Patent Description:
The following symbols and abbreviations are used, all of terms known in the art:
Total track length (TTL): the maximal distance, measured along an axis parallel to the optical axis of a lens, between a point of the front surface S1 of a first lens element L1 and an image sensor, when the system is focused to an infinity object distance.

Back focal length (BFL): the minimal distance, measured along an axis parallel to the optical axis of a lens, between a point of the rear surface S2N of the last lens element LN and an image sensor, when the system is focused to an infinity object distance.

Effective focal length (EFL): in a lens (or an assembly of lens elements L1 to LN), the distance between a rear principal point P' and a rear focal point F' of the lens.

F number (F/#): the ratio of the EFL to an entrance pupil diameter.

Multi-aperture cameras (or "multi-cameras", of which a "dual-camera" having two cameras is an example) are now standard for handheld electronic mobile devices (or simply "mobile devices", for example smartphones, tablets, etc.). A multi-camera usually comprises a wide field-of-view FOV camera ("Wide" or "W" camera with FOVw), and at least one additional camera with a narrower (than FOVw) field-of-view (Telephoto, "Tele" or "T" camera, also referred to as "TC", with FOVT). In general, the spatial resolution of the TC is constant (or "fixed") and may be for example <NUM>, <NUM>, or <NUM> times higher than the spatial resolution of the W camera. This is referred to as the TC having a fixed "zoom factor" (ZF) of, respectively, <NUM>, <NUM>, or <NUM>.

As an example, consider a dual-camera having a W camera and a TC with ZF of <NUM>. When zooming onto a scene, one may in general use W camera image data, which is digitally zoomed up to a ZF of <NUM>. For a ZF ≥ <NUM>, one may use TC image data, digitally zoomed for ZF > <NUM>. In some scenes, a high ZF is desired for capturing scene segments with high spatial resolution. In other scenes, a high ZF is undesired, as only (digitally zoomed) W camera image data may be available. This shows the trade-off between the applicability range of the TC on the one hand (which is larger for TCs with smaller ZF) and the TC's zoom capability on the other hand (which is larger for TCs with larger ZF). In general, both large applicability range and large zoom capability are beneficial. This cannot be achieved in known TCs having a fixed ZF.

For a given image sensor included in a TC, the TC's ZF is determined solely by its EFL. A TC that can switch continuously between two extreme (minimal and maximal) EFLs, EFLMIN and EFLMAX, for providing any ZF between minimal and maximal ZFs ZFMIN and ZFMAX, is described for example in co-owned international patent application <CIT>.

There is need for, and it would be beneficial to have a Tele camera that can provide all ZFs between ZFMIN and ZFMAX wherein ZFMAX ≥2x ZFMIN, continuously and in a slim camera module form factor having large aperture heights for a given camera module's height and by requiring relatively small lens stroke ranges for switching between ZFMIN and ZFMAX.

<CIT> relates to a lens unit incorporating, for example, a variable-magnification optical system, and to an image-sensing apparatus incorporating such a lens unit.

<CIT> relates generally to camera systems, and more specifically to small form factor camera and lens systems.

<NPL>) covers the entire evolution of zoom cameras in smartphones, from early days of the Samsung Galaxy K-zoom, through the latest iPhones and the Samsung Note8, to the future of folded zoom cameras. It also explains some of the mobile photography fundamentals and how vendors strike a fine balance between them.

<CIT> relates to a refracting zoom lens system having a shake correction function.

According to claim <NUM> of the present invention, there is provided a camera, comprising: an OPFE for a folding a first optical path OP1 to second optical path OP2; a lens including N lens elements, the lens being divided into four lens groups arranged along a lens optical axis and marked, in order from an object side of the lens to an image side of the lens, G1, G2, G3 and G4; and an image sensor, the camera is a folded Tele camera, the lens elements of a lens group do not move with respect to each other, G1 and G3 do not move with respect to each other, G2 and G4 do not move with respect to each other, the Tele camera is configured to change a zoom factor (ZF) continuously between ZFMIN corresponding to EFLMIN and ZFMAX corresponding to EFLMAX by moving G1 and G3 together relative to the image sensor and by moving G2 and G4 together relative to the image sensor, wherein ZFMAX/ZFMIN ≥ <NUM>, wherein switching from EFLMIN to EFLMAX or vice versa requires a lens stroke range S, and wherein a ratio R given by R = (EFLMAX - EFLMIN)/S fulfils R><NUM>.

In some examples, R><NUM>. In some examples, R><NUM>.

In some examples, ZFMAX/ZFMIN ≥<NUM>. In some examples, ZFMAX/ZFMIN ≥<NUM>.

In some examples, the configuration to change the ZF continuously includes a configuration to move G1 and G3 together relative to the image sensor over a small range larger than <NUM> and smaller than <NUM> and to move G2 and G4 together relative to the image sensor over a large range larger than <NUM> and smaller than <NUM>.

In some examples, the configuration to change the ZF continuously includes a configuration to move G1 and G3 together relative to the image sensor over a small range larger than <NUM> and smaller than <NUM>, and to move G2 and G4 together relative to the image sensor over a large range larger than <NUM> and smaller than <NUM>.

In some examples, the configuration to change the ZF continuously includes a configuration to move G2 and G4 together relative to the image sensor over a small range larger than <NUM> and smaller than <NUM>, and to move G1 and G3 together relative to the image sensor over a large range larger than <NUM> and smaller than <NUM>.

In some examples, the configuration to change the ZF continuously includes a configuration to move G2 and G4 together relative to the image sensor over a small range larger than <NUM> and smaller than <NUM>, and to move the G1 and G3 together relative to the image sensor over a large range larger than <NUM> and smaller than <NUM>.

In some examples, G1 and G3 are included in a single G13 carrier and G2 and G4 are included in a single G24 carrier.

In some examples, both the G24 carrier and the G13 carrier include rails for defining a position of the G13 carrier relative to the G24 carrier.

In some examples, a maximum stroke range of the G13 carrier is S13, a maximum stroke range of the G24 carrier is S24, and a ratio S24/S13><NUM>. In some examples, S24/S13><NUM>.

In some examples, the G24 and G13 carriers are movable by, respectively, G24 and G13 actuators. In some examples, one of the G24 actuator or the G13 actuator includes three or more magnets.

In some examples, the lens includes N=<NUM> lens elements.

In some examples, a power sequence of lens groups G1-G4 is positive-negative-positive-positive.

In some examples, G1 includes two lens elements with a positive-negative power sequence, G2 includes two lens elements with a negative-negative power sequence, G3 includes three lens elements with a positive-positive-positive power sequence, and G4 includes three lens elements with a positive-negative-positive power sequence.

In some examples, G1 includes two lens elements with a positive-negative power sequence, G2 includes two lens elements with a negative-positive power sequence, G3 includes three lens elements with a positive-negative-positive power sequence, and G4 includes three lens elements with a positive-negative-positive power sequence.

In some examples, G1 includes two lens elements with a negative-positive power sequence, G2 includes three lens elements with a positive-negative-negative power sequence, G3 includes three lens elements with a positive-negative-negative power sequence, and G4 includes two lens elements with a negative-positive power sequence.

In some examples, the camera has a F number F/#, the F/# at ZFMIN is F/#MIN, the F/# at ZFMAX is F/#MAX, and EFLMAX/EFLMIN > F/#MAX/F/#MIN. In some examples, EFLMAX/EFLMIN > F/#MAX/F/#MIN + <NUM>.

In some examples, a magnitude of an EFL of G2 |EFLG2| varies less than <NUM>% from a magnitude of an EFL of G3 |EFLG3|, and |EFLG2|, |EFLG3| < EFLMIN.

In some examples, lens groups G1 and G2 include <NUM> lens elements, and lens group G3 and G4 include <NUM> lens elements.

In some examples, the larger of a thickness TG2 of G2 and of a thickness TG1 of G1 is T(G1,G2)MAX, the smaller of TG2 and TG1 is T(G1,G2)MIN, and T(G1,G2)MIN/T(G1,G2)MAX <<NUM>. In some examples, <NUM><T(G1,G2)MIN/T(G1,G2)MAX <<NUM>.

In some examples, a ratio of a thickness TG4 of G4 and a thickness TG3 of G3 fulfill <NUM> <TG4/TG3<<NUM>.

In some examples, the larger of TG3 and TG4 is T(G3,G4)MAX, the smaller of TG3 and TG4 is T(G3,G4)MIN, and T(G1,G2)MAX/T(G3,G4)MIN <<NUM>. In some examples, <NUM><T(G3,G4)MIN/T(G3,G4)MAX <<NUM>. In some examples, <NUM><T(G1,G2)MAX/T(G3,G4)MIN <<NUM>.

In some examples, lens groups G1 and G4 include <NUM> lens elements, and lens groups G2 and G3 include <NUM> lens elements.

In some examples, the camera includes an aperture stop, and the aperture stop is located at a front surface of a first lens element of G2. In some examples, the aperture stop is located at a rear surface of a second lens element of G2. In some examples, aperture stop is located at the front surface of the first lens element of G3.

In some examples, an EFL of G1 (EFLG1) varies less than <NUM>% from an EFL of G4 (EFLG4), and both EFLG1 and EFLG4 vary by less than <NUM>% from (EFLMAX+EFLMIN)/<NUM>. In some examples, EFLG1 varies less than <NUM>% from EFLG4 and both EFLG1 and EFLG4 vary by less than <NUM>% from (EFLMAX+EFLMIN)/<NUM>. In some examples, EFLG4> 10xEFLMAX.

In some examples, EFLG1<<NUM>. 15xEFLG4, and both EFLG1 and EFLG4 vary by less than <NUM>% from (EFLMAX+EFLMIN)/<NUM>. In some examples, EFLG4> 10xEFLMIN.

In some examples, G1 and G3 have each at least two lens elements, and the first two lens elements in each of G1 and G3 are separated from each other on the lens optical axis by <<NUM>. In some examples, G1 and G3 have each at least two lens elements, and the first two lens elements in each of G1 and G3 are separated from each other on the lens optical axis by <<NUM>.

In some examples, first two lens elements in G2 and in G4 are separated from each other at margins of each lens element by <<NUM>. In some examples, first two lens elements in G2 and in G4 are separated from each other at margins of each lens element by <<NUM>.

In some examples, the N lens elements include a first lens element L1, a second lens element L2, an eighth lens element L8 and a ninth lens element L9, and L1 and L2 and L8 and L9 form respective doublet lenses.

In some examples, the N lens elements include a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a sixth lens element L6, a seventh lens element L7, an eight lens element L8 and a ninth lens element L9, L1 and L2, L3 and L4, and L8 and L9 form respective doublet lenses, and L6 and L7 form an inverted doublet lens.

In some examples, a maximum distance between lens elements of the moving groups G1 and G3 is smaller than <NUM>.

In some examples, the N lens elements include a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, an seventh lens element L7 and an eighth lens element L8, L1 and L2, L3 and L4, form respective inverted doublet lenses, and L7 and L8 form a doublet lens.

In some examples, a difference between distances of the OPFE from the front surface of the first lens element lens measured along an axis parallel to the lens optical axis for all ZFs is marked Δd, and a ratio of Δd and a lens thickness TLens fulfils Δd/TLens < <NUM> when Δd<<NUM>. In some examples, Δd/TLens < <NUM> for Δd<<NUM>.

In some examples, the camera has an aperture diameter DAMIN at EFLMIN and a minimum F number F/#MIN = EFLMIN/DAMIN, and F/#MIN is <<NUM>. In some examples, F/#MIN is < <NUM>. In some examples, F/#MIN is < <NUM>.

In some examples, the camera has an aperture diameter DAMAX at EFLMAX, and a maximum F number F/#MAX = EFLMAX/DAMAX, and <NUM><F/#MAX < <NUM>.

In some examples, DAMIN/DAMAX><NUM>. In some examples, DAMIN/DAMAX><NUM>. In some examples, DAMIN/DAMAX ><NUM>. In some examples, <NUM><DAMAX <<NUM>.

In some examples, F/#MIN = EFLMIN/DAMIN, F/#MAX = EFLMAX/DAMAX, and F/#MAX/ F/#MIN<<NUM> - <NUM>.

In some examples, the lens has a maximum total track length TTLMAX, and TTLMAX/EFLMAX <<NUM>. In some examples, TTLMAX/EFLMAX <<NUM>.

In some examples, the camera is configured to be focused by moving lens groups G1+G2+G3+G4 together as one lens.

In some examples, the camera is included in a camera module having a module height HM, the lens has a lens aperture height HA, both HM and HA are measured along an axis parallel to OP1, HM = <NUM> - <NUM>, HA = <NUM> - <NUM>, and HM <HA+<NUM>. In some examples, HM <HA+<NUM>.

In some examples, the OPFE is configured to be rotated for optical image stabilization (OIS) along two rotation axes, a first rotation axis parallel to OP1 and a second rotation axis perpendicular to both OP1 and OP2.

In some examples, the prism is a cut prism with a prism optical height HP measured along an axis parallel to OP1 and with a prism optical width WP measured along an axis perpendicular to both OP1 and OP2, and WP is larger than HP by between <NUM>% and <NUM>%.

In some examples, the lens is a cut lens with a cut lens aperture height HA measured along an axis parallel to OP1 and with a lens aperture width WA measured along an axis perpendicular to both OP1 and OP2, and WA is larger than HA by between <NUM>% and <NUM>%.

In some examples, EFLMAX is between <NUM> and <NUM>.

In some examples, the folded Tele camera is included in a dual-camera along with a Wide camera having a field-of-view larger than the folded Tele camera. In some examples, there is provided a smartphone comprising a dual-camera as above.

In some examples, there is provided a smartphone comprising any of the cameras above or below.

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 dual-camera <NUM> that comprises a folded continuous zoom T camera (or "FCZT camera") <NUM> as disclosed herein together with a W camera <NUM>. T camera <NUM> comprises an optical path folding element (OPFE) <NUM> e.g. a prism or mirror, a lens <NUM> with a plurality of lens elements (not visible in this representation) having a lens optical axis <NUM> and an image sensor <NUM>. OPFE folds an optical path from a first optical path <NUM> ("OP1") to a second optical path <NUM> ("OP2"). W camera <NUM> comprises a lens <NUM> with an optical axis <NUM> and an image sensor <NUM>.

<FIG> shows schematically an embodiment of a FCZT camera disclosed herein and numbered <NUM> in a first, minimal zoom state (with a minimal zoom factor ZFMIN) having a minimal EFL = EFLMIN. EFLMIN corresponds to a minimal ZFMIN. FCZT camera <NUM> comprises an OPFE <NUM>, a lens <NUM>, an (optional) optical element <NUM> and an image sensor <NUM>. Camera <NUM> is shown with ray tracing. Optical element <NUM> may be for example an infra-red (IR) filter, and/or a glass image sensor dust cover. Lens <NUM> is divided in four lens groups ("G1", "G2", "G3" and "G4"), wherein each lens group may include one or more lens elements. Lens elements included in each of G1, G2, G3 and G4 are fixedly coupled to each other, meaning that the lens elements included in each of G1, G2, G3 and G4 can move with respect to the lens elements included in any other lens group and with respect to other components included in camera <NUM> (such as image sensor <NUM>), but not with respect to each other. Further, G2 and G4 are fixedly coupled and move together as one group (group "G24" see marked). The G24 group is moved with a large stroke, G1+G2+G3+G4 are moved together as one lens with a small stroke, while G1 and G3 can move together independently of the G24 group.

<FIG> shows FCZT camera <NUM> schematically in a second, maximal zoom state (with a maximal zoom factor ZFMAX) having a maximal EFL=EFLMAX. The transition or switching from EFLMAX to EFLMIN can be performed continuously, i.e. camera <NUM> can be switched to any other ZF that satisfies ZFMIN ≤ ZF ≤ ZFMAX (or EFLMIN≤ EFL ≤ EFLMAX).

This functionality is known in zoom camera lenses that are used for example in relatively large handheld camera devices such as digital single-lens reflex (DSLR) cameras. Camera <NUM> can provide this known functionality while having size dimensions that allow it to be integrated in a camera module such as a G24 FCZT camera module <NUM> (<FIG>), which fits the size constraints of handheld (portable) electronic mobile devices such as smartphones. To clarify, all camera modules and optical lens systems disclosed herein may beneficially be included or incorporated in smartphones.

For changing ZF, the G24 group is moved with a large stroke, (e.g. of <NUM> or more) with respect to G1, G3 and image sensor <NUM>. In addition and dependent on the particular desired EFL, G1+G2+G3+G4 are moved together as one lens with a small maximum stroke Δd (Δd≤<NUM> see <FIG>, Δd≤<NUM> see <FIG>) with respect to image sensor <NUM>. Because of this movement required for ZF change, camera <NUM> is referred to as a "G24 FCZT camera". The G24 FCZT camera may include a G24 optical lens system as shown and described for example with reference to <FIG> and <FIG>.

For situations with camera <NUM> focused to infinity, a distance "d" between OPFE <NUM> and lens <NUM>, measured from OPFE <NUM> to the first surface of the first lens element in G1 along an axis parallel to the lens optical axis, shown (in <FIG>) in the EFLMin state (dMin) and (in <FIG>) in the EFLMax state (dMin), changes slighty for intermediate states EFLMin≤EFL≤ EFLMax as detailed in <FIG> and <FIG>. For any arbitrary pair of EFL states EFL<NUM> and EFL<NUM> (EFLMin≤ EFL<NUM>, EFL<NUM> ≤EFLMax) with respective distances d<NUM> and d<NUM> between OPFE <NUM> and lens <NUM>, a difference Δd=|d<NUM>-d<NUM>| between the distances fulfils Δd< <NUM>. A small Δd is beneficial for a slim camera module, as it allows using a small OPFE. After a ZF change, moving lens <NUM> by Δd with respect to image sensor <NUM> (and thus moving lens <NUM> by Δd with respect to OPFE <NUM>) is required to focus camera <NUM> to infinity.

<FIG> shows schematically another embodiment of a FCZT camera disclosed herein and numbered <NUM> in a first, minimal zoom state having EFLMIN. EFLMIN corresponds to a minimal ZFMIN. FCZT camera <NUM> comprises an OPFE <NUM>, a lens <NUM>, an (optional) optical element <NUM> and an image sensor <NUM>. Lens <NUM> is divided in four lens groups ("G1", "G2", "G3" and "G4"), wherein each lens group may include one or more lens elements. Lens elements included in each of G1, G2, G3 and G4 are fixedly coupled to each other. Further, G1 and G3 are fixedly coupled and move together as one group (group "G13" see marked), while G2 and G4 can move independently of the G13 group.

<FIG> shows FCZT camera <NUM> schematically in a second, maximal zoom state having EFLMAX. As in camera <NUM>, the transition or switching from EFLMAX to EFLMIN can be performed continuously, i.e. camera <NUM> can be switched to any other ZF that satisfies ZFMIN ≤ ZF ≤ ZFMAX.

For changing ZF, G13 group is moved with a large stroke, (e.g. of <NUM> or more) with respect to G2, G4 and image sensor <NUM>, while G2 and G4 do not move with respect to image sensor <NUM>. As of this movement required for ZF change, camera <NUM> is referred to as a "G13 FCZT camera". G13 FCZT camera may include a G13 optical lens system (<FIG>). For focusing, G1+G2+G3+G4 can be moved together as one lens with respect to image sensor <NUM>.

Table <NUM> shows values and ranges of various parameters of exemplary optical lens systems numbered <NUM> - <NUM> and of FCZT camera module <NUM>, which are shown and described next. These parameters include TTL, EFL, BFL, SD, TLens, Δd, HA, DA, HM, S given in mm, Half-field-of-view ("HFOV") given in degrees, power sequence, and F/#, N, NGi given without units. All of these parameters are defined above or below.

EFLMIN and EFLMAX, TTLMIN and TTLMAX, BFLMIN and BFLMAX, DAMIN and DAMAX, F/#MIN and F/#MAX, TMIN and TMAX and HFOVMIN and HFOVMAX refer respectively to minimum and maximum EFL, TTL, BFL, DA, F/#, T and HFOV that can be achieved in the respective example. Columns "MIN" and "MAX" refer respectively to minimum and maximum values in the range of values given in the other columns.

In optical lens system examples <NUM> and <NUM>, at both state EFLMIN and state EFLMAX TTL is given by TTLMIN. TTLMAX is given at a particular intermediate EFL state that corresponds to the maximum in the graphs shown in <FIG> and <FIG> respectively. In optical lens system example <NUM>, TTL at state EFLMIN is given by TTLMIN, and TTL at state EFLMAX is given by TTLMAX.

In optical lens system examples <NUM> and <NUM>, BFL at state EFLMIN is given by BFLMIN, and BFL at state EFLMAX is given by BFLMAX.

The optical aperture diameter ("DA") of a lens element is given by the larger of the DA values of the front or the rear surface. In all optical lens system examples <NUM> - <NUM>, DA at state EFLMIN is given by DAMIN, and DA at state EFLMAX is given by DAMAX.

The optical aperture height ("HA") of a lens element is given by the larger of the HA values of the front or the rear surface.

All values of optical lens system examples <NUM> - <NUM> are given for lenses without D-cut, so that DAMIN=HAMIN and DAMAX=HAMAX.

