Zoom Dual Aperture Camera with Folding Lens

Abstract

A zoom digital camera including a wide-angle sub-camera and a foldable fixed telephoto sub-camera. The foldable telephoto sub-camera can autofocus by moving its lens or a reflecting element inserted in the optical path between its lens and the corresponding image sensor. The foldable telephoto sub-camera is configured to have a low profile so that it can be integrated within a portable electronic device.

Description

[0001] Divisional Application

[0002] This application is a divisional application of the application with application number 202110964226.3, invention title "Zoom dual-aperture camera with folded lens", and applicant "Core Optoelectronics Co., Ltd.".

[0003] Cross-reference to Related Applications

[0004] This application claims the priority of U.S. Patent Application No. 14 / 717,258 filed on May 20, 2015 and U.S. Patent Application No. 14 / 455,906 filed on August 10, 2014, both of which have the title "Zoom dual-aperture camera with folded lens". Technical Field

[0005] The presently disclosed subject matter generally relates to the field of digital cameras, and in particular, to multi-aperture digital cameras. Background Art

[0006] In recent years, mobile devices such as cellular phones (in particular, smart phones), tablet computers, and laptop computers have become ubiquitous. Such devices typically include one or two compact digital cameras, for example, a main rear camera (i.e., a camera on the rear side of the device that faces away from the user and is often used for casual photography) and a secondary front camera (i.e., a camera located on the front side of the device and is often used for video conferencing).

[0007] Many of these cameras are designed similar to the traditional structure of digital still cameras, i.e., they include optical components (or a series of several optical elements and a main aperture) placed on top of an image sensor (hereinafter also simply referred to as "sensor"). The optical components (also referred to as "optical elements") refract the incident light rays and bend them to produce an image of the scene on the sensor.

[0008] The size of these cameras is mainly determined by the size of the sensor and the height of the optical device. These are typically combined by the focal length (f) of the lens and its field of view (FOV). A lens that must image a specific FOV on a sensor of a specific size has a specific focal length. Keeping the FOV constant, the larger the sensor size (e.g., in the X-Y plane), the larger the focal length and the height of the optical device.

[0009] As the size of mobile devices (and in particular, the thickness of devices such as smart phones) continues to decrease, the size of compact cameras is becoming an increasingly limiting factor in device thickness. Several approaches have been proposed to reduce the thickness of compact cameras in order to alleviate this constraint. Recently, multi-aperture systems have been proposed for this purpose. In such a system, instead of having one aperture with a series of optical elements, the camera is divided into several apertures, each aperture having dedicated optical elements and all sharing a similar field of view. Hereinafter, each such aperture, together with the optical device and sensor area on which an image is formed, is defined as a "sub-camera". Images from the sub-cameras are fused together to create a single output image.

[0010] In some multi-aperture camera designs, compared to the images created by a reference single-aperture camera, each sub-camera produces a smaller image on the image sensor. Thus, the height of each sub-camera can be less than the height of the single-aperture camera, thereby reducing the overall height of the camera and allowing for a thinner design of the mobile device.

[0011] Dual-aperture zoom cameras are known in which one sub-camera has a wide FOV ("wide-angle sub-camera") while the other has a narrow FOV ("telephoto sub-camera"). One problem with dual-aperture zoom cameras involves the height of the zoom telephoto sub-camera. There is a significant difference in the heights (also known as "total track length" or "TTL") of the telephoto ("T") and wide-angle ("W") sub-cameras. TTL is typically defined as the maximum distance between the object-side surface of the first lens element and the camera image sensor plane. In most micro-lenses, TTL is greater than the effective focal length (EFL) of the lens. The typical TTL / EFL ratio for a given lens (or lens unit) is about 1.3. In single-aperture smartphone cameras with 1 / 3 to 1 / 4" sensors, the EFL is typically between 3.5mm and 4.5mm, resulting in a FOV of 70° to 80°.

[0012] For example, assume one wishes to implement a dual-aperture X2 optical zoom in a smartphone, then it is natural to use EFL W = 3.5mm and EFL T = 2xEFL w = 7mm. However, in the absence of spatial constraints, the wide-angle lens would have an EFL W = 3.5mm and a TTL W of 3.5×1.3 = 4.55mm, while the telephoto lens would have an EFL T = 7mm and a TTL T equal to 7×1.3 = 9.1mm. Incorporating a 9.1mm lens in a smartphone camera could result in a camera height of about 10mm, which is unacceptable to many smartphone manufacturers.

[0013] An example of a solution to the above problem is described in the co-invented and co-owned PCT patent application PCT / IB2014 / 062180 entitled "Dual-aperture zoom digital camera". Some of the principles of this solution are shown in Figure 1 which Figure 1 schematically illustrates an embodiment of a dual-aperture zoom camera 100 with autofocus (AF), where (a) is a general isometric view and (b) is a sectional isometric view. The 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, an optical lens module 110, and a sensor 112. Similarly, sub-camera 104 includes an optical block 114 having an aperture 116, an optical lens module 118, and a sensor 120. Each optical lens module may include several lens elements as well as infrared (IR) filters 122a and 122b. Optionally, 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, with a small baseline 124 between the centers of the two apertures 108 and 116. Each sub-camera may also include AF mechanisms 126 and 128 controlled by a controller (not shown), respectively. For each sub-camera, the camera 100 is "thin" as represented by TTL / EFL. Typically, TTL W / EFL W > 1.1 and TTL T / EFL T < 1.0 (e.g., 0.85).

[0014] Although the zoom range in the camera 100 is approximately X2, it may be advantageous to further increase this range. However, this requires a further increase in the telephoto lens EFL (EFL T ), which will result in an increase in the height of the camera. Increasing the EFL T to an exemplary 12 mm will result in an undesirable camera height, e.g., 0.85 × 12 + 0.9 = 11.1 mm. SUMMARY OF THE INVENTION

[0015] As pointed out above, the requirements for digital cameras for portable electronic devices are related to the size and image quality of the cameras. Moreover, when the camera is installed inside a portable device, these requirements become even more important as opposed to other external camera units that can be attached to the portable device.

[0016] In the case of an internal (integral) camera unit, the camera needs to have as small a size as possible in order to fit within the thickness of the device in which it is mounted (preferably without protruding from the housing of the device), while being suitable for operation with a commonly used image sensor. This problem is even more important when using a telephoto lens with a long effective focal length (EFL) to obtain a relatively high zoom effect.

[0017] Accordingly, in one aspect of the presently disclosed subject matter, there is provided a zoom digital camera including a wide-angle sub-camera and a telephoto sub-camera. The wide-angle sub-camera includes 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.

[0018] 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 being positioned substantially perpendicular to the wide-angle lens symmetry axis. The telephoto sub-camera is configured to provide a telephoto image.

[0019] The camera further includes a first reflecting element having a first reflecting element symmetry axis that is substantially inclined 45 degrees with respect to the wide-angle lens symmetry axis and the telephoto lens symmetry axis and is operable to provide a folded optical path between the object and the telephoto image sensor. Accordingly, the telephoto sub-camera is considered to be folded and is referred to herein as a "folded telephoto sub-camera".

[0020] The wide-angle lens has a wide-angle field of view (FOV W ), and the telephoto lens has a telephoto field of view (FOV W ) that is narrower than the FOV T . According to a non-limiting example, the telephoto sub-camera provides an X5 zoom effect as compared to the wide-angle sub-camera.

