CN109298501B - Lens focusing device and method - Google Patents

Lens focusing device and method Download PDF

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Publication number
CN109298501B
CN109298501B CN201811257467.9A CN201811257467A CN109298501B CN 109298501 B CN109298501 B CN 109298501B CN 201811257467 A CN201811257467 A CN 201811257467A CN 109298501 B CN109298501 B CN 109298501B
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inner lens
ultrasonic motor
focusing
lens
linear ultrasonic
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CN109298501A (en
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吴羽峰
金尚忠
王赟
张益溢
严永强
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China Jiliang University
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China Jiliang University
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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/02—Mountings, adjusting means, or light-tight connections, for optical elements for lenses
    • G02B7/04—Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification
    • G02B7/10—Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification by relative axial movement of several lenses, e.g. of varifocal objective lens
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/28—Systems for automatic generation of focusing signals
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B13/00—Viewfinders; Focusing aids for cameras; Means for focusing for cameras; Autofocus systems for cameras
    • G03B13/32—Means for focusing
    • G03B13/34—Power focusing

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Lens Barrels (AREA)
  • General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)
  • Endoscopes (AREA)

Abstract

The invention discloses a lens focusing device and a focusing method. Relates to the technical field of focal length adjustment, and provides a novel focusing structure and a focusing method. The device preprocesses an input focal distance value through a control circuit board (12), converts the input focal distance value into voltage required by controlling a linear ultrasonic motor (03), realizes that the linear ultrasonic motor (03) drives a movable inner lens cone (07) to do linear motion, and further controls the position of a lens group 1(08) to change the focal length of a lens. And the displacement information fed back by the displacement sensor (05) is used for accurately adjusting the displacement information, so that the accurate focusing function of the lens is realized. The invention has simple structure, small volume and convenient and flexible focusing, and is suitable for devices such as mobile phone cameras, smaller endoscopes and the like.

