CN117835059A

CN117835059A - Autofocus actuator with movable image sensor and electronic device

Info

Publication number: CN117835059A
Application number: CN202211165892.1A
Authority: CN
Inventors: 李朝阳; 余林涛; 曹宏; 张友; 詹敏聪
Original assignee: Ruien Photoelectric Co ltd
Current assignee: Ruien Photoelectric Co ltd
Priority date: 2022-09-23
Filing date: 2022-09-23
Publication date: 2024-04-05

Abstract

The application provides an autofocus actuator with a movable image sensor and an electronic device. The autofocus actuator includes: an imaging lens; an image sensor; a movable frame relatively fixed to the image sensor so as to move the image sensor by movement of the movable frame, wherein the movable frame is provided with a driving coil; the fixed frame body is used for accommodating the movable frame body, is provided with a permanent magnet and is used for holding the camera lens, and the movable frame body can move along the optical axis direction relative to the fixed frame body through the magnetic action of the driving coil and the permanent magnet, so that the image sensor is driven to move along the optical axis direction; and a ball disposed between the movable frame and the fixed frame, for guiding movement of the movable frame when the movable frame moves relative to the fixed frame, and for holding the movable frame in a horizontal position, thereby holding the light receiving surface of the image sensor in a horizontal position relative to the imaging lens.

Description

Autofocus actuator with movable image sensor and electronic device

Technical Field

The present application relates to an autofocus actuator with a movable image sensor and an electronic device.

Background

The camera device can perform automatic focusing along the optical axis direction, and during the automatic focusing, the center of the image sensor is expected to be coincident with the optical axis of the lens, and the offset between the center and the optical axis is not expected, namely, the image sensor is not expected to tilt in the plane perpendicular to the optical axis. In order to solve this problem, therefore, a camera device is generally provided with an optical anti-shake function. For example as mentioned in US20190141248 A1.

The optical anti-shake function is used to control tilting occurring in a plane perpendicular to the optical axis, detect a corresponding position signal, and perform independent control. But this approach would make the control logic more complex.

Disclosure of Invention

In order to solve one of the above technical problems, the present application provides an autofocus actuator with a movable image sensor and an electronic device.

According to one aspect of the present application, there is provided an autofocus actuator having a movable image sensor, comprising: an imaging lens; an image sensor; a movable frame fixed relative to the image sensor so as to move the image sensor by movement of the movable frame, wherein the movable frame is provided with a driving coil; a fixed frame for accommodating the movable frame, provided with a permanent magnet and for holding the imaging lens, the movable frame being movable in an optical axis direction relative to the fixed frame by a magnetic action of the driving coil and the permanent magnet, thereby driving the image sensor to move in the optical axis direction; and a ball disposed between the movable frame and the fixed frame, for guiding movement of the movable frame when the movable frame moves relative to the fixed frame, and for holding the movable frame in a horizontal position, thereby holding a light receiving surface of the image sensor in a horizontal position relative to the imaging lens.

According to the autofocus actuator of at least one embodiment of the present application, the number of the balls is four, and the four balls are provided at four corner positions of the fixed frame and the movable frame, respectively.

According to the autofocus actuator of at least one embodiment of the present application, the movable frame includes four outer sides, and the fixed frame includes four inner sides that correspond to each other, the number of the driving coils and the permanent magnets is four, the four driving coils are disposed at the four outer sides, and the four permanent magnets are disposed at the four inner sides.

According to the autofocus actuator of at least one embodiment of the present application, four corner portions of the movable frame are provided with concave portions for accommodating the four balls, respectively.

According to the autofocus actuator of at least one embodiment of the present application, the four drive coils are individually controlled so as to maintain the light receiving surface of the image sensor in a horizontal position with respect to the imaging lens.

According to the autofocus actuator of at least one embodiment of the present application, the autofocus actuator further includes hall elements, the number of the hall elements is four, and the four hall elements are respectively disposed on four outer sides of the movable frame, so that the position of the movable frame is detected based on the respective magnetic actions of the four hall elements and the four permanent magnets, thereby performing individual control for each driving coil.

The automatic focusing actuator according to at least one embodiment of the present application further includes four elastic pieces which are respectively provided near four corner positions of the fixed frame and the movable frame, and connect the fixed frame with the movable frame so as to return the image sensor to an initial position and always maintain the light receiving surface of the image sensor at a position centered on the optical axis.

An autofocus actuator according to at least one embodiment of the present application further includes a substrate for mounting the image sensor and fixedly connected to the movable housing.

An autofocus actuator according to at least one embodiment of the present application further includes an infrared cut filter fixed relative to the substrate and disposed between the imaging lens and the image sensor.

According to another aspect of the present application, an electronic device includes: an autofocus actuator as described above.

