SYSTEMS AND CAMERAS FOR TIPPING THE FOCAL PLANE OF A SUPERMACOBILE IMAGE

Description

FIELD OF THE INVENTION

[0001] The subject matter disclosed herein relates in general to macro images and in particular to methods for obtaining such images with mobile telephoto ("Tele") cameras.BACKGROUND OF THE INVENTION

[0002] Multi-cameras (of which a "dual-camera" having two cameras is an example) are now widespread in portable electronic mobile devices (or just "mobile devices", e.g. smartphones, tablets, etc.). A multi-camera usually comprises a wide field-of-view (or "wide angle") FOV w camera ("Wide" or "W' camera), and at least one additional camera, e.g. with a narrower (than FOV w ) FOV, i.e. a "Tele" (or "T") camera with FOV T . A triple camera including a W camera, an ultra-wide (UW) camera and a double-folded Tele camera is shown in FIG. 5A-B.

[0003] A "Macro-photography" mode is becoming a popular differentiator. "Macro-photography" refers to photographing objects that are close to the camera, so that an image recorded on the image sensor is nearly as large as the actual object photographed. The ratio of object size to image size is the object-to-image magnification ("M").

[0004] A Macro camera providing large M can be realized with a mobile devices's Tele camera. Because of its large M, the camera can be referred to as "super-Macro camera" or "SM camera" and the image can be referred to as "super-Macro image" or "SM image". Tele cameras and methods for mobile super-Macro-photography are described for example in co-owned international patent application PCT / IB2021 / 054186.

[0005] Because of a Tele camera's large effective focal length (EFL) of 7mm or more, Tele cameras focused to close objects have a very shallow depth of field (DOF), see Table 1. The DOF is the distance between the nearest and the farthest objects that are in acceptably sharp focus in an image. Consequently, capturing Macro images in a Macro-photography mode with a Tele camera is very challenging. For example, for obtaining more beneficial lightning or more convenient capture experience, one may want to capture an object which is oriented at some angle θ with respect to the mobile device's rear surface and the Macro camera's focal plane (see FIG. 1A). This may result in an image that is only partially in focus. In standalone cameras such as digital single-lens reflex cameras (DSLRs), this challenge is solved by "Tilt-shift lenses" that allow to tilt the focal plane. However, there is no satisfactory solution to this challenge in miniature cameras of the type included in smartphones.

[0006] It would be beneficial to have a super-Macro camera in mobile devices that can tilt its focal plane.

[0007] US Patent Application Publication 2020 / 0220956 describes, "An image capturing device and a mobile electronic device are provided. The image capturing device includes a frame, a flexible circuit board connected to the frame, a camera lens assembly mounted at the middle of the frame, a first prism unit mounted at one end of the frame and at an object side of the camera lens assembly to receive light, a second prism unit mounted at another end of the frame and at an image side of the camera lens assembly, a first voice coil motor for driving the second prism unit to rotate about an X-axis direction in the frame, and a second voice coil motor for driving the second prism unit to rotate about a Y-axis direction in the frame. The first and second voice coil motors are electrically connected to the flexible circuit board. An overall appearance of a mobile electronic device is not affected."

[0008] Chinese Patent Application Publication CN111988454A describes, "The invention relates to a camera module and electronic equipment, and belongs to the technical field of camera modules. The camera module comprises at least two lenses, a reflecting piece, a driving piece and an image sensor. The shooting ranges of the at least two lenses are partially overlapped. The reflecting piece is arranged on the light emitting sides of the at least two lenses. The driving piece is connected with the reflecting piece and drives the reflecting piece to move to enable the reflecting piece to independently reflect light emitted from any one of the at least two lenses. The image sensor is located on the light emitting side of the reflecting piece and receives the light reflected by the reflecting piece."BRIEF DESCRIPTION OF THE INVENTION

