Patent Description:
The present disclosure relates in general to digital cameras, and more particularly to digital cameras with pop-out mechanisms and lenses.

In this application and for optical and other properties mentioned throughout the description and figures, the following symbols and abbreviations are used, all for 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 (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 digital cameras (or multi-cameras) are standard in today's mobile handheld electronic devices (or in short "mobile devices", e.g. smartphones, tablets, etc.). In general, a Wide camera having a Wide camera field-of-view (FOVw) of <NUM>-<NUM> degrees acts as the mobile device's main (or "primary") camera.

A main challenge is the design of Wide cameras that support ever higher image quality (IQ) and still fit into thin mobile devices with device heights of e.g. < <NUM>. One promising path for improving the Wide camera's IQ is the incorporation of larger image sensors.

<FIG> illustrates schematically the definition of various camera entities such as TTL, EFL and BFL. In most miniature lenses which are used in multi-cameras incorporated in mobile devices, the TTL is larger than the EFL, as shown in <FIG> e.g. for a Wide lens.

<FIG> shows an exemplary camera having a lens with a field of view (FOV), an EFL and an image sensor with a sensor width S. For fixed width/height ratios and a (rectangular) image sensor, the sensor diagonal (SD) is proportional to the sensor width and height. For example, a <NUM>/<NUM>" sensor has a SD of <NUM>. The horizontal FOV relates to EFL and sensor width S as follows: <MAT> This shows that a larger EFL is required for realizing a camera with a larger image sensor, but similar FOV. Incorporating larger image sensors in Wide cameras is desirable for improving the Wide camera's IQ, but it requires larger EFL for maintaining the same (Wide camera) FOV, resulting in larger TTL, which is undesirable as it impedes the integration of the Wide camera in a mobile device.

Pop-out cameras resolve this conflict. They combine the advantages of a large TTL when the camera is in use ("pop-out state"), and a slim design by collapsing the TTL to a collapsed TTL ("c-TTL") when the camera is not in use ("collapsed state"). The c-TTL is compatible with the height dimensions of modern mobile devices. Only in the pop-out state, the pop-out camera is operational as a camera. Pop-out cameras are described for example in co-owned international patent application <CIT>.

<CIT> describes an image capturing lens system with seven lenses.

It would be beneficial to have Wide camera lens designs that support pop-out Wide cameras including large image sensors such as <NUM>/<NUM>" or larger, i.e. having a SD ≥ <NUM>.

According to the invention, there is provided a lens system according to claim <NUM>.

Non-limiting examples of examples disclosed herein are described below with reference to figures attached hereto that are listed following this paragraph. Identical structures, elements or parts that appear in more than one figure are generally labeled with a same numeral in all the figures in which they appear. If identical elements are shown but numbered in only one figure, it is assumed that they have the same number in all figures in which they appear. The drawings and descriptions are meant to illuminate and clarify examples disclosed herein and should not be considered limiting in any way. In the drawings:.

<FIG> shows an example of a "<NUM>-group" (or "<NUM>") pop-out optical lens system <NUM> that comprises a pop-out lens <NUM> and an image sensor <NUM> disclosed herein. Pop-out optical lens system <NUM> is shown in a pop-out or extended state (i.e. focused to infinity). Pop-out lens <NUM> is divided into two lens groups which are separated by a big gap (BG), a first, object-sided lens group ("G1") and a second, sensor-sided lens group ("G2"). The thickness of G1 is indicated by TG1. Lens <NUM> includes a plurality of N lens elements Li (wherein "i" is an integer between <NUM> and N and wherein N may be for example between <NUM> and <NUM>). L1 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 "2i-<NUM>" being the number of the front surface) and a respective rear surface S2i (the index "2i" being the number of the rear surface). 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. The front surface and the rear surface may be in some cases aspherical. This is however not limiting.

