Single-aperture low f number ZOOM cameras

Abstract

A camera system is provided comprising a wide camera and at least one processor. The wide camera includes a lens assembly with a plurality of lens elements, a controllable aperture, and an image sensor having a full sensor diagonal (SD) between 5 mm and 25 mm. The wide camera defines a total track length (TTL) and is characterized by a dimensional relation TTL / SD < 0.8. The camera operates in a full field-of-view (F-FOV) state and in a zoom field-of-view (Z-FOV) state, where the F-FOV state provides a field of view larger than the Z-FOV state. The processor is configured to respond to a zoom input by switching between an F-FOV sensor readout from the entire sensor and a Z-FOV sensor readout from a cropped portion of the sensor defining an effective diagonal (SDz). In the Z-FOV state the processor further controls the aperture to provide a larger aperture diameter.

Description

[0001] SINGLE- APERTURE LOW F NUMBER ZOOM CAMERAS

[0002] FIELD

[0003] The present disclosure relates generally to the field of digital cameras used in mobile electronic devices (or simply “mobile devices”) and in particular to optical designs in such cameras.

[0004] DEFINITIONS

[0005] In the following disclosure and for optical and other properties mentioned throughout the description and figures, the following symbols and abbreviations are used, all of which are known in the art:

[0006] - Total track length (TTL): the maximal distance, measured along a direction parallel to the optical axis, between a point of the front surface Si of a first lens element Li of a lens (or “lens assembly”) and an image sensor, when a camera system including the lens is focused to an infinite object distance.

[0007] - Back focal length (BFL): the minimal distance, measured along a direction parallel to the first optical axis, between a point of the rear surface S2N of a last lens element LN of a lens (or “lens assembly”) and the image sensor, when a camera system including the lens is focused to an infinite object distance.

[0008] - Effective focal length (EFL): the distance between a rear principal point P' and a rear focal point F' of a lens assembly of lens elements Li to LN.

[0009] - f-number (f / #): the ratio of the EFL and the aperture diameter DA of the camera’ s entrance pupil: f / # = EFL / DA.

[0010] - Aperture diameter (DA): represents an entrance pupil diameter of an optical lens system.

[0011] - The entrance pupil is the optical image of the aperture stop, as 'seen' through the front aperture of the lens system. The front aperture is the object-side aperture of the lens.

[0012] - The optical lens system comprises an image sensor and a lens including a plurality of lens elements. Each lens element has two surfaces, a front surface (facing an object side) and a back surface (facing a sensor side).

[0013] - Clear aperture diameter (CA): represents an optically active aperture diameter of a surface of a lens element. BACKGROUND

[0014] Various mobile devices, such as smartphones, tablets etc. include compact digital cameras. These cameras are typically limited in size, to fit into the mobile device together with various additional electronic elements. To provide good low light sensitivity, strong “natural” Bokeh effect and high image resolution, such cameras are typically designed with a relative low f / #.

[0015] Recently, various compact digital cameras were introduced that can dynamically achieve a lower f / # by adapting an aperture diameter (DA) of a camera according to a scene condition and / or according to a zoom factor (ZF). Optical lens systems and methods for such compact digital cameras are disclosed in co-owned international patent application PCT / IB2024 / 057209, which is enclosed herein by reference in its entirety. Definitions and notations are identical to PCT / IB2024 / 057209 and are not repeated herein.

[0016] GENERAL DESCRIPTION

[0017] There is need in the art for a novel camera system configuration, configured to dynamically adjust f / # in accordance with field of view collected by the camera system. The present disclosure provides a camera system and a corresponding mobile device utilizing adaptive sensor readout associated with at least first and second fields of view, while adjusting at least one aperture of a lens assembly thereof, to provide a desired f / # variation and enhance image quality. Typically, dynamically achieving a lower f / # by adapting a DA of a camera according to a desired imaging condition is beneficial in providing improved image quality. Herein, further optical lens systems that dynamically achieve a lower f / # by adapting a DA are disclosed.

[0018] According to a broad aspect, the present disclosure provides a camera system, comprising a wide camera comprising a lens assembly having a plurality of lens elements, a controllable aperture, and an image sensor having a full sensor diagonal (SD) in a range between 5 mm and 25 mm, the wide camera defining a total track length TTL, the wide camera being characterized by dimensional relation TTL / SD <0.8, and at least one processor; the wide camera has a full field-of-view (F-FOV) state and a zoom field-of-view (Z-FOV) state, the F- FOV state being characterized by a field of view larger than the Z-FOV state; the processor is configured and operable to be responsive to a zoom input, and in response to switch between an F-FOV sensor readout and a Z-FOV sensor readout, in the F-FOV sensor readout the processor operates for readout from the entire sensor and in the Z-FOV readout the processor operates for readout from a cropped portion of the sensor defining an effective diagonal SDz; and in response to a zoom input, the processor is configured and operable to operate the controllable aperture to vary a respective aperture diameter (DA) such that the DA in the Z- FOV state is greater than the DA in the F-FOV state.