In the application, the image sensor is enabled to move, and the light receiving surface of the image sensor is always kept horizontal relative to the image pickup lens in the focusing process, so that a good anti-tilting effect is obtained. In this way, in the focusing operation, the deviation between the center of the light receiving surface of the image sensor and the center of the optical axis of the image pickup lens can be minimized.

In the present application, the driving coils for holding the four sides of the movable housing of the image sensor are provided with position sensors (hall elements), respectively, and the position and inclination of the image sensor are independently controlled, so that the light receiving surface of the image sensor can be always kept horizontal. In addition, balls for guiding the movement of the movable frame are provided at the respective corners, so that independent control can be realized without collision. Further, the horizontal displacement of the movable frame is restricted by the elastic pieces at the four corners, and the smooth focusing operation is realized by uniformly maintaining the resistance of the balls at the four positions.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application.

Fig. 1 is an external schematic view of an autofocus actuator according to an embodiment of the present application.

Fig. 2 is an internal schematic view of an autofocus actuator according to an embodiment of the present application.

Fig. 3 is an internal schematic view of an autofocus actuator according to an embodiment of the present application.

Fig. 4 is an internal schematic view of an autofocus actuator according to an embodiment of the present application.

Detailed Description

The present application is described in further detail below with reference to the drawings and embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant content and not limiting of the application. It should be further noted that, for convenience of description, only the portions relevant to the present application are shown in the drawings.

In addition, embodiments and features of embodiments in the present application may be combined with each other without conflict. The technical solutions of the present application will be described in detail below with reference to the accompanying drawings in combination with embodiments.

Unless otherwise indicated, the exemplary implementations/embodiments shown are to be understood as providing exemplary features of various details of some of the ways in which the technical concepts of the present application may be practiced. Thus, unless otherwise indicated, features of the various implementations/embodiments may be additionally combined, separated, interchanged, and/or rearranged without departing from the technical concepts of the present application.

The use of cross-hatching and/or shading in the drawings is typically used to clarify the boundaries between adjacent components. As such, the presence or absence of cross-hatching or shading does not convey or represent any preference or requirement for a particular material, material property, dimension, proportion, commonality between illustrated components, and/or any other characteristic, attribute, property, etc. of a component, unless indicated. In addition, in the drawings, the size and relative sizes of elements may be exaggerated for clarity and/or descriptive purposes. While the exemplary embodiments may be variously implemented, the specific process sequences may be performed in a different order than that described. For example, two consecutively described processes may be performed substantially simultaneously or in reverse order from that described. Moreover, like reference numerals designate like parts.

When an element is referred to as being "on" or "over", "connected to" or "coupled to" another element, it can be directly on, connected or coupled to the other element or intervening elements may be present. However, when an element is referred to as being "directly on," "directly connected to," or "directly coupled to" another element, there are no intervening elements present. For this reason, the term "connected" may refer to physical connections, electrical connections, and the like, with or without intermediate components.

For descriptive purposes, the present application may use spatially relative terms such as "under … …," under … …, "" under … …, "" lower, "" above … …, "" upper, "" above … …, "" higher "and" side (e.g., as in "sidewall"), etc., to describe one component's relationship to another (other) component as illustrated in the figures. In addition to the orientations depicted in the drawings, the spatially relative terms are intended to encompass different orientations of the device in use, operation, and/or manufacture. For example, if the device in the figures is turned over, elements described as "under" or "beneath" other elements or features would then be oriented "over" the other elements or features. Thus, the exemplary term "below" … … can encompass both an orientation of "above" and "below". Furthermore, the device may be otherwise positioned (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, when the terms "comprises" and/or "comprising," and variations thereof, are used in the present specification, the presence of stated features, integers, steps, operations, elements, components, and/or groups thereof is described, but the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof is not precluded. It is also noted that, as used herein, the terms "substantially," "about," and other similar terms are used as approximation terms and not as degree terms, and as such, are used to explain the inherent deviations of measured, calculated, and/or provided values that would be recognized by one of ordinary skill in the art.

According to one embodiment of the present application, an autofocus actuator having a movable image sensor is provided.

Fig. 1 shows an external schematic view of an autofocus actuator according to an embodiment of the present application. As shown in fig. 1, the autofocus actuator may include an imaging lens 100 and a fixed housing 200. Wherein the fixed frame 200 serves as an outer frame of an autofocus actuator and serves to hold the imaging lens 100.

Fig. 2 to 4 show internal schematic views of the autofocus actuator. The fixed frame 200 accommodates the movable frame 300. For example, the movable housing 300 may be provided inside the fixed housing 200. The movable housing 300 serves as a movable part (movable) of the autofocus actuator, and the fixed housing 200 serves as a fixed part (non-movable) of the autofocus actuator. The movable housing 300 can thus move relative to the fixed housing 200, wherein the direction of movement of the movable housing 300 is along the optical axis (e.g., the X direction shown in fig. 3).