[0021] A digital camera is operably connected to at least one image processor configured to process a telephoto image and a wide-angle image into an output image. A method of fusing images received through different optical paths into a single output image is provided, for example, in co-invented and co-owned PCT Patent Application No. 14 / 365,711 entitled "HIGH-RESOLUTION THIN MULTI-APERTURE IMAGING SYSTEMS" and in co-invented and co-owned U.S. Patent Application No. 14 / 365,711 entitled "DUAL APERTURE ZOOM DIGITAL CAMERA", and discloses a multi-aperture imaging system including a first camera having a first sensor that captures a first image and a second camera having a second sensor that captures a second image. Based on a zoom factor, either image can be selected as the main image or the auxiliary image. An output image having a viewpoint determined by the main image is obtained by registering the auxiliary image to the main image.

[0022] To further adapt to the size of the foldable telephoto sub-camera and the trend of electronic portable devices, and to minimize their thickness as much as possible, various features of the foldable telephoto sub-camera are specifically configured to enable a highly reduced foldable telephoto sub-camera. Reducing the height of the telephoto sub-camera enables reducing the overall height of the dual-aperture camera. In addition, a reduction in the height of the foldable telephoto sub-camera is achieved while maintaining the desired image quality.

[0023] Thus, in addition to the above features, according to various examples of the subject matter of the present disclosure, a zoom digital camera can include one or more of the following features (1) to (32) in any desired combination and arrangement.

[0024] (1) wherein the telephoto lens module of the foldable telephoto sub-camera includes a set of at least 3 lens elements, and wherein the lens elements in the set are designed to have a diameter that is substantially no more than the aperture of the telephoto sub-camera. As explained below, this is different from a conventional lens module, wherein the diameter of the lens is designed to be wider and wider towards the sensor.

[0025] (2) wherein the telephoto lens module of the foldable telephoto sub-camera includes a set of 3 to 5 lens elements.

[0026] (3) wherein the telephoto sub-camera further includes a substrate, a structure for holding the lens elements in place, and a camera housing.

[0027] (4) wherein the aperture of the telephoto sub-camera is designed to provide a sufficiently low F# (e.g., equal to or less than 3) to increase the light falling on the telephoto image sensor.

[0028] (5) Among them, the telephoto lens module is designed to be able to generate an image over the entire area of the telephoto image sensor. The telephoto image sensor can be, for example, a 1 / 3" image sensor or a 1 / 4" image sensor.

[0029] (6) Among them, the lens elements in the group are designed such that the blocked light does not exceed a specific percentage of the light entering the telephoto lens module (for example, no more than 25% of the light entering the telephoto lens module is blocked).

[0030] (7) Among them, according to one example, the telephoto sub - camera is configured to have the following technical parameters: EFL > 9mm, F# ≤ 3, and for all viewing angles, the light blockage does not exceed more than 25% of the light entering the aperture of the telephoto sub - camera.

[0031] (8) Among them, the telephoto sub - camera is characterized in that its height does not exceed 6.5 mm.

[0032] (9) Among them, the telephoto sub - camera is characterized in that its height does not exceed 5.7 mm.

[0033] (10) Among them, the telephoto image sensor is located in a plane substantially perpendicular to the axis of symmetry of the telephoto lens.

[0034] (11) Among them, the telephoto sub - camera includes a telephoto autofocus (AF) mechanism, which is configured to move the telephoto lens along the telephoto axis of symmetry; the AF mechanism is designed such that its height does not substantially exceed the height of the telephoto lens module.

[0035] (12) Among them, the AF mechanism includes one or more magnets coupled to corresponding coils, the magnets being laterally positioned on one or both sides of the telephoto lens module, and the height of the magnets does not substantially exceed the height of the telephoto lens module.

[0036] (13) Among them, the AF mechanism includes only one magnet coupled to a corresponding coil.

[0037] (14) Among them, the camera further includes a second reflecting element in the second optical path located between the telephoto lens module and the telephoto image sensor, the second reflecting element being configured to direct light propagating parallel to the second optical path to the first optical path, wherein the telephoto image sensor is located in a plane substantially perpendicular to the axis of symmetry of the wide - angle lens.

[0038] (15) Among them, the camera further includes a telephoto autofocus (AF) mechanism, which is configured to move the second reflecting element along the axis of symmetry of the second reflecting element.

[0039] (16) Among them, the wide - angle image sensor and the telephoto image sensor are mounted on a single printed circuit board.

[0040] (17) Wherein, at least one processor operatively connected to the camera is configured to determine a corresponding output field of view using a zoom factor (ZF).

[0041] (18) Wherein, the wide-angle lens module has a wide-angle field of view FOV W , and the telephoto lens module has a telephoto field of view FOV w narrower than the FOV T ; the camera further includes a mid-tele sub-camera, which includes a mid-tele lens module and a mid-tele image sensor having a field of view FOV w >FOV M >FOV T ; the mid-tele lens has a mid-tele lens axis of symmetry; the mid-tele camera is configured to provide a mid-tele image. M

[0042] (19) Wherein, the mid-tele sub-camera is configured with an EFL equal to the geometric mean of the EFL of the wide-angle sub-camera and the EFL of the telephoto sub-camera.

[0043] (20) Wherein, at least one processor operatively connected to the camera is configured to process the mid-tele image together with the telephoto image or the wide-angle image as an output image.

[0044] (21) Wherein, the mid-tele lens axis of symmetry is substantially perpendicular to the wide-angle lens axis of symmetry, and the mid-tele image sensor is located in a plane substantially perpendicular to the mid-tele lens axis of symmetry; and wherein, the telephoto image sensor is located in a plane substantially perpendicular to the telephoto lens axis of symmetry.

[0045] (22) Wherein, the camera further includes a mid-tele autofocus (AF) mechanism configured to move the mid-tele lens module along a mid-tele axis of symmetry substantially perpendicular to the wide-angle lens axis of symmetry; and a telephoto AF mechanism configured to move the telephoto lens module along the telephoto axis of symmetry; the height of either the mid-tele AF mechanism or the telephoto AF mechanism is substantially no more than the height of the telephoto lens module.

[0046] (23) Wherein, the mid-tele AF mechanism includes one or more magnets coupled to corresponding coils, the magnets being laterally positioned on one or both sides of the telephoto lens module, and the height of the magnets is substantially no more than the height of the telephoto lens module.

[0047] [[ID=३५]](24) Wherein, the mid-tele AF mechanism includes only one magnet coupled to a corresponding coil.

[0048] (25) Wherein, the camera further includes a third reflecting element inclined at approximately 45 degrees with respect to the wide-angle lens axis of symmetry and the mid-tele lens axis of symmetry; the third reflecting element is configured to provide a folded optical path between the object side and the mid-tele image sensor.

[0049] (26) Wherein, the camera further includes a fourth reflection element positioned in a fourth optical path between the mid - focal lens and the mid - focal image sensor, the fourth reflection element being configured to direct light propagating parallel to the second optical path to the first optical path, and the mid - focal image sensor is located in a plane substantially parallel to the axis of symmetry of the mid - focal lens.

[0050] (27) Wherein, the camera further includes a mid - focal autofocus (AF) mechanism configured to move the fourth reflection element along the axis of symmetry of the fourth reflection element.

[0051] (28) Wherein, the axis of symmetry of the mid - focal lens of the mid - focal sub - camera is substantially parallel to the axis of symmetry of the wide - angle lens, and the wide - angle image sensor and the mid - focal image sensor are mounted on a single printed circuit board.

[0052] (29) Wherein, the axis of symmetry of the mid - focal lens of the mid - focal sub - camera is substantially perpendicular to the axis of symmetry of the wide - angle lens, and the wide - angle image sensor and the mid - focal image sensor are mounted on a single printed circuit board.

