TWI764353B - Imaging correction unit and imaging module - Google Patents

Abstract

An imaging correction unit and an imaging module is provided. The imaging correction unit has an optical axis, and includes two lens elements. Each of the two lens elements has a plurality of microstructures, which are arranged on an optical surface of each of the two lens elements. Each of the microstructures has an inclined optical surface, and the inclined optical surface is tilted relative to the optical axis, and the two lens elements can rotate relative to the optical axis to correct the direction of the light beam passing through the imaging correction unit.

Description

Imaging correction unit and imaging module

The present invention relates to an optical unit and an optical module, and in particular, to an imaging correction unit and an imaging module.

At present, the camera shake correction function is usually an optical method of physically adjusting the optical axis, and the typical optical camera shake correction function is a lens movement type and a photographing element movement type. Furthermore, the camera shake correction function of the lens movement type corrects the optical axis by using a dedicated drive mechanism to move a part or all of the lens group for forming the image light of the subject in the direction of eliminating the camera shake relative to the imaging element. , which guides the image light of the subject to the imaging element. However, in this case, the lens-moving camera shake correction function requires a drive mechanism suitable for the shape and optical specifications of the correction lens for each lens group constituted by each camera. On the other hand, the camera-shake correction function in which the camera element is moved uses a dedicated drive mechanism to move the camera element according to the camera shake, thereby keeping the position of the camera element relative to the optical axis of the lens group constant. However, in the camera-shake correction function in which the imaging element is moved, it is necessary to design a dedicated drive mechanism for each imaging element of each camera.

Therefore, there has been proposed a structure in which an optical unit for correction is mounted on the optical axis of the optical lens, and the optical unit includes a movable prism for refracting light incident on the optical lens, and an actuator for driving the movable prism. An actuator and a power transmission mechanism including a shaft for transmitting the power of the actuator to the movable prism. Accordingly, it is not necessary to design the shape and drive mechanism of the correction lens for each camera, and the design can be simplified. However, in order to adjust the optical axis on a two-dimensional plane, it is usually necessary to configure actuators in different directions corresponding to the two dimensions. In addition, since the movable prism has a certain thickness, the optical unit will have a certain volume during production, and it is difficult to integrate it into the bodies of various cameras.

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

The imaging correction unit of the present invention has an optical axis and includes two lens elements. The two lens elements respectively have a plurality of microstructures, which are arranged on an 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 be rotated relative to the optical axis to correct the traveling direction of the light beam passing through the imaging correction unit.

The imaging module of the present invention includes the aforementioned imaging correction unit and a lens unit. The lens unit is used to enable the light beams passing through the two lens elements to be imaged in a predetermined imaging area of an imaging plane.

In an embodiment of the present invention, the angle range of the included angle between the inclined optical surfaces of the above-mentioned lens elements relative to the optical axis is greater than 45 degrees and less than 90 degrees.

In an embodiment of the present invention, a flat surface is provided around the optical surface of each lens element, each microstructure is convex or concave relative to the flat surface, and the angle between the inclined optical surface of each lens element relative to the flat surface The angle range is between 0 degrees and 45 degrees.

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

In an embodiment of the present invention, the above-mentioned two lens elements include a first lens element and a second lens element, and the 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 present invention, the optical behaviors of the first lens element and the second lens element described above are equivalent to wedge-shaped optical elements.

In an embodiment of the present invention, each of the above-mentioned optical surfaces has an axis of symmetry, and the microstructure of each lens element extends along a direction perpendicular to the axis of symmetry of each lens element, and along the axis of symmetry of each lens element arranged in parallel directions.

In an embodiment of the present invention, the above-mentioned imaging correction unit further includes an optical turning element, which has a light incident surface, a reflective optical surface and a light emitting surface, the reflective optical surface is connected to the light incident surface and the light emitting surface, and the optical turning element The light-emitting surface of the lens faces one of the first lens element and the second lens element, and the light-emitting surface is inclined relative to the optical axis.

