Multi- camera

Abstract

The present invention provides a mobile device, comprising: a first camera having a first field of view (FOV1) and a first image sensor; and a second camera having a second field of view (FOV2), a plurality of lens elements, a first reflective element, and a second image sensor, wherein FOV2 < FOV1, the second camera has an F-number less than or equal to 3, the first image sensor is configured to receive a first light ray coming from a first direction through a first optical path between an object and the first image sensor, and the second image sensor is configured to receive a second light ray coming from the first direction through a second optical path between the object and the second image sensor, the first reflective element is disposed in the second optical path between the plurality of lens elements and the second image sensor, and the first camera is an auto-focus camera.

Description

[Technical Field]

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Patent Application No. 14 / 717,258, filed May 20, 2015, and U.S. Patent Application No. 14 / 455,906, filed August 10, 2014, both of which are entitled “Zoom Dual Aperture Camera with Folding Lens”.

[0003] This disclosure is intended to provide a general overview of the field of digital cameras, and more particularly to multi-aperture digital cameras. [Previous Technology]

[0004] In recent years, mobile devices such as mobile phones (especially smartphones), tablets and laptops have become ubiquitous. Such devices typically include one or two small digital cameras, such as a primary rear camera (i.e., a camera on the back of the device, facing away from the user and often used for taking impromptu photos) and an auxiliary front camera (i.e., a camera on the front of the device and often used for video conferencing).

[0005] Many of these cameras are designed to resemble the traditional structure of a digital still camera, which includes an optical element (or a series of optical elements and a main aperture) placed on top of an image sensor (hereinafter referred to as the "sensor"). The optical element (also called the "optics") refracts and bends incoming light to produce an image of the scene on the sensor.

[0006] The size of such cameras is primarily determined by the size of the sensor and the height of the optics. These are typically linked by the focal length (f) of a lens and its field of view (FOV). A lens with a specific focal length must image a certain FOV onto a sensor of a certain size. Keeping the FOV fixed, the larger the sensor size (e.g., in the XY plane), the greater the focal length and the height of the optics.

[0007] As the size of mobile devices (especially the thickness of devices such as smartphones) continues to shrink, the size of small cameras has become an increasingly limiting factor for device thickness. Several methods have been proposed to reduce the size of small cameras to alleviate this limitation. Recently, multi-aperture systems have been proposed for this purpose. In such systems, instead of having a single aperture and a series of optical elements, the camera is divided into several apertures, each with its own dedicated optical elements, and all sharing a similar field of view. Hereinafter, each of these apertures, along with the optical elements and the sensor area on which the image is formed, is defined as a "sub-camera". Images from these sub-cameras are fused together to produce a single output image.

[0008] Compared to the image produced by a reference single-aperture camera, in some multi-aperture camera designs, each sub-camera produces a smaller image on the image sensor. Therefore, the height of each sub-camera can be smaller than that of a single-aperture camera, reducing the overall height of the camera and allowing for a thinner design of the mobile device.

[0009] Dual-aperture zoom cameras are known, in which one sub-camera has a wide FOV (“Wide Sub-camera”) and the other has a narrow FOV (“Tele Sub-camera”). One issue with dual-aperture zoom cameras is the height of the telephoto zoom sub-camera. The height (also commonly referred to as “total track length (TTL)”) of the telephoto (“T”) and wide-angle (“W”) sub-cameras differs significantly. TTL is typically defined as the maximum distance between the object-side surface of the first lens element and the plane of a camera image sensor. In most small lenses, TTL is greater than the effective focal length (EFL). The typical TTL / EFL ratio for a given lens (or lens unit) is approximately 1.3. In single-aperture smartphone cameras with 1 / 3-1 / 4” sensors, EFL is typically between 3.5 and 4.5 mm, resulting in FOVs of 70-80° respectively.

[0010] For example, suppose we want to achieve dual aperture x2 optical zoom in a smartphone, which would normally use EFLW=3.5 mm and EFLT=2×EFLW=7 mm. However, without space constraints, the wide-angle lens would have EFLW=3.5 mm and TTLW=3.5×1.3=4.55 mm, while the telephoto lens would have EFLT=7 mm and TTLT=7×1.3=9.1 mm. Incorporating a 9.1 mm lens into a smartphone camera would result in a camera height of approximately 10 mm, which is unacceptable to many smartphone manufacturers.

[0011] An example of a solution to the above problem is described in PCT / IB2014 / 062180, a co-invented and co-owned PCT patent application entitled "Dual Aperture Zoom Digital Camera". Some principles of this solution are shown in FIG1, which schematically illustrates an embodiment of a dual aperture zoom camera with autofocus (AF) and labeled 100, in (a) a generalized isometric view and (b) a sectional isometric view. Camera 100 includes two sub-cameras, labeled 102 and 104, each sub-camera having its own optics. Thus, sub-camera 102 includes an optical block 106 having an aperture 108 and an optical lens module 110, and a sensor 112. Similarly, sub-camera 104 includes an optical block 114 having an aperture 116 and an optical lens module 118, and a sensor 120. Each optical lens module may include several lens elements and an infrared (IR) filter 122a and 122b. Alternatively, some or all of the lens elements belonging to different apertures may be formed on the same substrate. The two sub-cameras are positioned adjacent to each other, having a small baseline (at 124) between the centers of the two apertures 108 and 116. Each sub-camera may further include an AF mechanism, 126 and 128, controlled by a controller (not shown). Camera 100 is referred to as “thin” in terms of TTL / EFL for each sub-camera. Typically, TTLW / EFLW > 1.1 and TTLW / EFLW < 1.0 (e.g., 0.85).

[0012] Although the zoom range in camera 100 is approximately x2, it would be advantageous to further increase this range. However, this would require a further increase in the telephoto lens EFL (EFLT), which would result in an increase in camera height. Increasing the EFLT to an example of 12 mm would result in an undesirable camera height of, for example, 0.85 × 12 + 0.9 = 11.1 mm. [Summary of the Invention]

[0013] As mentioned above, the requirements for digital cameras used in portable electronic devices are related to the size and image quality of such cameras. Moreover, unlike other external camera units that can be attached to portable devices, these requirements become even more important when the camera is to be installed inside the portable device.

[0014] For an internal (integrated) camera unit, the camera must have the smallest possible size to match the thickness of the device in which it is mounted (preferably without protruding from the housing of the device), and to be suitable for operation with commonly used image sensors. This problem is made more difficult when using a telephoto lens with a long effective focal length (EFL) to achieve a fairly high zoom effect.

[0015] Therefore, according to one aspect of the present disclosure, a zoom digital camera is proposed, comprising a wide-angle sub-camera and a telephoto sub-camera. The wide-angle sub-camera comprises a wide-angle lens module and a wide-angle image sensor, the wide-angle lens module having a wide-angle lens symmetry axis along a first optical path between an object side and the wide-angle image sensor. The wide-angle sub-camera is configured to provide a wide-angle image.

[0016] The telephoto sub-camera includes a telephoto lens module and a telephoto image sensor. The telephoto lens module has a telephoto lens symmetry axis along a second optical path, which is positioned substantially perpendicular to the wide-angle lens symmetry axis. The telephoto sub-camera is constructed to provide a telephoto image.

[0017] The camera further includes a first reflecting element having a first reflecting element symmetry axis that is substantially tilted at 45 degrees with respect to the symmetry axis of the wide-angle lens and the symmetry axis of the telephoto lens, and is configured to provide a folded optical path between the object and the telephoto image sensor. Therefore, the telephoto sub-camera is considered foldable and is referred to herein as a "foldable telephoto sub-camera".

[0018] The wide-angle lens has a wide field of view (FOVW) and the telephoto lens has a telephoto field of view (FOVT) that is narrower than the FOVW. According to a non-limiting example, the telephoto sub-camera provides X5 zoom performance compared to the wide-angle sub-camera.