[0053] (30) Wherein, at least one processor operatively connected to the camera is configured to determine a corresponding output field of view using a zoom factor (ZF).

[0054] (31) Wherein, at least one processor operatively connected to the camera is configured to output an output image formed by using the wide - angle image and the mid - focal image with a ZF for setting the FOV between FOV W and FOV M .

[0055] (32) Wherein, at least one processor operatively connected to the camera is configured to output an output image formed by using the mid - focal image and the telephoto image with a ZF for setting the FOV between FOV M and FOV T .

[0056] According to one example, the presently disclosed subject matter includes a digital camera configured to be integrated within a housing of an electronic device. The camera includes a wide - angle sub - camera, a telephoto sub - camera, and a telephoto autofocus (AF) mechanism;

[0057] 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 axis of symmetry along a first optical path between the 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, a telephoto image sensor, and a first mirror. The telephoto lens module has a telephoto lens axis of symmetry along a second optical path, and the telephoto lens axis of symmetry is positioned substantially perpendicular to the wide-angle lens axis of symmetry. The telephoto camera is configured to provide a telephoto image. The first mirror has a first mirror axis of symmetry that is substantially inclined 45 degrees with respect to the wide-angle lens axis of symmetry and the telephoto lens axis of symmetry, and is operable to provide a folded optical path between the object and the telephoto image sensor.

[0058] Wherein, the telephoto lens module includes a set of 3 to 5 lens elements, and wherein the lens elements in the set are designed to have a diameter that is substantially no more than the diameter of the aperture of the telephoto sub-camera, so as to enable an image to be generated over the entire area of the telephoto image sensor and to enable at least 75% of the light entering the telephoto lens module to pass towards the telephoto image sensor.

[0059] Wherein, the telephoto AF mechanism is configured to move the telephoto lens along the telephoto axis of symmetry. The AF mechanism includes one or more magnets coupled to corresponding coils, and the magnets are laterally positioned on one or both sides of the telephoto lens module, and the height of the magnets is substantially no more than the height of the telephoto lens module.

[0060] The subject matter of the present disclosure also contemplates mobile electronic devices such as cellular phones (e.g., smart phones), portable computers, notepads, tablet computers, watches, any type of electronic wearable device (e.g., bracelets, watches, helmets, glasses, etc.), etc., which are equipped with a digital camera as disclosed herein. According to some examples, the digital camera is fully integrated within the electronic device (i.e., without protruding from the housing of the electronic device).

[0061] The subject matter of the present disclosure also contemplates a folded telephoto sub-camera having a low camera profile as disclosed above. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Non-limiting examples of the embodiments disclosed herein are described below with reference to the accompanying drawings appended hereto, which are listed later in this paragraph. The drawings and the description are intended to illustrate and clarify the embodiments disclosed herein and should not be considered to limit in any way. The same elements in different drawings may be indicated by the same reference numerals.

[0063] Figure 1 Schematically shows the design of a dual-aperture camera with zoom and AF;

[0064] Figure 2AA zoom and autofocus dual-aperture camera with a collapsible telephoto lens module according to an example of the present disclosure is schematically shown in (a) a general isometric view and (b) a side view;

[0065] Figure 2B A zoom and autofocus dual-aperture camera with a collapsible telephoto lens module according to an example of the present disclosure is schematically shown in a general isometric view;

[0066] Figure 3 A zoom and autofocus dual-aperture camera with a collapsible telephoto lens module according to an example of the present disclosure is schematically shown in (a) a general isometric view and (b) a side view;

[0067] Figure 4 A zoom and autofocus dual-aperture camera with a collapsible telephoto lens module according to an example of the present disclosure is schematically shown in (a) a general isometric view and (b) a side view;

[0068] Figure 5 Details of an autofocus mechanism for moving a second mirror in the example shown are schematically shown in (a) a general isometric view and (b) a cross-sectional view taken along section A-A for use in Figure 4 the example shown.

[0069] Figure 6A A zoom and autofocus triple-aperture camera with a collapsible telephoto lens according to an example of the present disclosure is schematically shown in a general isometric view;

[0070] Figure 6B A zoom and autofocus triple-aperture camera with a collapsible telephoto lens according to an example of the present disclosure is schematically shown in a general isometric view;

[0071] Figure 6C A zoom and autofocus triple-aperture camera with a collapsible telephoto lens according to an example of the present disclosure is schematically shown in a general isometric view;

[0072] Figure 7 A zoom and autofocus triple-aperture camera with two collapsible lenses according to an example of the present disclosure is schematically shown in a general isometric view;

[0073] Figure 8 A zoom and autofocus triple-aperture camera with two collapsible telephoto lenses according to an example of the present disclosure is schematically shown in a general isometric view;

[0074] Figure 9Illustrates the resolution gain versus zoom factor in the user experience of (a) ideal continuous zoom; (b) a camera including two wide-angle and telephoto sub-cameras with 13-megapixel sensors and 2-megapixel viewers; and (c) a camera including three wide-angle, mid-range, and telephoto sub-cameras with 13-megapixel sensors and 2-megapixel viewers, as illustrated in the examples of the currently disclosed subject matter;

[0075] Figure 10A Illustrates a telephoto lens module having a five-element telephoto lens unit that can be used in a camera, according to an example of the currently disclosed subject matter;

[0076] Figure 10B Illustrates an embodiment of a telephoto lens module having a four-element telephoto lens unit that can be used in a camera disclosed herein, according to an example of the currently disclosed subject matter;

[0077] Figure 10C Illustrates a telephoto lens module having a three-element telephoto lens unit that can be used in a camera, according to an example of the currently disclosed subject matter;

[0078] 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 currently disclosed subject matter;

[0079] Figure 11B Illustrates the effect of blocked light, according to an example of the currently disclosed subject matter;

[0080] Figure 12 Schematically illustrates a camera module according to an example of the currently disclosed subject matter in (a) an isometric view and (b) an external view;

[0081] Figure 13 Schematically illustrates another camera module according to an example of the currently disclosed subject matter in (a) an isometric view and (b) an external view; and

[0082] Figure 14 Schematically illustrates a portable electronic device having an integrated dual-aperture camera with a foldable telephoto lens module, according to an example of the currently disclosed subject matter. DETAILED DESCRIPTION

[0083] It should be understood that when specific orientation and / or angular values are given herein, they are intended to include a range of acceptable values within the practical tolerances known in the relevant art.

[0084] In addition, for clarity, the term "substantially" is used herein to imply the possibility of variation within an acceptable range. According to one example, the term "substantially" 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 "substantially" as used herein should be interpreted to imply a possible variation of up to 5% above or below any specified value. According to another example, the term "substantially" as used herein should be interpreted to imply a possible variation of up to 2.5% above or below any specified value. The specified value can be an absolute value (e.g., substantially not exceeding 45°, substantially vertical, etc.) or relative (e.g., substantially not exceeding the height of x, etc.).

[0085] Note that in the current discussion, "aperture diameter" refers to the diameter of the aperture in a camera with a constant aperture size or the maximum aperture diameter in a camera with a variable aperture size.

[0086] As used herein, the phrases "for example", "such as", "like", "in an embodiment", and variations thereof describe non-limiting examples of the presently disclosed subject matter. It should be appreciated that, for clarity, certain features of the presently disclosed subject matter described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, for brevity, the various features of the presently disclosed subject matter described in the context of a single embodiment may also be provided separately or in any suitable sub-combination.

