CN112255817B

CN112255817B - Imaging correction unit and imaging module

Info

Publication number: CN112255817B
Application number: CN202011208668.7A
Authority: CN
Inventors: 刘权辉
Original assignee: Luxvisions Innovation Ltd
Current assignee: Luxvisions Innovation Ltd
Priority date: 2020-11-03
Filing date: 2020-11-03
Publication date: 2022-10-04
Anticipated expiration: 2040-11-03
Also published as: CN112255817A

Abstract

The invention provides an imaging correction unit and an imaging module, which have the advantages of small volume, low power consumption and high efficiency. The imaging correction unit has an optical axis and includes two lens elements. The two lens elements are respectively provided with a plurality of microstructures and are arranged on the optical surface of each lens element. Each microstructure has an inclined optical surface, each inclined optical surface is inclined relative to the optical axis, and the two lens elements can rotate relative to the optical axis so as to correct the traveling direction of the light beam passing through the imaging correction unit.

Description

Imaging correction unit and imaging module

Technical Field

The present disclosure relates to optical units and optical modules, and particularly to an imaging correction unit and an imaging module.

Background

At present, the camera shake correction function is usually an optical method for physically adjusting an optical axis, and typically, the optical camera shake correction function is a lens shift type or an imaging element shift type. Further, the lens-shift camera-shake correction function corrects the optical axis by moving a part or all of a lens group for forming image light of an object with respect to the image pickup element in a direction of eliminating camera shake by a dedicated drive mechanism, and guides the image light of the object to the image pickup element. However, in this way, the lens-shift-type camera-shake correction function requires designing a driving mechanism suitable for the shape or optical specification of the correction lens for each lens group of each camera. On the other hand, the camera shake correction function of the camera-moving type is to move the camera according to a camera shake by using a dedicated drive mechanism, thereby keeping the position of the camera with respect to the optical axis of the lens group constant. However, the camera-shake correction function of the camera-movement type also requires a dedicated drive mechanism to be designed for each camera according to the camera-shake correction function of each camera.

Therefore, there has been proposed a configuration in which an optical unit for correction including a movable prism for refracting light incident on the optical lens, an actuator for driving the movable prism, and a power transmission mechanism including a shaft for transmitting power of the actuator to the movable prism is attached to an optical axis of the optical lens. This eliminates the need to design the shape of the correction lens and the drive mechanism for each camera, and simplifies the design. However, in order to adjust the optical axis in a two-dimensional plane, it is generally necessary to dispose actuators in different directions corresponding to two dimensions. In addition, since the movable prism has a certain thickness, the optical unit has a certain volume in manufacturing, and is not easily integrated into the body of various cameras.

Disclosure of Invention

The invention provides an imaging correction unit and an imaging module, which have the advantages of small volume, low power consumption and high efficiency.

The imaging correction unit of the invention has an optical axis and comprises two lens elements. The two lens elements are respectively provided with a plurality of microstructures and are arranged on the optical surface of each lens element. Each microstructure has an inclined optical surface, each inclined optical surface is inclined relative to the optical axis, and the two lens elements can rotate relative to the optical axis so as to correct the traveling direction of the light beam passing through the imaging correction unit.

The imaging module comprises the imaging correction unit and the lens unit. The lens unit is used for imaging the light beams passing through the two lens elements in a preset imaging area of an imaging surface.

In an embodiment of the invention, an angle range of an included angle between the inclined optical surface of each lens element and the optical axis is greater than 45 degrees and less than 90 degrees.

In an embodiment of the invention, a flat surface is disposed around the optical surface of each lens element, each microstructure is convex or concave relative to the flat surface, and an included angle between the inclined optical surface of each lens element and the flat surface ranges from 0 degree to 45 degrees.

In an embodiment of the invention, each of the lens elements further has a connecting surface, the connecting surface connects the inclined optical surfaces of the adjacent microstructures, and the connecting surface is perpendicular to the flat surface.

In an embodiment of the invention, the two lens elements include a first lens element and a second lens element, and rotation directions of the first lens element and the second lens element relative to the optical axis are opposite to each other.

In an embodiment of the invention, the optical behavior of the first lens element and the second lens element is equivalent to a wedge-shaped optical element.

In an embodiment of the invention, each of the optical surfaces has a symmetry axis, and the microstructures of each of the lens elements extend along a direction perpendicular to the symmetry axis of each of the lens elements and are arranged along a direction parallel to the symmetry axis of each of the lens elements.