[0009] Various embodiments of the invention are defined by the appended claims 1 to 14.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Non-limiting examples of embodiments disclosed herein are described below with reference to figures attached hereto that are listed following this paragraph. The drawings and descriptions are meant to illuminate and clarify embodiments disclosed herein, and should not be considered limiting in any way. Like elements in different drawings may be indicated by like numerals. Elements in the drawings are not necessarily drawn to scale. FIG. 1A shows an exemplary SM capture scenario known in the art; FIG. 1B shows a SM image captured in a Portrait mode according to the scenario shown in FIG. 1A; FIG. 2A shows exemplarily a SM image capture scenario as disclosed herein; FIG. 2B shows a SM image captured in a Portrait mode according to the scenario shown in FIG. 2A; FIG. 3A shows an example of a known art double-folded camera in a cross-sectional view; FIG. 3B shows an example of a double folded camera with a tiltable focal plane disclosed herein in a cross-sectional view; FIG. 4A shows exemplarily a camera disclosed herein in a zero-tilt focal plane position; FIG. 4B shows the camera of FIG. 4A in a non-zero tilt focal plane position; FIG. 4C shows an embodiment of a method for automatic control of focal plane tilting disclosed herein; FIG. 5A shows an example of a mobile device that includes a double-folded SM camera with a tiltable focal plane as disclosed herein; FIG. 5B shows a known art double-folded Tele camera in a perspective view; FIG. 6A shows an I-OPFE module disclosed herein from a top view; FIG. 6B shows the I-OPFE module of FIG. 6A without an I-OPFE and without an OPFE holder in a perspective view; FIG. 6C shows the I-OPFE module in the same perspective view as FIG. 2B, but with the I-OPFE and the OPFE holder shown; FIG. 7 shows schematically an embodiment of a mobile device capable of tilting a focal plane disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0011] Cameras and images below qualify as "SM" if they support the two criteria: M of 1:5 - 25:1. Capture at an object-lens distance in the range of 30mm-750mm with an EFL in the range of 7mm-50mm.

[0012] A magnification of 1:5 and 25:1 refers respectively to a ratio of the physical size of the captured object being 1 and 25 to a size of the image of the captured object being 5 and 1, respectively.

[0013] It is noted that the above SM definition refers to both camera specifications (e.g. EFL in the range of 7mm-50mm) and image (or scene) specifications (e.g. object-lens distance in the range of 30mm-750mm). In particular, this means that a same camera may be used for image capture both in SM scenes (e.g. a scene with an exemplary object-lens distance of 100mm) as well in other scenes (e.g. a scene with an exemplary object-lens distance of 2m). When capturing SM scenes, the camera is referred to as SM camera. When capturing other scenes, the camera is referred to as Tele camera.

[0014] Table 1 shows the depth of field (DOF) in mm of a SM camera as function of its EFL (in mm) and an object's distance from the camera ("object-lens distance" or "u") in cm. For calculating DOF, a f number of f / 3 and a circle of confusion of 1.5µm was assumed. The DOF is presented for a range of EFL = 8mm - 40mm (column) and u = 2cm - 150cm (row).

[0015] FIG. 1A shows an exemplary SM capture scenario known in the art. Mobile device (100) (e.g. a smartphone) includes a SM camera (102) that has a focal plane (104). Focal plane (104) is oriented in parallel to a rear surface of mobile device (100) and has a certain DOF. The DOF extends to both sides of focal plane (104). SM camera (102) captures an object (106). Mobile device (100) is oriented at an angle α with respect to the orientation of object (106). Because of the shallow DOF (see Table 1), only parts of object (106) may lie within the DOF region and may be in focus (dotted area of object (106)). Other parts of object (106) may lie outside the DOF region and may be out of focus (white area of object (106)). Focal plane (104) forms an angle β=90 degrees with a normal (108) of mobile device (100)'s rear surface. Mobile device (100) is shown in "Portrait mode" orientation as known in the art, meaning that a length dimension of a camera image is parallel to a length dimension of the object. In other embodiments, mobile device (100) may be in "Landscape mode" orientation as known in the art.

[0016] FIG. 1B shows a SM image (110) captured in a Portrait mode according to the scenario shown in FIG. 1A. Only segments of object (106) that were within the DOF are in-focus, and the segments of object (106) that were outside of the DOF are out-of-focus. In this scenario, the DOF of the SM camera prevents all-in-focus object capture in a direction parallel to the image's Y-axis. In other scenarios, the DOF of the SM camera may prevent all-in-focus object capturing in a perpendicular direction that is parallel to the image's X-axis.

[0017] FIG. 2A shows exemplarily a SM image capture scenario as disclosed herein. Mobile device (200) (e.g. a smartphone) includes a SM camera (202) with a tiltable focal plane (204). "Tiltable" refers to the fact that focal plane (204) can be tilted to have an orientation that is not parallel to mobile device (200). Focal plane (104) forms an angle β < 90 degrees with a normal (208) of mobile device (200)'s rear surface.