[0087] Note that the term "optical block" as used herein refers to a lens module together with an autofocus mechanism.

[0088] Now turning to Figure 2A , which schematically shows, in (a) a general isometric view and (b) a sectional isometric view, an embodiment of a zoom and autofocus dual-aperture camera 200 with a collapsible telephoto lens disclosed herein. The isometric view is shown in relation to an XYZ coordinate system. The camera 200 includes two sub-cameras, a conventional wide-angle sub-camera 202 and a telephoto sub-camera 204.

[0089] The wide-angle camera 202 includes a wide-angle optical block having an optical lens module 210 (or simply referred to as "lens module") with a corresponding aperture 208 (indicating the object side of the camera) and a symmetric (and optical) axis 212 in the Y direction, and a wide-angle image sensor 214. The telephoto camera 204 includes a telephoto optical block having a corresponding aperture 218 and an optical lens module 220 having a telephoto lens symmetric (and optical) axis 222a, and a telephoto image sensor 224.

[0090] The camera 200 also includes a first flat reflective element (e.g., a mirror or prism) 226 inserted into the "telephoto" optical path. The telephoto optical path extends from an object (not shown) through a telephoto lens module (or simply referred to as "telephoto lens") to a telephoto sensor and is marked by arrows 222b and 222a. Arrow 222b indicates the 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, the reflective element will be referred to as a "mirror" hereinafter, however, this is merely exemplary and should not be construed as limiting in any way.

[0091] According to one example, the wide-angle image sensor 214 is located in the X-Z plane, while the telephoto image sensor is located in the X-Y plane that is substantially perpendicular to the axis of symmetry 222a of the telephoto lens. Various camera elements can be mounted on a substrate 232, e.g., a printed circuit board (PCB). It can be said that the telephoto sensor is "upright" as it is located in a plane that is substantially perpendicular to the plane of the wide-angle sensor 214 and the substrate 232.

[0092] It is noted that, as described hereinafter with reference to Figure 3 a telephoto sub-camera using a telephoto sensor in an upright position helps reduce the length of the telephoto sub-camera and thus reduces the overall camera footprint as compared to a telephoto sensor located in the X-Z plane.

[0093] According to one example, the mirror 226 is substantially inclined at 45° with respect to the telephoto lens axis of symmetry (222a) and arrow 222b. Thus, the telephoto optical path is "folded". Hereinafter, a telephoto lens having a folded optical path passing therethrough 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".

[0094] The wide-angle and telephoto sub-cameras can be fixed focus (FF) or auto focus (AF). When present, the AF mechanism for the wide-angle camera is typically indicated by the numeral 206 and, in one example, it can be similar to the Figure 1 mechanism shown. A new low-profile AF mechanism is described hereinafter with reference to Figure 12 and Figure 13

[0095] ​If an AF mechanism is included in the telephoto camera, the AF mechanism is applied such that the autofocus movement is along the Z-axis. The AF mechanism can be coupled to and operable to move the telephoto lens along the Z-axis in the direction shown by arrow 230 (i.e., parallel to its symmetry axis 222a). The telephoto lens movement range can be, for example, between 100 μm and 500 μm. The camera 200 can also include (or be operably connected to) a processing unit including one or more appropriately configured processors (not shown) for processing the telephoto image and the wide-angle image into an output image.

[0096] The processing unit can include hardware (HW) and software (SW) dedicated to operating with a digital camera. Alternatively, a processor of an electronic device (e.g., its local CPU) in which the camera is installed can be adapted to perform various processing operations related to the digital camera (including but not limited to processing the telephoto image and the wide-angle image into an output image).

[0097] According to some non-limiting examples, the camera 200 (and other cameras mentioned below) can have the dimensions and / or parameters shown in Table 1. These dimensions (given in millimeters) and parameters include the camera width W, the camera length L, the camera height H, the effective focal length EFL of the wide-angle sub-camera W , the wide-angle F-number F#W, the effective focal length EFL of the telephoto sub-camera T and the telephoto F-number F# T .

[0098] Figure W L H <![CDATA[EFL W > <![CDATA[EFL M > <![CDATA[EFL T > <![CDATA[F# w > <![CDATA[F# M > <![CDATA[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

[0099] 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

[0100] Table 1

[0101] For example, folding the telephoto lens module in the camera 200 (and in cameras 300 to 600 below) enables the use of a telephoto lens module with an EFL T of 12 mm while maintaining the overall camera height significantly lower than that of a camera using a normal upright telephoto lens with the same EFL T (e.g., 11.1 mm mentioned in the background section above).

[0102] To provide more clarity and avoid confusion in the following figures, some elements similar or identical to those in the camera 200 are mentioned but not shown with reference numerals.

[0103] Figure 2BAnother embodiment of a zoom and autofocus dual-aperture camera (200') with a foldable telephoto lens module disclosed herein is schematically shown in a general isometric view. Camera 200' includes elements that are substantially the same as those of camera 200, and such elements (when numbered) are correspondingly numbered with the same digits. The main difference between the two cameras lies in the relative positioning of the telephoto and wide-angle sub-cameras and the mirror 226 (e.g., on the substrate 232').

[0104] As shown, these elements are arranged such that camera 200' has a more "square" coverage area than camera 200. In particular, the width W in camera 200' is greater than the width W in camera 200, while the length L in camera 200' is less than the L in camera 200. Note that the illustrated configuration (where the sides of the wide-angle sub-camera are respectively parallel to the X and Z axes, and the telephoto lens is substantially aligned along the Z axis) is shown by way of example only, and in other embodiments, each sub-camera can be positioned differently. For example, the wide-angle sub-camera can have sides that are not parallel to the X, Y axes, and the telephoto lens can be aligned in a direction different from Z, as long as the optical axis before folding is parallel to the wide-angle camera symmetry axis. Camera 200' can have the exemplary dimensions and / or parameters shown in Table 1.

[0105] Figure 3 Another embodiment of a zoom and autofocus dual-aperture camera numbered 300 with a foldable telephoto lens disclosed herein is schematically shown in (a) a general isometric view and (b) a sectional isometric view. Camera 300 is substantially the same as camera 200, except that camera 300 includes a second mirror 302 inserted in the optical path between the telephoto lens and the telephoto sensor 224, which path is here marked by arrows 304a and 304b. Additionally, and different from cameras 200 and 200' (but as in camera 100), the telephoto sensor 224 is located in the X-Z plane (the same as the wide-angle sensor). According to one example, the wide-angle sensor and the telephoto sensor can be placed on the same substrate, e.g., a PCB. Alternatively, each sensor can be mounted on a separate PCB. The two mirrors can be substantially inclined at 45° with respect to the telephoto lens symmetry axis 222a.

[0106] As in camera 200, the wide-angle and telephoto sub-cameras can be fixed focus (FF) or autofocus (AF). As in camera 200, an AF mechanism (not shown) is coupled to and can operate to move the telephoto lens along the Z axis in the direction shown by arrow 230 (i.e., parallel to the symmetry axis 222a). Camera 300 can have, for example, the same dimensions and / or parameters as camera 200, or be larger along the Z axis (e.g., approximately 5 mm to 10 mm).

[0107] The camera 300 requires that the telephoto lens module be designed such that its back focal length (BFL), i.e., the distance along the optical path from the left-hand side of the telephoto lens barrel to the mirror and from there to the telephoto image sensor (the combined length of arrows 304a and 304b), is large enough to allow for the inclusion of a second mirror. Additionally, the folded telephoto geometry in the camera 300 allows for the direct mounting of the wide-angle image sensor and the telephoto image sensor on a single common PCB. Alternatively, each sensor can be mounted on a separate PCB. The camera 300 can have dimensions and / or parameters as shown, for example, in Table 1.