As used herein the term "front surface" of each lens element refers to the surface of a lens element located closer to the entrance of the camera (camera object side) and the term "rear surface" refers to the surface of a lens element located closer to the image sensor (camera image side).

Each lens group includes one or more lens elements Li. G1 may include ≥ <NUM> elements and G2 may include <NUM>-<NUM> elements. G2 may act as a field lens as known in the art.

<FIG> shows <NUM> pop-out optical lens system <NUM> in a collapsed state. Big gap BG is collapsed to a collapsed BG (marked "c-BG"), i.e. a distance between G1 and G2 is reduced, resulting in a collapsed TTL ("c-TTL"). c-BG may be in the range <NUM>-<NUM>. Only BG changes. No other distances in pop-out optical lens system <NUM>, such as distances between lens elements included in G1 and G2 respectively, change.

<FIG> shows an example of a "<NUM>-group" (or "<NUM>") pop-out optical lens system <NUM> that comprises a pop-out lens <NUM> having a thickness TLens and an image sensor <NUM> disclosed herein. Pop-out optical lens system <NUM> is shown in a pop-out state. Pop-out lens <NUM> is not divided into two lens groups. <FIG> shows <NUM> pop-out optical lens system <NUM> in a collapsed state. BFL is collapsed to a collapsed BFL (marked "c-BFL"), i.e. the distance between lens <NUM> and image sensor <NUM> is reduced, resulting in a c-TTL. c-BFL may be in the range <NUM>-<NUM>. Only BFL changes. No other distances in pop-out optical lens system <NUM>, such as distances between lens elements of lens <NUM>, change.

<NUM> pop-out optical lens system <NUM> and <NUM> pop-out optical lens system <NUM> can be included in a pop-out camera. For performing optical image stabilization (OIS), the pop-out camera may use several methods known in the art. Such methods may be "lens shift OIS", wherein the lens is moved relative to the image sensor and a camera hosting mobile device for OIS, or "sensor shift OIS", wherein the image sensor is moved relative to the lens and to a camera hosting mobile device for OIS.

All pop-out optical lens systems disclosed herein can be used in the pop-out camera examples described in co-owned PCT patent application <CIT>.

Wherein <FIG> shows <NUM> pop-out optical lens system <NUM> focused to infinity, <FIG> shows <NUM> pop-out optical lens system <NUM> focused to a closer object, e.g. focused to <NUM> according to a first focusing method referred to as "G1-G2 focusing". For G1-G2 focusing, G1 and G2 move by a focus stroke ΔfG1-G2 = TFocus - BG from a thickness given by BG to a thickness given by TFocus with respect to each other. BFL does not change, but BG changes. Values for BG and TFocus are given in Table <NUM> for all <NUM> lens systems disclosed herein. #BG indicates the surface that changes for G1-G2 focusing.

<FIG> shows <NUM> pop-out optical lens system <NUM> focused to a closer object, e.g. focused to <NUM> according to a second focusing method referred to as "lens focusing". For lens focusing, G1 and G2 move together as one lens by ΔfLens with respect to the image sensor. BG does not change, but BFL changes. Lens focusing is the standard method used in state of the art digital cameras in mobile electronic devices.

All <NUM> pop-out optical lens systems disclosed below can be both focused by G1-G2 focusing as well as by lens focusing. All <NUM> pop-out optical lens systems disclosed below are focused by lens focusing.

All pop-out optical lens systems disclosed below are shown in a pop-out state, where a pop-out camera including the optical lens system is operational.

In a collapsed state, all <NUM> pop-out optical lens system examples have a c-BG of <NUM>-<NUM>. In a collapsed state, all <NUM> pop-out optical lens systems examples have a c-BFL of <NUM>-<NUM>. A small c-BG and c-BFL respectively is beneficial for achieving a slim camera module that can be integrated in a slim mobile device such as a smartphone. To clarify, all lens systems disclosed herein may beneficially be included or incorporated in smartphones.