[0019] Such a digital camera is operated and connected to at least one image processor, which is configured to process telephoto and wide-angle images into a single output image. A method for fusing images received through different optical paths into a single output image is proposed, for example, in PCT patent application publication number WO2014 / 083489 entitled "High-Resolution Thin Multi-Aperture Imaging System," and U.S. patent application number 14 / 365,711 entitled "Dual-Aperture Zoom Digital Camera," both jointly invented and jointly owned, which are incorporated herein by reference and disclose a multi-aperture imaging system comprising a first camera having a first sensor for capturing a first image and a second camera having a second sensor for capturing a second image. Based on a zoom factor, either image can be selected as a primary or secondary image. An output image having a viewpoint determined by the primary image is obtained by registering the secondary image onto the primary image.

[0020] In order to further adapt the size of the folding telephoto sub-camera to the trend of electronic portable devices, and in an attempt to reduce its thickness as much as possible, various features of the folding telephoto sub-camera were specifically configured to achieve a folding telephoto sub-camera with a reduced height. This reduction in the height of the telephoto sub-camera enables a reduction in the overall height of a dual-aperture camera. Furthermore, this reduction in the height of the folding telephoto sub-camera is achieved while maintaining satisfactory image quality.

[0021] Therefore, in addition to the features described above, according to various examples of the subject matter of this disclosure, such zoom digital camera may include one or more of the following features (1) to (32) in any desired combination and substitution.

[0022] (1) The telephoto lens module of the folding telephoto sub-camera includes a group of at least three lens elements, wherein the lens elements in the group are designed to have a diameter that substantially does not exceed one aperture of the telephoto sub-camera. As explained below, this is different from conventional lens modules, whose lens diameters are designed to become wider toward the sensor.

[0023] (2) The telephoto lens module of the folding telephoto sub-camera contains a group of three to five lens elements.

[0024] (3) The telephoto sub-camera further includes a substrate, a structure for holding the lens elements in position, and a camera housing.

[0025] (4) The aperture of the telephoto sub-camera is designed to provide a sufficiently low F-number (F#) (e.g., equal to or less than 3) to increase the amount of light falling on the telephoto image sensor.

[0026] (5) wherein the telephoto lens module is designed to produce an image on a whole area of ​​the telephoto image sensor. The telephoto image sensor may be, for example, a 1 / 3” image sensor or a 1 / 4” image sensor.

[0027] (6) wherein the lens element in the group is designed such that the blocked light does not exceed a certain percentage of the light entering the telephoto lens module (e.g., no more than 25% of the light entering the telephoto lens module is blocked).

[0028] (7) In one example, the telephoto sub-camera is constructed to have the following technical parameters: EFL > 9 mm, F# < 3, and for all viewing angles, light blocking does not exceed 25% of the light entering the aperture of the telephoto sub-camera.

[0029] (8) The remote sub-camera is characterized by a height not exceeding 6.5 mm.

[0030] (9) The remote sub-camera is characterized by a height not exceeding 5.7 mm.

[0031] (10) wherein the remote image sensor is located on a plane that is substantially perpendicular to the axis of symmetry of the remote lens.

[0032] (11) wherein the telephoto sub-camera includes a telephoto autofocus (AF) mechanism configured to move the telephoto lens along the telephoto axis of symmetry; the AF mechanism is designed such that its height substantially does not exceed the height of a telephoto lens module.

[0033] (12) wherein the AF mechanism includes one or more magnets coupled to individual coils, which are laterally positioned on one or both sides of the telephoto lens module, the magnets having a height substantially not exceeding the height of the telephoto lens module.

[0034] (13) wherein the AF mechanism includes only one magnet coupled to an individual coil.

[0035] (14) The camera further includes a second reflective element positioned in a second optical path between the telephoto lens module and the telephoto image sensor. The second reflective element is configured to direct light rays propagating parallel to the second optical path toward the first optical path. The telephoto image sensor is located in a plane substantially perpendicular to the axis of symmetry of the wide-angle lens.

[0036] (15) The camera further includes a tele-autofocus (AF) mechanism configured to move the second reflective element along the axis of symmetry of the second reflective element.

[0037] (16) The wide-angle and long-range image sensor is mounted on a single printed circuit board.

[0038] (17) wherein at least one processor connected to such a camera is configured to determine an individual output field of view using a zoom factor (ZF).

[0039] (18) wherein the wide-angle lens module has a wide-angle field of view FOVW and the telephoto lens module has a telephoto field of view FOVT that is narrower than FOVW; the camera further includes an intermediate (Mid) sub-camera, which includes an intermediate lens module having a field of view FOVM that satisfies FOVW>FOVM>FOVT and an intermediate image sensor, the intermediate lens having an intermediate lens symmetry axis; the intermediate camera is constructed to provide an intermediate image.

[0040] (19) wherein the intermediate sub-camera is configured to have an EFL that is equal to the geometric mean of an EFL of the wide-angle sub-camera and an EFL of the telephoto sub-camera.

[0041] (20) wherein at least one processor connected to such a camera is configured to process the intermediate image together with the telephoto image or the wide-angle image into an output image.

[0042] (21) wherein the axis of symmetry of the intermediate lens is substantially perpendicular to the axis of symmetry of the wide-angle lens and the intermediate image sensor is located on a plane substantially perpendicular to the axis of symmetry of the intermediate lens; and wherein the remote image sensor is located on a plane substantially perpendicular to the axis of symmetry of the remote lens.

[0043] (22) The camera further includes: an intermediate autofocus (AF) mechanism configured to move the intermediate lens module along the intermediate axis of symmetry, the intermediate axis of symmetry being substantially perpendicular to the axis of symmetry of the wide-angle lens; and a telephoto AF mechanism configured to move the telephoto lens module along the telephoto axis of symmetry; either the intermediate AF mechanism or the telephoto AF mechanism has a height substantially not exceeding the height of the telephoto lens module.

[0044] (23) wherein the intermediate AF mechanism includes one or more magnets coupled to individual coils, which are laterally positioned on one or both sides of the telephoto lens module, the magnets having a height substantially not exceeding the height of the telephoto lens module.

[0045] (24) wherein the intermediate AF mechanism contains only one magnet coupled to an individual coil.

[0046] (25) The camera further includes a third reflective element that is substantially tilted at 45 degrees with respect to the axis of symmetry of the wide-angle lens and the axis of symmetry of the intermediate lens; the third reflective element is configured to provide a folded optical path between the object side and the intermediate image sensor.

[0047] (26) The camera further includes a fourth reflecting element, which is positioned in a fourth optical path between the intermediate lens and the intermediate image sensor. The fourth reflecting element is configured to direct light rays propagating parallel to the second optical path toward the first optical path. The intermediate image sensor is located in a plane substantially parallel to the axis of symmetry of the intermediate lens.

[0048] (27) The camera further includes an intermediate autofocus (AF) mechanism configured to move the fourth reflective element along the axis of symmetry of the fourth reflective element.

[0049] (28) wherein the axis of symmetry of one intermediate lens of the intermediate sub-camera is substantially parallel to the axis of symmetry of the wide-angle lens and the wide-angle and intermediate image sensors are mounted on a single printed circuit board.

[0050] (29) wherein the axis of symmetry of one intermediate lens of the intermediate sub-camera is substantially perpendicular to the axis of symmetry of the wide-angle lens and the wide-angle and intermediate image sensors are mounted on a single printed circuit board.

[0051] (30) wherein at least one processor connected to such a camera is configured to determine an individual output field of view using a zoom factor (ZF).

[0052] (31) wherein at least one processor connected to such a camera is configured to output an output image formed by using wide-angle and intermediate images, for a ZF in which the FOV is set between FOVW and FOVM.

[0053] (32) wherein at least one processor connected to such a camera is configured to output an output image formed by using intermediate and telephoto images, for a ZF in which the FOV is set between FOVM and FOVT.