[0018] SM camera (202) captures object (106). As in the scenario of FIG. 1A, mobile device (200) is oriented at an angle α with respect to the orientation of object (106). However and in contrast, focal plane (204) of SM camera (202) is tilted around a rotation axis parallel to the Z-axis so that focal plane (204) is oriented parallel to object (106). Despite the shallow DOF, all segments of object (106) lie within the DOF region and are thus in focus. Like mobile device (100) in FIG. 1A, mobile device (200) is shown in Portrait mode orientation.

[0019] FIG. 2B shows a SM image (210) captured in a Portrait mode according to the scenario shown in FIG. 2A. All segments of object (106) are in focus.

[0020] FIG. 3A shows an example of a first example of a known art double-folded camera numbered (300) in a cross-sectional view. Camera (300) includes a first object-side optical path folding element ("object OPFE" or "O-OPFE", for example a prism or a mirror) (302), a lens (304), a second image-side OPFE ("image OPFE" or "I-OPFE"- for example a mirror or a prism) (306) and an image sensor (308). Image sensor (308) is oriented in a plane parallel to the X-Y plane. Camera (300) has a focal plane (310) that is oriented parallel to the X-Z plane, i.e. perpendicular to image sensor (308) and parallel to a rear surface of a mobile device (not shown) that hosts camera (300). The optical path ("OP") of camera (300) is folded twice, from a first OP ("OP1") (312) that is perpendicular to focal plane (310) and parallel to the Y-axis, to a second OP ("OP2") (314) that is parallel to focal plane (310) and parallel to the X-axis, and then to a third OP ("OP3") (316) that is perpendicular to focal plane (310) and parallel to the Z-axis. I-OPFE (306) is oriented at an angle of 45 degrees with respect to image sensor (308) and with respect to both OP2 (314) and OP3 (316). In the following, this orientation of I-OPFE (306) is referred to as an I-OPFE's "zero-position" or "zero-tilt position". In a second example of a known art double folded camera (not shown), OP3 (316) is oriented parallel to OP1 (312) (i.e. parallel to the Y-axis) and image sensor (308) may be oriented in a plane parallel to the X-Z plane.

[0021] FIG. 3B shows an example of a first example of a double folded camera (320) with a tiltable focal plane (330) disclosed herein in a cross-sectional view. Similar to camera (300), camera (320) includes an O-OPFE (302'), a lens (304') and an image sensor (308') which may or may not be identical with respective elements in camera (300). In addition, camera (320) includes a tiltable I-OPFE (322) (for example a mirror or a prism). In other embodiments, lens (304') may be partitioned into two or more lens groups (not shown), wherein a first lens group including one or more lens elements may be located at an object side of O-OPFE (302') and a second lens group including one or more lens elements may be located at an image side of O-OPFE (302') and at an object side of tiltable I-OPFE (322). In yet other embodiments (not shown), lens (304') may be located at an object side of O-OPFE (302'), i.e. no lens elements may be located at an image side of O-OPFE (302'). The OP of camera (320) is folded twice, with identical partition into three OPs as shown in FIG. 3A. In particular, this means that image sensor (308') is oriented parallel to the X-Y plane and that tiltable focal plane (330) (in a zero-position) is oriented parallel to the X-Z plane. Tiltable I-OPFE (322) is shown in a zero-tilt position (like (306) in FIG. 3A) and in a tilted position with a tilt angle of φ with respect to its zero-tilt position. In a zero-tilt position, tiltable I-OPFE (322) is oriented parallel to the Y-axis and oriented at an angle of 45 degrees with respect to image sensor (308') and to OP2 (314) (which is parallel to the X-axis) and OP3 (316) (which is parallel to the Z-axis).

[0022] Here and in the following, a first I-OPFE tilt angle "φ" is defined by the rotation angle of I-OPFE (322) around a first I-OPFE rotation axis (324) that is parallel to the Y-axis and which may intersect the geometrical center of the reflecting surface of I-OPFE (322). By tilting I-OPFE (322) around first I-OPFE rotation axis (324), tiltable focal plane (330) is tilted around a first focal plane tilt axis that is parallel to the Z-axis.

[0023] A second I-OPFE tilt angle is defined by the rotation angle of I-OPFE (322) around a second I-OPFE rotation axis (not shown) that is parallel to I-OPFE (322)'s zero-tilt position, i.e. second I-OPFE rotation axis forms an angle of 45 degrees with both the X-axis and the Z-axis and is perpendicular to the Y-axis. By tilting I-OPFE (322) around the second I-OPFE rotation axis, tiltable focal plane (330) is tilted around a second focal plane tilt axis that is parallel to the X-axis.

