Patent Description:
The subject matter disclosed herein relates in general to digital cameras and in particular to actuators for yaw and pitch rotation in folded digital cameras included in smartphones.

Multi-cameras and folded cameras in electronic handheld devices (e.g. smartphones or tablets) are known. In a folded camera, a reflecting or optical path folding element (OPFE) such as a prism or a mirror and which includes a reflection surface, is added to tilt light propagation from a first optical path (e.g. perpendicular to the smart-phone back surface) to a second optical path (e.g. parallel to the smart-phone back surface).

Co-owned international patent application <CIT> describes in detail folded cameras comprising an actuator for rotating an OPFE with two, first and second, degrees of freedom in an extended rotation range around two respective rotation axes, and dual-cameras including such a folded camera together with an upright camera.

There is need and it would be beneficial to have folded cameras in which an OPFE carrying module allows for a large extended rotation range around two respective rotation axes, for example for yaw and pitch rotations, supports state-of-the-art industry standards e.g. with respect to drop tests, and has cost low manufacturing compatible with smartphone costs.

<CIT> shows a camera with an optical path folding element which can be rotated around two axes which are orthogonal to each other.

In various embodiments there are provided actuators for providing an extended two-degree of freedom rotation range to an OPFE (e.g. a prism or mirror) in mobile devices such as smartphones, comprising: a yaw sub-assembly having a yaw rotation axis; a pitch sub-assembly carrying the OPFE, the pitch sub-assembly including a pivot rotation mechanism and having a pitch rotation axis; and a stationary sub-assembly, wherein the actuator is operative to rotate the OPFE in two rotation directions, a first rotation for yaw around the yaw rotation axis and a second rotation for pitch around the pitch rotation axis, and wherein the rotation for pitch includes rotation using the pivot rotation mechanism.

An actuator as above or below is integrated in a folded camera. The folded camera may be a scanning Tele camera capable of scanning a scene in the two rotation directions.

In some embodiments, the yaw sub-assembly and the pitch sub-assembly form a master-slave arrangement, wherein the yaw sub-assembly acts as the master and the pitch sub-assembly acts as the slave.

In some embodiments, the pivot rotation mechanism includes a pivot located at two opposite sides of the OPFE and wherein the pitch rotation axis is close to a pitch sub-assembly center of gravity.

In some embodiments, the pivot rotation mechanism includes a ball-guided mechanism.

In some embodiments, the pivot rotation mechanism includes a pitch driving coil and a magnet.

The pitch driving coil surrounds the yaw rotation axis.

In some embodiments, the yaw sub-assembly includes at least one groove-ball mechanism.

In some embodiments, grooves of the at least one groove-ball mechanism are concentrically curved, with a center of the curvature on the yaw rotation axis.

In some embodiments, balls of the at least one groove-ball mechanism are guided by groove pairs that include each a groove on the yaw sub-assembly and a groove on the stationary sub-assembly.

In some embodiments, the at least one groove-ball mechanism includes at least <NUM> balls.

In some embodiments, balls of the at least one groove-ball mechanism are located in a plane that is perpendicular to the yaw rotation axis.

In some embodiments, the yaw rotation is sensed by at least one Hall sensor.

In some embodiments, the least one Hall sensor is located beneath the yaw sub-assembly and is fixedly coupled to the stationary sub-assembly.

In some embodiments, the yaw rotation is by an actuation mechanism including a yaw driving coil and a yaw driving magnet.

In some embodiments, the yaw driving magnet is concentrically curved.

In some embodiments, the yaw driving magnet is curved, with a center of curvature close to the yaw rotation axis.

In some embodiments, the yaw driving magnet is fixedly coupled to the yaw sub-assembly and the driving coil is fixedly coupled to the housing.

In some embodiments, the yaw driving magnet has two different magnet polarization directions and wherein the two different polarization directions are perpendicular to the yaw rotation axis.

In some embodiments, the yaw rotation axis is close to a common center of mass of the yaw sub-assembly and the pitch sub-assembly together.

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. In the drawings:.

<FIG> illustrates a folded camera <NUM> with a <NUM> degrees-of-freedom (DOF) optical path folding element (OPFE) with an extended rotation range disclosed in <CIT>. The term "extended rotation range" describes a rotation range larger than the <NUM>-<NUM> degrees necessary for another application, for example optical image stabilization (OIS). The extended rotation range may be a range equal to or greater than ± <NUM> degrees, ± <NUM> degrees or even between <NUM>-<NUM> in each degree of freedom (DOF), relative to an OPFE zero (non-rotated) state.