In all optical lens system examples <NUM> - <NUM>, the lens thickness ("TLens") at state EFLMIN is given by TLens ,MIN, and TLens at state EFLMAX is given by TLens ,MAX. HFOVMIN is obtained at EFLMAX and HFOVMAX is obtained at EFLMIN.

"N" represents the number of lens elements in a respective lens. "#NGi" represents the number of lens elements in a respective lens group Gi.

"S" is a stroke range that represents the maximum movement of lens groups required for changing a ZF from EFLMIN to EFLMAX or vice versa.

R = (EFLMAX - EFLMIN)/S is a ratio between a ZF range determined by the EFLs in the extreme states and the stroke range S.

T(Gi,Gi+<NUM>)MIN and T(Gi,Gi+<NUM>)MAX represent respectively a minimum and maximum thickness of lens groups Gi and Gi+<NUM>.

It is noted that a F/#, e.g. F/#MAX, can be increased by further closing an aperture of the lens. The same is valid for a ratio F/#MAX/F/#MIN.

For lens power sequences, "+" indicates a positive lens power and "-" indicates a negative lens power.

In particular, in embodiments disclosed herein, the following ranges are supported:.

<FIG> shows yet another embodiment of a FCZT camera module disclosed herein and numbered <NUM> in a perspective view. <FIG> shows camera module <NUM> in a side view. <FIG> shows camera module <NUM> in a first exploded view, and <FIG> shows camera module <NUM> in a second exploded view.

Camera module <NUM> comprises an OPFE module <NUM> with an OPFE <NUM> (e.g. a prism) that folds the light from OP1 to OP2, and a lens <NUM> divided into four lens groups G1-G4 included in four lens barrel sections (the barrel sections named after the group number), respectively G1 barrel <NUM>, G2 barrel <NUM>, G3 barrel <NUM> and G4 barrel <NUM> (see <FIG>). Camera module <NUM> further comprises a housing <NUM>, a top shield <NUM>, a first flex <NUM> (e.g. a flexible printed circuit board or "flex PCB"), a second flex <NUM> (e.g. a flex PCB), a sensor module <NUM> that includes an image sensor <NUM>, and an optional optical element (not shown). Housing <NUM> includes a first yoke <NUM> and a second yoke <NUM> (see e.g. <FIG>). Flex <NUM> additionally includes a pitch coil <NUM> and two yaw coils, a first yaw coil <NUM> and a second yaw coil <NUM>.

G1 barrel <NUM> and G3 barrel <NUM> are included in a "G13 carrier" <NUM>, and G2 barrel <NUM> and G4 barrel <NUM> are included in a "G24 carrier" <NUM>. The two barrels included in each of G13 carrier <NUM> and G24 carrier <NUM> do not move with respect to each other, but only with respect to the two barrels included in the other of G24 carrier <NUM> and in G13 carrier <NUM>, as well as with respect to image sensor <NUM>. Flex <NUM> includes a coil <NUM> and a position sensor <NUM> (<FIG>), e.g. a Hall sensor. G13 carrier <NUM> includes an "actuation" magnet <NUM> and a "position" magnet <NUM> that form, together with coil <NUM> and position sensor <NUM>, a "G13 carrier VCM" that actuates G13 carrier <NUM> with respect to image sensor <NUM>. G13 carrier VCM is a closed-loop VCM. Actuation magnet <NUM> and coil <NUM> form an actuation unit, and position magnet <NUM> and position sensor <NUM> form a position sensing unit. The actuation of G13 carrier <NUM> with respect to image sensor <NUM> may be along the optical axis of lens <NUM> and over a relatively small stroke of <NUM> - <NUM>. In the example shown, the actuation of G13 carrier <NUM> is over a stroke of about <NUM>. Flex <NUM> includes a coil assembly ("CA") <NUM> and a Hall sensor <NUM>. CA <NUM> may include <NUM> or more coils. G24 carrier <NUM> includes a magnet assembly ("MA") of three or more magnets which forms, together with CA <NUM> and Hall sensor <NUM>, a "G24 carrier VCM" that actuates G24 carrier <NUM> with respect to image sensor <NUM>. The G24 carrier VCM may additionally include a position sensing unit for controlling an actuation of G24 carrier <NUM> with respect to image sensor <NUM>. G24 carrier VCM" is a "large stroke" VCM for performing large stroke movements as described above or below, as e.g. described in PCT/IB2021/<NUM>. G24 carrier VCM is a closed-loop VCM.

The actuation of G24 carrier <NUM> with respect to image sensor <NUM> may be along the optical axis of lens <NUM> and over a relatively large stroke of <NUM> - <NUM>. In the example shown, the actuation of G24 carrier <NUM> is over a stroke of about <NUM>. Because the G24 carrier moves along a relatively large stroke and the G13 carrier moves along a relatively small stroke, camera module <NUM> is referred to as a "G24 FCZT camera module". A G24 FCZT camera module may include a G24 FCZT camera (<FIG>).

Camera module <NUM> has a module height HM and includes a camera aperture <NUM> with an aperture height HA. Module height HM and aperture height HA are both measured along the Y-axis in the coordinate system shown in <FIG> (i.e., along OP1). Aperture height HA is determined by the optical height ("HL" - see <FIG>, FIG. <NUM>) of the lens element that determines an aperture stop of camera <NUM>. For example, HM may be <NUM> and HA may be <NUM>. In general, HM may be in the range HM = <NUM> - <NUM> and HA may be in the range HA = <NUM> - <NUM>. Module length LM may be about <NUM>, in general <NUM>-<NUM>.