Table <NUM> shows the values and ranges that are included in lens system examples <NUM> - <NUM> disclosed below (SD, TTL, c-TTL, BG, c-BG, EFL, TG1, TFocus, dL1-L2, TLens, fLS, fN-<NUM> given in mm; Half-field-of-view ("HFOV") and <NUM> equivalent focal length ("<NUM> EqFL") are given in degrees, Abbe number v, #Ls and f number ("f/#") are given without units, and powers are given in inverse meter [<NUM>/m]. c-TTLMIN and c-TTLMAX respectively refer to a minimum and maximum c-TTL that can be achieved in the respective example. In general, in Table <NUM>, "MIN" and "MAX" refer respectively to minimum and maximum values in a range.

"#Ls" represents the number of the strongest lens element in a lens, i.e. the lens element with the smallest, positive focal length f. "fLS" represents the f of the strongest lens element in a lens. "fN-<NUM>" represents the f of the N-<NUM>th (i.e. the second to last) lens element in a lens. dL1-L2 represents a distance (or air gap) between L1 and L2.

For <NUM> type lens systems, LM refers to the last lens element in G1. The index "LM-<NUM>+LM" refers to properties of the two last lens elements in G1 together. For example, in example <NUM> LM-<NUM>+LM refers to properties of L5 and L6 together, in example <NUM> LM-<NUM>+LM refers to properties of L6 and L7 together, etc. For performing G1-G2 focusing, BG represents the thickness of surface "#BG" when focused to infinity. "TFocus" represents the thickness of surface "#BG" when focused to <NUM> and <NUM> respectively. The power of the entire G1 group is marked PG1, the power of the entire G2 group is marked PG2 and powers of individual lens elements are marked by the element number, i.e. the power of L1 is marked P<NUM>, the power of L2 is marked P<NUM>, etc. TG1 gives the thickness of G1.

In all the <NUM> lens system examples <NUM> - <NUM> disclosed below, ratios of TTL to EFL are in the range of TTL/EFL = <NUM> - <NUM>, ratios of TTL to SD are in the range of TTL/SD = <NUM> - <NUM> and ratios of c-TTL to SD are in the range of c-TTL/SD = <NUM> - <NUM>.

<FIG> shows an example of a <NUM> pop-out optical lens system disclosed herein and numbered <NUM>. Lens system <NUM> comprises a pop-out lens <NUM> divided into two lens groups G1 and G2, an image sensor <NUM> and, optionally, an optical element <NUM>. Optical element <NUM> may be for example infra-red (IR) filter, and/or a glass image sensor dust cover. Image sensor <NUM> may have a SD of <NUM>. G1 includes <NUM> lens elements and G2 includes one lens element. Optical rays pass through lens <NUM> and form an image on image sensor <NUM>. <FIG> shows <NUM> fields with <NUM> rays for each: the upper marginal-ray, the lower marginal-ray and the chief-ray. All further figures show these <NUM> rays as well.

Detailed optical data and surface data for pop-out lens <NUM> are given in Tables <NUM>-<NUM>. Table <NUM> provides surface types and Table <NUM> provides aspheric coefficients. The surface types are:.

Units are in mm except for refractive index ("Index") and Abbe #. Each lens element Li has a respective focal length fi, given in Table <NUM>. 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 following Tables.

The deflection point of L1 is located at a distance of <NUM> measured from the optical axis ("OA") at the rear surface. The magnitudes of the focal lengths of L<NUM> (|f<NUM>|) and of L<NUM> (|f<NUM>|) are similar, i.e. their magnitude may differ by < <NUM>%. The magnitudes |f<NUM>| and |f<NUM>| are pairwise much smaller than the magnitudes of all the focal lengths of the single lens elements L<NUM>, L<NUM>, L<NUM> and L<NUM>, i.e. |f<NUM>|, |f<NUM>| << |f<NUM>|, |f<NUM>|, |f<NUM>|, |f<NUM>. |For example |f<NUM>|, |f<NUM>|, |f<NUM>|, |f<NUM>| may be greater than |f<NUM>|, |f<NUM>| by more than <NUM>%. The ratio between the power of L1 (Pi) and PG1 fulfills P<NUM>/PG1=<NUM>. Specifically, Table <NUM> shows ratios Ifi/fil and |fi/f<NUM>| and ratios between each Pi and PG1.