As shown in fig. 4, the autofocus actuator may include an image sensor 400. Wherein the light receiving surface of the image sensor 400 is disposed toward the imaging lens 100, and receives light from the imaging lens 100 to image the subject. In the present application, the image sensor 400 may be fixed with respect to the movable frame 300. For example, the image sensor 400 may be fixed to the movable frame 300. In this application, it is preferable that the substrate 410 on which the image sensor 400 is mounted be provided. The image sensor 400 is fixed to a substrate 410. The substrate 410 may be fixedly connected to the movable frame 300, so that when the movable frame 300 moves along the optical axis direction, the substrate 410 moves along with the movable frame 300, thereby driving the image sensor 400 to move along with the movable frame 300.

The autofocus actuator may include an infrared cut filter 420 for filtering the infrared band. The infrared cut filter 420 may be fixed with respect to the substrate 410 and disposed between the imaging lens 100 and the image sensor 400. As shown in fig. 4, the substrate 410 may be formed in a structure having a cavity, wherein the image sensor 400 may be fixed to a lower inner side of the cavity, and the infrared cut filter 420 may be fixed to an upper inner side of the cavity, wherein the upper inner side is provided with a through hole that allows light from the photographing lens 100 to be transmitted to the image sensor 400 via the infrared cut filter 420. Thus, one module may be constituted by the substrate, the infrared cut filter, and the image sensor, and directly mounted to the movable frame 300.

The movable housing 300 is accommodated inside the fixed housing 200, and may be provided with a driving coil 310, the driving coil 310 being provided to an outer side surface of the movable housing. As shown in fig. 3, the drive coil 310 may be provided in the form of a racetrack coil. The driving coil 310 may be excited by a driving current transmitted through the flexible circuit board 500 such that the driving coil 310 receives the excitation of the driving current, thereby generating a corresponding magnetic field. In the present application, the movable frame may include four outer side surfaces. Drive coils 310 are provided on the four outer sides, respectively, as shown in fig. 2.

The fixed frame 200 may be provided with a permanent magnet 210. The permanent magnet 210 may interact with the drive coil 310. When an excitation current is applied to the driving coil 310, a magnetic field generated by the driving coil 310 may interact with a magnetic field of the permanent magnet 210, so that the movable frame 300 may be driven to move along the optical axis direction. Accordingly, the fixing frame 200 may include four inner sides, each of which is provided with a permanent magnet 210. The four permanent magnets 210 may be in one-to-one correspondence with the four driving coils 310.

In the present application, the hall element 320 may be fixed to the outer surface of the movable housing 300. The hall element 320 may interact with the permanent magnet 210 for detecting the position of the movable frame 300, and the hall element 320 may be connected with the flexible circuit board to provide a detection signal to the processor, from which the processor may determine the position of the movable frame 300 as a basis for the excitation current. In this application, the number of the hall elements 320 is four, and the four hall elements 320 are respectively disposed at four outer sides of the movable frame so as to individually control each driving coil 310 based on the respective magnetic actions of the four hall elements 320 and the four permanent magnets. In the present application, by providing the driving coils and the permanent magnets for moving the movable frame 300 on each of the four side surfaces, and in order to maintain the light receiving surface of the image sensor 400 fixed with respect to the movable frame 300 in a horizontal position with respect to the imaging lens 100, control of each driving coil 310 can be performed individually. The position control of the corresponding side is accomplished by detecting a position signal of the movable frame 300, for example, by a hall sensor of each side, and controlling the driving coil 310 of the corresponding side according to the position signal so as to interact with the permanent magnet 210. The hall element 320 may be disposed inside the racetrack coil, which may further reduce the space of the actuator.

According to the embodiment of the present application, in order to facilitate the movement of the movable frame 300 with respect to the fixed frame 200, a ball 600 may be provided between the movable frame 300 and the fixed frame 200, the ball 600 being used to guide the movement of the movable frame 300 when the movable frame 300 moves with respect to the fixed frame 200. As shown in fig. 2, four balls 600 may be provided. Four balls 600 are provided at four corner positions of the fixed frame 200 and the movable frame 300, respectively. As shown in fig. 3, a recess 330 may be provided at a corner of the outer side surface of the movable frame 300, wherein the recess 330 is configured to accommodate the ball 600. The balls 600 may be clamped on the outer side surfaces of the concave portions and the inner side surfaces of the corner portions of the fixed frame 200. As shown in fig. 2, the balls 600 may form two-point contact with the outer side surfaces of the concave portions, and may form two-point contact with the inner side surfaces of the corner portions of the fixed frame 200. This can keep the light receiving surface of the image sensor 400 horizontal with respect to the imaging lens 100, thereby obtaining good tilt prevention characteristics.