[0024] Depending on an orientation of an object that is to be captured such as object (106), it may be desired to tilt focal plane (330) around the first focal plane tilt axis, around the second focal plane tilt axis, or around a combination of the two. Given an orientation of a particular object that is to be captured such as object (106), it may be desired to tilt focal plane (330) around the first focal plane tilt axis when a mobile device including camera (320) (such as mobile device (700)) is held in a Portrait mode (or orientation) as known in the art for image capture, and it may be desired to tilt focal plane (330) around the second focal plane tilt axis when a mobile device including camera (320) is held in a Landscape mode as known in the art for image capture, or vice versa. This means that the decision whether to tilt the focal plane around the first or the second tilt axis depends both on the orientation of an object to be captured and on the orientation of the camera hosting mobile device.

[0025] For tilting a focal plane of a second example double folded camera (i.e. OP3 being parallel to the Y-axis and the image sensor being oriented in a plane parallel to the X-Z plane) around a first focal plane tilt axis that is parallel to the Z-axis, the I-OPFE may be tilted around an I-OPFE tilt axis that is parallel to the Z-axis. For tilting a focal plane of a second example double folded camera around a second focal plane tilt axis that is parallel to the X-axis, the I-OPFE may be tilted around an I-OPFE tilt axis that is parallel to the I-OPFE as well as oriented perpendicular to the Z-axis and forming an axis of 45 degrees with respect to the X-axis and the Y-axis.

[0026] Tiltable focal plane (330) of camera (320) is a tilted focal plane that is not perpendicular to OP (312), but forms an angle θ with a plane (334) that is oriented normal to OP (312). With reference to FIG. 1A and FIG. 2A, camera (320) can be used to capture an object such as (106) entirely in focus, if focal plane tilting is performed so that θ = α is approximately fulfilled (α being the angle between mobile device (200) and object (106), see FIG. 2A). "Approximately fulfilled" means here that because of the finite thickness of DOF (as shown in FIG. 1A and FIG. 2A), an object like object (106) can be captured entirely in focus also at an angle θ = α ± Δ. The magnitude of Δ depends on angle α and on object-lens distance "u".

[0027] For a tiltable focal plane such as (330), the object-lens distance u for an object in focus is measured along OP (312) from the FOV center to the camera lens. As can be seen in FIG. 3B, the tilting of the focal plane does not change u. In double folded camera (320), consecutive OPs (such as OP1 and OP2, OP2 and OP3 etc.) are oriented perpendicular to each other. In other examples, consecutive OPs may be oriented to each other at another angle, e.g. varying from 90 degrees by 10 degrees or 20 degrees or more. In particular, here an O-OPFE and / or an I-OPFE in a zero-tilt position may be oriented so that it folds an optical path towards the another angle.

[0028] FIGS. 4A-B show the relation between tilting angles φ and θ (as defined in FIG. 3B). For the sake of simplicity, the optical system of double-folded camera (320) is represented by a simpler regular or non-folded camera (400). For not too large angles φ for example up to φ=20 degrees, it can be assumed that tilting an image sensor of a non-folded camera such as image sensor (404) (similar to (308')) by angle φ with respect to its zero-tilt position at 90 degrees to the camera's OP (412) (similar to (316)) leads to a similar tilting angle θ as one obtains by tilting an I-OPFE such as I-OPFE (322) by the same tilting angle φ with respect to its zero-tilt position (at 45 degrees with respect to the double-folded camera's OP (314) and OP (316)). It is noted that this implies that focal plane tilting as described herein can be performed not only by a double-folded camera, but also by a regular or non-folded camera. Whereas in a double-folded camera such as (320) an I-OPFE such as (322) is tilted for focal plane tilting, in a regular camera the camera's lens is tilted with respect to the camera's image sensor and a mobile device hosting the regular camera, or the camera's image sensor is tilted with respect to the camera's lens and a mobile device hosting the regular camera.