<FIG> shows another example of a <NUM> pop-out optical lens system disclosed herein and numbered <NUM> Lens system <NUM> comprises a pop-out lens <NUM> divided into two lens groups G1 and G2, an image sensor <NUM> and, optionally, an optical element <NUM>. Image sensor <NUM> may have a SD of <NUM> ("<NUM>/<NUM>" sensor"). Table <NUM> provides surface types and Table <NUM> provides aspheric coefficients.

The power sequence for lens element from L1 to L7 is as follows: +--+-+- (plus-minus-minus-plus-minus-plus-minus). Specifically, lens powers Pi for lens element from L1 to L7 are given in Table <NUM>. L1, L2 and L4 are each formed meniscus with respect to the object side. L5 and L6 are each formed meniscus with respect to the image side. |f<NUM>| is much smaller than the |f| of all the focal lengths of the single lens elements L<NUM>, L<NUM>, and L<NUM>. That is, |f<NUM>|<< |f<NUM>|, |f<NUM>|, |f<NUM>|. For example, |f<NUM>|, |f<NUM>|, |f<NUM>| may be greater than |f<NUM>| by more than <NUM>%. L4 is made of glass, with a refractive index n > <NUM>. PG1 and P<NUM> are similar, i.e. PG1/ P<NUM> does not vary by more than <NUM>% from <NUM>. Specifically, Table <NUM> shows powers Pi, ratios |f/f<NUM>|, and ratios between each Pi and PG1.

<FIG> shows yet another example of a <NUM> pop-out optical lens system disclosed herein and numbered <NUM>. Lens system <NUM> comprises a pop-out lens <NUM> divided into G1 and G2, an image sensor <NUM> and, optionally, an optical element <NUM>. Image sensor <NUM> may have a SD of <NUM> ("<NUM>/<NUM>" sensor"). Table <NUM> provides surface types and Table <NUM> provides aspheric coefficients.

The power sequence for lens element from L1 to L7 is as follows: +-+--+- (plus-minus-plus-minus-minus-plus-minus). L5 and L6 (last <NUM> lens elements of G1) together have an Abbe-#L5+L6 = <NUM> and an EFLL5+L6 = <NUM>. |f<NUM>| is much smaller than the magnitude of all the focal lengths of the single lens elements L<NUM>, L<NUM>, L<NUM> L<NUM>, L<NUM>, i.e. |f<NUM>|<< |f<NUM>|, |f<NUM>|, |f<NUM>|, |f<NUM>|, |f<NUM>|. For example, |f<NUM>|, |f<NUM>|, |f<NUM>|, |f<NUM>|, |f<NUM>| may be greater than |f<NUM>| by more than <NUM>%. L2, L4 and L6 are made of glass, with a refractive index n > <NUM>. PG1 and P<NUM> are similar, i.e. PG1/ P<NUM> does not vary by more than <NUM>% from <NUM>. Specifically, Table <NUM> shows powers Pi, ratios |f/f<NUM>| and ratios between each Pi and PG1.

The power sequence for lens element from L1 to L7 is as follows: ++-+-+- (plus-plus-minus-plus-minus-plus-minus), see Table <NUM>. L5 and L6 (the last <NUM> lens elements of G1) together have an Abbe-#L5+L6 = <NUM> and an EFLL5+L6 = <NUM>. |f<NUM>| is much smaller than that of all the focal lengths of the single lens elements L<NUM>, L<NUM>, L<NUM> L<NUM>, L<NUM>, i.e. |f<NUM>|<< |f<NUM>|, |f<NUM>|, |f<NUM>|, |f<NUM>|, |f<NUM>|. For example, |f<NUM>|, |f<NUM>|, |f<NUM>|, |f<NUM>|, |f<NUM>| may be greater than |f<NUM>| by more than <NUM>%.

