Dual-camera integrated camera system and method thereof

Abstract

Embodiments of the present application provide a camera system which is provided with multiple cameras in a space-saving manner. A camera system can be provided which comprises an assembly for a first camera and a second camera. The first camera can be a camera for normal photography, and the second camera can be a macro imaging camera or another special purpose camera. The first camera comprises a first optical system comprising a first reflective optical element and a first lens unit, a first image sensor for capturing light which has transmitted through the first optical system, and a first actuator for driving the first lens unit. The second camera comprises a second optical system comprising a second reflective optical element and a second lens unit, a second image sensor for capturing light which has transmitted through the second optical system, and a second actuator for driving the second lens unit. The second lens unit is arranged in a space behind (or below) the first reflective optical element of the first optical system, as seen from the direction of light incidence on the first optical system.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to camera technology, and in particular to a digital camera system with integrated dual camera. BACKGROUND

[0002] Nowadays, mobile phones are usually equipped with a camera. Functions such as focusing (in particular, auto-focusing) or zooming (in particular, optical zooming as opposed to digital zooming) require a lens unit or one or more lenses in the lens unit to move along the optical axis. However, considering the slim profile of a typical mobile phone, the range of such axial movement is limited.

[0003] In recent years, the axial movement limitation has been reduced by employing a periscope optical system. In a periscope optical system, the incident light entering the aperture of the camera system of a mobile phone is reflected by a reflective optical element (e.g., a prism mirror or a conventional mirror with a reflective surface, which can be referred to simply as a mirror), and the reflected light is transmitted inside the mobile phone and received by an image sensor. Since the movement of the lens unit or one or more lenses is also performed inside the mobile phone (e.g., in a direction parallel to the main plane of the mobile phone), this scheme reduces the limitation on the range of movement as compared to the conventional case where the lens unit or lenses move in a direction perpendicular to the main plane. The reflection of light in such a system causes the light path to bend, which is similar to a submarine periscope. Therefore, a camera with such an optical system can be referred to as a periscope camera, and a zoom lens with such an optical system can be referred to as a periscope zoom lens.

[0004] A recent industry trend is to equip a mobile phone with two or more cameras. Two or more cameras can be provided for various purposes, e.g., to increase the amount of light, or to provide cameras with different focal lengths. Camera structures with different focal lengths support a wider range of focal lengths, but are limited in movement in a direction perpendicular to the main plane of the mobile phone.

[0005] Another case of having two or more cameras is to provide cameras for different purposes. In this regard, macro imaging cameras have been of particular interest. Macro imaging refers to close-range imaging of an object, e.g., imaging an object at a distance of 1 cm to 5 cm from the image sensor.

[0006] There is a need for a method that enables multiple cameras to be installed without excessively increasing the overall size of the camera system. SUMMARY

[0007] Embodiments of the present application provide a camera system with multiple cameras arranged in a space-saving manner.

[0008] According to a first implementation of the first aspect of the application, there is provided a camera system comprising an assembly for a first camera and a second camera. (The first camera can be a camera for general photography, the second camera can be a macro imaging camera or other specialized camera, as described below.) The first camera comprises: a first optical system comprising a first reflective optical element for reflecting first light into a direction perpendicular to an incident direction into a first lens unit; a first image sensor for capturing the first light having passed (or transmitted through) the first optical system; a first actuator for driving the first lens unit to move. The second camera comprises: a second optical system comprising a second reflective optical element for reflecting second light into a direction perpendicular to an incident direction into a second lens unit; a second image sensor for capturing the second light having passed the second optical system; a second actuator for driving the second lens unit to move. The second lens unit is arranged in a space behind (or below) the first reflective optical element of the first optical system, as seen from the direction of the incident of the first light into the first optical system. For example, when the first reflective optical element is placed on a main substrate of an electronic device (e.g. a smartphone) in which the camera system is arranged, the second lens unit can be arranged in the space between the first reflective optical element and the substrate. An optical axis of the first lens unit can be perpendicular to an optical axis of the second lens unit.

