CN114721120A

CN114721120A - Zooming device without zero detection sensor and control method thereof

Info

Publication number: CN114721120A
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: 2022-07-08
Anticipated expiration: 2042-03-10
Also published as: CN114721120B

Abstract

The invention relates to a zooming device without a zero position detection sensor and a control method thereof.A cam in the zooming device is sleeved on a lens cone and is provided with a spiral cam groove; the motor is connected with the cam through a transmission mechanism; the slide frame assembly is arranged in the lens cone, a driving guide pin is fixed on the slide frame assembly, 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 assembly and the lens move towards the front end under the combined action of the driving guide pin and the cam groove until the motor is locked; the motor drives the cam to rotate reversely to enable the sliding frame assembly and the lens to move reversely until the motor is locked, and the number Y of output pulses of the encoder is recorded; and marking a zero position if Y is equal to the total number of full stroke pulses W. 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

Zooming 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 of a large field of view and a low magnification, and can also carefully observe the part of a small field of view and a high magnification. In order to continuously change the imaging size, the zoom lens is produced. In recent years, the technology of zoom lenses is rapidly developed, and the zoom lenses are greatly broken through in the aspects of imaging quality, zoom ratio range, appearance size, field range and the like, so that the application fields of the zoom lenses are more and more extensive, and the zoom lenses play an important role in daily life, art and work from a camera instrument to a camera, a telescope, a microscope, a monitoring system and machine vision to a camera phone, and gradually develop towards the zoom ratio with large field of view, and also put higher requirements on lens positioning accuracy in the zoom focusing process. The existing optical imaging zoom lens mainly adopts a direct-current speed reduction motor to drive lenses of a zoom group, a compensation group and a focusing group to axially move, so that the aim of zooming and focusing of a lens is fulfilled, zero position detection of the lens and whether moving parts in a detection system normally move are related to at the beginning of electrifying the imaging system, and the zero position of the lens is determined by one or more position detection sensors such as a photoelectric switch, a touch switch, a potentiometer and the like, so that the above method can really solve the problems of zero position detection and whether moving parts of the system are jammed, but has the following defects: 1. use photoelectric switch to carry out the zero-bit detection structure complicacy, the opto-coupler separation blade that cooperation photoelectric switch used needs its position of accurate positioning at camera lens dress accent initial stage to guarantee that the camera lens can find correct zero-bit, but operate very loaded down with trivial details need adjust the position of opto-coupler separation blade repeatedly in actual production process, could reach anticipated effect, inefficiency. 2. The use touch switch and above photoelectric switch structure have similar problem promptly to adjust the position inefficiency repeatedly, again because touch switch is mechanical contact detection, long-term repeated contact causes structure such as touch switch easily that the screw becomes flexible thereby reduces zero position positioning accuracy. 3. The potentiometer structure has the advantages that due to the fact that the principle of the inner structure of the potentiometer is the same as that of the sliding rheostat, resistance is changed through changing of the contact position, the defect of short service life is naturally caused, output accuracy is easily reduced due to long-term repeated movement, and then positioning accuracy of a lens reset point is affected.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a zoom device without a zero detection sensor, which can reduce the system cost, reduce the volume and weight of the system and improve the stability of the system.

In order to solve the technical problem, the zoom device without a zero detection sensor comprises a rotary driving device, a cam, a sliding frame component and a controller; the rotary driving device adopts a motor integrated with an encoder, and the motor is arranged on the lens cone; the cam is sleeved on the lens cone and is provided with a spiral cam groove; the motor is connected with the cam through a transmission mechanism; the slide frame assembly is arranged in the lens barrel, the lens is fixed on the slide frame assembly, and the slide frame assembly is fixed with a driving guide pin which 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 pin moves along the axis direction of the lens barrel under the action of the cam groove, so that the sliding frame assembly and the lens are driven to move.

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

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

The controller is integrated on the control panel, and the control panel is fixed on the lens cone.

The motor adopts a Volvab 1331T012 SR-246: 1 IE2-50 DC speed reducing motor.

Furthermore, the invention also comprises an anti-backlash structure; the anti-backlash structure comprises a support plate and 3 eccentric shaft assemblies with the same structure; 3 eccentric shaft assemblies and driving guide pins 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 deviates 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 is fixed; the lens barrel is provided with a linear guide groove extending along the axial direction, the component supporting plate is fixed on the outer circumferential surface of the sliding frame component, and the guide groove bearing of each eccentric shaft component is positioned in the linear guide groove.