The deflection point of L1 is located at a distance of <NUM> measured from the OA at the front surface and at a distance of <NUM> measured from the OA at the rear surface. PG1 and P<NUM>, as well as PG1 and P<NUM> are similar, i.e. PG1/ P<NUM> as well as PG1/ P<NUM> do not vary by more than <NUM>% from <NUM>. L4 is made of glass, with a refractive index n > <NUM>. Specifically, Table <NUM> also shows powers Pi, ratios between each Pi and PG1, ratios |f/f<NUM>| and refractive indexes of each lens element.

<FIG> shows yet another example of a <NUM> pop-out optical lens system disclosed herein and numbered <NUM>. Lens system <NUM> comprises a pop-out lens <NUM> divided into G1 and G2, an image sensor <NUM> and, optionally, an optical element <NUM>. Image sensor <NUM> may have a SD of <NUM>. Table <NUM> provides just surface types and Table <NUM> provides aspheric coefficients.

A sequence of lens powers from L1 to L7 is as follows: ++-+-+- (plus-plus-minus-plus-minus-plus-minus). The deflection point of L1 is located at a distance of <NUM> measured from the OA at the front surface and at a distance of <NUM> measured from the OA at the rear surface. PG1 and P<NUM> as well as PG1 and P<NUM> are similar, i.e. PG1/ P<NUM> as well as PG1/ P<NUM> do not vary by more than <NUM>% from <NUM>. Specifically, Table <NUM> shows powers Pi and ratios between each Pi and PG1.

<FIG> shows yet another example of a <NUM> pop-out optical lens system disclosed herein and numbered <NUM>. Lens system <NUM> comprises a pop-out lens <NUM> divided into G1 and G2, an image sensor <NUM> and, optionally, an optical element <NUM>. Image sensor <NUM> may have a SD of <NUM>. G1 includes <NUM> lens elements and G2 includes one lens element. Table <NUM> provides surface types and Table <NUM> provides aspheric coefficients.

A sequence of lens powers from L1 to L6 is as follows: +-+-+- (plus-minus-plus-minus-plus-minus). PG1 and P<NUM> are similar, i.e. PG1/ P<NUM> does not vary by more than <NUM>% from <NUM>. Specifically, Table <NUM> shows powers Pi and ratios between each Pi and PG1.

<FIG> shows yet another example of a <NUM> pop-out optical lens system disclosed herein and numbered <NUM>. Lens system <NUM> comprises a pop-out lens <NUM> divided into G1 and G2, an image sensor <NUM> and, optionally, an optical element <NUM>. Image sensor <NUM> may have a SD of <NUM>. Table <NUM> provides surface types and Table <NUM> provides aspheric coefficients.

A sequence of lens powers from L1 to L7 is as follows: +--+-+- (plus-minus-minus-plus-minus-plus-minus). PG1 and P<NUM> are similar, i.e. PG1/ P<NUM> does not vary by more than <NUM>% from <NUM>. L4 and L6 are made of glass, with a refractive index n > <NUM>. Specifically, Table <NUM> shows powers Pi, ratios between each Pi and PG1 and the refractive indexes of lens elements.

A sequence of lens powers from L1 to L7 is as follows: +-++-+- (plus-minus-plus-plus-minus-plus-minus). PG1 and P<NUM> as well as PG1 and P<NUM> are similar, i.e. PG1/ P<NUM> as well as PG1/ P<NUM> do not vary by more than <NUM>% from <NUM>. L4 and L6 are made of glass, with a refractive index n > <NUM>. Specifically, Table <NUM> shows powers Pi, ratios between each Pi and PG1 and the refractive indexes of lens elements.