In an embodiment of the present invention, the light incident surface of the optical turning element is parallel to the optical axis, and the light beam entering the optical turning element from the light incident surface is reflected by the reflective optical surface, and then leaves the optical turning element through the light exit surface.

In an embodiment of the present invention, the rotation of the above-mentioned two lens elements relative to the optical axis is controlled by the same actuator.

Based on the above, through the configuration of the lens element with microstructure, the thickness of the lens element can be reduced, so that the imaging correction unit and the imaging module have the advantage of small volume. In addition, through the rotation of the lens element relative to the optical axis, the relative rotation angle of the imaging correction unit and the imaging module can be controlled by the same actuator, so as to achieve the function of optical jitter compensation, which has the advantages of low power consumption and high performance.

FIG. 1 is a schematic diagram of an imaging module according to an embodiment of the present 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 , the imaging module 200 of this embodiment includes an imaging correction unit 100 and a lens unit 210 . The lens unit 210 is used for enabling a light beam L passing through the optical turning element 110 and the two lens elements FL to be imaged in a predetermined imaging area of an imaging plane IS. For example, the light beam L is the image light forming the subject, and the imaging surface IS is the sensing surface of the image sensing element. For example, the image sensing element may include a Charge Coupled Device (CCD), a Complementary Metal-Oxide Semiconductor (CMOS), or other suitable types of optical sensing elements. In this embodiment and some other embodiments, the imaging module 200 further includes an actuator AC, and the actuator AC is, for example, 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 triangular element, and has a light incident surface S113 , a light emitting surface S111 and a reflective optical surface S112 . The reflective optical surface S112 is connected to the light incident surface S113 and the light exit surface S111 , the light incident surface S113 is parallel to the optical axis O, and the light exit surface S111 is inclined relative to the optical axis O. Furthermore, as shown in FIG. 1 , after the light beam L incident on the optical turning element 110 from the light incident surface S113 is reflected by the reflecting optical surface S112 , it leaves the optical turning element 110 through the light exit surface S111 . In this way, through 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, so that the optical elements therein can be configured compactly and thus have a small volume The advantages.

On the other hand, as shown in FIGS. 2A and 2B , the two lens elements FL respectively have a plurality of microstructures MS, and the microstructures MS are disposed on an optical surface AS of each lens element FL. Each microstructure MS has an inclined optical surface TS and a connecting surface LS. The connecting surface LS connects the inclined optical surfaces TS of adjacent microstructures MS, and each inclined optical surface TS is inclined relative to the optical axis O. On the other hand, as shown in FIG. 2A and FIG. 2B , each lens element FL also has a flat surface PS around the optical surface AS, each microstructure MS is convex or concave relative to the flat surface PS, and the connecting surface LS is vertical on the flat surface PS.

Further, as shown in FIG. 2A , in this embodiment, the optical surface AS of each lens element FL has a symmetry axis C, and the microstructures MS of each lens element FL are along the symmetry axis with each lens element FL C extends in a perpendicular direction and is aligned in a direction parallel to the symmetry axis C of each lens element FL. Also, when there is a tolerance between the microstructures MS, there may be a situation in which the pitch P between the microstructures MS and the side length of the microstructures MS are not equal. For example, as shown in FIGS. 2A and 2B , it is assumed that the amount of projection of the inclined optical surface TS of each lens element FL onto the optical surface AS of each lens element FL is in the direction parallel to the axis of symmetry C of each lens element FL. The length is a first length L1, and the microstructures MS of each lens element FL have a plurality of pitches P, and each pitch P is greater than or equal to the first length L1.