The control method of the zooming device without the zero detection sensor comprises the following steps:

the method comprises the following steps that firstly, a controller controls a motor to operate and drives a cam to rotate, so that a driving guide pin moves forwards along the axis direction of a lens barrel under the action of a cam groove, a sliding frame assembly and a lens are driven to move until the driving guide pin reaches a C end point at the front end and contacts with a B end point of the cam groove, and the motor is locked; setting the number of pulses output to the controller by the encoder in the process of driving the guide pin to move from the starting point to the C end point as X;

step two, judging the pulse quantity X output by the encoder and the total pulse quantity W of the driving guide pin moving in the cam groove in the full stroke for comparison, if X is larger than W, reporting alarm information, if X is smaller than or equal to W, controlling the motor to run reversely by the controller and driving the cam to rotate reversely, and driving the guide pin to move towards the rear end along the axis of the lens cone under the action of the cam groove so as to drive the sliding frame assembly and the lens to move reversely until the D end point of the driving guide pin at the rear end contacts with the A end point of the cam groove to stop the rotation of the motor; setting the pulse number output to the controller by the encoder in the process of driving the guide pin to move from the C endpoint to the D endpoint to be Y;

and step three, comparing the pulse quantity Y output by the encoder with the total pulse quantity W of the full stroke, reporting alarm information if Y is not equal to W, and indicating that the driving guide pin reaches the D end point and marking a zero position if Y is equal to W.

The invention has the beneficial effects that:

the invention drives the lens to move back and forth by controlling the positive rotation and the negative rotation of the motor and completes the zero position detection of the system by matching the locked rotor 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 size and the like. The invention does not simply mark the zero position by the rotation blockage of the unidirectional motor motion, but detects the system problem and adds the function of reporting alarm information while completing the zero position detection through the control logic, thereby having the advantages of stability and reliability.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Fig. 1 is a perspective view of a zoom apparatus without a zero detection sensor according to the present invention.

Fig. 2 is a top view of a zoom apparatus without a zero detection sensor according to the present invention.

Fig. 3 is a cross-sectional view of a zoom apparatus without a zero detection sensor according to the present invention.

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 an eccentric shaft assembly.

Fig. 8 is a perspective view of the anti-backlash structure in cooperation with a 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 linear guide groove; 21. a motor; 22. a driving gear set; 31. a cam; 311. a cam slot; 312. a protrusion; 32. a driven gear; 4. driving the guide pin; 5. a carriage assembly; 6. a lens; 7. a control panel; 81.

support plates

82, 83, 84. eccentric shaft assembly; 821. an eccentric shaft seat; 8211. a central shaft; 822. an eccentric shaft; 823. a guide groove bearing; 824. bearing compression nails; 825. a bearing compression washer; 833. a guide groove bearing; 843. a guide groove bearing; 85. shaft seat nails; 86. a screw; 9. and a nail guide roller.

Detailed Description

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

In the description of the present invention, unless otherwise explicitly specified or limited, the terms "connected," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other suitable relationship. The specific meanings of the above terms in the present invention can be specifically understood in specific cases by those of ordinary skill 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," or "beneath" a second feature includes the first feature being directly under or obliquely below the second feature, or simply means that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used in the orientation or positional relationship shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

As shown in fig. 1 to 3, the zoom apparatus without a zero position detecting sensor of the present invention includes a rotation driving device, a cam, a carriage assembly 5, a control board 7; the rotation 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 clamped with a notch on the inner side of the driven gear through a bulge 312 on the outer side of the cam; the slide frame assembly 5 is arranged in the lens barrel 1, and the lens 6 is fixed on the slide frame assembly 5 and can move along the axis direction of the lens barrel along with the slide frame assembly 5; the carriage assembly is fixed with a driving guide pin 4, and the driving guide pin 4 is positioned in the cam groove 311; the control board 7 is fixed on the lens cone and the controller on the control board is electrically connected with the motor and the encoder.

The motor adopts a Volvab 1331T012 SR-246: 1 IE2-50 direct-current speed reduction motor, a fifty-line incremental encoder is integrated at the tail of the motor, zero position detection of the zoom device is completed through the blocking and rotation detection functions of the encoder and a control board and the cooperation of reasonable control logic, and the motor has a power-on self-detection function of detecting whether a moving part moves normally.