[0108] Figure 4 An embodiment of a zoom and autofocus dual-aperture camera numbered 400 having a folded telephoto lens as disclosed herein is schematically shown in (a) a general isometric view and (b) a sectional isometric view. The camera 400 is substantially the same as the camera 300 except for autofocusing the telephoto sub-camera by moving the second mirror using an AF mechanism (see Figure 5 ) 402. The mechanism 402 moves the second mirror 302 in a direction perpendicular to its plane as indicated by arrow 430 (e.g., at 45° to the X-Y and X-Z planes). The mirror movement range can be, for example, between 100 μm and 500 μm. Alternatively, the second mirror 302 can be moved in other directions to focus the telephoto image captured by the telephoto sensor, e.g., along the Z-axis or the Y-axis. The camera 400 can have dimensions and / or parameters as shown, for example, in Table 1.

[0109] Figure 5 Details of the mechanism 402 are schematically shown in (a) a general isometric view and (b) a sectional view through section A-A. The mechanism 402 includes an electromagnetic actuator that includes a fixed member 404 and a moving member 406. The fixed member 404 includes four permanent magnets 408a to 408d. The moving member 406, shown here as having a cylindrical shape with a symmetry axis 410, includes a core 412 at least partially surrounded by a coil 414. The moving member 406 is mechanically coupled to the mirror 302 at one end 416 and to four springs 420a to 420d at the opposite end 418, which are in turn rigidly coupled to a fixed frame 422. The number of springs shown is provided by way of example only, and fewer (e.g., one) or more than four springs can be used. In use, a current through the coil 414 causes a magnetic force that causes the moving member 406 and the mirror 302 to move along the symmetry axis 410 as indicated by arrow 430.

[0110] Figure 6AAn embodiment of a zoom and autofocus triple-aperture camera 600 with one of the foldable telephoto lenses disclosed herein is schematically shown in a general isometric view. Camera 600 includes elements and functions such as those of camera 200. That is, camera 600 includes a wide-angle sub-camera 202 having a wide-angle lens 210 and a wide-angle sensor 214, a telephoto sub-camera 204 having a foldable telephoto lens 220, a mirror 226, and an "upright" telephoto sensor 224.

[0111] 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 "mid-tele" or "M") sub-camera 602 having a mid-tele lens 604 and a mid-tele sensor 606. The mid-tele sub-camera 602 has an EFL M and FOV M that are adjacent to the EFL and FOV of the wide-angle and telephoto sub-cameras, (see examples in Table 1). The symmetric (and optical) axis 612 of the mid-tele sub-camera is substantially parallel to the axis 212 of the wide-angle sub-camera 202 and the direction 222b in the telephoto sub-camera 204. Note that while the wide-angle and mid-tele sub-cameras are shown in a particular arrangement (the mid-tele sub-camera 602 is closer to the telephoto sub-camera 204), this order can be changed such that the wide-angle and mid-tele sub-cameras exchange positions. Camera 600 can have dimensions and / or parameters such as those shown in Table 1.

[0112] In use, the output FOV of camera 600 (and cameras 600', 600", 700, and 800) is defined by the zoom factor ZF. Such a FOV can be labeled "FOV ZF ". For example, when zoomed up to ZF = ZF M , the camera output is the same as that of a dual-aperture zoom camera having only a wide-angle and a mid-tele sub-camera, where the mid-tele sub-camera replaces the telephoto sub-camera. When zooming from ZF M to ZF T , the camera output is the same as that of a dual-aperture zoom camera having only a mid-tele and a telephoto sub-camera, where the mid-tele sub-camera replaces the wide-angle sub-camera. This provides a "continuous zoom" (i.e., resolution gain versus ZF) experience. A more detailed explanation of the term "continuous zoom" as used herein and examples of the continuous zoom experience obtained using the cameras disclosed herein are provided with respect to Figure 8

[0113] Figure 6B ​Another embodiment of a zoom and autofocus triple-aperture camera with a folded telephoto lens as disclosed herein and numbered 600' is schematically shown in a general isometric view. Camera 600' includes elements substantially the same as those of camera 600, but the wide-angle and mid-telephoto 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 mid-telephoto sub-cameras are interchangeable. Camera 600' may have dimensions and / or parameters as shown, for example, in Table 1.

[0114] Figure 6C Yet another embodiment of a zoom and autofocus triple-aperture camera with a folded telephoto lens as disclosed herein and numbered 600" is schematically shown in a general isometric view. Camera 600" includes elements substantially the same as those of cameras 600 and 600', but the positioning of the three sub-cameras is changed such that the folded telephoto lens is adjacent and parallel to the side 608 of the wide-angle sub-camera 202 and the side 610 of the mid-telephoto sub-camera 602. As in cameras 600 and 600', the positions of the wide-angle and mid-telephoto sub-cameras are interchangeable. Camera 600" may have dimensions and / or parameters as shown, for example, in Table 1.

[0115] Note that although a triple-aperture camera with an embodiment of a folded telephoto lens having Figures 6A to 6C is shown as including an "upright" telephoto sensor 224, other triple-aperture cameras with an embodiment of a folded telephoto lens may include a second mirror and a telephoto sensor positioned in the X-Z plane as in camera 300. Figure 7 One such embodiment is shown. Figure 7 Yet another embodiment of a zoom and autofocus triple-aperture camera with a folded telephoto lens as disclosed herein and numbered 700 is schematically shown in a general isometric view. Camera 700 can essentially be regarded as a camera in which the mid-telephoto sub-camera 602 is added to the elements of camera 300. Alternatively, it can be regarded as a camera in which a second mirror 302 is inserted into the optical path between the folded telephoto lens 220 and the telephoto sensor 224. Telephoto autofocus can be achieved by moving the second mirror 302 (as in camera 400, as indicated by arrow 430), or alternatively, by moving the telephoto lens (as in camera 300). Camera 700 may have dimensions and / or parameters as shown, for example, in Table 1.

[0116] Figure 8An embodiment of a zoom and autofocus triple-aperture camera numbered 800 with two folding lenses disclosed herein is schematically shown in a general isometric view. The camera 800 can be considered as a combined element present in the camera 200 with an added "folding" mid-tele sub-camera 802. Thus, similar to in the camera 200, the camera 800 can 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, an upright telephoto sensor 224, and a mirror 226. The folding mid-tele sub-camera 802 includes a mid-tele lens 804 and an upright mid-tele sensor 806. The added mirror 808 reflects the radiation arriving from the object side in the direction 810 parallel to the direction 222b and the axis 212 along the mid-tele lens symmetry axis 812 through the mid-tele lens 804 to the mid-tele sensor, thereby providing mid-tele image data, which can be combined with the wide-angle and telephoto sub-camera image data. In some examples, the mid-tele lens 804 can be moved (the movement shown by the arrow 830) along its axis 812 in the Z direction by an AF mechanism (not shown) to provide mid-tele autofocus, similar to the telephoto autofocus movement illustrated by the arrow 230 above.

[0117] An alternative embodiment (not shown) of a camera with folding mid-tele and telephoto lenses can include additional mirrors and "flat" mid-tele and telephoto sensors (similar to the embodiments shown in Figure 3 , Figure 4 and Figure 7 ). Additionally, according to this example, autofocus can be achieved by moving these mirrors instead of the lenses. The camera 800 can have dimensions and / or parameters such as those shown in Table 1. This configuration of the camera 800 enables, for example, the achievement of EFL M = 3 * EFL W and EFL T = 9 * EFL W , while maintaining the camera height less than 7 mm.