[0009] By arranging the second lens unit in the space behind (or below) the first reflective optical element of the first optical system, the space utilization is improved and the overall size of the camera system can be reduced.

[0010] According to a second implementation of the first aspect of the application, the second optical system and the second image sensor are arranged such that the second light incident on the second optical system is incident on the second image sensor parallel to the incident direction (i.e. incident on the second image sensor in a direction perpendicular to a light receiving surface of the second image sensor).

[0011] This arrangement of the second optical system and the second image sensor supports a flexible arrangement of the assembly. In particular, the direction of movement of the second lens unit does not need to be the same as the direction of light incident on the camera system.

[0012] Based on the first or second implementation of the first aspect of the application, according to a third implementation of the first aspect of the application, the second lens unit is driven by the second actuator to move within the space behind the first reflective optical element along a direction of the second lens unit

[0013] By limiting the movement of the second lens unit within the space behind the first reflective optical element, the space utilization can be improved, and the overall size of the image pickup system can be reduced.

[0014] According to the fourth implementation of the first aspect of the present application, based on any one of the first to third implementations of the first aspect of the present application, the second reflective optical element is arranged on one side of the space behind the first reflective optical element along the second optical axis direction of the second lens unit, and the second image sensor is arranged on the other side of the space behind the first reflective optical element.

[0015] Such an arrangement of the second reflective optical element and the second image sensor supports a compact design of the related components.

[0016] According to the fifth implementation of the first aspect of the present application, based on any one of the first to fourth implementations of the first aspect of the present application, the second actuator comprises: a coil fixed to the back of the reflective surface (e.g., the triangular hypotenuse of the prism reflector in the cross section) of the first reflective optical element; and a magnet fixed to the second lens unit.

[0017] Such an arrangement of the second actuator assembly supports efficient use of the space, and can reduce the overall size.

[0018] According to the sixth implementation of the first aspect of the present application, based on the fifth implementation of the first aspect of the present application, the second actuator further comprises a magnetic yoke arranged behind the magnet. The magnetic yoke can not be arranged on the side of the coil facing the magnet.

[0019] Arranging the magnetic yoke on the side of the coil facing the magnet can prevent the unwanted magnetic attraction force from the magnet.

[0020] According to the seventh implementation of the first aspect of the present application, based on the third implementation of the first aspect of the present application, the image pickup system further comprises one or more (e.g., two) guide shafts for guiding the movement of the second lens unit, the shaft direction of the guide shaft being parallel to the second optical axis direction.

[0021] By limiting the movement freedom of the second unit by the one or more guide shafts, precise movement of the second lens unit can be achieved.

[0022] According to an eighth implementation form of the first aspect of the application, based on any one of the first to seventh implementation forms of the first aspect of the application, the camera system further comprises a compression spring arranged around the guide shaft for pressing the second lens unit against a stop member on one side of the range in which the second lens unit is driven, wherein the pre-load of the compression spring is equal to or greater than the weight of the second lens unit.

[0023] By providing such a compression spring for pressing the second lens unit against the stop member with a pre-load equal to or greater than the weight of the second lens unit, a collision of the second lens unit with the stop member can be prevented when operating a device comprising the camera system, e.g. moving relative to the direction of gravity.

[0024] According to a ninth implementation form of the first aspect of the application, based on any one of the first to seventh implementation forms of the first aspect of the application, the camera system further comprises two compression springs arranged around the guide shaft for movably supporting the second lens unit from both sides. In this case, in contrast to the eighth implementation form, the second lens unit is not pressed against a stop member.

[0025] This provides another approach to prevent a collision of the second lens unit when operating a device comprising the camera system.

[0026] According to a tenth implementation form of the first aspect of the application, based on any one of the first to ninth implementation forms of the first aspect of the application, the camera system further comprises one or more illumination light sources arranged next to the second reflective optical element. Multiple light sources for e.g. white light and monochromatic light can be arranged. The illumination light sources can be arranged obliquely such that the light is emitted towards the optical axis of the light receiving surface of the second reflective optical element.