Lens <NUM> may be a "cut" (or "D-cut") lens as known in the art and shown in <FIG>, which shows a cut lens <NUM>. Cut lens <NUM> is cut along an axis parallel to the x axis at the sides marked <NUM> and <NUM>. At the sides marked <NUM> and <NUM>, lens <NUM> is not cut. Therefore, lens <NUM> has an optical lens width WL (measured along the x axis) which is larger than its optical lens height HL (measured along the Y-axis). Using a cut lens such as lens <NUM> is beneficial in folded cameras, as it supports slim camera height while still providing a relatively large aperture area (AA) of AA > HL<NUM> and AA > (HL/<NUM>)<NUM>·π. For a lens element that determines the aperture of a camera, the optical lens height and width is equivalent to the height and the width of the aperture of the lens, i.e. HL =HA and WL=WA. G4 included in G4 barrel <NUM> may be cut, meaning that WA > HA is fulfilled, as shown in <FIG>.

A cut lens has one or more lens elements Li that are cut, i.e. that have an optical width ("WLi") measured along a first axis perpendicular to the lens optical axis that is larger than an optical height ("HLi") measured along a second axis perpendicular to the lens optical axis, i.e. WLi > HLi. For example, a D-cut ratio of a cut lens may be <NUM>% - <NUM>%, meaning that WLi may be larger than HLi by <NUM>% - <NUM>%, i.e.. The cutting may reduce module height HM of the camera module above. This allows to realize a slim FCZT camera having a low HM to render it compatible with smartphone size constraints and having a relatively large aperture area, which is beneficial for achieving a low F/# camera having a relatively large signal-to-noise ratio ("SNR"). One may refer to the difference between HM and HA as a "height penalty" ("P") of the camera module, where P is to be minimized for a slim camera with relatively large SNR. Further design choices for minimizing penalty P are:.

Prism <NUM> may be a cut prism as known in the art, as shown exemplarily in <FIG>, which shows a cut prism numbered <NUM>. Cut prism <NUM> is cut along an axis parallel to the x axis at the side marked <NUM>. At the side marked <NUM>, prism <NUM> is not cut. As shown, an optical width of cut prism <NUM> ("WP", measured along the x axis) is larger than an optical height of cut prism <NUM> ("HP", measured along the Y-axis) by <NUM>% - <NUM>% (this representing a D-cut ratio). A cut prism may be beneficial for obtaining a slim camera having a low camera height that still lets in a relatively large amount of light.

<FIG> shows camera module <NUM> from <FIG> in a perspective view and without top shield <NUM>. <FIG> shows camera module <NUM> without top shield <NUM> from <FIG> in an exploded view.

<FIG> shows camera module <NUM> in a bottom view and with flex <NUM> partly removed for exposing pitch coil <NUM>, pitch position sensor <NUM> as well as two yaw coils <NUM> and <NUM> and yaw position sensor <NUM>. Yoke <NUM> and yoke <NUM> are visible.

<FIG> shows camera module <NUM> in a bottom view and with flex <NUM> as well as pitch coil <NUM>, pitch position sensor <NUM>, yaw coils <NUM> and <NUM> and yaw position sensor <NUM> partly removed for exposing pitch magnet <NUM> as well as two yaw magnets <NUM> and <NUM>. Pitch coil <NUM>, pitch position sensor <NUM> and pitch magnet <NUM> form together a, "first OIS VCM" for performing optical image stabilization (OIS) around a first OIS rotation axis. Yaw coils <NUM> and <NUM>, yaw position sensor <NUM> and yaw magnets <NUM> and <NUM> form together a "second OIS VCM" for performing OIS around a second OIS rotation axis. First OIS rotation axis is perpendicular to both OP1 and OP2, second OIS rotation axis is parallel to OP1.

<FIG> shows OPFE module <NUM> in a perspective top view. <FIG> shows OPFE module <NUM> in a perspective bottom view.

<FIG> shows G13 carrier <NUM> in a perspective bottom view.

<FIG> shows G13 carrier <NUM> in a bottom view. G13 carrier <NUM> includes a preload magnet <NUM> which is attracted to yoke <NUM>. G13 carrier <NUM> additionally includes two grooved rails <NUM>-<NUM> and <NUM>-<NUM> and two flat rails <NUM>-<NUM> and <NUM>-<NUM>.

<FIG> shows G24 carrier <NUM> in a perspective top view. G24 carrier <NUM> includes a preload magnet <NUM> which connects to yoke <NUM>. G24 carrier <NUM> additionally includes two grooved rails <NUM>-<NUM> and <NUM>-<NUM> and two grooved rails <NUM>-<NUM> and <NUM>-<NUM> and magnet assembly <NUM>.

Grooved rails <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> in G24 carrier <NUM> and grooved rails <NUM>-<NUM> and <NUM>-<NUM> and flat rails <NUM>-<NUM> and <NUM>-<NUM> in G13 carrier <NUM> include balls, so that they form ball-groove mechanisms that allow G13 carrier <NUM> to move on top of and relative to G24 carrier <NUM> and relative to image sensor <NUM> by means of G13 carrier VCM. G24 carrier <NUM> moves relative to G13 carrier <NUM> and relative to image sensor <NUM> by means of G24 carrier VCM.