Camera <NUM> includes a lens <NUM> with a lens optical axis, an OPFE <NUM> and an image sensor <NUM>. OPFE <NUM> has a reflection surface and may be for example a mirror or a prism. OPFE <NUM> folds light from a first optical path <NUM> to a second optical path <NUM>. First optical path <NUM> extends from the direction of a view section <NUM> (facing an object or scene) towards OPFE <NUM> and is substantially parallel to the X-axis (in the exemplary coordinate system). Second optical path <NUM> extends from OPFE <NUM> towards image sensor <NUM> and is substantially parallel to the Z-axis (in the exemplary coordinate system). Yaw rotation can be defined as rotation around an axis substantially parallel to the first optical path in the zero OPFE state. Pitch rotation can be defined as rotation around an axis substantially perpendicular to the yaw rotation axis and the lens optical axis.

The rotation of the OPFE can be done for example using OPFE actuator <NUM>, seen in <FIG>. 2DOF rotation may be used to describe rotation of the prism around two axes (each axis being a DOF); in camera <NUM>, the degrees of freedom are a yaw rotation <NUM> around yaw rotation axis <NUM> which is parallel to first optical path <NUM> (X-axis) when in zero state as defined above, and a pitch rotation <NUM> around a pitch rotation axis <NUM> which is parallel to the Y-axis.

As shown in <FIG>, camera <NUM> may be a part of a dual-camera <NUM>. Dual-camera <NUM> comprises camera <NUM> and an upright camera <NUM>. Upright camera <NUM> includes a lens <NUM> and an image sensor <NUM>. Cameras <NUM> and <NUM> may share some or all of respective fields of view (FOVs).

In the description below, directions are defined with reference to <FIG>. "Top" is the direction toward (facing) view section <NUM>. "Bottom" is the opposite direction.

<FIG> shows an embodiment of an OPFE actuator <NUM> disclosed herein in an exploded view. Actuator <NUM> comprises a yaw sub-assembly <NUM>, a pitch sub-assembly <NUM> and a stationary sub-assembly <NUM>. <FIG> shows details of each sub-assembly. Yaw and pitch sub-assemblies <NUM> and <NUM> are shown in (a) in two different perspective views and stationary sub-assembly <NUM> is shown in (b) in a perspective view (<NUM> degrees rotated around an axis <NUM> with respect to top view). Yaw sub-assembly <NUM> is included in stationary sub-assembly <NUM> and pitch sub-assembly <NUM> is included in yaw sub-assembly <NUM> in a master-slave arrangement. Yaw sub-assembly <NUM> is "dynamic" i.e. can be rotated around a yaw rotation axis <NUM> (e.g. parallel to the X-axis), while stationary sub-assembly <NUM> (as indicated by its name) is stationary i.e. not moving. Pitch sub-assembly <NUM> is rigidly coupled to an OPFE <NUM> and is rotatable around a pitch rotation axis <NUM> (e.g. parallel to the Y-axis) orthogonal to axis <NUM>. When operable to be rotated, yaw sub-assembly <NUM> rotates OPFE <NUM> around axis <NUM> relative to stationary sub-assembly <NUM> and pitch sub-assembly <NUM> (and the OPFE attached thereto) rotates around axis <NUM> relative to the yaw sub-assembly and the stationary sub-assembly. In some embodiments, yaw rotation axis <NUM> may be close to a center of mass of yaw sub-assembly <NUM> and pitch sub-assembly <NUM> together. Close to a center of mass of of yaw sub-assembly <NUM> and pitch sub-assembly <NUM> together may refer to a distance of e.g. less than <NUM>. In other examples, this may refer to a distance of e.g. less than <NUM> or less than <NUM>.

In yet other examples, close to a center of mass of pitch sub-assembly <NUM> may refer to a distance of e.g. less than <NUM>% of the module height MH. In other examples, this may refer to a distance of e.g. less than <NUM>% or less than <NUM>% of the module height MH. MH is defined in <FIG>. The yaw rotation uses one flat surface curved rail <NUM> and two curved V-grooves <NUM> formed in a bottom surface <NUM> of yaw sub-assembly <NUM> below OPFE <NUM> (top view in <FIG>). Rail <NUM> and curved V-grooves <NUM> are coupled operationally to three V-grooves <NUM> and included in stationary sub-assembly <NUM>. This setup of <NUM>, <NUM> and <NUM> is known in the art as "tolerance compensation" or "tolerance release". Rail <NUM> and V-grooves <NUM> are concentrically curved, wherein the center of the curvature is rotation axis <NUM>. The coupled rail and V-grooves form a groove-ball mechanism for yaw rotation of the OPFE.