A sequence of lens powers from L1 to L7 is as follows: +-+--+- (plus-minus-plus-minus-minus-plus-minus). PG1 and P<NUM> as well as PG1 and P<NUM> and PG1 and P<NUM> are similar, i.e. PG1/ P<NUM> as well as PG1/ P<NUM> as well as PG1/ P<NUM> do not vary by more than <NUM>% from <NUM>. Specifically, Table <NUM> shows powers Pi and ratios between each Pi and PG1.

A sequence of lens powers from L1 to L7 is as follows: +-+--+- (plus-minus-plus-minus-minus-plus-minus). PG1 and P<NUM> and PG1 and P<NUM> are similar, i.e. PG1/ P<NUM> as well as PG1/ P<NUM> do not vary by more than <NUM>% from <NUM>. Specifically, Table <NUM> shows powers Pi, and ratios between each Pi and PG1.

<FIG> shows yet another example of a <NUM> pop-out optical lens system disclosed herein and numbered <NUM>. Lens system <NUM> comprises a pop-out lens <NUM> divided into G1 and G2, an image sensor <NUM> and, optionally, an optical element <NUM>. Image sensor <NUM> may have a SD of <NUM>. G1 includes <NUM> lens elements and G2 includes <NUM> lens elements. Table <NUM> provides surface types and Table <NUM> provides aspheric coefficients.

A sequence of lens powers from L1 to L8 is as follows: ++-+-++- (plus-plus-minus-plus-minus-plus-plus-minus. PG1 and P<NUM> as well as PG1 and P<NUM> are similar, i.e. PG1/ P<NUM> as well as PG1/ P<NUM> do not vary by more than <NUM>% from <NUM>. Specifically, Table <NUM> shows powers Pi and ratios between each Pi and PG1.

The sequence of lens powers for lens element from L1 to L7 is as follows: +--+-++- (plus-minus-minus-plus-minus-plus-plus-minus). The deflection point of L1 is located at a distance of <NUM> measured from the OA at the rear surface. PG1 and P<NUM>, PG1 and P<NUM> and PG1 and P<NUM> are similar, i.e. PG1/ P<NUM> as well as PG1/ P<NUM> as well as PG1/ P<NUM> do not vary by more than <NUM>% from <NUM>. Specifically, Table <NUM> shows powers Pi and ratios between each Pi and PGi.

<FIG> shows an example of a <NUM> pop-out optical lens system disclosed herein and numbered <NUM>. Lens system <NUM> comprises a pop-out lens <NUM>, an image sensor <NUM> and, optionally, an optical element <NUM>. Image sensor <NUM> may have a SD of <NUM>. Table <NUM> provides surface types and Table <NUM> provides aspheric coefficients.

A thickness profile (the thickness being measured along the z-axis) of L5 taken along the y-axis and starting from lens <NUM>'s OA has a local maximum at the OA and a local minimum, wherein the location of the local minimum is not at L5's margin (or border), i.e. the local minimum is located at a distance smaller than DA/<NUM> from the OA. A thickness profile of L6 taken as see above for L5 has a local minimum at the OA and a local maximum, wherein the location of the local maximum is not at L6's margin. This property of L5 and L6 respectively is beneficial for achieving a lens with low Field curvature. The power sequence for lens elements L1 to L6 is plus-minus-plus-plus-plus-minus. L2 is a strong negative lens, its magnitude |f2| fulfils |f2|/EFL<<NUM>.

<FIG> shows another example of a <NUM> pop-out optical lens system disclosed herein and numbered <NUM>. Lens system <NUM> comprises a pop-out lens <NUM>, an image sensor <NUM> and, optionally, an optical element <NUM>. Image sensor <NUM> may have a SD of <NUM>. Table <NUM> provides surface types and Table <NUM> provides aspheric coefficients.