As shown in fig. 4-6, the zoom apparatus may further include a pin roller 9 mounted on the drive pin 4.

The zooming device can also comprise an anti-backlash structure; the anti-backlash 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 installed on the assembly support plate 81, and the driving guide pins 4 are installed on the assembly support plate 81 between the

eccentric shaft assemblies

83 and 84.

As shown in fig. 7, taking the eccentric shaft assembly 82 as an example, the eccentric shaft assembly includes an eccentric shaft seat 821, an eccentric shaft 822, a guide groove bearing 823, a bearing pressing pin 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 assembly supporting plate 81, can rotate around the axis of the matching hole and is fixed through a corresponding shaft base nail 85; eccentric shaft 822 is fixed on eccentric shaft seat 821 and its axis is deviated from the axis of eccentric shaft seat 821; the guide groove bearing 823 is mounted on the eccentric shaft 822 and is pressed and fixed by the bearing pressing pin 824 and the bearing pressing washer 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 sliding frame assembly 5 through 2 screws 86, and a guide groove bearing of each eccentric shaft assembly is positioned in the linear guide groove 11; as shown in fig. 8, the angle of each eccentric shaft seat is 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, and the guide groove bearing 823 is in close contact with the upper vertical surface of the linear guide groove 11, so as to respectively lock each shaft seat nail 85. 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 through the nail guide roller 9. The carriage assembly 5 generates only a linear motion in the direction of the lens barrel axis. Therefore, the backlash phenomenon in the zooming process of the lens can be eliminated, and the repeated positioning precision is improved.

As shown in fig. 9, the method for controlling the zoom apparatus without the zero detection sensor of the present invention specifically includes the following steps:

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

step two, judging the pulse quantity X output by the encoder and the total pulse quantity W of the driving guide pin in the cam groove for full travel to compare, if X is larger than W, it is indicated that the zoom device has problems and needs to report alarm information (possibly, a transmission system has problems), if X is smaller than or equal to W, the controller controls the motor to run in reverse, the driving gear and the driven gear drive the cam to rotate in reverse, the driving guide pin moves towards the rear end along the axis of the lens cone under the action of the cam groove, and therefore the sliding frame assembly and the lens are driven to move in reverse until the D end point of the driving guide pin reaching the rear end contacts with the A end point of the cam groove to block the motor; setting the pulse number output to the controller by the encoder in the process of driving the guide pin to move from the C endpoint to the D endpoint to be Y;

and step three, 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 problems and alarm information needs to be reported (possibly, the control panel has a jamming phenomenon due to a fault), and if Y is equal to W, indicating that the driving guide pin reaches the D end point, namely the zoom lens reaches the zero position, and marking the zero position.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A zooming device without a zero detection sensor is characterized by comprising a rotary driving device, a cam (31), a sliding frame assembly (5) and a controller; the rotary driving device adopts a motor (21) integrated with an encoder, and the motor (21) is arranged on the lens cone; 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 slide frame assembly (5) is arranged in the lens barrel (1), the lens (6) is fixed on the slide frame assembly (5), the slide frame assembly is fixed with a driving guide nail (4), and the driving guide nail (4) is positioned in the cam groove (311); the controller is electrically connected with the motor and the encoder; when the motor drives the cam to rotate, the driving guide pin moves along the axis direction of the lens barrel under the action of the cam groove, so that the sliding frame assembly and the lens are driven to move.

2. The zoom apparatus without a null sensor according to claim 1, wherein the motor (21) is connected to the cam through a gear train.

3. The zoom apparatus without a zero detection sensor according to claim 1, further comprising a guide pin roller (9) mounted on the drive guide pin (4).

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

5. The zoom apparatus without any zero position detecting sensor as claimed in claim 1, wherein the motor is a Fowler-Nordheim 1331T012 SR-246: 1 IE2-50 DC speed reduction motor.

6. The zoom apparatus without a zero detection sensor according to claim 3, further comprising an anti-backlash structure; the anti-backlash structure comprises a support plate (81) and 3 eccentric shaft assemblies with the same structure; 3 eccentric shaft assemblies and driving guide pins (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 deviates 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 is fixed; 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 sliding frame assembly (5) and a guide groove bearing of each eccentric shaft assembly is positioned in the linear guide groove (11).

7. A method of controlling a zoom apparatus without a zero detection sensor according to claim 1, characterized by: