position and marks the zero position.

The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims

1. The zooming device without the zero detection sensor is characterized by comprising a rotary driving device, a cam (31), a sliding frame component (5), a controller and a gap eliminating structure; the rotary driving device adopts a motor (21) integrated with an encoder, and the motor (21) is arranged on the lens barrel; the cam (31) is sleeved on the lens barrel (1) and is provided with a spiral cam groove (311); the motor (21) is connected with the cam (31) through a transmission mechanism; the sliding frame assembly (5) is arranged in the lens barrel (1), the lens (6) is fixed on the sliding frame assembly (5), the driving guide nail (4) is fixed on the sliding frame assembly, the driving guide nail (4) is positioned in the cam groove (311), and the driving guide nail (4) is provided with a guide nail roller (9); the controller is electrically connected with the motor and the encoder; when the motor drives the cam to rotate, the driving guide nail moves along the axial direction of the lens barrel under the action of the cam groove, so that the carriage assembly and the lens are driven to move; the motor adopts a Ful Ha Bei 1331T0124r246:1_IE2-50 direct-current speed reducing motor; the gap eliminating structure comprises a supporting plate (81) and 3 eccentric shaft assemblies with the same structure; the 3 eccentric shaft assemblies and the driving guide nails (4) are arranged on the assembly supporting plate (81); the eccentric shaft assembly comprises an eccentric shaft seat, an eccentric shaft and a guide groove bearing; the eccentric shaft is fixed on the eccentric shaft seat, the axis of the eccentric shaft is deviated from the axis of the eccentric shaft seat, and the guide groove bearing is arranged on the eccentric shaft; the eccentric shaft seat can drive the guide groove bearing to rotate around the axis of the eccentric shaft seat and be fixed; the lens barrel (1) is provided with a linear guide groove (11) extending along the axial direction, a supporting plate (81) is fixed on the outer circumferential surface of the carriage assembly (5), and a guide groove bearing of each eccentric shaft assembly is positioned in the linear guide groove (11).

2. A zoom apparatus without zero detection sensor according to claim 1, characterized in that the motor (21) is connected to the cam via a gear transmission.

3. The zoom apparatus without zero detection sensor according to claim 1, wherein the controller is integrated on a control board (7), and the control board (7) is fixed on the lens barrel.

4. A control method of a zoom apparatus according to claim 1, which does not require a zero detection sensor, characterized by comprising the steps of: