Camera module comprising an image rotation correction mechanism and optical element having a dach reflective surface

Abstract

The application discloses a camera module (1) of a field-of-view change camera, which can acquire high-quality images without losing the number of pixels. The camera module (1) comprises a field-of-view change mechanism (10), a lens (40), an image sensor (30) and an image rotation correction mechanism (20). The image rotation correction mechanism (20) is arranged between the field-of-view change mechanism (10) and the lens (40), and the image rotation correction mechanism (20) corrects the rotation of an image incident on the image sensor (30).

Description

TECHNICAL FIELD

[0001] The present invention relates to a camera module, and more particularly, to a camera module including an image rotation correction mechanism. The image rotation correction mechanism includes an optical element having a Dach reflecting surface. BACKGROUND

[0002] Recently, periscopic camera modules installed in mobile electronic devices such as smartphones have a field of view changing mechanism including in the periscope section. A reflecting element is rotatable about a predetermined axis, and the field of view of the camera can be changed by the rotation. This enables the mobile electronic device to perform object tracking and wide-angle photography.

[0003] Patent Document 1 discloses a field of view changing mechanism having a function of rotating a reflecting element about two axes, i.e., in the pitch direction and the yaw direction or the roll direction. By rotating the reflecting element in the pitch direction, field of view change in the vertical direction can be achieved, and by rotating the reflecting element in the yaw direction or the roll direction, field of view change in the horizontal direction can be achieved.

[0004] However, when the reflecting element is rotated in the yaw direction or the roll direction, the image incident on the image sensor is rotated in response to the rotation angle of the reflecting element.

[0005] As one of the possible solutions, the rotated image can be corrected to be horizontal by performing rotation and cropping processing on the image. Cropping here means cropping the desired part of the image received by the image sensor. Then, the number of pixels after the cropping processing is reduced to less than the maximum number of pixels that the image sensor can receive. As the rotation angle of the reflecting element becomes larger, i.e., the wider the field of view angle, the reduction in the number of pixels is more pronounced. In addition, the image processing related to cropping requires more time.

[0006] Therefore, in order to compensate for the rotation of the image without losing the number of pixels, an optical solution that does not require a calculation operation is more preferable than an image processing that requires a calculation. An optical system for image rotation correction can be constructed by using a reflecting element such as a prism or a mirror, as an optical solution for leveling the rotated image horizontally on the image sensor.

[0007] Patent Document 2 discloses a solution that uses a prism for reflecting light rays on three planes. Here the image can be corrected by rotating the prism about its optical axis. A rough design of the prism is seen in Figure 8 “(Case 1)”.

[0008] Patent Document 3 discloses a solution that uses two prisms having a fixed relative position. Here the image can be corrected by rotating the two prisms about the optical axis of the lens. A rough design of the two prisms is seen in Figure 8"(Case 2)".

[0009] In the solutions disclosed in Patent Document 2 and Patent Document 3, a prism totally reflects an image incident on an image sensor to reflect the entire imaging area with one plane, thereby increasing the size of the reflecting surface of the prism. In addition, in Patent Document 2, the number of light ray reflections in the optical system is 3, and in Patent Document 3, the number of light ray reflections in the optical system is 5. This lengthens the optical path required for image rotation correction and increases the size of the reflecting element itself, and thus a larger size actuator is required to rotate the reflecting element accordingly. Therefore, the camera module becomes larger.

[0010] Prior art documents are as follows, i.e., Patent Documents 1 to 3 described above.

[0011] (1) U.S. Patent No. 11006030

[0012] (2) International Publication No. WO 2009 / 123591

[0013] (3) U.S. Patent Application Publication No. 2009 / 0167933 SUMMARY

[0014] Problem to be solved by the invention

[0015] An object of the present application is to provide a camera module that does not rotate an image incident on an image sensor even if a field of view changing mechanism is activated. According to the present application, for a camera module having a telescope lens function, the total length of the optical system can be shortened, and the vibration isolation performance can be sufficiently achieved without employing an additional configuration as a camera shake compensation mechanism.

[0016] Method of solving the problem

[0017] In a first aspect, an embodiment of the present application provides a camera module. The camera includes a field of view changing mechanism, a lens, an image sensor, and an image rotation correction mechanism. The image rotation correction mechanism is disposed between the field of view changing mechanism and the lens, and corrects rotation of an image incident on the image sensor.