Four spring tabs 700 may also be included according to embodiments of the present application. Four elastic pieces 700 are provided near four corner positions of the fixed frame 200 and the movable frame 300, respectively, and connect the fixed frame 200 and the movable frame 300 so as to return the image sensor 400 to the initial position and maintain the light receiving surface of the image sensor 400 at a position centered on the optical axis at all times. Four spring plates 700 may be disposed near the four balls 600, respectively. As shown in fig. 4, the fixed frame 200 may be provided with an extension 220 extending toward the inside, and the movable frame 300 may be provided with a protrusion 340, wherein a portion of the elastic sheet 700 may be fixed to the lower side of the extension 220 and another portion of the elastic sheet 700 may be fixed to the protrusion 340. The movable housing 300 can be held by the spring 700 with respect to the fixed housing 200. After the driving coil 310 is energized and the movable housing 300 moves in the optical axis direction with respect to the fixed housing 200, the elastic piece 700 may return the movable housing 300 to the initial position, thereby returning the image sensor 400 to the initial position.

According to another aspect of the present application, there is also provided a camera apparatus. The camera device may comprise an autofocus actuator as described above. According to another aspect of the present application, there is also provided an electronic device, such as a smart phone, a tablet computer, etc., wherein the electronic device may carry the autofocus actuator.

In the description of the present specification, reference to the terms "one embodiment/manner," "some embodiments/manner," "example," "specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment/manner or example is included in at least one embodiment/manner or example of the present application. In this specification, the schematic representations of the above terms are not necessarily for the same embodiment/manner or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments/modes or examples. Furthermore, the various embodiments/modes or examples described in this specification and the features of the various embodiments/modes or examples can be combined and combined by persons skilled in the art without contradiction.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless explicitly defined otherwise.

It will be appreciated by those skilled in the art that the above embodiments are merely for clarity of illustration of the application and are not intended to limit the scope of the application. Other variations or modifications will be apparent to persons skilled in the art from the foregoing disclosure, and such variations or modifications are intended to be within the scope of the present application.

Claims

1. An autofocus actuator having a movable image sensor, comprising:

an imaging lens;

an image sensor;

a movable frame fixed relative to the image sensor so as to move the image sensor by movement of the movable frame, wherein the movable frame is provided with a driving coil;

a fixed frame for accommodating the movable frame, provided with a permanent magnet and for holding the imaging lens, the movable frame being movable in an optical axis direction relative to the fixed frame by a magnetic action of the driving coil and the permanent magnet, thereby driving the image sensor to move in the optical axis direction; and

and a ball disposed between the movable frame and the fixed frame, for guiding movement of the movable frame when the movable frame moves relative to the fixed frame, and for holding the movable frame in a horizontal position, thereby holding the light receiving surface of the image sensor in a horizontal position relative to the imaging lens.

2. The autofocus actuator of claim 1, wherein the number of balls is four, and the four balls are disposed at four corner positions of the fixed frame and the movable frame, respectively.

3. The autofocus actuator of claim 2, wherein the movable housing includes four outer sides, and the fixed housing includes four inner sides disposed correspondingly, the number of the driving coils and the permanent magnets is four, the four driving coils are disposed at the four outer sides, and the four permanent magnets are disposed at the four inner sides, respectively.

4. The autofocus actuator according to claim 3, wherein recessed portions for accommodating the four balls are provided at four corner positions of the movable frame.

5. The autofocus actuator of claim 3, wherein the four drive coils are individually controlled to maintain a horizontal position of the light receiving surface of the image sensor relative to the imaging lens.

6. The autofocus actuator of claim 5, further comprising hall elements, the number of the hall elements being four, the four hall elements being disposed on four outer sides of the movable housing, respectively, so as to detect the position of the movable housing based on respective magnetic actions of the four hall elements and the four permanent magnets, thereby individually controlling each driving coil.

7. The autofocus actuator according to claim 1, further comprising four elastic pieces that are provided near four corner positions of the fixed frame and the movable frame, respectively, and that connect the fixed frame and the movable frame so as to return the image sensor to an initial position and to keep the light receiving surface of the image sensor at a position centered on the optical axis at all times.

8. The autofocus actuator of claim 1, further comprising a substrate for carrying the image sensor and fixedly connected to the movable housing.

9. The autofocus actuator of claim 8, further comprising an infrared cut filter fixed relative to the substrate and disposed between the imaging lens and the image sensor.

10. An electronic device, comprising: the autofocus actuator of any one of claims 1 to 9.