[0029] FIG. 4A shows exemplarily camera (400) in a zero-tilt focal plane position. Camera (400) includes a lens (402) and a tiltable image sensor (404) and it is focused to a focal plane (410) perpendicular to the Y-axis to some object-lens distance u, covering a certain horizontal field of view (FOV) of a scene. Titltable image sensors are known in the art. In FIG. 4A, image sensor (404) is shown in a zero-tilt position. In the zero-tilt position, image sensor (404) is oriented perpendicular to the Y-axis. As known in the art, the optical system is designed so that focal plane (410) is oriented parallel to image sensor (404), parallel to a rear surface of a mobile device (not shown) that hosts camera (400) and perpendicular to OP (412) of camera (400). Three exemplary field (or "object") points (with rays numbered 1-3) are shown: a first field point ("FP1") at a position right of a center of the FOV, a second field point ("FP3") at the FOV center and a third field point ("FP3") at a position left of the FOV center. Designing the optical system so that the focal plane (410) of camera (400) is oriented parallel to image sensor (404) means that fields 1-3 at a same object-lens distance u are in focus. Field points at u are in focus if all rays emerging from this field point propagate a same optical path length ("OPL"), so all rays of FP1, FP2 and FP3 propagate a specific OPL (respectively OPL1, OPL2 and OPL3). OPL1, OPL2 and OPL3 come to lie on focal plane (410). The width of sensor (404) is marked "S", while the width of the FOV is marked "X".

[0030] FIG. 4B shows camera (400) in a non-zero tilt focal plane position. Image sensor (404) is now tilted, oriented in a plane not perpendicular to the Y-axis, but forming an angle φ with the X-axis. When image sensor (404) is tilted, OPL1, OPL2 and OPL3 do not come to lie on a focal plane (410) perpendicular to the Y-axis, but on a focal plane (410) that forms some an angle ≠90 degrees with the Y-axis and an angle θ with the X-axis. Object-lens distance u and lens-image distance v are not constant with respect to x such as shown in FIG. 4A, but depend on x, i.e. u=u(x) and v=v(x). For FP1, u1=u center +Δu1 and v1=v center +Δv1. For FP3, u3=u center +Δu3 and v3=v center +Δv3. "u center " and "v center " refer to an object-lens distance at a center position of the FOV and a lens-image distance at a center position of the image sensor respectively. For FP2, there is no change, u2=u center and v2=v center . We assume that FP1 and FP3 are located symmetrically with respect to FP2, so that Δu1=-Δu3 and Δv1=-Δv3. In the following, we will consider FP1 only. If not stated otherwise explicitly, here and in the following the object-lens distance u refers to u center .

[0031] The thin lens equation depends now on x, too (equation 1): 1 EFL = 1 u x + 1 v x

[0032] Tables 2-4 show exemplarily the relationship of focal plane tilt stroke θ and combinations of SM camera examples (characterized by EFL in mm) and object-lens distances u (in mm) for three image sensor tilt angles φ1=5deg (Table 2), φ2=20deg (Table 3) and φ3=40deg (Table 4). From Tables 2-4 it is evident that for tilting the focal plane around a first focal plane rotation axis or a second focal plane rotation axis by a particular focal plane tilt stroke θ P ("P" for particular), a particular I-OPFE rotation stroke φ P is required, wherein φ P is smaller for closer object-lens distances u. This means that for performing a same focal plane tilt stroke θ P at two different object-lens distances u 1 , u 2 , wherein u 1 <u 2 , at u 1 a smaller amount of rotation (i.e. a smaller rotation stroke φ P ) of the I-OPFE is required than at u 2 . In other words, for a particular amount of focal plane tilting the following is fulfilled: the smaller the object-lens distance, the smaller the required I-OPFE rotation stroke φ P to achieve the particular amount of focal plane tilting.

[0033] The tilting of the focal plane may be by controlled by a human user or automatically by an algorithm.

[0034] FIG. 4C shows an embodiment of a method for automatic control of focal plane tilting disclosed herein. In a first step (422), an object of interest ("OOI") detector such as OOI detector (742) (FIG. 7) may detect an OOI and its position within a SM camera's FOV. The OOI may be selected by a user and / or proposed by an algorithm, e.g. by using a saliency map or an object detection algorithm. In some embodiments, OOI detector (742) may use Wide (W) or Ultrawide (UW) image data for detecting an OOI. In step (424), a tilt estimator such as tilt estimator (744) (FIG. 7) may calculate a relative tilt between the SM camera's focal plane and the OOI. For tilt estimation, image data from the SM or the W or UW camera may be used, e.g. RGB or photodiode autofocus (PDAF) image data. In other embodiments, depth map data from an additional camera, e.g. from a Time-of-Flight (TOF) camera may be used. Based on the tilt estimation, in step (426) I-OPFE control (746) (FIG. 7) may use calibration data such as presented in Table 2-4, e.g. as a Look-Up-Table (LUT), to calculate I-OPFE control signals that are transmitted to an I-OPFE actuator (such as I-OPFE actuator (724)) which tilts the focal plane in order to align the SM camera's focal plane with OOI's orientation.