In an embodiment of the invention, the image calibration unit further includes an optical turning element having an incident surface, a reflective optical surface and an exit surface, the reflective optical surface connects the incident surface and the exit surface, the exit surface of the optical turning element faces one of the two lens elements, and the exit surface is inclined with respect to the optical axis.

In an embodiment of the invention, the light incident surface of the optical turning element is parallel to the optical axis, and a light beam incident on the optical turning element from the light incident surface is reflected by the reflective optical surface and exits the optical turning element through the light exiting surface.

In an embodiment of the invention, the rotation of the two lens elements with respect to the optical axis is controlled by the same actuator.

Based on the above, the configuration of the lens element with the microstructure can reduce the thickness of the lens element, so that the imaging correction unit and the imaging module have the advantage of small volume. In addition, the lens element rotates relative to the optical axis, and the imaging correction unit and the imaging module can control the relative rotation angle thereof by the same actuator, so that the function of optical shake compensation is achieved, and the advantages of low power consumption and high efficiency are achieved.

Drawings

FIG. 1 is a schematic view of an imaging module of an embodiment of the invention;

FIG. 2A is a schematic front view of the lens element of FIG. 1;

FIG. 2B is a schematic cross-sectional view of the lens element of FIG. 1;

FIG. 2C is a schematic diagram of the two lens elements of FIG. 1 in an initial state;

fig. 3 is a schematic view of the optical path of the lens element of fig. 1 as it is rotated relative to the optical element.

[ description of reference numerals ]

100: imaging correction unit

110: optical turning element

200: imaging module

210: lens unit

AC: actuator

AS: optical surface

C: axis of symmetry

CS: circumferential end face

FL: two-lens element

FL1: a first lens element

FL2: second lens element

IS: image plane

L: light beam

L1: a first length

LS: connecting surface

And (2) MS: microstructure

O: optical axis

And (3) OS: outside surface

P: distance between

P1: first position

P2: second position

PS: flat surface

S111: light emitting surface

S112: reflective optical surface

S113: light incident surface

And TS: inclined optical surface

θ ₁ 、θ ₂ 、θ _r : included angle

Detailed Description

FIG. 1 is a schematic view of an imaging module according to an embodiment of the invention. Fig. 2A is a schematic front view of the lens element of fig. 1. Fig. 2B is a schematic cross-sectional view of the lens element of fig. 1. Referring to fig. 1, an imaging module 200 of the present embodiment includes an imaging correction unit 100 and a lens unit 210. The lens unit 210 IS used for imaging the light beam L passing through the optical turning element 110 and the two lens elements FL in a predetermined imaging area of the imaging surface IS. For example, the light beam L IS image light forming an object, and the imaging surface IS a sensing surface of the image sensor. For example, the image sensor Device may include a Charge Coupled Device (CCD), a Complementary Metal-Oxide Semiconductor (CMOS) or other suitable type of optical sensor Device. In this and some other embodiments, the imaging module 200 further includes an actuator AC, such as but not limited to a voice coil motor. In detail, the actuator AC can control the relative rotation of the two lens elements FL.

Specifically, as shown in fig. 1, the imaging correction unit 100 has an optical axis O, and the imaging correction unit 100 includes an optical turning element 110 and two lens elements FL. For example, the optical turning element 110 is a prism and has a light incident surface S113, a light emitting surface S111 and a reflective optical surface S112. The reflective optical surface S112 connects the light incident surface S113 and the light emitting surface S111, the light incident surface S113 is parallel to the optical axis O, and the light emitting surface S111 is inclined with respect to the optical axis O. As shown in fig. 1, the light beam L incident on the optical turning element 110 through the light incident surface S113 is reflected by the reflective optical surface S112 and then exits the optical turning element 110 through the light exiting surface S111. Thus, by the configuration of the optical turning element 110, the imaging correction unit 100 and the imaging module 200 of the present invention can change the traveling direction of the image light formed by the subject, and the configuration of the optical elements therein can be made compact, thereby having the advantage of small volume.

On the other hand, AS shown in fig. 2A and 2B, the two lens elements FL respectively have a plurality of microstructures MS, and the microstructures MS are disposed on the optical surface AS of each lens element FL. Each microstructure MS has an inclined optical surface TS and a connecting surface LS connecting the inclined optical surfaces TS of adjacent microstructures MS, and each inclined optical surface TS is inclined with respect to the optical axis O. On the other hand, AS shown in fig. 2A and 2B, the periphery of the optical surface AS of each lens element FL further has a flat surface PS, each microstructure MS is convex or concave with respect to the flat surface PS, and the connecting surface LS is perpendicular to the flat surface PS.