[0054] According to one example, the subject of this disclosure includes a digital camera configured to be integrated within a housing of an electronic device, the camera comprising: a wide-angle sub-camera, a telephoto sub-camera and a telephoto autofocus (AF) mechanism;

[0055] The wide-angle sub-camera includes a wide-angle lens module and a wide-angle image sensor. The wide-angle lens module has a wide-angle lens symmetry axis along a first optical path between an object side and the wide-angle image sensor. The wide-angle sub-camera is configured to provide a wide-angle image. The telephoto sub-camera includes a telephoto lens module and a telephoto image sensor. The telephoto lens module has a telephoto lens symmetry axis along a second optical path. The telephoto lens symmetry axis is positioned substantially perpendicular to the wide-angle lens symmetry axis. The telephoto sub-camera is configured to provide a telephoto image. A first mirror has a first mirror symmetry axis that is substantially tilted at 45 degrees with respect to both the wide-angle lens symmetry axis and the telephoto lens symmetry axis, and is designed to provide a folded optical path between the object and the telephoto image sensor.

[0056] The telephoto lens module includes a group of three to five lens elements, wherein the lens elements in the group are designed to have a diameter that substantially does not exceed the diameter of one aperture of the telephoto sub-camera, enabling the generation of an image on a whole area of ​​the telephoto image sensor, and enabling at least 75% of the light entering the telephoto lens module to pass toward the telephoto image sensor.

[0057] The telephoto AF mechanism is configured to move the telephoto lens along the telephoto axis of symmetry; the telephoto AF mechanism includes one or more magnets coupled to individual coils, which are laterally positioned on one or both sides of the telephoto lens module, the magnets having a height substantially not exceeding the height of the telephoto lens module.

[0058] This disclosure also relates to a mobile electronic device, such as a mobile phone (e.g., a smartphone), a portable computer, a notebook, a tablet computer, a watch, any type of wearable electronic device (e.g., a bracelet, watch, helmet, glasses, etc.), or the like, equipped with a digital camera as disclosed herein. According to some examples, such a digital camera is completely integrated within the electronic device (i.e., it does not protrude from the housing of the electronic device).

[0059] This disclosure also relates to a folding telephoto camera having the low camera profile as disclosed above.

Implementation Method

[0061] It should be understood that when a specific direction and / or angle value is proposed herein, it means that the value is within a range that is acceptable within the practical tolerances known in the relevant field.

[0062] Furthermore, for clarity, the term "substantial" is used herein to imply the possibility of variation in a value within an acceptable range. According to one example, the term "substantial" as used herein should be interpreted to imply a possible variation of up to 10% above or below any specified value. According to another example, the term "substantial" as used herein should be interpreted to imply a possible variation of up to 5% above or below any specified value. According to yet another example, the term "substantial" as used herein should be interpreted to imply a possible variation of up to 2.5% above or below any specified value. Specified values ​​can be absolute (e.g., substantial means not exceeding 45°, substantial is vertical, etc.) or relative (e.g., substantial means not exceeding x in height, etc.).

[0063] It should be noted that, in this discussion, "aperture diameter" refers to the diameter of one aperture in a camera with a fixed aperture size or the maximum aperture diameter in a camera with a variable aperture size.

[0064] As used herein, the phrases “for example,” “such as,” “for instance,” “in one embodiment,” and variations thereof describe non-limiting instances of the subject matter of this disclosure. It is understood that certain features of the subject matter of this disclosure in individual embodiments may also be combined and provided in a single embodiment for clarity. Conversely, various features of the subject matter of this disclosure in a single embodiment may also be provided individually or in any suitable sub-combination for brevity.

[0065] It should be noted that, as used herein, the term “optical block” refers to the lens module and the autofocus mechanism.

[0066] Turning to Figure 2A, which schematically shows an embodiment of a zoom and autofocus dual-aperture camera 200 with a folding telephoto lens disclosed herein, with (a) a general isometric view and (b) a cross-sectional isometric view. The isometric view is shown in relation to an XYZ coordinate system. The camera 200 includes two sub-cameras, a general wide-angle sub-camera 202 and a telephoto sub-camera 204.

[0067] The wide-angle camera 202 includes a wide-angle optical block having an individual aperture 208 (indicating the object side of the camera) and an optical lens module 210 (or simply "lens module"), and a wide-angle image sensor 214. The optical lens module 210 has a symmetry (optical) axis 212 in the Y direction. The telephoto camera 204 includes a telephoto optical block having an individual aperture 218 and an optical lens module 220, and a telephoto image sensor 224. The optical lens module 220 has a telephoto lens symmetry (optical) axis 222a.

[0068] Camera 200 further includes a first flat reflective element (e.g., a mirror or prism) 226 inserted within a "telephoto" optical path. The telephoto optical path extends from an object (not shown) through the telephoto lens module (or simply "telephoto lens") to a telephoto image sensor and is indicated by arrows 222b and 222a. Arrow 222b indicates a direction from the object side of the camera and is substantially parallel to the axis of symmetry 212 of the wide-angle sub-camera. For simplicity, this reflective element is referred to as a "mirror" below; however, this is merely an example and should not be considered a limitation.

[0069] According to one example, the wide-angle image sensor 214 is located in an XZ plane, while the telephoto image sensor is located in an XY plane substantially perpendicular to the telephoto lens axis of symmetry 222a. Various camera elements can be mounted on a substrate 232, such as a printed circuit board (PCB). It can be claimed that the telephoto image sensor is "upright" because it is located in a plane substantially perpendicular to both the wide-angle sensor 214 and the substrate 232.

[0070] Obviously, using a telephoto sub-camera that has a telephoto image sensor in an upright position helps to reduce the length of the telephoto sub-camera and thus the overall camera footprint, compared to a telephoto sub-camera that is positioned in the XZ plane, as described below with respect to Figure 3.

[0071] According to one example, the reflector 226 is substantially tilted at 45° with respect to the axis of symmetry (222a) of the telephoto lens and with respect to arrow 222b. The telephoto optical path is therefore "folded". Hereinafter, a telephoto lens having a folded optical path passing through it is referred to as a "folded telephoto lens", and a telephoto sub-camera having such a folded lens is referred to as a "folded telephoto sub-camera".

[0072] Both wide-angle and telephoto sub-cameras can be fixed focus (FF) or auto focus (AF). When present, one type of AF mechanism for wide-angle cameras is generally indicated by reference numeral 206, and in one instance, it may be similar to the mechanism shown in Figure 1. A new, low-profile AF mechanism is described below with respect to Figures 12 and 13.

[0073] If an AF mechanism is incorporated in a telephoto sub-camera, it is applied such that the autofocus movement is along the Z-axis. An AF mechanism may be coupled to a telephoto lens and may be operated to move the telephoto lens along the Z-axis in the direction indicated by an arrow 230 (i.e., parallel to its axis of symmetry 222a). The telephoto lens movement range may be, for example, between 100-500 μm. The camera 200 may further include (or otherwise operate connected to) a processing unit containing one or more appropriately configured processors (not shown) to process the telephoto and wide-angle images into an output image.

[0074] The processing unit may include specific hardware (HW) and software (SW) specifically designed for operation with the digital camera. Alternatively, the processor (e.g., its native CPU) of one of the electronic devices installed in the camera may be suitable for performing various processing operations with respect to the digital camera (including, but not limited to, processing telephoto and wide-angle images into output images).

[0075] According to some non-limiting examples, camera 200 (and other cameras described below) may have the dimensions and / or parameters as shown in Table 1. These dimensions (in millimeters) and parameters include: camera width W, camera length L, camera height H, effective focal length EFLM of the wide-angle sub-camera, wide-angle F-number F#W, effective focal length EFLT of the telephoto sub-camera, and telephoto F-number F#T. picture W L H EFL W EFLM EFL T F# W F# M F# T 2A 5-12 20-50 4-8 2-8 5-25 2-3 2-5 2B 10-25 10-40 4-8 2-8 5-25 2-3 2-5 3 5-12 20-50 4-8 2-8 5-25 2-3 2-5 4 5-12 20-50 4-8 2-8 5-25 2-3 2-5 6A 5-12 25-60 4-8 2-5 4-10 8-30 2-3 2-3 2-5 6B 5-12 20-50 4-8 2-5 4-10 8-30 2-3 2-3 2-5 6C 10-25 10-40 4-8 2-5 4-10 8-30 2-3 2-3 2-5 7 5-12 25-60 4-8 2-5 4-10 8-30 2-3 2-3 2-5 8 10-25 20-50 4-8 2-8 4-20 8-30 2-3 2-5 2-5 Table 1

[0076] For example, the folding of the telephoto lens module in camera 200 (and cameras 300-600 below) enables the use of a telephoto lens module having an EFLT of 12 mm while maintaining the overall camera height significantly lower than that of a typical upright telephoto lens using the same EFLT (e.g., 11.1 mm as described earlier in the previous art section).