[0027] Providing one or more illumination light sources next to the second reflective optical element, e.g. next to the aperture of the second optical system, can facilitate imaging using the second camera.

[0028] According to an eleventh implementation form of the first aspect of the application, based on any one of the first to ninth implementation forms of the first aspect of the application, the camera system further comprises a transparent illumination light source arranged in front of the light receiving surface of the second reflective optical element.

[0029] This can reduce the spatial requirements for the illumination light source compared to the tenth implementation form. Furthermore, a more uniform illumination of the subject to be imaged can be possible since no tilting is required. Although an illumination light source which is not completely transparent can affect the image quality, this can be acceptable depending on the use of the second camera.

[0030] According to a twelfth implementation form of the first aspect of the application, based on any one of the first to twelfth implementation forms of the first aspect of the application, the substantially transparent illumination light source is an OLED light source.

[0031] This provides a convenient implementation of the substantially transparent illumination light source.

[0032] According to a thirteenth implementation form of the first aspect of the application, based on any one of the first to twelfth implementation forms of the first aspect of the application, the second reflective optical element is a prism mirror or a mirror.

[0033] This provides a convenient implementation of the second reflective optical element.

[0034] According to a fourteenth implementation form of the first aspect of the application, based on any one of the first to thirteenth implementation forms of the first aspect of the application, the second lens unit is driven for auto focus or manual focus.

[0035] This provides an example of a particular application of driving the second lens unit.

[0036] According to a fifteenth implementation form of the first aspect of the application, based on any one of the first to fourteenth implementation forms of the first aspect of the application, the second camera is a camera for macro imaging.

[0037] According to a sixteenth implementation form of the first aspect of the application, based on any one of the first to fourteenth implementation forms of the first aspect of the application, the second camera is for one or more of skin imaging, glucose measurement, blood flow measurement, fundus examination, water content measurement, or sugar content measurement.

[0038] These provide possible applications of the second camera for which the arrangement of the application can be advantageous.

[0039] According to a seventeenth implementation form of the first aspect of the application, based on the sixteenth implementation form of the first aspect of the application, the camera system further comprises one or more illumination light sources arranged next to the second reflective optical element, wherein the illumination light sources are for one or more of skin imaging, glucose measurement, blood flow measurement, fundus examination, water content measurement, or sugar content measurement.

[0040] This is advantageous in that illumination light sources can be provided which are specifically for the purpose of the second camera.

[0041] According to an eighteenth implementation form of the first aspect of the application, based on any one of the first to seventeenth implementation forms of the first aspect of the application, no infrared cut filter is arranged in front of the light receiving surface of the second reflective optical element.

[0042] This reduces the number of components when the second camera does not need an infrared cut filter.

[0043] According to a nineteenth implementation form of the first aspect of the application, based on any one of the first to eighteenth implementation forms of the first aspect of the application, the camera system further comprises a mechanism for selectively inserting one or more filters in front of the light receiving surface of the second reflective optical element among a plurality of filters.

[0044] According to a twentieth implementation form of the first aspect of the application, based on any one of the first to nineteenth implementation forms of the first aspect of the application, the first optical system and the first image sensor are arranged such that light incident on the first optical system is reflected by the first reflective optical element in a direction substantially perpendicular to the direction of incidence, and passes through the first lens unit, and is incident on the first image sensor substantially parallel to the direction of incidence (i.e. on the first image sensor in a direction substantially perpendicular to the light receiving surface of the first image sensor).

[0045] This arrangement of the first optical system and the first image sensor supports a flexible arrangement of components. In particular, the direction of movement of the first lens unit does not need to be the same as the direction of light incident on the camera system.

[0046] According to a twenty-first implementation form of the first aspect of the application, based on any one of the first to twentieth implementation forms of the first aspect of the application, the camera system comprises an optical image stabilization (OIS) unit for OIS of the first camera, wherein the OIS unit is configured to drive the first image sensor.