Further, AS shown in fig. 2A, in the present embodiment, each lens element FL has an axis of symmetry C on the optical surface AS, and the microstructures MS of each lens element FL extend in a direction perpendicular to the axis of symmetry C of each lens element FL and are arranged in a direction parallel to the axis of symmetry C of each lens element FL. Also, when there is a tolerance between the microstructures MS, there may be a case where the pitch P between the microstructures MS is not equal to the side length of the microstructures MS. For example, AS shown in fig. 2A and 2B, the length of the projection amount of the inclined optical surface TS of each lens element FL projected on the optical surface AS of each lens element FL in the direction parallel to the symmetry axis C of each lens element FL is a first length L1, the microstructures MS of each lens element FL have a plurality of pitches P therebetween, and each pitch P is greater than or equal to the first length L1.

For example, in the present embodiment, the included angle θ between the inclined optical surface TS of each lens element FL and the optical axis O ₁ Is greater than 45 degrees and less than 90 degrees, and the angle theta of the inclined optical surface TS of each lens element FL with respect to the flat surface PS ₂ Is in the range of 0 to 45 degrees. As shown in fig. 2C, after the centers of the lens elements FL and the symmetry axes C are aligned, the two lens elements FL are rotated by the initial angle θ using the centers as the origin _r As an initial use state. For example, in the present embodiment, the initial angle θ _r Is 45 degrees.

AS shown in fig. 2A and 3, each lens element FL further has an outer surface OS and a circumferential end surface CS, and the outer surface OS and the optical surface AS face each other. That is, in the present embodiment, the outline of each lens element is circular, but the present invention is not limited thereto, and in other embodiments, the outline of the lens element may be any shape as long as the microstructure MS described above is disposed near the optical axis.

Further, AS shown in fig. 1 and 2A, the two lens elements FL include a first lens element FL1 and a second lens element FL2, the light emitting surface S111 of the optical turning element 110 faces the first lens element FL1, the outer side surface OS of the first lens element FL1 faces the optical turning element 110, the optical surface AS of the first lens element FL1 faces the optical surface AS of the second lens element FL2, and the outer side surface OS of the second lens element FL2 faces the lens unit 210. Moreover, the first lens element FL1 and the second lens element FL2 can both rotate relative to the optical axis O, and in the present embodiment, the optical behavior of the first lens element and the second lens element can be equivalent to that of a general wedge-shaped optical element but can have a relatively thin thickness due to the configuration of the microstructure MS. Thus, the imaging correction unit 100 and the lens unit 210 can achieve the function of optical shake compensation. The correction process when the lens element FL is rotated relative to the optical element will be further explained below, with reference to fig. 3.

Fig. 3 is a schematic diagram of an optical path when the lens element FL of fig. 1 is rotated with respect to the optical element. As shown in fig. 3, when the lens element FL rotates at an angle with respect to the optical axis O, the imaging position where the light beam L passing through the lens element FL IS incident on the imaging surface IS may be changed to move from the first position P1 to the second position P2. Further, in the present embodiment, the rotation of the first lens element FL1 and the second lens element FL2 with respect to the optical axis O can be controlled by the same actuator AC, and the rotational directions in which the first lens element FL1 and the second lens element FL2 rotate with respect to the optical axis O are opposite to each other. For example, as shown in fig. 2C and 3, when viewed from the direction from the two lens elements FL to the image plane IS, the rotation direction of the first lens element FL1 IS counterclockwise, and the direction of the second lens element FL2 IS clockwise. In this way, by the arrangement of the two lens elements FL capable of rotating relative to the optical axis O, the imaging correction unit 100 and the imaging module 200 can control the relative rotation angle thereof by the same actuator AC, so as to achieve the function of optical shake compensation, and further have the advantages of low power consumption and high performance.

In summary, the imaging correction unit and the imaging module of the invention can reduce the thickness of the lens element by the configuration of the lens element with the microstructure, thereby having the advantage of small volume. In addition, the lens element rotates relative to the optical axis, and the imaging correction unit and the imaging module can control the relative rotation angle thereof by the same actuator, so that the function of optical shake compensation is achieved, and the advantages of low power consumption and high efficiency are achieved.