[0118] Figure 9 The (a) in Figure 9 illustrates the user experience of resolution gain versus ZF in the case of ideal optical zoom.

[0119] For example, assuming that the wide-angle and telephoto sub-cameras have an EFL T = 5 * EFL W satisfying EFL S。In this case, the starting resolution (ZF = 1) will be 2M for the viewer. As ZF increases through digital zoom of the sub - camera, the 2M pixels of the viewer will sample a smaller "new" FOV (which helps for higher resolution). This new FOV is a function of ZF, i.e., FOV ZF = FOV W / ZF. According to PXC = 13M / (ZF) 2 , the new FOV ZF is sampled by a smaller number of pixels (PXC) in the wide - angle sub - camera (which helps for lower resolution). As long as PXC > 2M (or ZF < (13 / 2) 0 . 5 = DZC), the perceived resolution will increase with ZF. For ZF close to 1, the resolution increase will be similar to that of optical zoom. For digital ZF close to DZC, the resolution increase will be much lower. For digital ZF > DZC, the resolution will remain constant. The formula describing the resolution gain (RG) achieved by digital zoom of the wide - angle sub - camera as a function of ZF can be written as:

[0120] RG = RG(W) * (1 + CQ * (ZFC - 1) * sqrt(tanh(((ZF - 1) / CQ * (ZFC - 1)) 2 )))

[0121] 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 the wide - angle sub - camera image without any digital zoom.

[0122] In Figure 9 (b), RG follows this formula for 1 < ZF < 5. At ZF = 5 (defined as "transition ZF" or ZF t ), the output switches to the T sub - camera with a corresponding RG(T) = 5, where RG(T) is the perceived object resolution of the T sub - camera image without any digital zoom. In a similar way, the continuous resolution gain with ZF after the sub - camera switch follows:

[0123] RG = RG(T) * (1 + CQ * (DZC - 1) * sqrt(tanh(((ZF / ZFT - 1) / CQ * (DZC - l)) 2 )))

[0124] From Figure 9 (b), it can be seen that the user experience of the resolution gain with ZF is very different from that in the case of ideal optical zoom.

[0125] Figure 9Figure (c) shows the resolution gain versus ZF for the user experience in the common case of a 13M sub - camera and a 2M viewer with a three - aperture camera, which includes a wide - angle sub - camera with an EFL W and an intermediate mid - telephoto sub - camera with an EFL M = 2.35×EFL W and a telephoto sub - camera with an EFL T = 5*EFL W In this case, there are two sub - camera conversion ZFs t1 = 2.35 and ZF t2 = 5. Correspondingly, there are three resolution gains RG(W)=1, RG(M)=2.35, and RG(T)=5. The figure shows the following RG behavior:

[0126] From ZF = 1 to ZF = 2.35, RG = RG(W)*(1 + CQ*(DZC - 1)*sqrt(tanh(((ZF / l - 1) / CQ*(DZC - 1)) 2 )));

[0127] From ZF = 2.35 to ZF = 5, RG = RG(M)*(1 + CQ*(DZC - 1)*sqrt(tanh(((ZF / ZFT1 - 1) / CQ*(DZC - 1)) 2 )));

[0128] From ZF = 5 onwards, RG = RG(T)*(1 + CQ*(DZC - 1)*sqrt(tanh(((ZF / ZFT2 - 1) / CQ*(DZC - 1)) 2 ))).

[0129] It can be seen that in this case, the resolution gain versus ZF for the user experience is very close to that in ideal optical zoom.

[0130] Thus, according to an example of the currently disclosed subject matter, given EFL W and EFL T , a mid - telephoto sub - camera with a corresponding EFL W can be selected based on the geometric mean of the EFL T value and the EFL M value. According to this example, EFL is selected based on the equation M , where, in some cases, EFL M is equal to

[0131] As mentioned above, it is desirable to design a camera with as small a size as possible in order to be suitable for operation with a commonly used image sensor and to match the thickness of an electronic device (e.g., a smartphone) in which the camera is installed (preferably without protruding from the housing of the device). Thus, in the multi-aperture (e.g., dual-aperture) cameras disclosed herein, it is desirable to keep the height of the folded telephoto sub-camera as low as possible. Different from a normal camera (e.g., an upright sub-camera), in the folded telephoto sub-camera disclosed herein, the height of the camera is related to the dimension of the module in the y-axis as shown in, for example, FIG. 2, and largely depends on the diameter of the largest lens among the lenses in the corresponding lens module.

[0132] Meanwhile, it is also desirable to achieve good image resolution while providing a high zoom effect (e.g., ZF = X5 or greater), so the aperture in the folded telephoto sub-camera must be kept large enough to enable an adequately small F# (e.g., F# = 3 or less). It is noted that the larger the EFL of the telephoto sub-camera, the larger the aperture must be to maintain a given F#.

[0133] In addition, in many conventional lens modules having a sensor larger than the aperture (e.g., upright wide-angle or telephoto lens modules), the diameter of the lens is designed to be wider and wider towards the sensor so that it fits the field of view angle of the light entering the camera aperture, which is intended to fall on the entire area of the sensor. In the folded lens unit, this conventional design of increasing the lens diameter will result in a larger camera height and is thus undesirable.

[0134] Therefore, a new folded telephoto sub-camera is disclosed herein, which has a lens module with a set of lens elements designed to reduce the height while keeping the light blocking below a specific value and allowing the incident light to be projected onto the entire area of the image sensor.

[0135] According to an example of the currently disclosed subject matter, the lens elements in the lens module are not designed to have an increasingly larger diameter towards the sensor. Instead, the diameter of each lens element in the lens module of the folded telephoto sub-camera is reduced in size. The diameter of each lens is determined to be as small as possible while maintaining sufficient light passing through the lens towards the sensor to obtain desired camera characteristics (e.g., resolution and SNR) and enabling the continuation and provision of an image over the entire area of the image sensor (i.e., the active pixel area of the sensor). The image sensor can be, for example, a 1 / 3" image sensor and a 1 / 4" image sensor.

[0136] According to some examples, the diameter of the largest lens element in a telephoto lens module (including at least 3 lens elements) is substantially no more than the diameter of the aperture (218) for allowing light to enter the telephoto sub-camera (i.e., the telephoto sub-camera aperture). Thus, the diameter of the telephoto sub-camera aperture can contribute to defining the maximum diameter of the lens elements in the telephoto lens module.

[0137] 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 the diameter of the telephoto sub-camera aperture by more than 10%. According to another example, the diameter of the largest lens element in the telephoto lens module does not exceed the diameter of the telephoto sub-camera aperture by more than 5%. According to yet another example, the diameter of the largest lens element in the telephoto lens module does not exceed the diameter of the telephoto sub-camera aperture by more than 2.5%. Examples of the design parameters of the foldable telephoto sub-camera according to these principles are described below with reference to FIGS. 10 and 11 and Tables 2 to 7.

[0138] Figures 10A to 10C Various exemplary telephoto lens modules (numbered 220a, 220b, or 220c), including foldable telephoto lenses, that can be used in the zoom dual-aperture cameras disclosed herein are shown. Each module includes a corresponding set of lens elements. Figure 10A Also shown are the aperture stop 218, the axis of symmetry 222a in the "z" direction, the telephoto sensor 224, and the additional cover plate 223.