Description

Lens focusing device and method
Technical Field
The invention relates to the technical field of focal length adjustment, in particular to a lens focusing device and a focusing method.
Background
Focusing is to find the best sharp point of imaging by adjusting the distance between a lens and an image sensor, so that a picture or a video is clearer and has better quality.
Most of the existing lens focusing is performed by using a focusing motor, and the focusing motor not only requires small volume, but also needs precise focusing, so that the manufacturing cost is increased. The focus motor size is limited, so the size of the focus motor limits the size of the entire focus structure.
The existing linear ultrasonic motor has a linear actuator to drive the lens group to move, and the use of the linear actuator causes the volume of a focusing mechanism of the lens to be larger. Thus limiting the volume of some products.
Disclosure of Invention
In order to solve the above problems, the present invention provides a lens focusing apparatus and a focusing method.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a lens focusing apparatus, comprising:
the lens barrel comprises an outer lens barrel (01), an elastic washer (02), a linear ultrasonic motor (03), a hard washer (04), a displacement sensor (05), a micro spring (06), a movable inner lens barrel (07), a first lens group (08), an inner lens barrel (09), a second lens group (10), an optical sensor (11) and a control circuit board (12).
The first lens group (08) is connected with the movable inner lens cone (07) and moves along with the movement of the movable inner lens cone. The second lens group (10) is connected with the inner lens cone (09) and is fixed.
The movable inner lens cone (07) is directly used as a rotor of the linear ultrasonic motor (03), so that the whole device is smaller in size.
The miniature spring (06) is connected with the movable inner lens cone (07), and the displacement sensor (05) judges the actual distance value of focal length adjustment according to the compression and extension amount of the spring.
The elastic washers (02) are fixed at two ends of the linear ultrasonic motor (03), so that the linear ultrasonic motor (03) is fixed, and a sufficient space is provided for the operation of the linear ultrasonic motor (03).
The optical sensor (11) is connected with the control circuit board (12) at the tail end of the inner lens cone (09), and the control circuit board (12) is positioned at the tail end of the whole device and is connected with the outer lens cone (01).
The control circuit board (12) comprises a central processing unit, an image processing module, a displacement voltage conversion module and a displacement feedback module.
The image processing module is used for processing the image on the optical sensor (11) so as to ensure that the image imaging quality is better.
The displacement voltage conversion module converts a focusing distance value input from the outside into a voltage required by driving the linear ultrasonic motor (03). Driving a linear ultrasonic motor (03).
The displacement feedback module compares the actual distance value of the lens movement transmitted back by the displacement sensor (05) with the preset distance value for analysis, and sends the distance difference value to the central processing unit.
The linear ultrasonic motor (03) comprises: a piezoelectric element (13), an endoscope cylinder hole (14) and a metal cuboid (15).
The material of the metal cuboid (15) is phosphor blueThe stator of the motor is formed by adhering the piezoelectric elements (13) to the copper on four sides. The piezoelectric elements are hard piezoelectric materials, and their polarization direction is the thickness direction, the outer surface is the positive electrode, and the inner surface is the negative electrode. The outer surface has two silver electrodes separated by an insulator. The hole of the inner lens cone (09) is slightly larger than the movable inner lens cone (07). Two silver electrodes of the piezoelectric element (13) are respectively connected with Ea，EbThe metal rectangular parallelepiped (15) is grounded.
EaThe calculation formula of (a) is as follows:
Ea＝AE sin(2πfEt)
Ebthe calculation formula of (a) is as follows:
Eb＝AE sin(2πfEt+φ)
wherein A isEAnd fERespectively the amplitude and frequency of the applied voltage, phi being EaAnd EbThe phase difference between them, t is the time.
The piezoelectric element (13) generates two modes under different voltages, one mode is called a first expansion mode, and the other mode is a second expansion mode. When E isa＝EbIn this case, the piezoelectric element (13) undergoes a first expansion mode, i.e., repeated contraction and expansion. When E isa＝-EbThe piezoelectric element (13) is caused to expand in a second mode of contraction and expansion to the left and right. 1/4 is given between the first expansion mode and the second expansion mode, so that the surface of the inner lens barrel hole (14) generates movement with an elliptical track, the movement is transmitted to the movable inner lens barrel (07) through friction force, and the movable inner lens barrel (07) is driven to do linear movement to change the focal length of the lens.
The focusing method of the lens focusing device is characterized by comprising the following steps:
(1) the central processing unit is used for receiving the focusing distance signal and sending the signal to the displacement voltage conversion module.
(2) And then the displacement voltage conversion module is used for converting the displacement voltage, sending the required voltage to the linear ultrasonic motor (03) and controlling the movement of the first lens group (08).
(3) The displacement sensor (05) sends back the actual distance value of the movement of the adjustable lens, and the actual distance value is analyzed and compared through a displacement feedback module to see the distance of the movement of the adjustable lens group. And then the distance value is sent to a central processing unit.
(4) Repeating the steps (1), (2) and (3) until the required position is adjusted.
The lens focusing device and the lens focusing method are characterized in that the central processing unit, the displacement voltage conversion module, the linear ultrasonic motor (03) and the displacement sensor (05) form a closed-loop control system, and better imaging effect and more accurate focusing are ensured.
Drawings
Fig. 1 is a structural diagram (side cross-sectional view) of a lens focusing apparatus and a focusing method according to the present invention.
Fig. 2 is a structural view of the linear ultrasonic motor (03).
Fig. 3 is a schematic diagram of the voltage connection of the linear ultrasonic motor (03).
Fig. 4 shows a first expansion mode of the piezoelectric element (13).
Fig. 5 shows a second mode of expansion of the piezoelectric element (13).