Claims

1. An imaging correction unit characterized by having an optical axis, and comprising:

two lens elements respectively provided with a plurality of microstructures and arranged on the optical surface of each lens element, wherein each microstructure is provided with an inclined optical surface, each inclined optical surface is inclined relative to the optical axis, and the two lens elements can rotate relative to the optical axis so as to correct the traveling direction of the light beam passing through the imaging correction unit,

wherein the periphery of the optical surface of each lens element is provided with a flat surface, each microstructure is convex or concave relative to the flat surface, and the included angle of the inclined optical surface of each lens element relative to the flat surface ranges from 0 degree to 45 degrees,

each lens element further has a connecting surface connecting the inclined optical surfaces of the adjacent microstructures, the connecting surface is perpendicular to the flat surface, and the inclination of each inclined optical surface with respect to the optical axis is the same.

2. The imaging correction unit of claim 1, wherein the angular range of the angle of the tilted optical surface of each of the lens elements with respect to the optical axis is greater than 45 degrees and less than 90 degrees.

3. The imaging correction unit of claim 1, wherein the two lens elements comprise a first lens element and a second lens element, and rotational directions in which the first lens element and the second lens element rotate with respect to the optical axis are opposite to each other.

4. The imaging correction unit of claim 3, wherein the optical behavior of the first lens element and the second lens element is equivalent to a wedge-shaped optical element.

5. The imaging correction unit of claim 1, wherein each of the optical surfaces has an axis of symmetry thereon, and the plurality of microstructures of each of the lens elements extend in a direction perpendicular to the axis of symmetry of each of the lens elements and are aligned in a direction parallel to the axis of symmetry of each of the lens elements.

6. The imaging correction unit of claim 1, wherein the imaging correction unit further comprises an optical turning element having an incident surface, a reflective optical surface and an exit surface, the reflective optical surface connecting the incident surface and the exit surface, the exit surface of the optical turning element facing one of the two lens elements, and the exit surface being inclined with respect to the optical axis.

7. The image correction unit of claim 6, wherein the incident surface of the optical turning element is parallel to the optical axis, and the light beam incident on the optical turning element from the incident surface is reflected by the reflective optical surface and exits the optical turning element through the exit surface.

8. An imaging module, comprising:

an imaging correction unit having an optical axis, and the imaging correction unit includes:

two lens elements respectively provided with a plurality of microstructures and arranged on an optical surface of each lens element, wherein each microstructure is provided with an inclined optical surface, each inclined optical surface is inclined relative to the optical axis, and the two lens elements can rotate relative to the optical axis so as to correct the traveling direction of a light beam passing through an imaging correction unit, wherein the periphery of the optical surface of each lens element is provided with a flat surface, each microstructure is convex or concave relative to the flat surface, the included angle of the inclined optical surface of each lens element relative to the flat surface ranges from 0 degree to 45 degrees, each lens element is also provided with a connecting surface, the connecting surface is connected with the inclined optical surfaces of the adjacent microstructures, the connecting surface is vertical to the flat surface, and the inclination of each inclined optical surface relative to the optical axis is the same; and

and the lens unit is used for enabling the light beams passing through the two lens elements to be imaged in a preset imaging area of an imaging surface.

9. The imaging module of claim 8, wherein the angular extent of the included angle of the tilted optical surface of each of the lens elements with respect to the optical axis is greater than 45 degrees and less than 90 degrees.

10. The imaging module of claim 8, wherein the two lens elements include a first lens element and a second lens element, and rotational directions of the first lens element and the second lens element that rotate relative to the optical axis are opposite to each other.

11. The imaging module of claim 10, wherein the optical behavior of the first lens element and the second lens element is equivalent to a wedge-shaped optical element.

12. The imaging module of claim 8, wherein each of the optical faces has an axis of symmetry thereon, and the plurality of microstructures of each of the lens elements extend in a direction perpendicular to the axis of symmetry of each of the lens elements and are aligned in a direction parallel to the axis of symmetry of each of the lens elements.

13. The imaging module of claim 8, wherein the image correction unit further comprises an optical turning element having an incident surface, a reflective optical surface and an exit surface, the reflective optical surface connecting the incident surface and the exit surface, the exit surface of the optical turning element facing one of the two lens elements, and the exit surface being inclined with respect to the optical axis.

14. The imaging module of claim 13, wherein the light incident surface of the optical turning element is parallel to the optical axis, and the light beam incident on the optical turning element from the light incident surface exits the optical turning element through the light emitting surface after being reflected by the reflective optical surface.