<FIG> shows position magnet <NUM> included in G13 carrier <NUM> in a perspective view. Position sensor <NUM> included in flex <NUM> is also shown. Together, position magnet <NUM> and position sensor <NUM> form a position sensing unit <NUM> that controls the actuation of G13 carrier <NUM>. Position sensing unit <NUM> is a large stroke position sensing unit as known in the art and e.g. described in PCT/IB2021/<NUM>.

<FIG> shows components of FCZT camera module <NUM> in a minimum zoom state in a perspective view. In this example, in the minimum zoom state with ZFMIN, EFLMIN may be ≥<NUM> and a minimal F/# may be F/#MIN ≥<NUM>. G4 included in G4 barrel <NUM> may be a cut (or D-cut) lens as known in the art, i.e. G4 may have an optical lens width (WL) and an optical lens height (HL) that fulfill WL>HL. In other examples, further lens groups or all lens groups may be D-cut.

<FIG> shows components of FCZT camera module <NUM> in an intermediate zoom state in a perspective view. In this intermediate zoom state having some zoom factor ZFINT, an EFLINT may be <NUM>.

<FIG> shows components of FCZT camera module <NUM> in a maximum zoom state in a perspective view. In this example, in the maximum zoom state having a maximum zoom factor ZFMAX, an EFLMAX may be <NUM>-<NUM> and a maximal F/# may be F/#MAX<<NUM>.

In a "G13 FCZT camera module" including a G13 FCZT camera (<FIG>), the G13 carrier moves along a relatively large stroke and the G24 carrier moves along a relatively small stroke. Based on G24 FCZT camera module <NUM>, a G13 FCZT camera module may be realized by exchanging G24 carrier VCM and G13 carrier VCM, i.e. the large stroke G24 carrier VCM may be used to actuate a G13 carrier such as G13 carrier <NUM> over a relatively large stroke, and the G13 carrier VCM may be used to actuate a G24 carrier such as G24 carrier <NUM> over a relatively small stroke. In the G13 FCZT camera module, a yoke that attracts G24 carrier <NUM> such as yoke <NUM> and a yoke that attracts G13 carrier <NUM> such as yoke <NUM> respectively may be located at positions different than the ones shown for G24 FCZT camera module <NUM>.

<FIG> show a G24 optical lens system disclosed herein and numbered <NUM> which may be included into a G24 FCZT camera like camera <NUM>. <FIG> shows optical lens system <NUM> in a first, minimal zoom state having an EFLMIN=<NUM>. <FIG> shows optical lens system <NUM> in a second, maximum zoom state having an EFLMAX=<NUM>. The transition or switching from EFLMAX to EFLMIN or vice versa can be performed continuously, i.e. a FCZT camera such as FCZT camera <NUM> including system <NUM> can be switched to any other EFL that satisfies EFLMIN≤ EFL ≤ EFLMAX.

Optical lens system <NUM> comprises a lens <NUM> having a lens optical axis <NUM>, an (optional) optical element <NUM> and an image sensor <NUM>. System <NUM> is shown with ray tracing. Optical element <NUM> may be for example an infra-red (IR) filter, and/or a glass image sensor dust cover. Like lens <NUM>, lens <NUM> is divided into four lens groups G1, G2, G3 and G4. G1 includes (in order from an object to an image side of optical system <NUM>) lens elements L1-L2, G2 includes L3-L4, G3 includes L5-L7 and G4 includes L8-L10. The lens elements included in each lens group are fixedly coupled to each other. Distances between the lens groups are marked d4 (between G1 and G2), d8 (between G2 and G3), d14 (between G3 and G4) and d20 (between G4 and optical element <NUM>). Lens <NUM> includes a plurality of N lens elements Li. In lens <NUM>, N=<NUM>. L<NUM> is the lens element closest to the object side and LN is the lens element closest to the image side, i.e. the side where the image sensor is located. This order holds for all lenses and lens elements disclosed herein. Each lens element Li comprises a respective front surface S2i-<NUM> (the index "<NUM>-<NUM>" being the number of the front surface) and a respective rear surface S2i (the index "<NUM>" being the number of the rear surface), where "i" is an integer between <NUM> and N. This numbering convention is used throughout the description. Alternatively, as done throughout this description, lens surfaces are marked as "Sk", with k running from <NUM> to 2N.

It is noted that G24 optical lens system <NUM> as well as all other optical lens systems disclosed herein are shown without D-cut.

Detailed optical data and surface data for system <NUM> are given in Tables <NUM>-<NUM>. The values provided for these examples are purely illustrative and according to other examples, other values can be used.

Surface types are defined in Table <NUM>. "Stop" in the Comment column of Table <NUM> indicates where the aperture stop of the lens is located. The coefficients for the surfaces are defined in Table <NUM>. The surface types are:.

where {z, r} are the standard cylindrical polar coordinates, c is the paraxial curvature of the surface, k is the conic parameter, rnorm is generally one half of the surface's clear aperture, and An are the polynomial coefficients shown in lens data tables. The Z axis is positive towards image. Values for optical lens diameter D are given as a clear aperture radius, i.e. D/<NUM>. The reference wavelength is <NUM>. Units are in mm except for refraction index ("Index") and Abbe #. The FOV is given as half FOV (HFOV). The definitions for surface types, Z axis, CA values, reference wavelength, units, focal length and HFOV are valid for all further presented tables.