[0019] According to some embodiments, the aperture diameter (DA) in the Z-FOV state (DAz- FOV) and the cropped sensor diagonal (SDz) satisfy a relation DAz-FOV / SDz > 1.5 x DAF- FOV / SD, where DAF-FOV is the aperture diameter in the F-FOV state and SD is the full sensor diagonal.

[0020] According to some embodiments, the lens assembly comprises a plurality of N lens elements.

[0021] According to some embodiments, the aperture diameter DA at the F-FOV state and the full sensor diagonal satisfy a relation 0.2 < DAF-FOV / SD < 0.5.

[0022] According to some embodiments, the controllable aperture diameter at the Z-FOV state DAz-FOV is greater than the controllable aperture diameter at the F-FOV state DAF-FOV by at least 20%, by at least 30% or by at least 40%.

[0023] According to some embodiments, DAz-FOV is at least 1.5 x DAF-FOV.

[0024] According to some embodiments, the effective diagonal SDz associated with the cropped portion of the sensor is reduced from the full sensor diagonal by at least 25%, or by at least 50%

[0025] According to some embodiments, an F number (f / #) at the F-FOV state, defined by EFL / DAF-FOV, is in a range between 1.5 and 2.5, where EFL is the effective focal length of the lens assembly. In some embodiments f / # at the F-FOV state is in the range between 1.5 and 2. In some embodiments f / # at the F-FOV state satisfies f / # < 1.9. or f / # < 1.8.

[0026] According to some embodiments, an F number (f / #) at the Z-FOV state, defined by EFL / DAz-FOV, is in a range between 1.1 and 1.5. In some embodiments, f / # at the Z-FOV state satisfies f / # < 1.4, or f / # < 1.3.

[0027] According to some embodiments, a ratio of the F-number in the F-FOV state to the F- number in the Z-FOV state is greater than 1.25, or greater than 1.3, or greater than 1.4.

[0028] According to some embodiments, the image sensor operates in the F-FOV state by binning sensor pixels.

[0029] According to some embodiments, the image sensor operates in the Z-FOV state using individual pixels.

[0030] According to some embodiments, in the F-FOV camera state the image sensor is operated in a first pixel resolution, and in the Z-FOV camera state the image sensor is operated in a second pixel resolution higher than the first pixel resolution.

[0031] According to some embodiments, the controllable aperture is located at an object side of the lens assembly.

[0032] According to some embodiments, the controllable aperture is located between two lens elements out of the plurality of lens elements.

[0033] According to some embodiments, the effective focal length (EFL) is between 2 mm and

[0034] 15 mm.

[0035] According to some embodiments, the effective focal length (EFL) is between 2 mm and

[0036] 10 mm.

[0037] According to some embodiments, the effective focal length (EFL) is between 2 mm and

[0038] 7.5 mm.

[0039] According to some embodiments, DAz-FOV / SDz > 2 x DAF-FOV / SD.

[0040] According to some embodiments, DAz-FOV / SDz > 2.5 x DAF-FOV / SD.

[0041] According to some embodiments, DAz-FOV / SDz > 2.75 x DAF-FOV / SD.

[0042] According to some embodiments, TTL / SD < 0.75.

[0043] According to some embodiments, TTL / SD < 0.7.

[0044] According to some embodiments, TTL / SD > 0.6

[0045] According to some embodiments, the angular field of view at the F-FOV state is in the range of 75degrees to 95degrees, or in the range between 80degrees and 90degrees

[0046] According to some embodiments, the full sensor diagonal (SD) is between 7.5 mm and 20 mm, or between 7.5 mm and 15 mm.

[0047] According to some embodiments, transition between the F-FOV state and the Z-FOV state is discrete, thereby defining a two-state virtual zoom camera.

[0048] According to some embodiments, transition between the F-FOV state and the Z-FOV state is continuous, thereby defining a continuous virtual zoom camera.

[0049] According to some embodiments, the second pixel resolution corresponds to a full sensor resolution of at least 48 megapixels.

[0050] According to some embodiments, the camera system is configured to be embedded within a mobile electronic device.

[0051] According to some embodiments, the camera system is included / embedded in an electronic device.

[0052] According to a broad aspect, the present disclosure provides an electronic device comprising a camera system, and at least one processor, the camera system comprising a wide camera comprising a lens assembly having a plurality of lens elements, a controllable aperture, and an image sensor having a full sensor diagonal (SD) in a range between 5 mm and 25 mm, the wide camera defining a total track length TTL, the wide camera being characterized by dimensional relation TTL / SD <0.8, the wide camera has a full field-of-view (F-FOV) state and a zoom field-of-view (Z-FOV) state, the F-FOV state being characterized by a field of view larger than the Z-FOV state; the processor is configured and operable to be responsive to a zoom input, and in response to switch between an F-FOV sensor readout and a Z-FOV sensor readout, in the F-FOV sensor readout the processor operates for readout from the entire sensor and in the Z-FOV readout the processor operates for readout from a cropped portion of the sensor defining an effective diagonal SDZ; and in response to a zoom input, the processor is configured and operable to operate the controllable aperture to vary a respective aperture diameter (DA) such that the DA in the Z-FOV state is greater than the DA in the F-FOV state.

[0053] According to some embodiments, the electronic device is a small form factor electronic device.

[0054] According to some embodiments, the electronic device is a mobile device.

[0055] According to some embodiments, the mobile device is a smartphone.

[0056] According to yet another broad aspect, the present disclosure provides A camera system, comprising: a Wide camera and a processor, the Wide camera comprising a lens with a plurality of N lens elements LI - LN and having a total track length TTL, an effective focal length EFL, an adaptive aperture AA, and an image sensor having a full sensor diagonal SD in the range of 5mm to 25mm, wherein the Wide camera is a zoom camera, wherein a ratio TTL / SD < 0.8, wherein the Wide camera has a full field-of-view (F-FOV) camera state and a F-FOV lens aperture diameter DAF-FOV, wherein a ratio of DAF-FOV / SD is in the range 0.2 - 0.5, wherein the Wide camera has a zoom field-of-view (Z-FOV) camera state that fulfills Z- FOV < F-FOV, a Z-FOV lens aperture diameter DAZ-FOV and a zoom sensor diagonal SDz < SD, wherein for switching between the F-FOV camera state and the Z-FOV camera state, the AA is operational to switch between DAF-FOV and DAZ-FOV such that DAZ-FOV > 1.2x DAF-FOV, wherein the processor is operational to crop the image sensor such that SDz < 0.8x SD, and wherein DAZ-FOV / SDZ > 1.5X DAF-FOV / SD. The camera system may be configured in accordance with any one of the parameters described herein.

[0057] BRIEF DESCRIPTION OF THE DRAWINGS

[0058] 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:

[0059] Figs. 1A and IB illustrate schematically a camera system utilizing adjustable aperture variation and digital zoom according to some embodiments of the present disclosure, fig. 1 A exemplifies wide field imaging and Fig. IB exemplifies zoom imaging;

[0060] Figs. 2A and 2B show another example of a virtual zoom camera system according to some embodiments of the present disclosure, Fig. 2A shows the camera in wide field imaging conditions and Fig. 2B shows the camera in zoom imaging condition;

[0061] Figs. 3 A and 3B show an additional example of a virtual zoom camera according to some embodiments of the present disclosure, Fig. 3A shows the camera in wide field imaging conditions and Fig. 3B shows the camera in zoom imaging condition; and

[0062] Figs. 4A and 4B exemplify an electronic device, or a smartphone, including a camera system according to some embodiments of the present disclosure, Fig. 4a shows a back view and Fig. 4B shows a side view of the device.

[0063] DETAILED DESCRIPTION

[0064] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding. However, it will be understood by those skilled in the art that the presently disclosed subject matter may be practiced without these specific details. In other instances, well-known methods have not been described in detail so as not to obscure the presently disclosed subject matter. It is appreciated that certain features of the presently disclosed subject matter, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the presently disclosed subject matter, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

[0065] Figs. 1A and IB exemplify a camera system 100 according to some embodiments of the present disclosure. Camera system 100 is configured as a wide field camera system and includes a lens assembly, exemplified by lenses 102a and 102b, a controllable aperture 110 and an image sensor 104. The image sensor may have a selected full sensor diagonal (SD) selected in accordance with desired camera functionality and dimensions. In some preferred embodiments, the sensor diagonal may be between 5 mm and 25 mm. The camera system 100 may include or be coupled to a controller or at least one processor 500 configured and operable to operate the sensor 104 and receive readout data from the sensor, and to operate the controllable aperture 110.

[0066] Typically, the processor 500 is configured and operable to be response to a zoom input (e.g., from a user) and in response to a zoom input request, the controller operates to switch between a F-FOV sensor readout and a Z-FOV sensor readout and to operate the controllable aperture 110 to vary a respective aperture diameter (DA) such that the DA in the Z-FOV state is greater than the DA in the F-FOV state. In the F-FOV sensor readout the processor operates for readout from the entire sensor, using the entire region of the sensor (optionally utilizing binned pixels) and in the Z-FOV readout the processor operates for readout from a cropped portion of the sensor 104 defining an effective diagonal SDz, smaller than full SD.