[0047] It is advantageous to provide the OIS unit to drive the first image sensor instead of the first lens unit, compared to embodiments where the OIS unit is arranged behind (or below) the first reflective optical element in order to leave space for a second lens unit behind (or below) the first reflective optical element. It is noted that an electronic image stabilization (EIS) mechanism can be provided instead of or in addition to the OIS.

[0048] According to a twenty-second implementation of the first aspect of the application, based on any one of the first to twenty-first implementations of the first aspect of the application, the first actuator comprises a coil fixed to a housing of the camera system and a magnet fixed to the first lens unit, the magnet being arranged opposite the coil.

[0049] According to a twenty-third implementation of the first aspect of the application, based on any one of the first to twenty-second implementations of the first aspect of the application, the first lens unit is driven for auto-focusing or manual focusing.

[0050] According to a twenty-fourth implementation of the first aspect of the application, based on any one of the first to twenty-third implementations of the first aspect of the application, the first lens unit comprises a zoom lens.

[0051] According to a second aspect of the application, a camera system assembly is provided. The camera system assembly comprises: a second optical system comprising a second reflective optical element and a second lens unit; a second image sensor for capturing light that has passed through the second optical system; a second actuator for driving the second lens unit, wherein, seen from a light incidence direction, the second lens unit is arranged in a space behind the first reflective optical element of the first optical system.

[0052] The advantages obtained with the second aspect of the application and possible implementations of the second aspect of the application are similar to the first aspect of the application. Herein, they will not be repeated.

[0053] According to a third aspect of the application, a method of imaging using a camera system according to any one of the first to twenty-fourth implementations of the first aspect of the application is provided. The method comprises: activating the camera system; in response to a user input, selecting an imaging mode using the second camera; automatically focusing on a subject by driving the second lens unit; in response to a user input, capturing an image using the second camera and storing data of the image in a storage device.

[0054] The advantages obtained with the third aspect of the application and possible implementations of the third aspect of the application are similar to the first aspect of the application. It should be understood that any features described in connection with one aspect of the application can also be suitably applied to the other aspects, mutatis mutandis. BRIEF DESCRIPTION OF DRAWINGS

[0055] For describing the technical solutions of the embodiments of the present application, please refer to the accompanying drawings, in which:

[0056] Figure 1 An exemplary embodiment of a periscopic optical system according to the present application is shown;

[0057] Figure 2 is a schematic diagram of a camera system provided by embodiments of the present application;

[0058] Figure 3 shows an arrangement of some components of a camera system provided by embodiments of the present application;

[0059] Figure 4 is a cross-section of a camera system provided by embodiments of the present application, and shows the optical path;

[0060] Figure 5 is a cross-section of a camera system provided by embodiments of the present application, in another orientation, and shows the arrangement of actuators;

[0061] Figure 6 shows a mobile phone provided by embodiments of the present application;

[0062] Figure 7 is a flowchart of a method of imaging using a camera system provided by embodiments of the present application.

[0063] Throughout the drawings, like reference numerals can be used to designate like or similar features. DETAILED DESCRIPTION

[0064] Embodiments of the present application will now be described with reference to the accompanying drawings. Those skilled in the art will understand that the present summary is not limited to the particular embodiments described below.

[0065] Modern mobile phones are typically equipped with a camera. Focusing (e.g. auto-focusing) requires movement of the lens unit along the optical axis to change the optical path length from the lens unit to the image sensor of the camera, and this axial movement requires a certain range. Zooming requires movement of one or more elements in the lens unit along the optical axis to change the focal length (and thus the angle of view), which in turn requires a certain axial length of the lens unit to support this movement. However, given the slim profile of a typical mobile phone, this range of axial movement or axial length of the lens unit is limited.