Movements between the lens groups required for continuously switching lens <NUM> between EFLMIN and EFLMAX as well as F/# and HFOV are given in Table <NUM>. Note that here and in other optical lens systems disclosed herein, the F/# can be increased by further closing the lens aperture. For switching lens <NUM> any state between the extreme states EFLMIN and EFLMAX, a maximum movement (or stroke "s") of G24 lens group S=<NUM> is required, as detailed in Table <NUM>. A ratio R of the EFL differences in the extreme states and S is R= (EFLMAX - EFLMIN)/S = <NUM>, as well detailed in Table <NUM>. Maximizing R is desired, as, (<NUM>) for a given ZF range, determined by EFLMAX - EFLMIN, a smaller stroke S is required for switching between EFLMAX and EFLMIN, or, (<NUM>) for a given stroke S, a larger ZF range, determined by EFLMAX - EFLMIN, is provided. In addition, G1+G2+G3+G4 together must be moved as one lens with respect to image sensor <NUM> as specified in <FIG> gives the values for Δd, as defined in <FIG>. As visible, Δd <<NUM>. A small Δd is beneficial.

L1, L2 are uniformly close to each other. A lens pair Li, Li+<NUM> is "uniformly close to each other", if for all values between OA and DA/<NUM> (i.e. a margin of Li or Li+<NUM>) along the y-axis, the lens pair fulfils all of these three criteria:.

Lens pair L1, L2 is a "doublet lens", what is beneficial for achieving low chromatic aberration. Herein, a lens pair Li, Li+<NUM> is defined a "doublet lens" if it fulfils all of these three criteria:.

Herein, a lens pair Li, Li+<NUM> is defined an "inverted doublet lens", if it fulfils all of these three criteria:.

Table <NUM> shows all doublet lenses and inverted doublet lenses that are included in the optical lens system examples <NUM> - <NUM> disclosed herein as well as values thereof (Max-d, µ, σ given in mm, n and v given without units). "Type" specifies whether the lens pair is a doublet lens ("D") or an inverted doublet lens ("ID").

<FIG> show another G24 optical lens system <NUM> disclosed herein that may be included into a G24 FCZT camera like camera <NUM>. <FIG> shows optical lens system <NUM> in a minimal zoom state having an EFLMIN=<NUM>. <FIG> shows optical lens system <NUM> in a maximum zoom state having an EFLMAX=<NUM>. The transition or switching from EFLMAX to EFLMIN or vice versa can be performed continuously.

Optical lens system <NUM> comprises a lens <NUM> having a lens optical axis <NUM>, an (optional) optical element <NUM> and an image sensor <NUM>. System <NUM> is shown with ray tracing. Lens <NUM> is divided into G1, G2, G3 and G4. G1 includes L1-L2, G2 includes L3-L4, G3 includes L5-L7 and G4 includes L8-L10.

Detailed optical data and surface data for system <NUM> are given in Tables <NUM>-<NUM>. Surface types are defined in Table <NUM>. Movements between the lens groups required for continuously switching lens <NUM> between EFLMIN and EFLMAX as well as F/# and HFOV are given in Table <NUM>. The coefficients for the surfaces are defined in Table <NUM>.

<FIG> show a G13 optical lens system <NUM> disclosed herein that may be included into a G13 FCZT camera like camera <NUM>. <FIG> shows optical lens system <NUM> in a minimal zoom state having an EFLMIN=<NUM>. <FIG> shows optical lens system <NUM> in an intermediate zoom state having an EFLMID=<NUM>. <FIG> shows optical lens system <NUM> in a maximum zoom state having an EFLMAX=<NUM>. The transition or switching from EFLMAX to EFLMIN or vice versa can be performed continuously.

Optical lens system <NUM> comprises a lens <NUM> having a lens optical axis <NUM>, an (optional) optical element <NUM> and an image sensor <NUM>. System <NUM> is shown with ray tracing. Lens <NUM> is divided into G1, G2, G3 and G4. G1 includes L1-L2, G2 includes L3-L5, G3 includes L6-L8 and G4 includes L9-L10.

Furthermore, for the sake of clarity the term "substantially" is used herein to imply the possibility of variations in values within an acceptable range. According to one example, the term "substantially" used herein should be interpreted to imply possible variation of up to <NUM>% over or under any specified value. According to another example, the term "substantially" used herein should be interpreted to imply possible variation of up to <NUM>% over or under any specified value. According to a further example, the term "substantially" used herein should be interpreted to imply possible variation of up to <NUM>% over or under any specified value.

Claim 1:
A camera, comprising:
an optical path folding element (OPFE) for folding a first optical path OP1 to second optical path OP2;
a lens including N lens elements, the lens being divided into four lens groups arranged along a lens optical axis and marked, in order from an object side of the lens to an image side of the lens, G1, G2, G3 and G4; and
an image sensor,
wherein the camera is a folded Tele camera,
wherein the lens elements of a lens group do not move with respect to each other, wherein G1 and G3 do not move with respect to each other,
wherein G2 and G4 do not move with respect to each other,
wherein the Tele camera is configured to change a zoom factor (ZF) continuously between a minimum zoom factor marked ZFMIN corresponding to a minimal effective focal length marked EFLMIN and a maximum zoom factor marked ZFMAX corresponding to a maximal effective focal length marked EFLMAX by moving G1 and G3 together relative to the image sensor and by moving G2 and G4 together relative to the image sensor,
wherein <MAT>
wherein switching from EFLMIN to EFLMAX or vice versa requires a lens stroke range S, and
wherein a ratio R given by R = (EFLMAX - EFLMIN)/S fulfils R><NUM>.