[0139] Lens modules 220a, 220b, or 220c include 5, 4, and 3 lens elements respectively (or are simply referred to as "elements"). The lens elements are labeled 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 noted that the examples described herein include at least 3 lens elements, which can provide sufficient imaging quality.

[0140] Detailed optical data and aspherical surface data are given in Table 2 and Table 3 for lens module 220a, Table 4 and Table 5 for lens module 220b, and Table 6 and Table 7 for lens module 220c. The unit of the radius of curvature (R), the lens element thickness, and / or the distance between elements along the axis of symmetry and the diameter is expressed in mm. "N d " is the refractive index. "V d " is a parameter indicating the chromatic aberration of the lens material. A large V d indicates a small chromatic aberration, and vice versa. "BKZ" is N d and V d For known glass, the equation of the aspherical surface profile is expressed as follows:

[0141]

[0142] Where “r” is the distance from the axis of symmetry (and perpendicular to it), k is the cone coefficient, c = 1 / R, where R is the radius of curvature, and α is the coefficient given in Tables 3, 5, and 7. Note that the maximum value of r (“max r”) is equal to the diameter / 2. Also note that in Table 2 (and in Tables 4 and 6 below), the distances between various elements (and / or surfaces) are measured on the axis of symmetry Z, where the aperture is at Z = 0. Each number is measured from the previous surface.

[0143] # Radius (R) Distance <![CDATA[N d / V d > Diameter Conical coefficient k 1 Infinity -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 Infinity 0.21 BK7 6.0 0 13 Infinity 0.187 6.0 0 14 Infinity 0 6.1 0

[0144] Table 2

[0145] # <![CDATA[α1]]> <![CDATA[α2]]> <![CDATA[α3]]> <![CDATA[α4]]> <![CDATA[α5]]> <![CDATA[α6]]> <![CDATA[α7]]> <![CDATA[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 -1.10111E-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-3 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 6.206E-07 10 0 -2.7777E-03 7.1318E-04 3.0673E-05 -2.3126E-06 -2.9513E-06 5.1524E-07 0.00.0E+00 11 0 -3.8232E-03 4.8687E-04 4.8505E-05 2.2064E-06 -4.0755E-06 5.8813E-07 0.0000E+00

[0146] Table 3

[0147] Radius Distance <![CDATA[N d / V d > Diameter Conical coefficient k 1 Infinity -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 Infinity 0.210 BK7 8.0 11 Infinity 0.894 8.0 12 Infinity 0.000 8.0

[0148] Table 4

[0149] # <![CDATA[α1]]> <![CDATA[α2]]> <![CDATA[α3]]> <![CDATA[α4]]> <![CDATA[α5]]> <![CDATA[α6]]> <![CDATA[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

[0150] Table 5

[0151] # Radius Distance <![CDATA[N d / V d > Diameter Conical coefficient k 1 Infinity 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 Infinity 0.210 BK7 8.0 9 Infinity 0.200 8.0

[0152] Table 6

[0153] # <![CDATA[α1]]> <![CDATA[α2]]> <![CDATA[α3]]> <![CDATA[α4]]> <![CDATA[α5]]> <![CDATA[a6]]> <![CDATA[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

[0154] Table 7

[0155] Define the following terms: The “lens optical height” “H” is the maximum diameter of the optically used area of each lens element (i.e., the area where light passes directly from the camera aperture to the sensor to form an image). The terms for a four-element lens module are illustrated in Figure 11A Each element L n has a corresponding optical height “H n ”. The illustration shows H / 2 as the distance between the axis of symmetry and the tip of the marked arrow. The “camera optical height” is the maximum optical height among all lens elements, which is H1 in this case.

[0156] The “percentage of blocked light” (for each viewing angle) is defined as the percentage of light that arrives at the camera from a very distant object at a specific viewing angle (horizontal and vertical), enters the camera aperture, but does not reach the image sensor. It is worth noting that the relative light blocking increases as the diameter of the lens element decreases. Figure 11BIllustrated is the blocking 224400 of a portion of light caused by a diaphragm 250 inserted (by way of example) between elements L3 and L4 of a four-element telephoto lens. The diaphragm (also simply referred to as the "stop") is configured to prevent light from reaching the lens edge and scattering in all directions.

[0157] According to the presently disclosed subject matter, the diameter of the lens elements in the telephoto lens module is determined such that the light blocked by the diaphragm does not prevent more than a predetermined percentage of the incident light from reaching the image sensor.

[0158] The telephoto lenses disclosed above allow the use of large telephoto sensors (>4.5 mm × 3.35 mm) that enable high pixel counts (e.g., 13 megapixels). They provide a low camera optical height, which enables a low camera module height (e.g., <1.25*(1 + EFL / F#) = 1.25*(1 + camera aperture), see also Figure 12 and Figure 13 .

[0159] The folded telephoto lenses disclosed herein allow for long EFLs (e.g., >10 mm) for high zoom and low F# (e.g., <3) for all viewing angles to obtain more light and optical resolution and a low percentage of blocked light (<25%). As shown above, the folded telephoto lens module can include, for example, 3 to 5 lens elements. This combination of lens elements enables high image quality to be obtained at a low price.

[0160] Note that the lens elements of the telephoto lens module are held in place by a special structure (e.g., a barrel), e.g., by a plastic barrel (cold barrel). Thus, the telephoto lens module discussed herein is considered to include a structure (barrel) that holds the lens elements in place and a substrate (e.g., one or more PCBs). One or two magnets can be positioned on or on the side of the substrate as Figure 12 and Figure 13 illustrated. In any case, their height does not substantially exceed the height of the telephoto lens module.

[0161] Figure 12 Shown in (a) an isometric view and (b) an exterior view is a camera 1200 disclosed herein and numbered 1200. The camera 1200 includes a dual-magnet (1202 and 1204) dual-coil (1206 and 1208) AF mechanism for a folded telephoto lens. Each pair of magnet-coils is arranged to provide a force that moves the telephoto lens 1210 along its axis of symmetry. The force (and motion) is reacted (and reversed) by a spring 1212.

[0162] Figure 13The camera numbered 1300 disclosed herein is shown in (a) an isometric view and (b) an external view. Compared with the camera 1200, the camera 1300 includes a single coil (1306) and a spring (1312) AF mechanism of a single magnet (1302) of a folding telephoto lens. Figure 12 and Figure 13 The AF mechanism illustrated in is configured to operate according to the principle of a voice coil actuator (VCA, commonly referred to as a "magnetic actuator").

[0163] This AF mechanism is specifically designed to maintain a low camera profile. According to one example, the AF mechanism is designed to laterally fit on one or both sides of the telephoto lens module, while the other sides remain partially separated from the AF mechanism.

[0164] Specifically, one or two magnets (magnetically coupled to the corresponding coils) are designed to have a height that is generally no more than the height of the telephoto lens module, so as to avoid any significant contribution to the overall height of the folding telephoto sub-camera.

[0165] 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 positioned upright on one or both sides of the telephoto lens module, the other two planes perpendicular to the magnets (on the object side, marked by the arrow OS; and on the substrate side, marked by the arrow SS) remain separated from the magnets. Generally speaking, this design of the AF mechanism and the magnets particularly significantly reduces (or in some configurations, completely avoids) the increase in the total height of the telephoto sub-camera that may have been caused by the AF mechanism.

[0166] According to one example, the height of the magnet 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 magnet does not exceed the height of the telephoto lens module by more than 10%. According to another example, the height of the magnet does not exceed the height of the telephoto lens module by more than 5%. According to another example, the height of the magnet does not exceed the height of the Tele lens module by more than 2.5%.