[0066] In recent years, the limitations of axial movement have been reduced by employing a periscopic optical system. Figure 1An exemplary embodiment of such a periscope optical system 100 is shown. Light entering the camera system aperture of the phone is reflected by a reflective optical element 102 (e.g., a prism mirror or a conventional mirror with a reflective surface; the latter can simply be referred to as a mirror) to a direction substantially perpendicular to the direction of incidence (e.g., a direction parallel to the main plane of the phone), and the reflected light passes through a lens unit 104 and is received by an image sensor 106. Since the lens unit or elements therein are moved parallel to the main plane of the phone, the restriction on the range of movement is reduced compared to the conventional case where the lens unit or lens is moved in a direction perpendicular to the main plane of the phone. The reflection of light in such a system causes the light path to bend, which is similar to a submarine periscope, and thus a camera with such an optical system can be referred to as a periscope camera, and a zoom lens with such an optical system can be referred to as a periscope zoom lens.

[0067] In recent years, mobile terminals such as phones can be equipped with multiple cameras for various purposes. For example, different cameras can be arranged in one camera system for different purposes. In this regard, macro imaging cameras have been of interest. Macro imaging refers to close-range imaging of an object, e.g., imaging of an object at a distance of 1 cm to 5 cm from the image sensor.

[0068] It is desirable in the industry to be able to install multiple cameras without excessively increasing the overall size of the camera system.

[0069] Figure 2 is a schematic diagram of a camera system provided by an embodiment of the present invention. The camera system 200 includes a first camera 210 and a second camera 220. The first camera 210 includes a first optical system 212 including a first reflective optical element 218 and a first lens unit 219, a first image sensor 214 for capturing light that has passed through the first optical system 212, and a first actuator 216 for driving the first lens unit 219. The second camera 220 includes a second optical system 222 including a second reflective optical element 228 and a second lens unit 229, a second image sensor 224 for capturing light that has passed through the second optical system 222, and a second actuator 226 for driving the second lens unit 229. The first and second lens units can be driven for auto focus or manual focus. The camera system 200 can have a controller 230 to control the operation of various components of the camera system for various purposes, e.g., driving the lens units by the actuators for auto focus and other purposes. The camera system 200 can also have a memory and / or storage device 240 to store data and instructions.

[0070] The first camera 210 can be used for ordinary photography, while the second camera 220 can be used for macro imaging. However, this is not limiting. The second camera 220 can be an imaging device for the purpose of skin measurement, glucose (blood sugar) measurement, blood flow measurement, fundus examination, water content measurement, sugar content (or concentration) measurement, etc. It should be noted that macro imaging can also be used for these purposes.

[0071] In some embodiments, the camera system includes an optical image stabilization (OIS) unit for OIS of the first camera, wherein the OIS unit is configured to drive the first image sensor. Advantageously, the OIS unit is provided to drive the first image sensor instead of the first lens unit when compared to embodiments in which the OIS unit is disposed behind (or below) the first reflective optical element. Disposing the OIS unit behind (or below) the first reflective optical element is used to leave space for the second lens unit behind (or below) the first reflective optical element, as described below. It should be noted that an electronic image stabilization (EIS) mechanism can be provided instead of or in addition to the OIS.

[0072] In some embodiments, the first lens unit can include a telephoto lens. As used herein, a telephoto lens is a lens having a long focal length (e.g., longer than 100 mm).

[0073] In some embodiments, the first actuator can include a coil fixed to a housing of the camera system and a magnet fixed to the first lens unit, the magnet being disposed opposite the coil.

[0074] The second lens unit 229 can be disposed in a space behind the first reflective optical element 218 of the first optical system 212. The first reflective optical element 218 can be a prism mirror or a conventional mirror having a reflecting surface (typically a plane) (the latter conventional mirror can simply be referred to as a mirror. The reflecting surface, when a plane, can be referred to as a plane mirror.) In the present disclosure, the space "behind" the first reflective optical element is a space behind the first reflective optical element as viewed from the direction in which light is incident on the first optical system. By disposing the second lens unit 229 of the second optical system 222 behind the first reflective optical element 218 of the first optical system 212, the additional space required to provide the second camera in the camera system can be minimized.

[0075] It should be noted that the aperture position of the camera on a mobile terminal such as a mobile phone is not limited. For example, the aperture can be disposed on the back of the mobile terminal, on the front of the mobile terminal, or on both the back and the front of the mobile terminal.