[0035] The calibration data may include tilt angles of four I-OPFE rotation axes and object-lens distances for controlling the tilting of the focal plane around two focal plane rotation axes. The calibration data may include tilt angles of two I-OPFE rotation axes and object-lens distances for controlling the tilting of the focal plane around one focal plane rotation axis. In other embodiments, the focal plane may not be aligned with the OOI orientation, but the focal plane and the OOI orientation may be tilted with respect to each other in a defined way, so that an artistic (or aesthetic) combination of in-focus and out-of-focus segments in the SM image are formed. For example, the artistic combination of in-focus and out-of-focus segments in the SM image may be a Bokeh effect that can be controlled via focal plane tilting. In some examples, the artistic combinations may be used to highlight particular objects or particular segments of a scene.

[0036] In other examples referring to a regular or non-folded camera, in step (426) a lens tilt controller or an image sensor tilt controller may use calibration data to calculate lens control signals or image sensor control signals that tilt the focal plane by tilting the camera's lens and / or the camera's image sensor in order to align the focal plane and OOI's orientation.

[0037] In yet other examples referring to a camera that has an optical path which is folded more than twice, e.g. 3 times or 4 times or more, in step (426) an OPFE tilt controller may use calibration data to calculate OPFE control signals that tilt the focal plane by tilting one of the camera's OPFEs by means of an OPFE actuator in order to align the focal plane and the OOI orientation. A camera that has an optical path which is folded 3 times or 4 times respectively includes two or more OPFEs (e.g. prisms and / or mirrors) and has 4 optical path segments OP1-OP4 or 5 optical path segments OP1-OP5 respectively, wherein consecutive OPs (such as OP1 and OP2 etc.) may be oriented at an angle of 90 degrees relative to each other or they may be oriented at another angle.

[0038] In step (428), a SM image is captured. In some embodiments, a plurality of SM images is captured that together form a video stream. In some examples, different artistic combinations of in-focus and out-of-focus segments in particular SM images of the video stream may be used to highlight particular objects or particular segments of a scene.

[0039] In some embodiments and for a scanning SM camera, W image data may be used to steer the native FOV N of the scanning SM camera to an OOI.

[0040] FIG. 5A shows an example of a mobile device numbered (500) that includes a double-folded SM camera (502) with a tiltable focal plane as disclosed herein. Mobile device (500) includes a multi-camera that comprises, in addition to a Tele camera that acts as SM camera (502), a Wide (or "W') camera (504) having a Wide FOV W and an Ultra-Wide (or "UW') camera (506) having an Ultra-Wide FOV UW . The multi-camera is integrated in the rear-facing (or world-facing) surface (508) of mobile device (500). Mobile device (500) may include some or all of components of mobile device (700). Mobile device (500) may for example be a smartphone.

[0041] FIG. 5B shows a known art double-folded Tele camera (520) in a perspective view. Camera (520) includes an object OPFE (522) (e.g. a prism), a lens (524), an I-OPFE (526) (e.g. a mirror) and an image sensor (528). Camera (520) has three OPs, OP1 (532), OP2 (534) and OP3 (536). Double-folded Tele camera (520) is implemented according to the first example as described above, i.e. OP1 (532) is parallel to the Y-axis, OP2 (534) is parallel to the X-axis, OP3 (536) is parallel to the Z-axis. Image sensor (528) is oriented in a plane parallel to the X-Y plane.

[0042] FIG. 6A-C shows a tiltable I-OPFE module (600) that enables tilting an OPFE in a range of about ±30 degrees. FIG. 6A shows I-OPFE module (600) as from a top view. I-OPFE module (600) comprises an I-OPFE (602) (e.g. a mirror or a prism) in an OPFE holder (604), and an OPFE tilt mechanism (610). OPFE tilt mechanism (610) rotates I-OPFE (602) around one axis of rotation (606) located at pivot ball (612) and parallel to the Z-axis. Support balls (614) and (616) mediate the rotation. OPFE tilt mechanism (610) also comprises a voice coil motor ("VCM") actuator (620) that has a VCM magnet (622) and a VCM coil (624) for rotational actuation. The VCM actuation is sensed by a sensing and compression magnet (632) and a Hall sensor (634).