[0077] To provide greater clarity and avoid confusion in the following figures, some elements similar to or the same as those in camera 200 may be described, but are shown without reference numerals.

[0078] FIG2B is a schematic isometric view showing another embodiment of a zoom and autofocus dual-aperture camera (200') with a folding telephoto lens module disclosed herein. Camera 200' includes substantially the same elements as camera 200, and such elements (when labeled) are therefore labeled with the same numbers. The two cameras differ mainly in the relative positioning (e.g., on substrate 232') of the telephoto and wide-angle sub-cameras and the reflector 226.

[0079] As shown, these elements are configured such that camera 200' occupies a space that is "more square" than camera 200. In particular, the width W in camera 200' is greater than the width W in camera 200, and the length L in camera 200' is less than the length L in camera 200. Note that the configuration shown, in which the sides of the wide-angle sub-camera are parallel to the X and Z axes respectively and the telephoto lens is substantially aligned along the Z axis, is shown only as an example, and in other embodiments, the sub-cameras may be positioned in different ways. For example, the wide-angle sub-camera may have sides that are not parallel to the X and Y axes, and the telephoto lens may be aligned in a direction other than Z, provided that the optical axis (before folding) is parallel to the axis of symmetry of the wide-angle camera. Camera 200' may have the dimensions and / or parameters shown in the examples in Table 1.

[0080] Figure 3 schematically illustrates another embodiment of a zoom and autofocus dual-aperture camera with a folding telephoto lens module, disclosed herein and designated 300, with (a) a general isometric view and (b) a cross-sectional isometric view. Camera 300 is substantially identical to camera 200, except that camera 300 includes a second mirror 302 inserted in the optical path between the telephoto lens and the telephoto image sensor 224, the path being indicated herein by arrows 304a and 304b. Furthermore, unlike in cameras 200 and 200' (but as in camera 100), the telephoto image sensor 224 is located in the XZ plane (as in the wide-angle sensor). According to one example, the wide-angle and telephoto image sensors may be placed on the same substrate, such as a PCB. Alternatively, the respective sensors may be mounted on a separate PCB. Both mirrors may be substantially tilted at 45° with respect to the telephoto lens axis of symmetry 222a.

[0081] As in camera 200, both the wide-angle and telephoto sub-cameras can be either fixed focus (FF) or autofocus (AF). As in camera 200, an AF mechanism (not shown) can be coupled to the telephoto lens and can be operated to move the telephoto lens along the Z-axis in the direction indicated by an arrow 230 (i.e., parallel to its axis of symmetry 222a). For example, camera 300 can have the same dimensions and / or parameters as camera 200 or be larger along the Z-axis (e.g., approximately 5-10 mm).

[0082] Camera 300 requires that the telephoto lens module be designed such that its back focal length (BFL) is large enough to enable the inclusion of the second reflector. The back focal length (BFL) is the distance along the optical path from the left-hand side of the telephoto lens barrel to the reflector and from there to the telephoto image sensor (the combined length of arrows 304a and 304b). Furthermore, the folded telephoto geometry within camera 300 allows for direct mounting of both the wide-angle and telephoto image sensors on a single common PCB. Alternatively, the individual sensors can be mounted on a separate PCB. Camera 300 may have, for example, the dimensions and / or parameters shown in Table 1.

[0083] Figure 4 schematically illustrates an embodiment of a zoom and autofocus dual-aperture camera with a folding telephoto lens, disclosed herein and designated 400, with (a) a general isometric view and (b) a cross-sectional isometric view. Camera 400 is substantially identical to camera 300, except that the telephoto sub-camera is autofocused by moving the second mirror using an AF mechanism (see: Figure 5) 402 coupled thereto. Mechanism 402 moves the second mirror 302 in a direction perpendicular to its flat plane, as indicated by arrow 430 (e.g., 45° for the XY and XZ planes). The range of mirror movement can be, for example, between 100 and 500 μm. Alternatively, the second mirror 302 can be moved in other directions to focus on its image captured by the telephoto image sensor, for example, along the Z-axis or Y-axis. Camera 400 may have, for example, the dimensions and / or parameters shown in Table 1.

[0084] Figure 5 schematically shows details of mechanism 402 in (a) a general isometric view and (b) a cross-sectional view through section AA. Mechanism 402 includes an electromagnetic actuator comprising a stationary element 404 and a moving element 406. The stationary element 404 includes four permanent magnets 408a-d. The moving element 406, shown herein in a cylindrical shape with an axis of symmetry 410, includes an iron core 412, which is at least partially surrounded by a coil 414. The moving element 406 is mechanically coupled to a reflector 302 at one end 416 and to four springs 420a-d at the opposite end 418, which are then rigidly coupled to a stationary frame 422. The number of springs shown is provided by way of example only, and fewer (e.g., one) or more springs may be used. In use, the current through coil 414 generates a magnetic force that causes movable element 406 and reflector 302 to move along axis of symmetry 410, as indicated by arrow 430.

[0085] FIG6A is a schematic isometric view showing an embodiment of a zoom and autofocus three-aperture camera 600 with a folding telephoto lens disclosed herein. The camera 600 includes, for example, the elements and functionality of a camera 200. That is, the camera 600 includes a wide-angle sub-camera 202 with a wide-angle lens 210 and a wide-angle sensor 214, a telephoto sub-camera 204 with a folding telephoto lens 220, a mirror 226, and an "upright" telephoto image sensor 224.

[0086] In this example, the three sub-cameras are substantially aligned along a common axis in the Z direction. As in camera 200, telephoto lens autofocus is achieved by moving the telephoto lens along the Z axis in the direction indicated by arrow 230. However, in addition to the elements of camera 200, camera 600 further includes a second telephoto (referred to as "intermediate (M)") sub-camera 602, which has an intermediate lens 604 and an intermediate sensor 606. Intermediate sub-camera 602 has an EFLM and FOVM between the wide-angle and telephoto sub-cameras (see: examples in Table 1). A symmetric (optical) axis 612 of the intermediate sub-camera is substantially parallel to axis 212 of wide-angle sub-camera 202 and direction 222b of telephoto sub-camera 204. Note that although the wide-angle and intermediate sub-cameras are shown in a specific configuration (intermediate sub-camera 602 is closer to the telephoto sub-camera 204), this order can be changed so that the positions of the wide-angle and intermediate sub-cameras are interchanged. Camera 600 may have, for example, the scales and / or parameters shown in Table 1.

[0087] In use, an output FOV of camera 600 (and cameras 600', 600", 700, and 800) is defined by a zoom factor (ZF). This FOV can be denoted as "FOVZF". For example, when zoomed to ZF=ZFM, the camera output is the same as that of a dual-aperture zoom camera that only has a wide-angle and an intermediate sub-camera, where the intermediate sub-camera replaces the telephoto sub-camera. When zoomed from ZFM to ZFT, the camera output is the same as that of a dual-aperture zoom camera that only has an intermediate and a telephoto sub-camera, where the intermediate sub-camera replaces the wide-angle sub-camera. This provides a "continuous zoom" (i.e., resolution gain pair (vs.) ZF) experience. A more detailed explanation of the term "continuous zoom" as used herein, and an example of a continuous zoom experience obtained with a camera disclosed herein, is presented with reference to Figure 8.

[0088] Figure 6B is a schematic isometric view showing another embodiment of a zoom and autofocus three-aperture camera with a folding telephoto lens, as disclosed herein and denoted as 600'. Camera 600' includes substantially the same elements as camera 600, but the wide-angle and intermediate sub-cameras are aligned along the Z direction, while the telephoto sub-camera has the Z direction as its axis of symmetry. As in camera 600, the positions of the wide-angle and intermediate sub-cameras are interchangeable. Camera 600' may have, for example, the dimensions and / or parameters shown in Table 1.

[0089] Figure 6C is a schematic isometric view showing yet another embodiment of a zoom and autofocus three-aperture camera with a folding telephoto lens disclosed herein and denoted as 600”. Camera 600” includes substantially the same elements as cameras 600 and 600’, but the positioning of the three sub-cameras is altered such that the folding telephoto lens is adjacent to and parallel to a side 608 of the wide-angle sub-camera 202 and a side 610 of the middle sub-camera 602. As in cameras 600 and 600’, the positions of the wide-angle and middle sub-cameras are interchangeable. Camera 600” may have, for example, the dimensions and / or parameters shown in Table 1.

[0090] Note that although the embodiments of the three-aperture camera with a folding telephoto lens in Figures 6A-6C are shown as including a “vertical” telephoto image sensor 224, other embodiments of the three-aperture camera with a folding telephoto lens may include a second mirror and a telephoto image sensor positioned in the XZ plane, as in camera 300. One such embodiment is shown in Figure 7. Figure 7 is a schematic isometric view showing yet another embodiment of a zoom and autofocus three-aperture camera with a folding telephoto lens disclosed herein and designated 700. Camera 700 can be substantially regarded as a camera in which an intermediate sub-camera 602 is attached to the elements of camera 300. Alternatively, it can be regarded as a camera in which the second mirror 302 is inserted in the optical path between the folding telephoto lens 220 and the telephoto image sensor 224. Remote autofocus can be achieved by moving the second reflecting mirror 302 (as in camera 400) or by moving the telephoto lens (as in camera 300). Camera 700 may have, for example, the dimensions and / or parameters shown in Table 1.

[0091] FIG8 is a schematic isometric view showing an embodiment of a zoom and autofocus three-aperture camera with two folding lenses disclosed herein and labeled 800. Camera 800 can be considered as combining the elements present in camera 200 with an additional "folding" intermediate sub-camera 802. Thus, as in camera 200, camera 800 may include a wide-angle sub-camera 202 with a wide-angle lens and a wide-angle sensor, a telephoto sub-camera 204 with a folding telephoto lens, a vertical telephoto image sensor 224, and a mirror 226. The folding intermediate sub-camera 802 includes an intermediate lens 804 and a vertical intermediate sensor 806. An additional mirror 808 reflects radiation arriving from the object side in a direction 810 parallel to direction 222b and axis 212, along an intermediate lens axis 812, through an intermediate lens 804 to an intermediate sensor, thus providing intermediate image data that can be combined with wide-angle and telephoto sub-camera image data. In some instances, the intermediate lens 804 can be moved along its axis 812 in the Z direction (moved as indicated by arrow 830) by an AF mechanism (not shown) to provide intermediate autofocus, similar to the telephoto autofocus described above by arrow 230.

[0092] An alternative embodiment of a camera with folding intermediate and telephoto lenses (not shown) may include additional mirrors and "flat" intermediate and telephoto image sensors (similar to the embodiments shown in Figures 3, 4, and 7 for the telephoto lens). Furthermore, according to this embodiment, autofocus can be achieved by moving these mirrors instead of these lenses. The camera 800 may have, for example, the dimensions and / or parameters shown in Table 1. This configuration of the camera 800 enables, for example, EFLM=3*EFLW and EFLT=9*EFLW while maintaining a camera height of less than 7 mm.

[0093] Figure 9a illustrates the user experience of resolution gain for ZF in an ideal optical zoom scenario. Figure 9b illustrates the user experience of resolution gain for ZF in a common scenario with two 13-megapixel (13M) sub-cameras (one wide-angle sub-camera and one telephoto sub-camera) and a 2-megapixel (2M) viewfinder (e.g., a display).

[0094] For example, suppose the wide-angle and telephoto sub-cameras have an EFL such that EFLT = 5 * EFLW. In this case, the initial resolution (ZF = 1) will be 2M for the observer. As ZF increases by the digital zoom of the sub-camera, the observer's 2M pixels will sample a smaller "new" FOV (resulting in higher resolution). This new FOV is a function of ZF, i.e.: FOVZF = FOVW / ZF. The new FOVZF is sampled from a smaller number of pixels (PXC) in the wide-angle sub-camera (resulting in lower resolution), according to PXC = 13M / (ZF)². As long as PXC > 2M (or ZF < (13 / 2)0.5 = DZC), the perceived resolution will increase with ZF. For a ZF close to 1, the resolution increase will be similar to the resolution increase of an optical zoom. For a digital ZF close to DZC, the resolution increase will be much lower. For a given digital zoom level (ZF) > digital zoom level (DZC), the resolution will remain constant. The formula describing the resolution gain (RG) achieved by digital zoom of a wide-angle sub-camera as a function of ZF can be written as: RG = RG(W)*(1 + CQ*(ZFC – 1)* sqrt(tanh(((ZF – 1) / CQ*(ZFC – 1)) 2)))

[0095] Where CQ (typically between 0.7 and 0.8) represents the camera quality at maximum resolution, and RG(W) is the perceived object resolution of a wide-angle sub-camera image without any digital zoom.

[0096] In Figure 9b, RG follows this formula for 1 < ZF < 5. When ZF = 5 (defined as "transition ZF" or ZFt), the output switches to a sub-camera T with a corresponding RG(T) = 5, where RG(T) is the perceived object resolution of the image from a sub-camera T without any digital zoom. Similarly, the continuous resolution gain with ZF after sub-camera switching follows: RG = RG(T)*(1 + CQ*(DZC – 1)* sqrt(tanh(((ZF / ZFT – 1) / CQ*(DZC – 1))2)))

[0097] As can be seen from Figure 9b, the resolution gain for ZF users is very different from that in an ideal optical zoom situation.

[0098] Figure 9c illustrates the user experience of resolution gain versus ZF in a common scenario involving a 13M sub-camera and a 2M viewfinder in a three-aperture camera, which includes a wide-angle sub-camera with EFLW, an intermediate sub-camera with EFLM = 2.35 * EFLW, and a telephoto sub-camera with EFLT = 5 * EFLW. In this scenario, there are two sub-camera transitions ZFt1 = 2.35 and ZFt2 = 5. Correspondingly, there are three resolution gains RG(W) = 1, RG(M) = 2.35, and RG(T) = 5. This figure illustrates the following RG behavior:

[0099] From ZF=1 to ZF=2.35, RG = RG(W)*(1 +CQ*(DZC-1)* sqrt(tanh(((ZF / 1-1) / CQ*(DZC-1))2)));

[0100] From ZF=2.35 to ZF=5, RG = RG(M)*(1 +CQ*(DZC – 1)* sqrt(tanh(((ZF / ZFT1 – 1) / CQ*(DZC – 1))2)));

[0101] Continuing forward from ZF=5, RG = RG(T)*(1 +CQ*(DZC – 1)* sqrt(tanh(((ZF / ZFT2 – 1) / CQ*(DZC – 1))2))).

[0102] As can be seen, in this case, the resolution gain for ZF is very close to the user experience in an ideal optical zoom.

[0103] Therefore, according to one example of the subject matter of this disclosure, given an EFLW and EFLT, an intermediate sub-camera with an individual EFLM can be selected based on the geometric mean of the EFLW and EFLT values. According to this example, the EFLM is selected based on the equation =>, where in some cases, the EFLM equals 1 / 2.