[0076] Figure 3 An arrangement of some components of the camera system provided by an embodiment of the present application is shown. The second optical system 222 includes a second reflective optical element 228 and a second lens unit 229. The second reflective optical element 228 can be a prism mirror or a conventional mirror having a reflecting surface (typically a plane). (The latter conventional mirror can simply be referred to as a mirror. The reflecting surface when a plane can be referred to as a plane mirror.) In Figure 3 , it can be seen that the second lens unit 229 of the second optical system 222 is arranged in the space behind the first reflective optical element 218 of the first optical system 212.

[0077] The second optical system 222 including the second reflective optical element 228 and the second lens unit 229 and the second image sensor 224 are arranged such that the incident light is reflected by the second reflective optical element 228 of the second optical system 222 to a direction substantially perpendicular to the direction of incidence (e.g., substantially parallel to the direction of the substrate of the electronic device including the camera system or substantially parallel to the direction of the main plane of the electronic device) and passes through the second lens unit 229 to be incident on the second image sensor 224, the light incident on the second image sensor 224 can be substantially perpendicular to the main plane. Figure 4 Such a light path is shown. In alternative embodiments, the second image sensor can be substantially parallel to the main plane and a third reflective optical element can be provided to direct the light that has passed through the second lens unit 229 onto the image sensor.

[0078] The second lens unit 229 is driven by a second actuator (not shown in Figure 3 ; see Figure 5 ) within the space behind the first reflective optical element 218.

[0079] In some embodiments, the second reflective optical element 228 is arranged on one side of the space behind the first reflective optical element 218 and the second image sensor 224 is arranged on the other side of the space behind the first reflective optical element 218. The second reflective optical element 228 and the second lens unit 229 can form a periscopic optical system.

[0080] The lens unit can be driven by an actuator. The actuator can utilize electromagnetic interaction between a magnet and a coil.

[0081] As Figure 5As shown, in some embodiments, the second actuator 226 includes a coil 510 fixed to the back of the reflecting surface of the first reflecting optical element 218 and a magnet 520 fixed to the second lens unit 229. The driving force for moving the second lens unit in the direction of the second optical axis of the second lens unit is the Lorentz force exerted on the magnet 520. A sensor (e.g., a Hall sensor) can be disposed in the coil 510 to detect the position of the second lens unit 229. The position information can be used in a servo mechanism for controlling the movement of the second lens unit 229.

[0082] In some embodiments, a magnetic yoke is not provided on the side of the coil facing the magnet. This is to prevent the attractive force between the magnetic yoke on the coil and the magnet, which can hinder the movement of the lens unit. In some embodiments, a magnetic yoke 530 can be provided behind the magnet.

[0083] In some embodiments, one or more guide shafts are provided for guiding the movement of the second lens unit 229. In Figure 5 Two such guide shafts 540 are shown in

[0084] In some embodiments, a resilient member can be provided to prevent the lens unit from colliding when the mobile terminal in which the camera system is housed is operated (e.g., moved or accelerated with respect to the direction of gravity). A compression spring (e.g., a coil spring) that is fitted over the guide shaft can be used as the resilient member.

[0085] In some embodiments, a compression spring can be provided for pressing the second lens unit 229 against a member on the side of the range in which the second lens unit 229 is driven. The member can be a stopper dedicated to stopping the movement of the lens unit, or a face on some other component or housing of the camera system.

[0086] The compression spring is shown in Figure 3 as a coil spring 310. As shown in Figure 3 The compression spring can be provided around one guide shaft 320. The pre-load of the compression spring is equal to or greater than the weight of the second lens unit 229, thereby preventing the second lens unit 229 from moving due to gravity when the mobile terminal in which the camera system is housed is operated. The driving force of the actuator can overcome the pre-load to move the lens unit according to the instructions from the controller.

[0087] In some embodiments, instead of providing a compression spring to press the lens unit against the side of the range in which the second lens unit moves, two compression springs can be provided to movably support the second lens unit from both sides.