For example, in this embodiment, the angle range of the included angle _θ1 of the inclined optical surface TS of each lens element FL with respect to the optical axis O is greater than 45 degrees and less than 90 degrees, while the inclined optical surface TS of each lens element FL has an angle range greater than 45 degrees and less than 90 degrees. The angle range of the included angle θ ₂ with respect to the flat surface PS is between 0 degrees and 45 degrees. Furthermore, as shown in FIG. 2C , after the centers of the lens elements FL and the relative symmetry axes C are aligned, the two lens elements FL will be respectively rotated by the initial angle θ _r with the center as the origin to serve as the initial use state. For example, in this embodiment, the initial included angle θ _r is 45 degrees.

Furthermore, as shown in FIGS. 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 are opposed to each other. That is to say, in this embodiment, the contour of each lens element is a circle, but the present invention is not limited to this. It is sufficient to arrange the above-mentioned microstructure MS there.

Further, as shown in FIG. 1 and FIG. 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 , and the first lens element FL1 The outer surface OS of the 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 surface OS of the second lens element FL2 faces the lens unit 210 . In addition, both the first lens element FL1 and the second lens element FL2 can rotate relative to the optical axis O, and in this embodiment, through the configuration of the microstructure MS, the optical behavior of the first lens element and the second lens element will be Can be equivalent to a general wedge-shaped optical element, but can have a relatively thin thickness. In this way, 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 relative to the optical element. As shown in FIG. 3 , when the lens element FL is rotated by an angle relative to the optical axis O, the imaging position of the light beam L passing through the lens element FL incident on the imaging surface IS can be changed, and moved from the first position P1 to the second position P1. Location P2. Further, in this embodiment, the rotation of the first lens element FL1 and a second lens element FL2 relative to the optical axis O can be controlled by the same actuator AC, and the first lens element FL1 and the second lens element FL2 are opposite to each other. The directions of rotation about the optical axis O are opposite to each other. For example, as shown in FIGS. 2C and 3 , when viewed from the direction of the two lens elements FL toward the imaging plane IS, the rotation direction of the first lens element FL1 is counterclockwise, and the direction of the second lens element FL2 is clockwise Clockwise. In this way, through the configuration of the two-lens element FL that can be rotated relative to the optical axis O, the imaging correction unit 100 and the imaging module 200 can be controlled by the same actuator AC to control their relative rotation angles, so as to achieve the function of optical jitter compensation, and then It has the advantages of low power consumption and high performance.

To sum up, the imaging correction unit and the imaging module of the present invention can reduce the thickness of the lens element through the configuration of the lens element with the microstructure, thereby having the advantage of small volume. In addition, through the rotation of the lens element relative to the optical axis, the relative rotation angle of the imaging correction unit and the imaging module can be controlled by the same actuator, so as to achieve the function of optical jitter compensation, which has the advantages of low power consumption and high performance.

100: Imaging correction unit 110: Optical steering element 200: Imaging module 210: Lens unit AC: Actuator AS: Optical surface C: Symmetry axis CS: Circumferential end face FL: Two lens elements FL1: First lens element FL2: No. Two-lens element IS: Imaging surface L: Light beam L1: First length LS: Connection surface MS: Microstructure O: Optical axis OS: Outer surface P: Pitch P1: First position P2: Second position PS: Flat surface S111: Light exit surface S112: Reflective optical surface S113: Light incident surface TS: Inclined optical surface θ ₁ , θ ₂ , θ _r : included angle

FIG. 1 is a schematic diagram of an imaging module according to an embodiment of the present 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 element of FIG. 1 in an initial state. FIG. 3 is a schematic diagram of the optical path of the lens element of FIG. 1 when it is rotated relative to the optical element.