[0104] As described above, it is desirable to design a camera with the smallest possible dimensions to accommodate operation with commonly used image sensors and to fit the thickness of an electronic device (e.g., a smartphone) in which the camera is mounted (preferably without protruding from the device's housing). Therefore, in a multi-aperture (e.g., dual-aperture) camera disclosed herein, it is desirable to maintain the height of a folding telephoto sub-camera as low as possible. Unlike conventional cameras (e.g., cantilever sub-cameras), in a folding telephoto sub-camera disclosed herein, the camera height is relative to the module's dimensions along the y-axis, for example, as shown in Figure 2, and primarily depends on the diameter of the largest lens among the lenses in the individual lens modules.

[0105] At the same time, it is also desirable to achieve good image resolution and provide high zoom performance (e.g., ZF=X5 or larger), and therefore the aperture diameter in the folding telephoto sub-camera must be kept sufficiently large to achieve a sufficiently small F# (e.g., F#=3 or smaller). Obviously, the larger the EFL of the telephoto sub-camera, the larger the aperture must be to maintain a given F#.

[0106] Furthermore, in many conventional lens modules (e.g., upright wide-angle or telephoto lens modules) where the sensor is larger than the aperture, the diameter of these lenses is designed to increase towards the sensor, so that, in order to accommodate the field of view of light entering the camera aperture, it is intended to fall over the entire area of ​​the sensor. In a folding lens unit, this conventional design of increasing the lens diameter would result in a larger camera height and is therefore undesirable.

[0107] Therefore, a new folding telephoto sub-camera is disclosed herein as a lens module having a group of lens elements, which is designed to have a reduced height while maintaining light blocking below a certain value and allowing incoming light to be projected onto the entire area of ​​the image sensor.

[0108] According to an example of the present disclosure, the lens elements in the lens module are not designed to have a diameter that increases toward the sensor. Instead, the individual lens elements in the lens module of this type of folding telephoto sub-camera are scaled down. The diameter of each lens is determined to be as small as possible while maintaining sufficient light transmission through the lens toward the sensor to obtain the desired camera quality (e.g., resolution and signal-to-noise ratio (SNR)) and enabling the continuous provision of an image across the entire area of ​​the image sensor (i.e., the active pixel area of ​​the sensor). These image sensors may be, for example, 1 / 3” and 1 / 4” image sensors.

[0109] According to certain examples, the diameter of the largest lens element in the telephoto lens module (which contains at least 3 lens elements) is substantially no larger than the aperture (218) to allow light to enter the telephoto sub-camera (i.e., the telephoto sub-camera aperture). Therefore, the diameter of the telephoto sub-camera aperture can help define the maximum diameter of the lens element in the telephoto lens module.

[0110] According to one example, the diameter of the largest lens element in the telephoto lens module is less than or equal to the diameter of the telephoto sub-camera aperture. According to another example, the diameter of the largest lens element in the telephoto lens module does not exceed 10% of the diameter of the telephoto sub-camera aperture. According to yet another example, the diameter of the largest lens element in the telephoto lens module does not exceed 5% of the diameter of the telephoto sub-camera aperture. According to yet another example, the diameter of the largest lens element in the telephoto lens module does not exceed 2.5% of the diameter of the telephoto sub-camera aperture. Examples of folding telephoto sub-camera design parameters based on these principles are described below with reference to Figures 10 and 11 and Tables 2-7.

[0111] Figures 10A-10C show various examples of telephoto lens modules (reference numerals 220a, 220b, or 220c) that can be used in a zoom dual-aperture camera disclosed herein, which include a folding telephoto lens. Each module includes individual groups of lens elements. Also shown in Figure 10A are the aperture stop 218, the axis of symmetry 222a in the "z" direction, the telephoto image sensor 224, and the additional cover plate 223.

[0112] Lens modules 220a, 220b, or 220c respectively include 5, 4, and 3 lens elements (or simply "elements"). These lens elements are designated as L1, L2, L3, L4, and L5 (in lens module 220a), L1, L2, L3, and L4 (in lens module 220b), and L1, L2, and L3 (in lens module 220c). It is evident that the examples described herein include at least three lens elements, which can provide sufficient image quality.

[0113] Detailed optical and aspherical surface data are provided in the following tables, Tables 2 and 3 for lens module 220a, Tables 4 and 5 for lens module 220b, and Tables 6 and 7 for lens module 220c. The units for radius of curvature (R), lens element thickness, and / or distance between elements along the axis of symmetry, and diameter are expressed in mm. “Nd” is the refractive index, and “Vd” is a parameter indicating the chromatic aberration of the lens material. A large Vd indicates a small chromatic aberration, and vice versa. “BK7” is a known glass with one of the known Nd and Vd values. The equation for the aspherical surface profile is expressed as: where “r” is the distance from (and perpendicular to) the axis of symmetry, k is the conic coefficient, c = 1 / R, where R is the radius of curvature, and α is a coefficient provided in Tables 3, 5, and 7. Note that the maximum value of r, “max r”, is diameter / 2. It should also be noted that in Table 2 (and in Tables 4 and 6 below), the distances between various elements (and / or surfaces) are measured along the axis of symmetry Z, where the aperture is at Z=0. Each number is measured from the previous surface. # Radius (R) distance N d / V d diameter Conic coefficient k 1 unlimited -0.324 4.0 0 2 4.938499 0.779 1.544921 / 55.9149 4.0 2.2402 3 53.73119 0.074 4.0 28 4 4.310708 1.217 1.635517 / 23.9718 4.0 1.2159 5 2.127431 0.509 3.5 -0.9831 6 7.374006 0.678 1.544921 / 55.9149 3.6 10.8851 7 -147.731 0.604 3.5 -12.2 8 -2.28889 0.742 1.635517 / 23.9718 3.5 -7.6686 9 -2.97793 0.082 3.9 -5.7863 10 2.411553 0.6 1.544921 / 55.9149 4.1 -6.0953 11 3.111521 6.982 4.0 -8.4191 12 Infinite 0.21 BK7 6.0 0 13 Infinite 0.187 6.0 0 14 unlimited 0 6.1 0 Table 2 # α1 α2 α3 α4 α5 α6 α7 α8 2 0 -2.5699E-03 -6.5546E-04 -2.4933E-05 -1.9717E-05 9.1450E-07 1.8986E-08 0.0000E+00 3 0 4.7508E-04 -4.3516E-04 -6.5166E-05 -4.2148E-07 1.0572E-06 4.4021E-08 0.0000E+00 4 0 -9.1395E-03 2.5655E-04 -4.5210E-05 7.4472E-06 -1.1011E-06 2.8410E-07 0.0000E+00 5 0 -1.0827E-02 1.0372E-03 5.0554E-05 -9.5710E-06 1.1448E-05 -2.2474E-06 0.0000E+00 6 0 -9.5074E-03 1.0268E-03 2.4209E-04 1.1234E-04 3.9355E-06 -9.7194E-06 7.9430E-07 7 0 -3.6269E-03 8.7662E-04 7.0010E-04 6.5578E-05 -2.0053E-05 -4.1923E-06 0.0000E+00 8 0 -1.2355E-02 1.8611E-03 1.5007E-04 -9.4899E-05 -8.0223E-06 -3.1794E-06 0.0000E+00 9 0 -7.3112E-03 9.3354E-04 2.5951E-06 -4.0614E-06 -8.8752E-06 -1.6836E-06 6.2706E-07 10 0 -2.7777E-03 7.1318E-04 3.0673E-05 -2.3126E-06 -2.9513E-06 5.1524E-07 0.0000E+00 11 0 -3.8232E-03 4.8687E-04 4.8505E-05 2.2064E-06 -4.0755E-06 5.8813E-07 0.0000E+00 Table 3 # radius distance N d / V d diameter Conic coefficient k 1 unlimited -0.420 4.0 2 4.114235 1.674 1.544921 / 55.9149 4.0 -0.6679 3 -14.5561 0.073 4.0 15.3789 4 76.19695 1.314 1.635517 / 23.9718 3.9 -10.0000 5 3.726602 1.130 3.6 -0.3699 6 5.336503 1.407 1.635517 / 23.9718 3.8 -9.4625 7 9.356809 0.839 3.6 -12.2000 8 2.76767 0.512 1.544921 / 55.9149 3.8 -3.0862 9 2.342 3.457 4.0 -2.3717 10 unlimited 0.210 BK7 8.0 11 unlimited 0.894 8.0 12 unlimited 0.000 8.0 Table 4 # α1 α2 α3 α4 α5 α6 α7 2 0 3.1365E-04 -2.4756E-04 -3.2950E-05 -3.1474E-06 -6.6837E-07 -9.3198E-08 3 0 1.1887E-03 -5.1479E-04 -7.0886E-06 -6.6567E-06 7.3082E-07 -2.1508E-07 4 0 -6.7467E-03 1.6492E-03 -1.7937E-04 2.4668E-05 -6.1495E-08 -5.8827E-07 5 0 -1.8460E-02 3.8467E-03 -5.0388E-04 9.0675E-05 6.3951E-06 -4.2041E-06 6 0 -1.0557E-03 5.4851E-04 -1.1124E-04 1.2112E-04 -1.4549E-05 -1.0474E-06 7 0 -1.3355E-02 7.1465E-03 -1.8536E-03 4.1411E-04 -8.4044E-06 -6.4049E-06 8 0 -5.9360E-02 6.4070E-03 4.1503E-04 -2.5533E-04 4.3694E-05 -5.0293E-06 9 0 -5.6451E-02 9.0603E-03 -5.9225E-04 -1.1000E-04 2.2464E-05 -1.5043E-06 Table 5 # radius distance N d / V d Diameter Conic coefficient k 1 unlimited 0.060 5.0 0.00 2 7.942 1.682 1.534809 / 55.6639 5.0 -7.2579 3 -15.778 2.040 5.0 17.1752 4 -2.644 2.143 1.639078 / 23.2529 5.0 -5.3812 5 -7.001 0.063 5.0 -8.3079 6 2.300 1.193 1.534809 / 55.6639 5.0 -0.5654 7 3.373 7.787 5.0 -0.1016 8 unlimited 0.210 BK7 8.0 9 unlimited 0.200 8.0 Table 6 # α1 α2 α3 α4 α5 α6 α7 2 0 -3.4545E-04 -2.6977E-04 -6.3091E-06 -7.6965E-07 0.0000E+00 0.0000E+00 3 0 -1.2414E-03 -3.0118E-04 1.6812E-05 -1.6865E-06 1.9446E-07 -1.1391E-08 4 0 3.0073E-03 -4.8811E-04 9.4948E-05 -5.7587E-06 1.0543E-07 0.0000E+00 5 0 3.6847E-03 -4.8608E-04 7.2121E-05 -2.9304E-06 0.0000E+00 0.0000E+00 6 0 -1.5774E-02 1.4580E-03 -2.6302E-04 2.3905E-05 -1.1017E-06 0.0000E+00 7 0 -8.6658E-03 1.2548E-03 -3.6145E-04 5.0797E-05 -3.8486E-06 1.1039E-07 Table 7