In <FIG>, balls <NUM> are shown located within V-grooves <NUM> and flat surface curved rail <NUM>. The balls may have an exemplary diameter greater than <NUM>, compared with <NUM> in a standard smartphone camera, allowing for improved drop immunity since their larger diameter provides a larger surface or contact area of balls in the rails and is less sensitive to drops.

OPFE actuator <NUM> further comprises a yaw driving coil <NUM> and one pitch driving coil <NUM>, shown in the bottom view in <FIG>. Pitch driving coil <NUM> surrounds yaw rotation axis <NUM>. Yaw driving coil <NUM> is positioned in a hole <NUM> of (and is part of) stationary sub-assembly <NUM>, i.e. is fixedly coupled to stationary sub-assembly <NUM>.

<FIG> shows an exploded view of the yaw and pitch sub-assemblies, with (a) showing yaw sub-assembly <NUM> without the pitch sub-assembly, (b) showing pitch sub-assembly <NUM> and (c) showing a cross section of yaw sub-assembly <NUM> in a YZ plane.

<FIG> shows pitch sub-assembly <NUM> with OPFE <NUM> in two rotated states, rotated down and rotated up. The pitch rotation around axis <NUM> is enabled by a pivot rotation mechanism <NUM> that includes a pivot located at two sides of the OPFE, wherein the rotation axis is close to (and in some cases on) a pitch sub-assembly center of mass. Close to a pitch sub-assembly center of mass may refer to a distance of e.g. less than <NUM>. In other examples, this may refer to a distance of e.g. less than <NUM> or less than <NUM>.

In yet other examples, close to a center of mass of pitch sub-assembly <NUM> may refer to a distance of e.g. less than <NUM>% of the module height MH. In other examples, this may refer to a distance of e.g. less than <NUM>% or less than <NUM>% of the module height MH.

Pivot rotation mechanism <NUM> is formed by sockets <NUM> in yaw sub-assembly <NUM>, sockets <NUM> in pitch sub-assembly <NUM> and balls <NUM> fixed in sockets <NUM> and <NUM>. Like balls <NUM>, balls <NUM> have an exemplary diameter larger than <NUM>, allowing for improved drop immunity since their larger diameter provides a larger surface or contact area and is less sensitive to drops.

Pitch rotation using a pivot ball-guide mechanism contrasts with the rail-based pitch movement in PCT/IB2019/<NUM>. The pivot ball based design disclosed herein is advantageous as of its small size and allows robust manufacturing of the pivot rotation mechanism.

<FIG> shows an embodiment of an OPFE actuator <NUM> disclosed herein in a perspective view. Actuator <NUM> comprises a yaw sub-assembly <NUM>, a pitch sub-assembly <NUM> carrying OPFE <NUM> and a stationary sub-assembly <NUM>. A module height ("MH") may be <NUM> - <NUM>. A prism width ("PW") may be <NUM> - <NUM>.

OPFE actuator <NUM> further comprises a yaw driving magnet <NUM> (<FIG>) for driving the yaw rotation. Exemplarily and as shown in <FIG>, yaw driving magnet <NUM> may be a <NUM>-pole single magnet. In contrast, in PCT/IB2019/<NUM>, the yaw driving magnet has only two poles. The arrows show the magnetic polarization direction. The design disclosed herein is advantageous in that it provides a higher magnetic field leading to a higher actuation force.

<FIG> shows various views with more details of parts of yaw sub-assembly <NUM> and stationary sub-assembly <NUM>. Views (a) and (b) show cross sections through OPFE actuator <NUM>, and views (c) and (d) show cross sections through stationary sub-assembly <NUM>. As mentioned, yaw sub-assembly <NUM> is carried by stationary sub-assembly <NUM>. OPFE actuator <NUM> further comprises a yaw stopping mechanism divided into a drop stopping mechanism and a rotation stopping mechanism. The drop stopping mechanism includes a drop stopper <NUM> that prevents yaw sub-assembly <NUM> from falling out of stationary sub-assembly <NUM> in case the OPFE actuator (or a device such as smartphone that includes the camera and actuator) is dropped. Exemplarily, stopper <NUM> may be made of plastic, while a part of stationary sub-assembly <NUM> in contact with stopper <NUM> may be made of metal. The rotation stopping mechanism includes a rotation stopper <NUM> that limits the rotation range of yaw sub-assembly <NUM>. Exemplarily, rotation stopper <NUM> may be made of plastic, while a part of stationary sub-assembly <NUM> in contact with stopper <NUM> may be made of metal. In contrast, in PCT/IB2019/<NUM> there is only one metal stopper that performs all functions. The design disclosed herein is advantageous in that there are no plastic parts that may hit a metal if a device such as smartphone that includes the camera and actuator is dropped, or because of any other event that may create undesirable particles.

<FIG> shows in (a) yaw sub-assembly <NUM> without pitch sub-assembly <NUM> and in (b), (c) and (d) details of yaw sensing magnets <NUM> and <NUM> used for sensing yaw rotation position at <NUM> different yaw rotation positions. View (b) is at a negative rotation position, view (c) is at a zero rotation position and view (d) is at a positive rotation position. Magnets <NUM> and <NUM> are are fixedly coupled to yaw sub-assembly <NUM> and are flat, in contrast with magnets used for the same purpose in PCT/IB2019/<NUM>, which are not flat. Flat magnets may be beneficial from a manufacturing or cost point of view. Flat yaw sensing magnets <NUM> and <NUM> have a tapered shape <NUM> to enable sensing with large movements. In some embodiments, only one yaw sensing magnet may be used.

The yaw sensing magnets may be combined with Hall effect bar sensors (or "Hall bars") <NUM> for rotation position sensing. Hall bar sensors <NUM> are fixedly coupled to stationary sub-assembly <NUM> and are placed beneath yaw sub-assembly <NUM> as shown in (d). In comparison to PCT/IB2019/<NUM>, where the curved driving magnet was also sensing magnet, the driving mechanism and the sensing mechanism are separated here, allowing for a more precise sensing with lesser parts. The separation driving mechanism and the sensing mechanism allows for a large rotation radius (i.e. lever) for the driving force and a small rotation radius for sensing the rotation with higher precision.

Yaw sub-assembly embodiments disclosed herein may support a yaw rotation range of e.g. ±<NUM> to ±<NUM> degrees.

<FIG> shows pitch sub-assembly <NUM> including an exemplary magnet Hall bar arrangement. Pitch driving and sensing magnets <NUM> are fixedly coupled to pitch sub-assembly <NUM>, and pitch sensing Hall bars <NUM> are fixedly coupled to yaw sub-assembly <NUM>. In each axis, multiple Hall sensors can be used to allow small rotations per A2D controller (driver) reading from the Hall bars and improve linearity of the sensing. In contrast, in PCT/IB2019/<NUM>, a single Hall bar was used for each axis.

Pitch sub-assembly embodiments disclosed herein may support a pitch rotation range of e.g. ±<NUM> to ±<NUM> degrees.

<FIG> shows details of two different embodiments using two controller/drivers (a X (Yaw) and a Y (Pitch) controller) that receive inputs from e.g. a smartphone application processor (AP) and from an inertial sensor (e.g. a gyro) and provide currents to two coils of a driving mechanism (actuator). The pitch sub-assembly form a master-slave arrangement, wherein the yaw sub-assembly acts as the master and the pitch sub-assembly acts as the slave.

<FIG> shows pitch sub-assembly <NUM> and yaw driving magnet <NUM>. Yaw driving magnet <NUM> is also used as a pitch preload magnet. The "preload" is a force directed to attach pitch sub-assembly <NUM> to pivot rotation mechanism <NUM>. A yoke assembly <NUM> including two yokes, yoke <NUM> and yoke <NUM>, is attached to the pitch sub-assembly <NUM> to minimize a return torque/force and simplify the design. In some embodiments, the distance between yoke <NUM> and yoke <NUM> is used to define a return force. In other embodiments, the distance between yoke assembly <NUM> and yaw driving magnet <NUM> is used to define the return force. In an alternative embodiment, the pitch preload may use a single yoke.

Claim 1:
An actuator (<NUM>), comprising:
a yaw sub-assembly (<NUM>) having a yaw rotation axis (<NUM>);
a pitch sub-assembly (<NUM>) carrying an optical path folding element (OPFE) (<NUM>), the pitch sub-assembly (<NUM>) including a pivot rotation mechanism (<NUM>) and having a pitch rotation axis (<NUM>); and
a stationary sub-assembly <NUM>), and
a yaw driving magnet (<NUM>) for driving the yaw rotation,
wherein the actuator (<NUM>) is operative to rotate the OPFE (<NUM>) in two rotation directions, a first rotation for yaw around the yaw rotation axis (<NUM>) and a second rotation for pitch around the pitch rotation axis (<NUM>), and wherein the rotation for pitch includes rotation using the pivot rotation mechanism (<NUM>),
wherein the actuator (<NUM>) is integrated in a folded camera (<NUM>),
and wherein the pitch rotation mechanism comprising a pitch driving coil (<NUM>) and a magnet (<NUM>), wherein the pitch driving coil (<NUM>) surrounds the yaw rotation axis (<NUM>);
characterized by the yaw driving magnet (<NUM>) serving also for preloading the pitch sub-assembly (<NUM>) to pitch rotation mechanism (<NUM>).