100: Imaging correction unit

110: Optical steering element

200: Imaging module

210: Lens Unit

AC: Actuator

AS: Optical Surface

CS: Circumferential face

FL1: first lens element

FL2: Second lens element

IS: Imaging surface

L: Beam

S111: light-emitting surface

S112: Reflective Optical Surface

S113: light incident surface

FL: Two lens elements

O: Optical axis

OS: outer surface

Claims (18)

An imaging correction unit has an optical axis, and the imaging correction unit includes: an optical turning element, which has a light incident surface, a reflective optical surface and a light emitting surface, and the reflective optical surface connects the light incident surface and the light emitting surface. and two lens elements, respectively having a plurality of microstructures, arranged on an optical surface of each of the lens elements, wherein each of the microstructures has an inclined optical surface, each of the inclined optical surfaces is inclined relative to the optical axis, and the optical steering The light-emitting surface of the element is inclined relative to the optical axis and faces one of the two lens elements, and the two lens elements can be rotated relative to the optical axis to correct the traveling direction of a light beam passing through the imaging correction unit. The imaging correction unit according to claim 1, wherein the angle range of the 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. The imaging correction unit of claim 1, wherein the periphery of the optical surface of each of the lens elements has a flat surface, each of the microstructures is convex or concave with respect to the flat surface, and the inclination of each of the lens elements The angle of the included angle between the optical surface and the flat surface ranges from 0 degrees to 45 degrees. The imaging correction unit according to claim 3, wherein each of the lens elements further has a connection surface, the connection surface connects the inclined optical surfaces of the adjacent microstructures, and the connection surface is perpendicular to the flat surface. The imaging correction unit of claim 1, wherein the two lens elements include a first lens element and a second lens element, and the rotation directions of the first lens element and the second lens element are rotated relative to the optical axis opposite to each other. The imaging correction unit of claim 5, wherein the optical behavior of the first lens element and the second lens element is equivalent to a wedge-shaped optical element. The imaging correction unit according to claim 1, wherein each of the optical surfaces has an axis of symmetry, the microstructures of each of the lens elements extend along a direction perpendicular to the axis of symmetry of each of the lens elements, and along a direction perpendicular to the axis of symmetry of each of the lens elements The axes of symmetry of each of the lens elements are aligned in a parallel direction. The imaging correction unit according to claim 1, 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 is reflected by the reflective optical surface, and passes through The light exit surface leaves the optical turning element. The imaging correction unit of claim 1, wherein the rotation of the two lens elements relative to the optical axis is controlled by the same actuator. An imaging module, comprising: an imaging correction unit with an optical axis, and the imaging correction unit includes: two lens elements, respectively having a plurality of microstructures, arranged on an optical surface of each of the lens elements, wherein each of the The microstructure has an inclined optical surface, each of the inclined optical surfaces is inclined relative to the optical axis, and the two lens elements can be rotated relative to the optical axis to correct the traveling direction of a light beam passing through the imaging correction unit; and a lens unit for enabling the light beam passing through the two lens elements to be imaged in a predetermined imaging area of an imaging plane. The imaging module according to claim 10, wherein the angle range of the 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. The imaging module of claim 10, wherein the periphery of the optical surface of each of the lens elements has a flat surface, each of the microstructures is convex or concave relative to the flat surface, and the inclination of each of the lens elements The angle of the included angle between the optical surface and the flat surface ranges from 0 degrees to 45 degrees. The imaging module of claim 12, wherein each of the lens elements further has a connecting surface, the connecting surface is connected to the inclined optical surface of the adjacent microstructure, and the connecting surface is perpendicular to the flat surface. The imaging module of claim 10, wherein the two lens elements comprise a first lens element and a second lens element, and the rotation directions of the first lens element and the second lens element are rotated relative to the optical axis opposite to each other. The imaging module of claim 14, wherein optical behaviors of the first lens element and the second lens element are equivalent to wedge-shaped optical elements. The imaging module of claim 10, wherein each of the optical surfaces has an axis of symmetry, and the microstructures of each of the lens elements extend along a direction perpendicular to the axis of symmetry of each of the lens elements, and along a direction perpendicular to the axis of symmetry of each of the lens elements The axes of symmetry of each of the lens elements are aligned in a parallel direction. The imaging module of claim 10, 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 is reflected by the reflective optical surface, and passes through The light exit surface leaves the optical turning element. The imaging module of claim 10, wherein the rotation of the two lens elements relative to the optical axis is controlled by the same actuator.

Images