[0114] The following term is defined: “Lens optical height” “H” is the maximum diameter of the optical usable area (i.e., the area through which light passes directly from the camera aperture to the sensor to form an image) of each lens element. This term is illustrated in Figure 11A for a four-element lens module. Each element Ln has an individual optical height “Hn”. The figure shows H / 2 as the distance between the axis of symmetry and the tip of the arrow. “Camera optical height” is the maximum optical height among all lens elements, in this example H1.

[0115] "Percentage of light blocked" (per viewpoint) is defined as the percentage of light rays that reach the camera from a very distant object at a given viewpoint (horizontal and vertical) and enter the camera aperture without reaching the image sensor. Clearly, the relative light blocking increases as the diameter of the lens element decreases. Figure 11B illustrates the partial light blocking 240 caused by an aperture stop 250 inserted (for example) between elements L3 and L4 of a four-element telephoto lens. Also simply referred to as an "aperture stop," the aperture stop is constructed to prevent light from reaching the lens edge and scattering in all directions.

[0116] According to the present disclosure, the diameter of the lens element in the telephoto lens module is determined such that the light blocked by the aperture does not prevent more than a predetermined percentage of incoming light from reaching the image sensor.

[0117] The telephoto lens disclosed above allows for the use of a larger telephoto image sensor (>4.5 mm × 3.35 mm), enabling a high total pixel count (e.g., 13 megapixels). It provides a low camera 1.25, which enables a low camera module height (e.g., <1.25*(1+EFL / F#)=1.25*(1+camera aperture)), see also Figures 12 and 13.

[0118] The folding telephoto lens disclosed herein allows for a long EFL (e.g., >10 mm), a low F# (e.g., <3) for high zoom, resulting in more light and optical resolution, and a low percentage of light blocking (<25%) for all viewing angles. As shown above, a folding telephoto lens module may include, for example, 3 to 5 lens elements. This combination of lens elements enables high image quality to be achieved at a low cost.

[0119] It should be noted that the lens element of this type of telephoto lens module is fixed in position by a special structure (e.g., a cylinder), for example, by means of a plastic basin (cold cylinder). Therefore, the telephoto lens module discussed herein is considered to include its structure (cylinder) for fixing the lens element in position and a substrate (e.g., one or more PCBs). The one or two magnets may be positioned on the substrate, as shown in Figures 12 and 13, or on the side of the substrate. In either case, its height is substantially no greater than the height of this type of telephoto lens module.

[0120] Figure 12 shows a camera disclosed herein and labeled 1200, illustrated in (a) an isometric view and (b) an external view. The camera 1200 includes an AF mechanism with two magnets (1202 and 1204) and two coils (1206 and 1208) for a folding telephoto lens. Each pair of magnets-coils is configured to provide a force to move a telephoto lens 1210 along its axis of symmetry. This force (and movement) is countered (and reversed) by a spring 1212.

[0121] Figure 13 shows a camera disclosed herein and labeled 1300, in (a) an isometric view and (b) an external view. Compared to camera 1200, camera 1300 includes an AF mechanism for a folding telephoto lens, comprising a magnet (1302), a coil (1306), and a spring (1312). The AF mechanism shown in Figures 12 and 13 is constructed to operate based on the principle of a voice coil actuator (VCA) (commonly referred to as a "magnetic actuator").

[0122] This AF mechanism is specially designed to maintain a low camera profile. In one example, the AF mechanism is designed to be mounted laterally on one or two sides of the telephoto lens module, while the other sides remain untouched by the AF mechanism components.

[0123] Specifically, one or two magnets (magnetically coupled to individual coils) are designed to have a height substantially no greater than the height of the telephoto lens module, thereby avoiding any significant contribution to the overall height of the folding telephoto sub-camera.

[0124] This design is illustrated in Figure 12 (showing an AF design with two magnets) and Figure 13 (showing an AF design with one magnet). Note that although the magnets are upright positioned on one or both sides of the telephoto lens module, they are kept out of contact with the magnets by two other planes perpendicular to the magnets (on the object side indicated by arrow OS and the substrate side indicated by arrow SS). In summary, this design of the AF mechanism and magnets clearly reduces (or completely avoids in some configurations) the increase in the overall height of the telephoto sub-camera, which might otherwise be caused by the AF mechanism.

[0125] According to one example, the height of the magnets is less than or equal to the height of the telephoto lens module (e.g., defined by the highest lens). According to another example, the height of the magnets does not exceed 10% of the height of the telephoto lens module. According to another example, the height of the magnets does not exceed 5% of the height of the telephoto lens module. According to yet another example, the height of the magnets does not exceed 2.5% of the height of the telephoto lens module.

[0126] The camera as a whole (including the AF mechanism) can be encapsulated in a low-profile mechanical package (housing) 1250 with a height HT (total height), referring to FIG12(b), enabling the inclusion of a zoom dual or triple aperture camera disclosed herein in a low-profile mobile phone such that HT is equal to or less than 6.5 mm and in some instances equal to or less than 5.7 mm.