[0018] In combination with the first aspect, in a possible implementation manner, the image rotation correction mechanism includes an optical element having a Dach reflecting surface and an actuator, wherein the actuator rotates the optical element having the Dach reflecting surface around a predetermined axis.

[0019] With reference to the first aspect, in a possible implementation manner, the image rotation correction mechanism rotates the optical element with the Dach reflective surface around the predetermined axis by an angle which is synchronous with a rotation angle of the reflective element in the field-of-view changing mechanism.

[0020] With reference to the first aspect, in a possible implementation manner, a relationship between a rotation angle (Rc) of the optical element with the Dach reflective surface and a rotation angle (Rs) of the reflective element in the field-of-view changing mechanism satisfies the following conditional expression:

[0021] 0.4Rs < Rc < 0.6Rs.

[0022] With reference to the first aspect, in a possible implementation manner, the optical element with the Dach reflective surface includes two reflective surfaces, wherein the optical element with the Dach reflective surface rotates around an axis which is perpendicular to an intersection line of the two reflective surfaces and bisects an angle formed by the two reflective surfaces.

[0023] With reference to the first aspect, in a possible implementation manner, in the optical element with the Dach reflective surface, a light ray on an optical axis is reflected only once.

[0024] With reference to the first aspect, in a possible implementation manner, when assembled in the camera module, a height occupied by the optical element with the Dach reflective surface is lower than a height occupied by the reflective element in the field-of-view changing mechanism.

[0025] The second aspect, the embodiments of the present application provide a smart phone, comprising the camera module according to any one of the possible implementation manners of the above-mentioned first aspect.

[0026] The third aspect, the embodiments of the present application provide a camera, comprising the camera module according to any one of the possible implementation manners of the above-mentioned first aspect.

[0027] The fourth aspect, the embodiments of the present application provide an image rotation correction mechanism. The image rotation correction mechanism includes an optical element with a Dach reflective surface and an actuator. The actuator rotates the optical element with the Dach reflective surface around a predetermined axis.

[0028] With reference to the fourth aspect, in a possible implementation manner, the optical element with the Dach reflective surface includes two reflective surfaces, wherein the predetermined axis is perpendicular to an intersection line of the two reflective surfaces and bisects an angle formed by the two reflective surfaces. BRIEF DESCRIPTION OF DRAWINGS

[0029] For a more clear description of the embodiments of the present application, the accompanying drawings will be briefly described as needed below. Obviously, in the following description, the drawings only show some embodiments of the present application, and even other drawings in these drawings can be drawn by those skilled in the art without paying creative labor.

[0030] Figure 1 The configuration of the camera module according to the embodiment of the present application is shown.

[0031] Figure 2 The arrangement relationship between the reflecting element of the field-of-view changing mechanism for the camera module and the optical element with the Dach reflecting surface of the image rotation correction mechanism according to the embodiment of the present application is shown.

[0032] Figure 3 is a schematic diagram according to the embodiment of the present application, for explaining the operation of the optical element with the Dach reflecting surface of the image rotation correction mechanism.

[0033] Figure 4 is a perspective view of the camera module according to the embodiment of the present application, for showing the initial state of the reflecting element in the field-of-view changing mechanism and the initial state of the optical element with the Dach reflecting surface in the image rotation correction mechanism, and the state of the image along the optical path.

[0034] Figure 5 is a perspective view of the camera module according to the embodiment of the present application, for showing the specific state of the reflecting element rotating when the field-of-view changing mechanism is activated but the image rotation correction mechanism is not activated, and the state of the image along the optical path.

[0035] Figure 6 is a perspective view of the camera module according to the embodiment of the present application, for showing the specific state of the reflecting element rotating when the field-of-view changing mechanism is activated and the specific state of the optical element with the Dach reflecting surface synchronously rotating when the image rotation correction mechanism is activated, and the state of the image along the optical path.

[0036] Figure 7 The relationship between the rotation of the reflecting element of the field-of-view changing mechanism for the camera module and the rotation of the optical element with the Dach reflecting surface of the image rotation correction mechanism according to the embodiment of the present application is shown.

[0037] Figure 8 is a schematic diagram according to the embodiment of the present application, for comparing the shape of the optical element with the Dach reflecting surface and the shape of the prism in patent document 2 and patent document 3.

[0038] Figure 9This is a schematic diagram according to an embodiment of the present invention, used to compare the size of the reflective element of the field-of-view changing mechanism and the size of the optical element with a Dach reflective surface of the image rotation correction mechanism. Detailed Implementation

[0039] The camera module according to the present invention includes a field-of-view alteration mechanism, a lens, an image sensor, and an image rotation correction mechanism as components. The image rotation correction mechanism is disposed between the field-of-view alteration mechanism and the lens, and includes an optical element having a Dach reflective surface. In the image rotation correction mechanism, the optical element having the Dach reflective surface is held in an actuator and can rotate about a predetermined axis. The rotation of the image incident on the image sensor can be corrected by axially rotating the optical element having the Dach reflective surface in the image rotation correction mechanism, the axial rotation being synchronized with the rotation of the reflective element in the field-of-view alteration mechanism.

[0040] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0041] Figure 1 The configuration of a camera module 1 according to an embodiment of the present invention is shown. In the camera module of this embodiment, light enters the image sensor 30 from the object side toward the image side through the field-of-view changing mechanism 10, the image rotation correction mechanism 20, and the lens 40.

[0042] The field-of-view alteration mechanism 10 includes a reflective element 11, which is rotatably held about two axes. As described above, the field of view in the vertical direction can be changed by rotating the reflective element 11 in the pitch direction, and the field of view in the horizontal direction can be changed by rotating the reflective element 11 in the yaw or roll direction.

[0043] The image rotation correction mechanism 20 includes an optical element 21 with a Dach reflective surface, which is rotatably held about an axis and driven by an actuator. Here, the Dach surface refers to two planes intersecting at a right angle (90 degrees), which have the function of flipping the image up and down or left and right in the optical system. The optical element 21 with the Dach reflective surface has two reflective surfaces intersecting at a right angle to form the Dach surface.

[0044] Figure 2 The arrangement of the reflective element 11 of the field-of-view alteration mechanism 10 for the camera module 1 and the optical element 21 with a Dach reflective surface in the image rotation correction mechanism 20, according to an embodiment of the present invention, is illustrated. Figure 2 In the left view, from Figure 1 The top view (top view) of the camera module 1 shows the reflective element 11 and the optical element 21 with a reflective surface. Similarly, inFigure 2 In the right view of Fig. 10, the light path of the image "F" on the right side and the left side is shown, and the image "F" reflected by the optical element 21 with a Dach reflective surface is flipped in the horizontal direction. Similarly, in the right view of Fig. 11, the light path of the image "F" on the upper side and the lower side is shown, and the image "F" reflected by the optical element 21 with a Dach reflective surface is flipped in the vertical direction. Thus, the image "F" reflected by the optical element 21 with a Dach reflective surface is flipped upward and downward, and also flipped left and right, but no rotation occurs in the initial state. Here, when the optical element 21 with a Dach reflective surface is rotated about the rotation axis 22, the image "F" reflected by the optical element 21 with a Dach reflective surface is also rotated accordingly, as shown in the left view of Fig. 12. Thus, for the rotation of the image "F" caused by the rotation of the reflecting element 11 in the roll direction by the operation of the field-of-view changing mechanism 10, the image "F" reflected by the optical element 21 with a Dach reflective surface can be rotated in the opposite direction by rotating the optical element 21 with a Dach reflective surface about a predetermined axis by a certain angle (synchronously with the rotation of the reflecting element 11), so that the rotation of the image "F" can be corrected. Figure 1

[0045] Figure 3 Figure 3 Figure 2 Figure 3 Figure 3 Figure 3 Figure 3

[0046] Figure 4 ​​​​​​​​is a perspective view of a camera module according to an embodiment of the present application, for showing the initial state of the reflecting element 11 in the field-of-view changing mechanism 10 and the initial state of the optical element 21 with a Dach reflecting surface in the image rotation correction mechanism 20. In addition, the state of the image along the optical path is also shown. The image of the subject is described as the letter "F". In the initial state, the reflecting element 11 reflects but does not rotate the image "F", and the optical element 21 with a Dach surface also reflects but does not rotate the image "F". At this time, the image "F" is flipped up / down and left / right, but not rotated. Subsequently, the image "F" enters the image sensor 30 through the lens 40, and is flipped up / down and left / right in turn. Therefore, the image "F" is not finally rotated.

[0047] Figure 5 is a perspective view of a camera module 1 according to an embodiment of the present application, for showing a specific state in which the reflecting element 11 is rotated when the field-of-view changing mechanism 10 is activated but the image rotation correction mechanism 20 is not activated. In addition, the state of the image along the optical path is also shown. Here, similar to Figure 4 In the state shown, since the reflecting element 11 is rotated in the roll direction by the operation of the field-of-view changing mechanism 10, the image "F" reflected by the reflecting element 11 is rotated. Since the image rotation correction mechanism 20 is not operated, the image "F" reflected by the optical element 21 with a Dach reflecting surface is also in a rotated state. Therefore, the image "F" incident on the image sensor 30 remains rotated.

[0048] Figure 6 is a perspective view of a camera module 1 according to an embodiment of the present application, for showing a specific state in which the reflecting element 11 is rotated when the field-of-view changing mechanism 10 is activated and a specific state in which the optical element 21 with a Dach reflecting surface is synchronously rotated when the image rotation correction mechanism 20 is activated. In addition, the state of the image along the optical path is also shown. Here, similar to Figure 4 Since the field-of-view changing mechanism 10 is operated and the reflecting element 11 is rotated in the roll direction, the image "F" reflected by the reflecting element 11 is rotated. However, in Figure 6 In the state shown, since the image rotation correction mechanism 20 is operated and the optical element 21 with a Dach reflecting surface is synchronously rotated by a predetermined rotation axis 22 by a certain angle, the image "F" reflected by the optical element 21 with a Dach reflecting surface is corrected for rotation. Therefore, the image "F" finally incident on the image sensor 30 is leveled horizontally and does not rotate.

[0049] Figure 7The relationship between the rotation of the reflecting element 11 of the field-of-view changing mechanism 10 for the camera module 1 and the rotation of the optical element 21 with a Dach reflecting surface of the image rotation correction mechanism 20 according to an embodiment of the present application is shown. It is assumed that the field-of-view changing mechanism 10 operates such that the reflecting element 11 is rotated by Rs (degrees) in the roll direction to change the field-of-view. Figure 7 The right-hand side of the figure schematically shows the relationship between the rotation (angle Rs) of the reflecting element 11 in the field-of-view changing mechanism 10 and the resulting field-of-view tilt (i.e. the rotation (angle Ra) of the image). Basically, in general, the relationship between the angle Rs and the angle Ra is as follows:

[0050] 0.8 Rs < Ra < 1.2 Rs.

[0051] With respect to the relationship between the angle of incidence and the angle of reflection at the reflecting surface, when the reflecting surface is rotated, the angle of incidence also changes, the change in the angle of reflection is twice the change in the angle of incidence. Thus, as shown in Figure 3 the image rotation in the optical element 21 with a Dach reflecting surface caused by the reflection is twice the rotation (angle Rc) of the optical element 21 with a Dach reflecting surface itself. Therefore, basically, the rotation (angle Rc) of the optical element 21 with a Dach reflecting surface required to correct the image rotated by the angle Rs is half of the angle Rs rotation, but in fact, the relationship between the angle Rs and the angle Rc is as follows:

[0052] 0.4 Rs < Rc < 0.6 Rs.

[0053] Therefore, in order to maintain the above relationship between the angle Rs and the angle Rc of the camera module 1, the optical element 21 with a Dach reflecting surface is rotated by activating the image rotation correction mechanism 20 and the unrotated image can be transmitted onto the image sensor 30 by the simultaneous rotation of the reflecting element 11 caused by the operation of the field-of-view changing mechanism 10.

[0054] Figure 8 is a schematic view according to an embodiment of the present application for comparing the shape of the optical element 21 with a Dach reflecting surface and the shape of the prism in patent document 2 and patent document 3. First, the reflection of light along the optical axis is considered. In the optical element 21 with a Dach reflecting surface according to the present application, the reflection number of the light ray along the optical axis is 1. On the other hand, in the prism of patent document 2, the reflection number of the light ray along the optical axis is 3, and in the prism of patent document 3, the reflection number of the light ray along the optical axis is 5.