[0067] This is exemplified in Figs. 1A and IB showing a smaller aperture 110 in Fig. IB with respect to that of Fig. 1 A, combined with readout from central cropped portion of the sensor 104. Generally, when operating in a F-FOV state, the camera system 100 utilizes readout from the entire sensor area, to provide image data of a wide field of view. This is while in the Z-FOV state, the camera system reads the image data from a cropped portion of the sensor area, focusing on a selected portion of the field of view to provide enlarged (zoom) image data. Variation of the aperture size provides respective variation in f / # of the lens assembly, and effectively reduces the f / #, thereby improving image quality in terms of sharpness, while in the F-FOV state, the aperture is relatively narrow to enable a relatively high image quality over entire F-FOV, for example by enhancing a depth of focus of the camera system.

[0068] The controller, or processor 500, is generally configured to operate the camera system in response to user input or to input commands received otherwise. Typically, when capturing an image, the controller may adjust one or more optical parameters of the camera system and operate to readout data collected by pixels of the sensor. In this connection, an image capture command may include an indication of a desired field of view, being a wide FOV or a narrow / zoom FOV. While the following description relates to optical design and optical parameters of the camera system, it should be understood that selection of a camera state, adjustment of the controllable aperture, and selection of readout area of the sensor are determined and operated by the at least one processor.

[0069] The optical lens systems disclosed in the following are operational to perform low f / # virtual zoom capturing according to embodiments of the present disclosure, and a resulting low f / # virtual zoom camera can be used in a mobile device. To clarify, all examples of optical lens systems disclosed herein are beneficial to be used in a smartphone, a tablet etc. Values and dimensions of a camera and a mobile device including optical lens systems used in Wide cameras are disclosed herein are presented in Table 1.

[0070] “N” gives the number of lens elements of a lens.

[0071] SD is the (full) sensor diagonal of an image sensor (in mm).

[0072] “DA” gives the aperture diameter (in mm), wherein f / # = EFL / DA.

[0073] “D3 / 2” gives a clear aperture (CA) of surface 3 (“S3”) as mechanically defined by adaptive (controllable) aperture (AA) 110.

[0074] “Di / 2” gives a clear aperture (CA) of surface 1 (“SI”) as mechanically defined by AA 210

[0075] A (diagonal) field-of-view (“FOV”) is given in degrees.

[0076] “ZF” gives a zoom factor.

[0077] “dLi-L2” is a minimum distance between a first lens element Li and a second lens element L2. The minimal distance may allow for inserting blades that act as mechanical AA.

[0078] DA, EFL, TTL, SD, du-L2 are given in mm.

[0079] AL gives a difference in an amount of light entering a central part of image sensor 104 or 204 in the second camera state compared to the first camera state. AL = (f / #i / f / #2)2.

[0080] Table 1

[0081] Figs. 2A and 2B and Figs. 3A and 3B show camera system and the respective lens assembly (lens system) according to some embodiments of the present disclosure providing the optical parameters mentioned in table 1. Figs. 2A and 2B show an optical lens system forming a camera system 100 operational to perform low f / # virtual zoom capturing as disclosed in PCT / IB2024 / 057209 Ji ned to the assignee of the present disclosure. Optical lens system includes a lens assembly 102 including a plurality of lens elements, in this example N = 8 lens elements LI to L8, and having a lens optical axis 108, an image sensor 104 and an optional optical element 106, for example an infrared (“IR”) filter. The lens assembly 102 and the image sensor 104 are packed to provide a desired EFL of the camera system 100. Camera system 100 further includes an adaptive / controllable aperture (“AA”) 110 located along path of light collected by the lens assembly 102, e.g., between two lens elements out of the plurality of lens elements. In this example, AA 110 is located between LI and L2. In Fig. 2A, Camera system 100 is shown in a first camera state, where AA 110 is relatively closed, so that an aperture diameter DAi such as DAF-FOV is achieved. A FOV 114 of optical lens system 100 is indicated by angle a. In the first camera state, an entire SD of image sensor 104 is used, and a full FOV (F-FOV) of the optical lens assembly 102 is captured. More specifically, lens assembly 102 images light from FOV 114 onto entire image sensor 104, as indicated by light cone 112. In the first camera state, a f / # is f / #i, which is given by f / #i = EFL / DAi. To obtain image data of the entire FOV, a controller (not specifically shown) operates the camera system 100 to provide readout from the entire region of the sensor 104, optionally utilizes binned pixels to maintain a desired resolution of the image data.

[0082] A minimum distance between LI and L2 (“dLi-L2”) may be relatively large, e.g. du-L2 > 0.3mm, to accommodate the controllable aperture 110. A relatively large du-L2 is beneficial for implementing an AA such as AA 110, which requires a certain physical distance between the lens elements.