[0127] Figure 14 shows a schematic diagram of an example of a portable electronic device according to one embodiment of the present disclosure, the portable electronic device having an integrated dual-aperture camera with a folding telephoto lens module. As shown in the image, camera 1450 (including a dual-aperture camera with a folding telephoto lens module and a camera housing) is fully integrated into the portable electronic device 1400 and does not protrude from the housing of the device. The camera is oriented within the portable device so that its longitudinal dimension is horizontally positioned relative to the device. Due to the folded optical path of the telephoto sub-camera, it can have a structure that does not protrude from the housing of the electronic device (e.g., a smartphone) to provide a high zoom effect (e.g., X5 or larger).

[0128] Although this disclosure has been described with reference to certain embodiments and generally associated methods, alternations and variations of such embodiments and methods will be apparent to those skilled in the art. This disclosure is to be understood not as limited to the specific embodiments described herein, but only as defined by the scope of the appended claims. [Simplified Explanation of the Diagram]

[0060] Non-limiting examples of the embodiments disclosed herein are described below with reference to the accompanying drawings, which are listed after this paragraph. These drawings and descriptions are intended to illustrate and explain the embodiments disclosed herein and should in no way be considered limiting. The same elements in different drawings may be indicated by the same reference numerals. Figure 1 schematically illustrates the design of a dual-aperture camera with zoom and autofocus (AF); Figure 2A schematically illustrates, in (a) a general isometric view and (b) a side view, a dual-aperture camera with zoom and autofocus having a folding telephoto lens module according to an example of the present disclosure; Figure 2B schematically illustrates, in (a) a general isometric view, a dual-aperture camera with zoom and autofocus having a folding telephoto lens module according to an example of the present disclosure; Figure 3 schematically illustrates, in (a) a general isometric view and (b) a side view, a dual-aperture camera with zoom and autofocus having a folding telephoto lens module according to an example of the present disclosure; Figure 4 schematically illustrates, in (a) a general isometric view and (b) a side view, a dual-aperture camera with zoom and autofocus having a folding telephoto lens module according to an example of the present disclosure; Figure 5 schematically shows details of the autofocus mechanism for moving the second mirror in the example shown in Figure 4, using (a) a general isometric view and (b) a cross-sectional view through section AA; Figure 6A schematically shows a zoom and autofocus three-aperture camera with a folding telephoto lens according to an example of the present disclosure, using a general isometric view; Figure 6B schematically shows a zoom and autofocus three-aperture camera with a folding telephoto lens according to an example of the present disclosure, using a general isometric view; Figure 6C schematically shows a zoom and autofocus three-aperture camera with a folding telephoto lens according to an example of the present disclosure, using a general isometric view; Figure 7 schematically shows a zoom and autofocus three-aperture camera with two folding lenses according to an example of the present disclosure, using a general isometric view; Figure 8 schematically shows a zoom and autofocus three-aperture camera with two folding telephoto lenses according to an example of the present disclosure, using a general isometric view. Figure 9 shows graphs illustrating: (a) user experience of resolution gain versus zoom factor in an ideal continuous zoom; (b) user experience of resolution gain versus zoom factor for a camera comprising two (wide-angle and telephoto) sub-cameras including a 13-megapixel sensor and a 2-megapixel viewfinder; and (c) user experience of resolution gain versus zoom factor for a camera comprising three (wide-angle, intermediate, and telephoto) sub-cameras according to an example of the present disclosure.Figure 10A shows a telephoto lens module with a five-element telephoto lens unit according to an example of the present disclosure, which can be used in a camera; Figure 10B shows a telephoto lens module with a four-element telephoto lens unit according to an example of the present disclosure, which can be used in a camera disclosed herein; Figure 10C shows a telephoto lens module with a three-element telephoto lens unit according to an example of the present disclosure, which can be used in a camera; Figure 11A illustrates the term "lens optical height" H / 2 for each lens element of a four-element lens unit according to an example of the present disclosure; Figure 11B illustrates the light-blocking effect according to an example of the present disclosure; Figure 12 schematically shows a camera module according to an example of the present disclosure in (a) an isometric view and (b) an external view. Figure 13 schematically illustrates another camera module according to one embodiment of the present disclosure with (a) an isometric view and (b) an external view; and Figure 14 schematically illustrates a portable electronic device with an integrated dual-aperture camera having a folding telephoto lens module according to one embodiment of the present disclosure.

Claims

1. A multi-camera system, comprising: A first camera, the first camera including a first lens module and a first image sensor, the first camera having a first field of view (FOV1); a second camera, the second camera including a second lens module and a second image sensor, the second camera having a second field of view (FOV2); and a third camera, the third camera including a third lens module and a third image sensor, the third camera having a third field of view (FOV3), wherein the first camera, the second camera and the third camera are configured to receive incident light from a first direction, wherein the second lens module and the third lens module are configured to move along the first direction, and wherein the first camera, the second camera and the third camera are arranged along a second direction perpendicular to the first direction.

2. The multi-camera system as described in claim 1, wherein the first field of view (FOV1), the second field of view (FOV2), and the third field of view (FOV3) are different from each other.

3. The multi-camera system as described in claim 2, wherein the second camera is placed adjacent to the third camera, and wherein the third field of view (FOV3) is greater than the second field of view (FOV2).

4. A multi-camera system, comprising: A first camera, the first camera including a first lens module and a first image sensor, the first camera having a first field of view (FOV1); a second camera, the second camera including a second lens module and a second image sensor, the second camera having a second field of view (FOV2) different from the first field of view (FOV1); and a third camera, the third camera including a third lens module and a third image sensor, the third camera having a third field of view (FOV3) different from the first field of view (FOV1), wherein the first camera, the second camera and the third camera are arranged sequentially along a first direction, wherein the second camera and the third camera are configured to receive incident light from a second direction perpendicular to the first direction, and wherein at least one of the first lens module and the second lens module is configured to be moved by a first autofocus mechanism to perform autofocus (AF).

5. The multi-camera system as claimed in claim 4, wherein the first lens module comprises at least three lens elements.

6. The multi-camera system as claimed in claim 5, wherein the first lens module comprises five lens elements.

7. The multi-camera system as claimed in claim 6, wherein the third lens module is configured to be moved by a second autofocus mechanism for autofocus (AF).

8. The multi-camera system as described in claim 6, wherein the third field of view (FOV3) is different from the second field of view (FOV2).

9. The multi-camera system as described in claim 8, wherein the third field of view (FOV3) is greater than the second field of view (FOV2).

10. The multi-camera system as described in claim 8, wherein the second field of view (FOV2) is greater than the third field of view (FOV3).

11. The multi-camera system as claimed in claim 9, wherein at least one lens module configured to be moved by the first autofocus mechanism for autofocus (AF) is the first lens module.

12. The multi-camera system as described in claim 11, wherein the first field of view (FOV1) < the second field of view (FOV2) < the third field of view (FOV3).

13. A multi-camera system, comprising: A first camera, comprising a first lens module and a first image sensor, the first lens module having at least three lens elements, the first camera having a first field of view (FOV1); a second camera, comprising a second lens module and a second image sensor, the second camera having a second field of view (FOV2) larger than the first field of view (FOV1); and a third camera, comprising a third lens module and a third image sensor, the third camera having a third field of view (FOV3) different from the first field of view (FOV1), wherein the first camera and the second camera are arranged along a first direction, wherein the third camera is positioned such that an axis along the first direction does not intersect any part of the third camera, and wherein at least one of the first lens module, the second lens module and the third lens module is configured to move along a third direction perpendicular to the first direction.

14. The multi-camera system as claimed in claim 13, wherein the first lens module comprises five lens elements.

15. The multi-camera system as described in claim 14, wherein the second field of view (FOV2) is less than the third field of view (FOV3).

16. The multi-camera system as described in claim 13, wherein the second camera is placed next to the first camera and the third camera.

17. The multi-camera system as claimed in claim 15, wherein at least one of the second lens module and the third lens module is configured to move along the third direction.

18. The multi-camera system as claimed in claim 15, wherein the first lens module is configured to be moved by an autofocus mechanism for autofocus (AF).

19. The multi-camera system as described in claim 16, wherein the second field of view (FOV2) is less than the third field of view (FOV3).

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