[0043] FIG. 6B shows OPFE module (600) without I-OPFE (602) and OPFE holder (604) in a perspective view. Yoke (636) is visible. FIG. 6C shows OPFE module (600) in the same perspective view as FIG. 2B, but with I-OPFE (602) and OPFE holder (604) shown. The axis of rotation (606) is marked.

[0044] By using two separate magnets (622) and (632), OPFE module (600) allows for separation of sensing and actuation. Hall sensor (634) is decoupled from the magnetic field of coil (624). Rotation axis (606) is at relatively large distance from VCM actuator (620), providing a large lever for rotational actuation. Rotation axis (606) is at relatively short distance from Hall sensor (634) so that sensing of large rotational OPFE actuation can be performed within a small stroke.

[0045] FIG. 7 shows schematically an embodiment of a mobile device (e.g. a smartphone) capable of tilting a focal plane disclosed herein and numbered (700). Mobile device (700) comprises a SM camera (710) which is a double-folded camera that includes a lens (712), an image sensor (714), an O-OPFE (716) and an O-OPFE actuator (718), an I-OPFE (722) and an I-OPFE actuator (724), both for rotational actuation of O-OPFE and I-OPFE respectively. Rotational actuation of I-OPFE is performed for a method disclosed herein. Calibration data for rotational actuation of I-OPFE according to a control signal from I-OPFE control (744) is stored on a first memory (726) (e.g. an EEPROM or "electrically erasable programmable read-only memory") or on a third memory (750) (e.g. a NVM or "non-volatile memory"). SM lens (712) may have a fixed EFL providing a fixed zoom factor (ZF), or an adaptable EFL providing an adaptable ZF. The adaptation of the focal length may be discrete or continuous, i.e. a discrete number of varying focal lengths for providing two or more discrete zoom states having particular respective ZFs, or the adaptation of the ZF may be continuous. O-OPFE actuator (718) and I-OPFE actuator (724) may actuate O-OPFE (716) and I-OPFE (722) respectively for focal plane tilting, OIS and, in case SM camera (710) is a scanning folded camera, for FOV scanning. I-OPFE actuator (724) may actuate I-OPFE (722) around two perpendicular axes, in dependence of a desired focal plane tilt direction.

[0046] Mobile device (700) further comprises a W camera module (730) including a W lens (732), an image sensor (734) and a second memory (736).

[0047] Mobile device (700) may further comprise an application processor (AP) (740). AP (730) comprises an OOI detector (742), a tilt estimator (744) for estimating a relative tilt between mobile device (700) and an OOI that is to be captured. The tilt estimation of (744) is used by I-OPFE control (746) to calculate control signals for I-OPFE actuator (724) which rotates I-OPFE (722) according to the control signals.

[0048] SM camera (710) may have an EFL of e.g. 7mm - 50mm or more, a diagonal FOV of 5degree - 40degree and a f number of f / # = 1.5 - 7.5. W camera (730) may have an EFL of e.g. 2.5mm - 15mm, a diagonal FOV of 50deg - 130deg and f / # = 1.0 - 3.5.

[0049] SM camera (710) may be a scanning camera. By rotational actuation of O-OPFE (716) and I-OPFE (722), the native (diagonal) FOV (FOV N ) of SM camera (710) can be steered for scanning a scene. FOV N may be 10-40 degrees, and a scanning range of FOV N may be ±5degree - ±35 degree. For example, a scanning SM camera with 20 degree FOV N and ±20 FOV N scanning covers a Tele FOV of 60 degree.

[0050] While this disclosure has been described in terms of certain embodiments and generally associated methods, alterations and permutations of the embodiments and methods will be apparent to those skilled in the art. The disclosure is to be understood as not limited by the specific embodiments described herein, but only by the scope of the appended claims.