[0083] FIG. IB shows the same camera system 100 of FIG. 1 A in a second camera state. A FOV 118 of optical lens system 100 in the second camera state is indicated by angle P, smaller than angle a. With respect to the first camera state of FIG. 1 A: AA 110 is relatively opened, so that an aperture diameter DA2 larger than DAi is achieved. Only a central part of image sensor 104 is used for readout, providing capture of image data of a zoom FOV (Z-FOV) of camera system 100. Specifically, in this non-limiting example only about half of a SD of image sensor 104 is used providing zoom field of view, i.e., camera system 100 images light from FOV 118 onto a central region of image sensor 104, as indicated by light cone 116. In the second camera state, the f / # is f / #2, given by f / #2 = EFL / DA2 < f / #i. A difference in an amount of light (“AL”) entering a central part of the image sensor 104 in the first compared to the second camera state is given by AL. For the camera system 100 of this example, AL = 2.13. In the second camera state, a central part of image sensor 104 receives more than two times the amount of light as compared with the first camera state, as a result of the wider aperture AA 110.

[0084] It should be noted that the zoom operation of the camera system 100 can be applied by providing readout data from central portion of the sensor, without any change in position of the lenses of lens assembly 102. Variation in aperture 110 opening results in variation in f / # and amount of collected light, providing improved image and illumination quality at the zoom state, while maintaining a relatively high image quality in the wide field of view state.

[0085] In some examples, image sensor 104 may be a binning sensor. Image sensor 104 may be operational to perform 4-binning, or 9-binning, or 16-binning or even 36-binning. In the first camera state, the binning sensor 104 may be operated in binning mode. In the second camera state, the binning sensor may be operated in a higher resolution mode, for example in full resolution mode or in an intermediate resolution mode with a resolution between the binning mode and the full resolution mode. This allows the camera system to maintain resolution of the output image data between F-FOV and Z-FOV image collection modes. Generally, when using 4-binning mode in the first (F-FOV) camera state and full resolution mode in the second camera state (Z-FOV, using half of a SD), a same output resolution is achieved. With respect to a combined larger pixel in the first camera state, a single smaller pixel in the second camera state may receive 2.13 / 4 ~ 53% of the amount of light. Without changing the aperture, the single smaller pixel in the second camera state may only receive 1 / 4 ~ 25% of the amount of light compared to a combined larger pixel. When using 16- binning mode in the first camera state and full resolution mode in the second camera state, with respect to a combined larger pixel in the first camera state, a single smaller pixel in the second camera state receives 2.13 / 16 ~ 13% of an amount of light. Without changing the aperture, the single smaller pixel in the second camera state would only receive 1 / 16 ~ 6% of an amount of light compared to a combined larger pixel.

[0086] As half of a SD of image sensor 104 is used, the camera system including lens assembly 102 may be referred as a “low f / # 2x virtual Wide zoom camera”, indicating a switching between F-FOV and Z-FOV states.

[0087] Detailed optical data and surface data of lens assembly 102 are given in Tables 2 and 4 for the example of the lens elements in Figs. 2A-2B. The values provided for these examples are purely illustrative and according to other examples, other values can be used.

[0088] Surface types are defined in Table 2 and the coefficients for the surfaces are defined in Table 4. Table 3 lists characteristics that are different in the first camera state and in the second camera state. The surface types are: a) Plano: flat surfaces, no curvature b) Q type 1 (QT1) surface sag formula:

[0089] Qo°n(x) = 1 Qion= -(5 - 6%) Q2con= 15 - 14x(3 - 2%) Q °n= -{35 - 12x[14 - x(21 - 10x)]J Qon= 70 - 3x{168 - 5x[84 - llx(8 - 3x)]}

[0090] Qcon=_[126>x(1260 - llx{420 - x[720 - 13x(45 - 14x)]})] c) Even Aspheric (ASP) surface sag formula: 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 Anare the polynomial coefficients shown in lens data tables. The Z axis is positive towards image. Values for CA are given as a clear aperture radius, i.e. CA / 2. The reference wavelength is 555.0 nm. Units are in mm except for refraction index (“Index”) and Abbe #. Each lens element Li has a respective focal length f, given in Table 2. The FOV is given as half FOV (HFOV). “D3 / 2” and “D4 / 2” in Table 2 gives a clear aperture (CA) of surface 3 (“S3”) and

[0091] F number S3 Aperture S4 Aperture H-FOV

[0092] Radius (D / 2) Radius (D / 2) [deg]

[0093] [mm] [mm]

[0094] 1.31 2.474 2.376 24.0

[0095] 1.91 1.596 1.549 41.7 surface 3 (“S4”) respectively as mechanically defined by AA 110. “DA” gives an entrance pupil diameter as used for calculating f / #. DA is determined by “D3 / 2” and “D4 / 2” in both the first and the second camera state.

[0096]

[0097] Table 2

[0098] Table 2 (continued)

[0099]

[0100] Table 3

[0101]

[0102] Table 4

[0103] Table 4 (cont.)

[0104]

[0105]

[0106]

[0107] Table 4 (cont.) Figs. 3 A and 3B show another camera system 200 utilizing a different design of the lens assembly 202 thereof, and operational to perform low f / # virtual zoom capturing according to some embodiments of the present disclosure. Camera system 200 includes a lens assembly 202 including a plurality of N = 8 lens elements LI to L8 and having a lens optical axis 208, an image sensor 204 and an optional optical element 206, for example an IR filter. Further, Camera system 200 is designed with a selected EFL suitable to allow the camera to be embedded within a selected electronic device. Camera system 200 includes an AA 210 located downstream of lens LI with respect to direction of propagation of light into the camera system. In Fig. 3A Camera 200 is shown in a first camera state, where AA 210 is relatively closed, so that an aperture diameter DAi such as DAF-FOV is achieved. A FOV 214 of optical lens system 200 is indicated by angle a. In the first camera state, an entire SD of image sensor 204 is captured. Optical lens system 200 images light from FOV 214 onto the entire light collection surface of the image sensor 204, as indicated by extreme top light cone 212. In the first camera state, f / #i = EFL / DAi.

[0108] Fig. 3B shows the camera system 200 of Fig. 3A in a second camera state, Z-FOV configured for zoom imaging. A FOV 218 of the camera system 200 in the second camera state is indicated by angle p. With respect to the first camera state (F-FOV) of Fig. 2A, AA 210 is relatively opened, so that an aperture diameter DA2 > DAi is achieved. Only a central part of image sensor 204 is used to capture a Z-FOV image data of a scene by camera system 200. Specifically, as exemplified here only half of a SD of image sensor 204 is used. Camera system 200 images light from FOV 218 onto a central region of image sensor 204, as indicated by extreme top light cone 216. In the second camera state, f / #2 = EFL / DA2 < f / #i. A difference in an amount of light (“AL”) is about AL = 1.87. In the second camera state, a central part of image sensor 204 receives more than 1.5 times the amount of light as compared with the first camera state as a result of wider aperture AA 210.

[0109] In some examples, image sensor 204 may be a binning sensor. Image sensor 204 may be operational to perform 4-binning, or 9-binning, or 16-binning or even 36-binning of the light sensitive pixels thereof. In the first camera state (F-FOV), the binning sensor may be operated in binning mode. In the second camera state (Z-FOV), the binning sensor may be operated in a higher resolution mode.

[0110] In 4-binning mode and with respect to a combined larger pixel in the first camera state, a single smaller pixel in the second camera state receives 1.87 / 4 ~ 47% of an amount of light as would be collected by a binned pixel in the first camera state F-FOV. When using 16-binning mode in the first camera state and full resolution mode in the second camera state, with respect to a combined larger pixel in the first camera state, a single smaller pixel in the second camera state receives 1.87 / 16 ~ 12% of an amount of light as would be collected by a binned pixel in the first camera state F-FOV.

[0111] As half of a SD of image sensor 204 is used in the second, Z-FOV, state, the camera including camera system 200 may be referred to as a “low f / # 2x virtual Wide zoom camera”. Detailed optical data and surface data of camera system 200 are given in Tables 5 -7 for the example of the lens elements in Figs. 3 A and 3B. The values provided for these examples are purely illustrative and non-limiting. In other examples, other values can be used in accordance

[0112]

[0113]

[0114] Table 5 (Cont.) with actual camera design. Surface types are defined in Table 5 and the coefficients for the surfaces are defined in Table 7. Table 6 lists characteristics that are different in the first camera state and in the second camera state. Typically, the camera system parameters of Tables 5-7 include basic camera design EFL = 6.55mm, F number = See Table 6, HFOV = See Table 6.

[0115] Table 6

[0116]

[0117] Table 7

[0118]

[0119] Table 7 (Cont.)

[0120] Table 7 (Cont.) Generally, the camera system according to some embodiments of the present disclosure may be configured to be embedded within a mobile electronic device, e.g., smartphone, tablet, etc. More specifically, such electronic devices typically have a relatively small form factor, limiting maximal EFL of the camera system and limiting the ability to provide optical zoom. Accordingly, the camera system of the present disclosure enables a “digital” zoom, while maintaining and potentially improving image quality by adjusting f / # in accordance with a zoom condition.

[0121] Fig. 4A and 4B exemplify a mobile electronic device 400, illustrated as a smartphone. Fig. 4A shows a back side of the smartphone and Fig. 4B shows a side view, the camera system 100 can be seen in the back side of the device 400 and may protrude slightly from the device’s thickness as shown in Fig. 4B. Smartphone 400 is exemplified here as including a single camera, however it should be understood that the smartphone may include several cameras having selected optical characteristics, where at least one camera system is configured according to the present disclosure.

[0122] Unless otherwise stated, the use of the expression “and / or” between the last two members of a list of options for selection indicates that a selection of one or more of the listed options is appropriate and may be made.

[0123] 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.

[0124] All patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present disclosure.

Claims

WHAT IS CLAIMED IS:

1. A camera system, comprising: a wide camera comprising a lens assembly having a plurality of lens elements, a controllable aperture, and an image sensor having a full sensor diagonal (SD) in a range between 5 mm and 25 mm, the wide camera defines a total track length TTL, the wide camera is characterized by dimensional relation TTL / SD <0.8, and at least one processor; wherein the Wide camera has a full field-of-view (F-FOV) state and a zoom field-of-view (Z-FOV) state, where the F-FOV state is characterized by a field of view larger than the Z-FOV state; wherein the processor is configured and operable to be response to a zoom input, and in response to switch between a F-FOV sensor readout and a Z-FOV sensor readout, where in F- FOV sensor readout the processor operates for readout from the entire sensor and in the Z-FOV readout the processor operates for readout from a cropped portion of the sensor defining an effective diagonal SDz; and wherein in response to a zoom input, the processor is configured and operable to operate the controllable aperture to vary a respective aperture diameter (DA) such that the DA in the Z- FOV state is greater than the DA in the F-FOV state.

2. The camera system of claim 1, wherein the aperture diameter (DA) in the Z-FOV state (DAz-FOV) and the cropped sensor diagonal (SDz) satisfy a relation DAz-FOV / SDz > 1.5 x DAF- FOV / SD, where DAF-FOV is the aperture diameter in the F-FOV state and SD is the full sensor diagonal.

3. The camera system of claim 1 or 2, wherein the lens assembly comprises a plurality of N lens elements.

4. The camera system of any one of claims 1 to 3, wherein the aperture diameter DA at the F-FOV state and the full sensor diagonal satisfy a relation 0.2 < DAF-FOV / SD < 0.5.

5. The camera system of any one of claims 1 to 4, wherein the controllable aperture diameter at the Z-FOV state DAz-FOV is greater than the controllable aperture diameter at the F-FOV state DAF-FOV by at least 20%.

6. The camera system of any one of claims 1 to 5, wherein the controllable aperture diameter at the Z-FOV state DAz-FOV is greater than the controllable aperture diameter at the F-FOV state DAF-FOV by at least 30%.

7. The camera system of any one of claims 1 to 6, wherein the controllable aperture diameter at the Z-FOV state DAz-FOV is greater than the controllable aperture diameter at the F-FOV state DAF-FOV by at least 40%.

8. The camera system of any one of claims 1 to 7, wherein the effective diagonal SDz associated with the cropped portion of the sensor is reduced from the full sensor diagonal by at least 25%.

9. The camera system of any one of claims 1 to 8, wherein the effective diagonal SDz associated with the cropped portion of the sensor is reduced from the full sensor diagonal by at least 50%.

10. The camera system of any one of claims 1 to 9, wherein an F number (f / #) at the F-FOV state, defined by EFL / DAF-FOV, is in a range between 1.5 and 2.5, where EFL is the effective focal length of the lens assembly.

11. The camera system of any one of claims 1 to 10, wherein an F number (f / #) at the F-FOV state, is in a range between 1.5 and 2.

12. The camera system of any one of claims 1 to 9, wherein an F number (f / #) at the F-FOV state satisfies f / # < 1.9.

13. The camera system of any one of claims 1 to 9, wherein an F number (f / #) at the F-FOV state satisfies f / # < 1.8.

14. The camera system of any one of claims 1 to 13, wherein an F number (f / #) at the Z-FOV state, defined by EFL / DAz-FOV, is in a range between 1.1 and 1.5.

15. The camera system of any one of claims 1 to 13, wherein an F number (f / #) at the Z-FOV state satisfies f / # < 1.4.

16. The camera system of any one of claims 10 to 15, wherein a ratio of the F-number in the F-FOV state to the F-number in the Z-FOV state is greater than 1.25.

17. The camera system of any one of claims 10 to 15, wherein a ratio of the F-number in the F-FOV state to the F-number in the Z-FOV state is greater than 1.4.

18. The camera system of any one of claims 1 to 17, wherein the image sensor operates in the F-FOV state by binning sensor pixels.

19. The camera system of claim 18, wherein the image sensor operates in the Z-FOV state using individual pixels.

20. The camera system of claim 18 or 19, wherein in the F -F OV camera state the image sensor is operated in a first pixel resolution, and wherein in the Z-FOV camera state the image sensor is operated in a second pixel resolution higher than the first pixel resolution.