[0167] The entire camera (including the AF mechanism) can be encapsulated in a low-profile mechanical package (housing) 1250 with a height H T (total height), see Figure 12 in (b) of, so that it is possible to include the zoom dual-aperture or triple-aperture camera disclosed herein in a low-profile mobile phone, such that H T is equal to or less than 6.5 mm, and in some examples, equal to or less than 5.7.

[0168] Figure 14A schematic diagram showing an example of a portable electronic device having an integrated dual-aperture camera with a collapsible telephoto lens module according to an example of the presently disclosed subject matter is illustrated. As depicted in the figure, the camera 1450 (including a dual-aperture camera having a collapsible telephoto lens module and a camera housing) is fully integrated within the portable electronic device 1400 and does not protrude from the device housing. The camera is oriented within the portable device such that its longitudinal dimension is positioned horizontally with respect to the device. Due to the collapsible optical path of the telephoto sub-camera, it can provide a high zoom effect (e.g., X5 or greater) while having a structure that does not protrude from the housing of the electronic device (e.g., a smart phone).

[0169] Although the present disclosure has been described in terms of certain embodiments and generally associated methods, changes and permutations of the embodiments and methods will be apparent to those skilled in the art. The present disclosure is to be understood as not being limited to the specific embodiments described herein, but rather is defined only by the scope of the appended claims.

Claims

1. A multi-camera, comprising: A wide-angle sub-camera, including a first aperture, a wide-angle lens module, and a first image sensor, wherein the wide-angle lens module has a first lens symmetry axis along the optical path between the object and the first image sensor, and wherein the first image sensor is located in a first sensor plane; And A telephoto sub-camera, including a second aperture, a telephoto lens module having a plurality of lens elements, a second image sensor, and a plurality of reflecting elements including at least a first reflecting element and a second reflecting element, and wherein the second image sensor is located in a second sensor plane, Wherein, the wide-angle sub-camera has a first field of view FOV1, Wherein, the telephoto sub-camera has a second field of view FOV2 < FOV1, Wherein, the height of the wide-angle sub-camera is 4 mm to 8 mm, and the height of the telephoto sub-camera is 4 mm to 8 mm, Wherein, the plurality of lens elements of the telephoto sub-camera includes a first lens element closest to the object side, and the aperture of the first lens element is greater than or equal to the aperture of any other lens element of the telephoto lens module, Wherein, the first reflecting element and the second reflecting element of the telephoto sub-camera are arranged such that the first reflecting element is closer to the second aperture and the second reflecting element is closer to the second image sensor, Wherein, the first reflecting element and the second reflecting element are parallel and operable to provide an optical path between the object and the second image sensor, Wherein, the first sensor plane and the second sensor plane are parallel to each other and both are substantially perpendicular to the first lens symmetry axis, and Wherein, the first reflecting element of the telephoto sub-camera is closer to the first aperture than the second reflecting element of the telephoto sub-camera.

2. The multi-camera according to claim 1, wherein, The first sensor plane and the second sensor plane are the same.

3. The multi-camera according to claim 2, wherein, The first image sensor and the second image sensor are placed on a single printed circuit board.

4. The multi-camera according to claim 1, wherein, The first sensor plane and the second sensor plane are not the same.

5. The multi-camera according to claim 4, wherein, The first image sensor and the second image sensor are placed on a single printed circuit board.

6. The multi-camera according to claim 1, wherein, The telephoto sub-camera is an autofocus camera.

7. The multi-camera according to claim 6, wherein, The second reflecting element is operably movable to perform autofocus.

8. The multi-camera according to claim 1, wherein, Both the wide-angle sub-camera and the telephoto sub-camera are autofocus cameras.

9. The multi-camera according to claim 8, wherein, The second reflecting element is operably movable to perform autofocus of the telephoto sub-camera.

10. The multi-camera according to claim 1, wherein, The telephoto sub-camera has a camera width W in the range of 5 mm to 12 mm and a camera length L in the range of 20 mm to 50 mm.

11. The multi-camera according to claim 1, wherein, Further includes a processor, the processor is configured to reduce the change of color or brightness during smooth transition by using information including the white balance or exposure time of the wide-angle sub-camera and the telephoto sub-camera, and reduce parallax artifacts by using image pixel information, and output a video output image with the smooth transition when switching between a lower zoom factor (ZF) value and a higher ZF value.

12. A multi-camera, comprising: Wide-angle sub-camera, including a first aperture, a wide-angle lens module, and a first image sensor, wherein the wide-angle lens module has a first lens axis of symmetry along the optical path between the object and the first image sensor, and wherein the first image sensor is located in a first sensor plane; and Telephoto sub-camera, including a second aperture, a telephoto lens module having a plurality of lens elements, a second image sensor, and a plurality of reflecting elements including at least a first reflecting element and a second reflecting element, and wherein the second image sensor is located in a second sensor plane, Mid-range sub-camera, including a mid-range lens module and a third image sensor, wherein the wide-angle sub-camera has a first field of view FOV1, wherein the telephoto sub-camera has a second field of view FOV2, wherein the mid-range sub-camera has a third field of view FOV3, wherein FOV2 < FOV3 < FOV1 or FOV2 < FOV1 < FOV3, wherein the height of the wide-angle sub-camera is from 4 mm to 8 mm, the height of the telephoto sub-camera is from 4 mm to 8 mm, and the height of the mid-range sub-camera is from 4 mm to 8 mm, wherein the plurality of lens elements of the telephoto sub-camera includes a first lens element closest to the object side, and wherein the aperture of the first lens element is greater than or equal to the aperture of any other lens element of the telephoto lens module, wherein the first reflecting element and the second reflecting element of the telephoto sub-camera are arranged such that the first reflecting element is closer to the second aperture and the second reflecting element is closer to the second image sensor, wherein the first reflecting element and the second reflecting element are parallel and operable to provide an optical path between the object and the second image sensor, wherein the first sensor plane and the second sensor plane are substantially perpendicular to the first lens axis of symmetry, and wherein the first reflecting element of the telephoto sub-camera is closer to the first aperture than the second reflecting element of the telephoto sub-camera.

13. The multi-camera according to claim 12, wherein, The first sensor plane and the second sensor plane are the same.

14. The multi-camera according to claim 13, wherein, The first image sensor and the second image sensor are placed on a single printed circuit board.

15. The multi-camera according to claim 12, wherein, The first sensor plane and the second sensor plane are not the same.

16. The multi-camera according to claim 15, wherein, The first image sensor and the second image sensor are placed on a single printed circuit board.

17. The multi-camera according to claim 12, wherein, The telephoto sub-camera is an autofocus camera.

18. The multi-camera according to claim 17, wherein, The second reflecting element is operably movable to perform autofocus.

19. The multi-camera according to claim 12, wherein, Both the wide-angle sub-camera and the telephoto sub-camera are autofocus cameras.

20. The multi-camera according to claim 19, wherein, The second reflecting element is operably movable to perform autofocus of the telephoto sub-camera.

21. The multi-camera according to claim 12, wherein, The telephoto sub-camera has a camera width W in the range of 5 mm to 12 mm and a camera length L in the range of 20 mm to 50 mm.

22. The multi-camera according to claim 12, wherein, It further includes a processor configured to reduce changes in color or brightness during smooth transitions by using information including white balance or exposure time of a wide-angle sub-camera and a telephoto sub-camera, and to reduce parallax artifacts by using image pixel information, and output a video output image having the smooth transition when switching between a lower zoom factor (ZF) value and a higher ZF value.

Images