Fig. 6 is a block diagram of the control circuit board (12).
Fig. 7 is a flowchart of adjusting the focal length.
The reference numbers illustrate:
01 outer lens cone, 02 elastic washer, 03 linear ultrasonic motor, 04 hard washer, 05 displacement sensor, 06 miniature spring, 07 movable inner lens cone, 08 first lens group, 09 inner lens cone, 10 second lens group, 11 optical sensor, 12 control circuit board, 13 piezoelectric element, 14 inner lens cone hole, 15 metal cuboid.
Detailed Description
In order to explain the concrete flow of the present invention, the following detailed description is made with reference to the accompanying drawings.
Referring to fig. 1, a lens focusing apparatus and a focusing method. The lens focusing device of the present invention comprises: 01 outer lens cone, 02 elastic washer, 03 linear ultrasonic motor, 04 hard washer, 05 displacement sensor, 06 miniature spring, 07 movable inner lens cone, 08 first lens group, 09 inner lens cone, 10 second lens group, 11 optical sensor, 12 control circuit board.
The first lens group (08) is connected with the movable inner lens cone (07) and moves along with the movement of the movable inner lens cone. The second lens group (10) is connected with the inner lens cone (09) and is fixed.
The movable inner lens cone (07) is directly used as a rotor of the linear ultrasonic motor (03), so that the whole device is smaller in size.
The miniature spring (06) is connected with the movable inner lens cone (07), and the displacement sensor (05) judges the actual distance value of focal length adjustment according to the compression and extension amount of the spring.
The elastic washers (02) are fixed at two ends of the linear ultrasonic motor (03), so that the linear ultrasonic motor (03) is fixed, and a sufficient space is provided for the operation of the ultrasonic motor.
The optical sensor (11) is connected with the control circuit board (12) at the tail end of the inner lens cone (09), and the control circuit board (12) is positioned at the tail end of the whole device and is connected with the outer lens cone (01).
Referring to fig. 2, the linear ultrasonic motor (03) comprises: 13 piezoelectric elements, 14 endoscope cylinder holes and 15 metal cuboids.
The metal cuboid (15) is made of phosphor bronze, and the phosphor bronze has the characteristics of metal and has good wear resistance and elasticity. The stator of the motor is formed by adhering piezoelectric elements (13) on four sides. The piezoelectric elements are hard piezoelectric materials, and their polarization direction is the thickness direction, the outer surface is the positive electrode, and the inner surface is the negative electrode. The outer surface has two silver electrodes separated by an insulator. The hole of the inner lens cone (09) is slightly larger than the movable inner lens cone (07).
Referring to FIG. 3, the piezoelectric elements (13) are all connected to E at one endaThe other end of the piezoelectric element (13) is connected with EbThe metal rectangular parallelepiped (15) is grounded. The principle of the linear ultrasonic motor (03) is as follows:
Eathe calculation formula of (a) is as follows:
Ea＝AE sin(2πfEt)
Ebthe calculation formula of (a) is as follows:
Eb＝AE sin(2πfEt+φ)
wherein A isEAnd fERespectively the amplitude and frequency of the applied voltage, phi being EaAnd EbThe phase difference between them, t is the time.
The piezoelectric element (13) generates two modes under different voltages, one mode is called a first expansion mode (refer to fig. 4), and the other mode is called a second expansion mode (refer to fig. 5). When E isa＝EbIn this case, the piezoelectric element (13) undergoes a first expansion mode, i.e., repeated contraction and expansion. When E isa＝-EbThe piezoelectric element (13) is caused to expand in a second mode of contraction and expansion to the left and right. 1/4 is given between the first expansion mode and the second expansion mode, so that the surface of the inner lens barrel hole (14) generates movement with an elliptical track, the movement is transmitted to the movable inner lens barrel (07) through friction force, and the movable inner lens barrel (07) is driven to do linear movement to change the focal length of the lens.
Referring to fig. 6, the control circuit board (12) includes a central processing unit, an image processing module, a displacement piezoelectric transformation module, and a displacement feedback module. The image processing module, the displacement piezoelectric conversion module and the displacement feedback module are in bidirectional communication with the central processing unit to form small closed-loop control.
The central processing unit is used for receiving the focusing distance signal and sending the signal to the displacement voltage conversion module.
The image processing module is used for processing the image on the optical sensor (11) so as to ensure that the image imaging quality is better.
The displacement voltage conversion module converts a focusing distance value input from the outside into a voltage required by driving the linear ultrasonic motor (03). Driving a linear ultrasonic motor (03).
The displacement feedback module compares the actual distance value of the lens movement transmitted back by the displacement sensor (05) with the preset distance value for analysis, and sends the distance difference value to the central processing unit.
Referring to fig. 7, the focusing method of the lens focusing device specifically includes the following steps:
(1) the central processing unit is used for receiving the focusing distance signal and sending the signal to the displacement voltage conversion module.
(2) And then the displacement voltage conversion module is used for converting the displacement voltage, sending the required voltage to the linear ultrasonic motor (03) and controlling the movement of the first lens group (08).
(3) The displacement sensor (05) sends back the actual distance value of the movement of the adjustable lens, and the actual distance value is analyzed and compared through a displacement feedback module to see the distance of the movement of the adjustable lens group. And then the distance value is sent to a central processing unit.
(4) Repeating the steps (1), (2) and (3) until the required position is adjusted.
The central processing unit, the displacement voltage conversion module, the linear ultrasonic motor (03) and the displacement sensor (05) form a closed-loop control system, so that a better imaging effect and more accurate focusing are ensured.
The above description is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can make better adjustments and improvements without departing from the principle of the present invention, and such adjustments and improvements should be covered within the scope of the present invention.