L1 and L2 as well as L3 and L4 have a uniform distance to each other. For all values between OA and DA/<NUM> along the y-axis, the average of the distance between L1 and L2 ("µL1-L2") and L3 and L4 ("µL3-L4") respectively measured along the z-axis is µdL1-L2=<NUM> and µdL3-L4=<NUM>, the standard deviation of the average being σdL1-L2=<NUM> and σdL3-L4=<NUM>. Ratios of σ and µ are σdL1-L2/µL1-L2=<NUM> and σdL3-L4/µL3-LF4=<NUM> for L1, L2 and L3, L4 respectively. Ratios of the distance at the OA between L1 and L2 ("dL1-L2") and L3 and L4 ("dL3-L4") respectively and TLens are dL1-L2/TLens=<NUM>% and dL3-L4/ TLens=<NUM>%. L1 and L2 are very close to each other and resemble a doublet lens.

The power sequence for lens elements L1 to L7 is minus-plus-plus-minus-minus-plus-minus. L6 has a deflection point that is not located at the OA, what is beneficial for achieving a lens with low Field curvature. A thickness profile of L6 taken along the y-axis and starting from lens <NUM>'s OA has a local maximum at the OA and a local minimum, wherein the location of the local minimum is not at L6's margin. This is beneficial for achieving low Field curvature. All the surfaces of L1-L5 are convex. The signs of the sequence of fi's for lens elements L1 to L8 is minus-minus-plus-minus- minus-plus-plus-minus.

L1 and L2, L2 and L3 as well as L3 and L4 have a uniform distance to each other. For all values between OA and DA/<NUM> along the y-axis, average distances are µdL1-L2=<NUM>, µdL2-L3=<NUM> and µdL3-L4=<NUM>, the standard deviation of the average being σdL1-L2=<NUM>mm, σdL2-L3=<NUM> and σdL3-L4=<NUM>. Ratios of the standard deviation and the average distances are odL1-L2/µL1-L2=<NUM>, odL2-L3/µL2-L3=<NUM> and σdL3-L4/µL3-L4=<NUM> for L1, L2 and L2, L3 and L3, L4 respectively. Ratios of OA distances dL1-L2=<NUM>, dL2-L3=<NUM> and dL3-L4=<NUM> and TLens are dL1-L2/ TLens=<NUM>%, dL2-L3/ TLens=<NUM>% and dL3-L4/ TLens=<NUM>% respectively.

While this disclosure has been described in terms of certain examples and generally associated methods, alterations and permutations of the examples and methods will be apparent to those skilled in the art within the scope of the claims.

The disclosure is to be understood as not limited by the specific examples described herein, but only by the scope of the appended claims.

It is appreciated that certain features of the presently disclosed subject matter, which are, for clarity, described in the context of separate examples, may also be provided in combination in a single example within the scope of the claims.

Conversely, various features of the presently disclosed subject matter, which are, for brevity, described in the context of a single example, may also be provided separately or in any suitable sub-combination within the scope of the claims.

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.

It should be understood that where the claims or specification refer to "a" or "an" element, such reference is not to be construed as there being only one of that element.

Claim 1:
A lens system for a compact digital camera, comprising:
an image sensor having a sensor diagonal SD; and
a lens with a field of view FOV > 60deg and having a f number (f/#), a lens thickness ("TLens"), a back focal length (BFL), an effective focal length (EFL) and N≥<NUM> lens elements L1-LN arranged along a lens optical axis (OA) starting with L1 from an object side toward an image side, each lens element Li having a respective focal length fi, with a magnitude |fi|, the lens having a pop-out total track length TTL <<NUM> in a pop-out state and a collapsed total track length c-TTL in a collapsed state, wherein the lens system is configured to switch from a pop-out state to a collapsed state by collapsing BFL to a collapsed BFL, wherein SD≥<NUM>, wherein BFL > <NUM> × TTL, and wherein a ratio c-TTL/ SD < <NUM>.