Claims

1. A camera (300, 400), comprising: an object side optical path folding element, O-OPFE, (302, 522, 716) for folding a first optical path, OP1, (312, 532) to a second optical path, OP2, (314, 534); a lens (304, 524, 712); an image side optical path folding element, I-OPFE, (306, 526, 602, 722) with a reflecting surface for folding OP2 (314, 534) to a third optical path, OP3, (316, 536), wherein OP1 (312) and OP2 (314, 534) and OP3 (316, 536) are perpendicular to each other; an I-OPFE actuator (718, 724); and an image sensor (308, 404, 528, 714, 734) with an image plane oriented parallel to a X-Y plane in an exemplary orthogonal XYZ coordinate system; wherein the camera (102, 202, 502, 710) has a focal plane (310), wherein in a zero-tilt focal plane position the focal plane is parallel to a X-Z plane, wherein in a zero-tilt I-OPFE position, the reflecting surface of the I-OPFE (306, 526, 602, 722) forms an angle of 45 degrees with both the X-axis and the Z-axis and is parallel to the Y-axis, wherein the I-OPFE actuator (718, 724) is operative to tilt the focal plane around a first focal plane rotation axis that is parallel to the Z-axis by rotational actuation of the I-OPFE (306, 526, 602, 722) around a first I-OPFE rotation axis that is parallel to the Y-axis; and characterized in that: the camera is a super-Macro, SM camera, wherein the super-Macro camera supports the following criteria of: - having a magnification, M, of 1: 5-25:1, - performing capture at an object-lens distance in the range of 30mm-750mm with an effective focal length, EFL, in the range of 7mm-50mm; and the I-OPFE actuator (718, 724) is operative to tilt the focal plane around a second focal plane rotation axis parallel to the X-axis by rotational actuation of the I-OPFE (306, 526, 602, 722) around a second I-OPFE rotation axis that is parallel to the reflecting surface of the I-OPFE at the zero-tilt I-OPFE position and perpendicular to the Y-axis.

2. The camera (300, 400) of claim 1, wherein the SM camera (102, 202, 502, 710) is focused to object-lens distances of 3.0-15cm.

3. The camera (300, 400) of claim 1, wherein the SM camera (102, 202, 502, 710) is focused to object-lens distances of 15-50cm.

4. The camera (300, 400) of claim 1, wherein the focal plane is tilted by 0-20 degrees around the first focal plane rotation axis and / or the second focal plane rotation axis.

5. The camera (300, 400) of claim 4, wherein the I-OPFE (306, 526, 602, 722) is tilted by 0-20 degrees around the first I-OPFE rotation axis for tilting the focal plane by 0-20 degrees around the first focal plane rotation axis, and / or the I-OPFE (306, 526, 602, 722) is tilted by 0-20 degrees around the second I-OPFE rotation axis for tilting the focal plane by 0-20 degrees around the second focal plane rotation axis.

6. The camera (300, 400) of claim 1, wherein the focal plane is tilted by 0-40 degrees around the first focal plane rotation axis and / or the second focal plane rotation axis.

7. The camera (300, 400) of claim 6, wherein the I-OPFE (306, 526, 602, 722) is tilted by 0-40 degrees around the first I-OPFE rotation axis for tilting the focal plane by 0-40 degrees around the first focal plane rotation axis and / or the I-OPFE (306, 526, 602, 722) is tilted by 0-40 degrees around the second I-OPFE rotation axis for tilting the focal plane by 0-40 degrees around the second focal plane rotation.

8. The camera (300, 400) of claim 1, wherein the focal plane is tilted by 0-60 degrees around the first focal plane rotation axis and / or the second focal plane rotation axis.

9. The camera (300, 400) of claim 1, wherein the focal plane is tilted by 0-80 degrees around the first focal plane rotation axis and / or the second focal plane rotation axis.

10. The camera (300, 400) of claim 1, wherein calibration data is used to calculate control signals for tilting the focal plane around the first focal plane rotation axis and the second focal plane rotation axis, and wherein the calibration data is dependent on the distance between the SM camera (102, 202, 502, 710) and an object to be captured.

11. The camera (300, 400) of claim 1, wherein a first rotation stroke around the first or the second I-OPFE rotation axis is required for tilting the focal plane around the first focal plane rotation axis or the second focal plane rotation axis by a particular focal plane tilt stroke when the focal plane is located at a first distance from the SM camera (102, 202, 502, 710), wherein a second rotation stroke around the first or the second I-OPFE rotation angle is required for tilting the focal plane around the first focal plane rotation axis or the second focal plane rotation axis by the same particular focal plane tilt stroke when the focal plane is located at a second distance from the SM camera (102, 202, 502, 710), wherein the second distance is larger than the first distance, and wherein the first rotation stroke is smaller than the second rotation stroke.

12. The camera of any of the preceding claims, wherein the SM camera has an effective focal length of 7-40mm.

13. A mobile device (100, 200, 500, 700) comprising the SM camera (102, 202, 502, 710) of claim 1 and including an application processor (AP) (740) configured to control the tilting of the focal plane.

14. The mobile device (100, 200, 500, 700) of claim 13, wherein the mobile device (100, 200, 500, 700) is a smartphone.