[0088] In some embodiments, the illumination light source 330 can be arranged beside the second reflective optical element 228. In some embodiments, the illumination light source is arranged obliquely so that the light emission direction is oblique to the axis normal to the light receiving surface of the second optical system.

[0089] In other embodiments, the illumination light source can be a substantially transparent illumination light source arranged in front of the light receiving surface of the second reflective optical element 228. In some embodiments, the substantially transparent illumination light source can be an organic light-emitting diode (OLED) light source. Such a substantially transparent illumination light source is not completely transparent in the optical path, which can degrade the image quality. However, depending on the purpose of the second camera, the requirement on the image quality can not be stringent, and it can be acceptable to arrange a substantially transparent illumination light source in front of the light receiving surface of the second optical system. For example, in imaging for skin measurement, glucose (blood sugar) measurement, blood flow measurement, water content measurement, or sugar content (or concentration) measurement, the image quality can not be critical.

[0090] When the second camera is a macro imaging camera, it is convenient to have one or more light sources beside (or in front of) the light receiving surface of the second optical system 220. When the second camera is used for other purposes, such as skin measurement, glucose (blood sugar) measurement, blood flow measurement, fundus examination, water content measurement, sugar content (or concentration) measurement, the illumination light source can be used for that particular purpose. For example, the illumination light source can be a visible light source, an infrared light source, or an ultraviolet light source.

[0091] Different filters can be used for imaging for different purposes. For example, ordinary photography usually requires the use of an infrared filter (i.e. an infrared cut filter) to eliminate the infrared component from the incident light, because digital image sensors are usually sensitive to infrared light, while the human eye is not sensitive to infrared light. When the second camera is used for purposes other than ordinary photography, the second camera can not need an infrared filter. In some embodiments, multiple filters with different characteristics can be provided, and there can be a mechanism for selectively inserting one or more filters in front of the light receiving surface of the second optical system.

[0092] According to another aspect, the camera system described in embodiments of the present application can be incorporated into a mobile terminal such as a mobile phone (e.g. a smartphone). Figure 6 The back of the mobile terminal provided by embodiments of the present application is shown. The aperture 620 of the first camera and the aperture 630 of the second camera are visible on the housing 610 of the mobile terminal.

[0093] According to another aspect, there is provided a method of imaging using a camera system according to any of the above embodiments of the present application, such as Figure 7 The method 700 comprises the following steps: activating the camera system (710); in response to a user input (720), selecting an imaging mode using the second camera; automatically focusing on a subject to be imaged by driving the second lens unit (730); in response to a user input, capturing an image by the second camera and storing data of the image in a storage device (740).

[0094] Although various embodiments are described above and illustrated in the drawings, the present application is not limited to the specific embodiments described or illustrated.

[0095] It should be noted that the terms "first", "second", and the like used herein are used to distinguish between like or similar items having substantially the same function. It should be understood that these terms do not imply any temporal or priority order. For example, a recitation of "a second element of the second item" does not necessarily mean that there is a first element of the second item. In this context, the term "second element" is merely used to distinguish it from some first element disclosed elsewhere in the present application.

[0096] The unit division disclosed in the embodiments of the present application is not restrictive, and the embodiments can use other component division configurations.

[0097] Some functions can be implemented in the form of a computer program for causing a processor or computing device to perform one or more functions, where appropriate. For example, various signal processing and control functions can be implemented as computer programs. The computer program can be implemented on a non-transitory computer readable storage medium. The storage medium can be any medium capable of storing a computer program, such as a USB drive, a flash drive, a read-only memory (ROM) and a random-access memory (RAM) and the like solid-state memory; magnetic storage medium, such as removable or non-removable hard disk; or optical storage medium, such as optical disc.

[0098] The above description is only used to illustrate various embodiments of the present application and is not used to limit the scope of the present application. Any changes that can be easily thought of by those skilled in the art in view of the present application should be within the scope of the present application. For example, individually disclosed measures can be combined in a single embodiment as appropriate, as long as the measures are not mutually exclusive.