21. The camera system of any one of claims 1 to 20, wherein the controllable aperture is located at an object side of the lens assembly.

22. The camera system of any one of claims 1 to 20, wherein the controllable aperture is located between two lens elements out of the plurality of lens elements.

23. The camera system of any one of claims 1 to 22, wherein the effective focal length (EFL) is between 2 mm and 15 mm.

24. The camera system of claim 23, wherein the effective focal length (EFL) is between 2 mm and 10 mm.

25. The camera system of claim 14, wherein the effective focal length (EFL) is between 2 mm and 7.5 mm.

26. The camera system of claim 2, wherein DAz-FOV / SDz > 2 x DAF-FOV / SD.

27. The camera system of claim 2, wherein DAz-FOV / SDz > 2.5 x DAF-FOV / SD.

28. The camera system of claim 2, wherein DAz-FOV / SDz > 2.75 x DAF-FOV / SD.

29. The camera system of claim 1, wherein TTL / SD < 0.75.

30. The camera system of claim 1, wherein TTL / SD < 0.7.

31. The camera system of claim 1, wherein TTL / SD > 0.6.

32. The camera system of claim 1, wherein an angular field of view at the F-FOV is in the range of 75deg to 95deg.

33. The camera system of claim 1, wherein an angular field of view at the F-FOV is in the range of 80deg to 90deg.

34. The camera system of any one of claims 1 to 33, wherein the full sensor diagonal (SD) is between 7.5 mm and 20 mm.

35. The camera system of any one of claims 1 to 34, wherein the full sensor diagonal (SD) is between 7.5 mm and 15 mm.

36. The camera system of any one of claims 1 to 35, wherein transition between the F-FOV state and the Z-FOV state is discrete, thereby defining a two-state virtual zoom camera.

37. The camera system of any one of claims 1 to 35, wherein transition between the F-FOV state and the Z-FOV state is continuous, thereby defining a continuous virtual zoom camera.

38. The camera system of claim 20, wherein the second pixel resolution corresponds to a full sensor resolution of at least 48 megapixels.

39. The camera system of any one of claims 1 to 38, wherein the camera system is configured to be embedded within a mobile electronic device.

40. The camera system of any one of claims 1 to 39, being included in an electronic device.

41. An electronic device comprising a camera system, and at least one processor, the camera system comprising: a wide camera comprising a lens assembly having a plurality of lens elements, a controllable aperture, and an image sensor having a full sensor diagonal (SD) in a range between 5 mm and 25 mm, the wide camera defines a total track length TTL, the wide camera is characterized by dimensional relation TTL / SD <0.8, and wherein the wide camera has a full field-of-view (F-FOV) state and a zoom field-of-view (Z-FOV) state, where the F-FOV state is characterized by a field of view larger than the Z-FOV state; wherein the processor is configured and operable to be response to a zoom input, and in response to switch between a F-FOV sensor readout and a Z-FOV sensor readout, where in F-FOV sensor readout the processor operates for readout from the entire sensor and in the Z-FOV readout the processor operates for readout from a cropped portion of the sensor defining an effective diagonal SDz; and wherein in response to a zoom input, the processor is configured and operable to operate the controllable aperture to vary a respective aperture diameter (DA) such that the DA in the Z-FOV state is greater than the DA in the F-FOV state.

42. The electronic device of claim 31, wherein the electronic device is a small form factor electronic device.

43. The electronic device of claim 31 or 32, wherein the electronic device is a mobile device.

44. The electronic device of any one of claims 31 to 33, wherein the mobile device is a smartphone.

45. A camera system, comprising: a wide camera and a processor, the Wide camera comprising a lens with a plurality of N lens elements LI - LN and having a total track length TTL, an effective focal length EFL, an adaptive aperture AA, and an image sensor having a full sensor diagonal SD in the range of 5mm to 25mm, wherein the Wide camera is a zoom camera, wherein a ratio TTL / SD < 0.8, wherein the Wide camera has a full field-of-view (F-FOV) camera state and a F-FOV lens aperture diameter DAF-FOV, wherein a ratio of DAF-FOV / SD is in the range 0.2 - 0.5, wherein the Wide camera has a zoom field-of-view (Z-FOV) camera state that fulfills Z- FOV < F-FOV, a Z-FOV lens aperture diameter DAZ-FOV and a zoom sensor diagonal SDz < SD,wherein for switching between the F-FOV camera state and the Z-FOV camera state, the AA is operational to switch between DAF-FOV and DAZ-FOV such that DAZ-FOV > 1.2X DAF-FOV, wherein the processor is operational to crop the image sensor such that SDz < 0.8x SD, and wherein DAZ-FOV / SDZ > 1.5X DAF-FOV / SD.

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