[0055] The reflection number is directly related to the size of the corresponding element (e.g. prism). Figure 8The table in the above describes the size of each element in each optical system using the optical ray diameter D. The width (W) x length (L) x height (H) of the optical element 21 having the Dach reflecting surface according to the present application is D x 1.5D x D. On the other hand, the prism of Patent Document 2 requires a size of D x 3.5D x 2D or more, and the prism of Patent Document 3 requires a size of 2D x 3D x D or more. As described above, by using the optical element 21 having the Dach reflecting surface according to the present application, since it is not necessary to reflect the entire imaging area in one plane as in the prisms of Patent Document 2 and Patent Document 3, and the number of times of light ray reflection along the optical axis is limited to 1, it is possible to reduce the size of the camera module 1.

[0056] Figure 9 is a schematic view according to an embodiment of the present application for comparing the size of the reflecting element 11 of the field of view changing mechanism 10 and the size of the optical element 21 having the Dach reflecting surface of the image rotation correction mechanism 20. As described above, the size of the optical element 21 having the Dach reflecting surface according to the present application can be reduced compared to the prior art. Specifically, when assembled in the camera module 1, the actual vertical height H2 of the optical element 21 having the Dach reflecting surface can be smaller than the actual vertical height H1 of the reflecting element 11 of the field of view changing mechanism 10.

[0057] As described above, the operation of the field of view changing mechanism 10 has been described in connection with the case where the reflecting element 11 rotates in the roll direction upon image rotation. However, similarly, the image rotates in the case where the reflecting element 11 rotates in the yaw direction. Therefore, it should be understood that the above description applies to the reflecting element 11 rotating in the roll direction or the yaw direction.

[0058] By using the camera module according to the present application, it is possible to provide a field of view changing camera capable of obtaining high image quality without losing the number of pixels. Furthermore, a small-sized image rotation correction mechanism can be realized according to the present application.

[0059] The above description shows the embodiments provided by the present application, but is not intended to limit the present application. Any modification, equivalent replacement or improvement made without departing from the spirit and principle of the present application should be included in the protection scope of the present application.

[0060] Symbol explanation

[0061] 1: camera module

[0062] 10: field of view changing mechanism

[0063] 11: reflecting element

[0064] 20: image rotation correction mechanism

[0065] 21: optical element with Dach reflective surface

[0066] 30: image sensor

[0067] 40: lens

Claims

1. A camera module, characterized in that, include: The field-of-view alteration mechanism, lens, image sensor, and image rotation correction mechanism, among which, The image rotation correction mechanism is disposed between the field-of-view changing mechanism and the lens; The image rotation correction mechanism corrects the rotation of the image incident on the image sensor; The image rotation correction mechanism includes an optical element with a Dach reflective surface and an actuator; The actuator causes the optical element with the Dach reflective surface to rotate around a predetermined axis at a certain angle, the angle being synchronized with the rotation angle of the reflective element in the field-of-view changing mechanism.

2. The camera module according to claim 1, characterized in that, The relationship between the rotation angle Rc of the optical element with the Dach reflective surface and the rotation angle Rs of the reflective element in the field-of-view changing mechanism satisfies the following conditional expression: 0.4Rs <Rc<0.6Rs。 3. The camera module according to claim 1, characterized in that, The optical element with a Dach reflective surface includes two reflective surfaces; The predetermined axis is perpendicular to the line of intersection of the two reflective surfaces and bisects the angle formed by the two reflective surfaces.

4. The camera module according to any one of claims 1 to 3, characterized in that, In the optical element with the Dach reflective surface, the number of light reflections along the optical axis is only 1.

5. The camera module according to any one of claims 1 to 3, characterized in that, When assembled in the camera module, the optical element with the Dach reflective surface occupies a lower height than the reflective element in the field-of-view alteration mechanism.

6. A smartphone, characterized in that, Includes the camera module according to any one of claims 1 to 5.

7. A camera, characterized in that, Includes the camera module according to any one of claims 1 to 5.

8. An image rotation correction mechanism, characterized in that, include: Optical elements and actuators with Dach reflective surfaces; The actuator causes the optical element with the Dach reflective surface to rotate around a predetermined axis at a certain angle, which is synchronized with the rotation angle of the reflective element in the field-of-view changing mechanism.

9. The image rotation correction mechanism according to claim 8, characterized in that, The optical element with a Dach reflective surface includes two reflective surfaces; The predetermined axis is perpendicular to the line of intersection of the two reflective surfaces and bisects the angle formed by the two reflective surfaces.

Images