Claims

1. An image pickup system characterized by comprising: comprising components for a first camera and a second camera, the first camera comprising: a first optical system comprising a first reflective optical element for reflecting first light into a direction perpendicular to the direction of incidence into a first lens unit; a first image sensor for capturing the first light having transmitted through the first optical system; a first actuator for driving the first lens unit to move; the second camera comprising: a second optical system comprising a second reflective optical element for reflecting second light into a direction perpendicular to the direction of incidence into a second lens unit; a second image sensor for capturing the second light having transmitted through the second optical system; a second actuator for driving the second lens unit to move, wherein the second lens unit is arranged in a space behind the first reflective optical element of the first optical system as seen from the direction of incidence of the first light onto the first optical system.

2. The camera system according to claim 1, wherein the second optical system and the second image sensor are arranged such that the second light incident onto the second optical system is incident onto the second image sensor in a direction perpendicular to a light receiving surface of the second image sensor.

3. The camera system according to claim 1, wherein the second lens unit is driven by the second actuator to move within the space behind the first reflective optical element in a second optical axis direction of the second lens unit.

4. The camera system according to claim 1, wherein the second reflective optical element is arranged on one side of the space behind the first reflective optical element in the second optical axis direction of the second lens unit, the second image sensor being arranged on the other side of the space behind the first reflective optical element.

5. The camera system according to claim 4, wherein the second actuator comprises a coil fixed to a back surface of a reflective surface of the first reflective optical element, and a magnet fixed to the second lens unit.

6. The camera system according to claim 5, wherein the second actuator further comprises a yoke arranged behind the magnet.

7. The camera system according to claim 3, wherein a guide shaft for guiding movement of the second lens unit is further included, an axis direction of the guide shaft being parallel to the second optical axis direction.

8. The camera system according to claim 7, wherein a compression spring for pressing the second lens unit against a member on one side of a range in which the second lens unit is driven is further included, wherein a preload of the compression spring is equal to or greater than a weight of the second lens unit.

9. The camera system according to claim 7 or 8, characterized in that, two compression springs for movably supporting the second lens unit from both sides are further included.

10. The camera system according to any one of claims 1 to 8, wherein, a light source is further included arranged beside the second reflective optical element.

11. The camera system according to any one of claims 1 to 8, wherein, a transparent light source is further included arranged in front of a light receiving surface of the second reflective optical element.

12. The camera system according to claim 11, wherein, the light source is an OLED light source.

13. The camera system according to any one of claims 1 to 8, wherein, the second reflective optical element is a prism mirror or a mirror.

14. The camera system according to any one of claims 1 to 8, wherein, the second lens unit is driven for focusing.

15. The camera system according to any one of claims 1 to 8, wherein, the second camera is a camera for macro imaging.

16. The camera system according to any one of claims 1 to 8, wherein, the second camera is used for one or more of skin imaging, glucose measurement, blood flow measurement, fundus examination, water content measurement, or sugar content measurement.

17. The camera system according to any one of claims 1 to 8, wherein, The first optical system and the first image sensor are arranged such that light incident on the first optical system is reflected by the first reflective optical element in a direction substantially perpendicular to the direction of incidence, transmitted through the first lens unit, and incident on the first image sensor in a direction substantially perpendicular to a light-receiving surface of the first image sensor.

18. The camera system according to any one of claims 1 to 8, wherein, An optical image stabilization (OIS) unit for OIS of the first camera is also included, wherein the OIS unit is configured to drive the first image sensor.

19. The camera system according to any one of claims 1 to 8, wherein, The first actuator includes a coil fixed to a housing of the camera system and a magnet fixed to the first lens unit, the magnet being arranged opposite the coil.

20. The camera system according to any one of claims 1 to 8, wherein, The first lens unit is driven for focusing.

21. The camera system according to any one of claims 1 to 8, wherein, The first lens unit includes a zoom lens.

22. The camera system according to any one of claims 1 to 8, wherein, An optical axis of the first lens unit is perpendicular to an optical axis of the second lens unit.

23. A terminal device, comprising: A camera system according to any one of claims 1 to 22 is included.

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