Claims (2)

1. A lens focusing apparatus, comprising:
the ultrasonic imaging device comprises an outer lens cone (01), an elastic washer (02), a linear ultrasonic motor (03), a hard washer (04), a displacement sensor (05), a micro spring (06), a movable inner lens cone (07), a first lens group (08), an inner lens cone (09), a second lens group (10), an optical sensor (11) and a control circuit board (12); the elastic washers (02) are fixed at two ends of the linear ultrasonic motor (03), so that on one hand, the linear ultrasonic motor (03) is fixed, and on the other hand, enough space is provided for the operation of the linear ultrasonic motor (03); the linear ultrasonic motor (03) comprises: a piezoelectric element (13), an endoscope cylinder hole (14) and a metal cuboid (15); rectangular metalThe body (15) is made of phosphor bronze, and the piezoelectric elements (13) are adhered to the four sides to form a stator of the motor; the piezoelectric elements are hard piezoelectric materials, the polarization direction of the piezoelectric elements is the thickness direction, the outer surface is a positive electrode, and the inner surface is a negative electrode; the outer surface is provided with two silver electrodes, and the two electrodes are separated by an insulator; the hole of the inner lens cone (09) is slightly larger than the movable inner lens cone (07); two silver electrodes of the piezoelectric element (13) are respectively connected with Ea，EbThe metal cuboid (15) is grounded;
Eathe calculation formula of (a) is as follows:
Ea＝AEsin(2πfEt)
Ebthe calculation formula of (a) is as follows:
Eb＝AEsin(2πfEt+φ)
wherein A isEAnd fERespectively the amplitude and frequency of the applied voltage, phi being EaAnd EbThe phase difference between the two, t is time;
the piezoelectric element (13) can generate two modes under the action of different voltages, one mode is called as a first expansion mode, and the other mode is a second expansion mode; when E isa＝EbWhen the piezoelectric element (13) is in the first expansion mode, repeated contraction and expansion can be generated; when E isa＝-EbWhen the piezoelectric element (13) is in the second expansion mode, the left side is contracted, and the right side is expanded; 1/4 time difference is given between the first expansion mode and the second expansion mode, so that the surface of the inner lens barrel hole (14) can generate movement with an elliptical track, the movement is transmitted to the movable inner lens barrel (07) through friction force, and the movable inner lens barrel (07) is driven to do linear movement so as to change the focal length of the lens;
the miniature spring (06) is connected with the movable inner lens barrel (07), and the displacement sensor (05) judges the actual distance value of focal length adjustment according to the compression and extension amount of the spring; the first lens group (08) is connected with the movable inner lens barrel (07) and moves along with the movement of the movable inner lens barrel (07); the second lens group (10) is connected with the inner lens cone (09) and is fixed; the movable inner lens cone (07) is directly used as a rotor of the linear ultrasonic motor (03), so that the whole device is smaller in size.
2. A lens focusing device according to claim 1, wherein said control circuit board (12) comprises a central processing unit, an image processing module, a displacement voltage conversion module, a displacement feedback module;
the image processing module is used for processing the image on the optical sensor (11) so as to ensure that the image imaging quality is better;
the displacement voltage conversion module is used for converting a focusing distance value input from the outside into a voltage required by driving the linear ultrasonic motor (03);
the displacement feedback module compares the actual distance value of the lens movement transmitted back by the displacement sensor (05) with the preset distance value for analysis and sends the distance difference value to the central processing unit;
the central processing unit, the displacement voltage conversion module, the linear ultrasonic motor (03) and the displacement sensor (05) form a closed-loop control system, so that a better imaging effect and more accurate focusing are ensured.
CN201811257467.9A 2018-10-26 2018-10-26 Lens focusing device and method Active CN109298501B (en)

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CN111103698B (en) * 2019-12-31 2021-04-16 中国船舶重工集团公司第七一七研究所 Cassegrain is target surface position micromatic setting for camera lens
CN114077031B (en) * 2020-08-12 2023-03-10 华为技术有限公司 Ultrasonic piezoelectric motor, camera module and electronic equipment
CN112217991B (en) * 2020-09-28 2022-02-15 北京环境特性研究所 Image acquisition device, focus adjusting device and focus adjusting method
CN114280778A (en) * 2021-11-24 2022-04-05 歌尔光学科技有限公司 Intelligent glasses and image distance adjusting method thereof
CN116454718B (en) * 2023-06-13 2023-08-11 深圳市镭硕光电科技有限公司 Laser device

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US8587648B2 (en) * 2004-06-01 2013-11-19 SeeScan, Inc. Self-leveling camera head
JP2006075289A (en) * 2004-09-08 2006-03-23 Olympus Corp Endoscope
CN101911465B (en) * 2007-12-07 2013-03-27 株式会社尼康 Vibration actuator and imager
CN101425762B (en) * 2008-07-30 2011-10-12 博立码杰通讯(深圳)有限公司 Ultrasonic straight line motor and automatic focusing/zooming system driven thereby
CN102313961A (en) * 2011-09-06 2012-01-11 中国科学院长春光学精密机械与物理研究所 Cam focusing mechanism employing backlash elimination gear
JP6187186B2 (en) * 2013-11-25 2017-08-30 コニカミノルタ株式会社 Lens barrel and lens unit
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