Optical system and camera module

Abstract

To miniaturize and thin an optical system and a camera module.SOLUTION: Wherein the optical system includes a first lens group, a second lens group, a third lens group, a first lens driving device that shifts the second lens group in a direction parallel to an optical axis of the optical system, and a second lens driving device that tilts the third lens group in a direction inclined with respect to the optical axis, - 6.0 <f / f2 <- 2.0, ih / f <0.4, 0.7 <TTL / f <1.0, and 2.4 <Fno <7.0, where f is an actual focal distance, f2 is a focal distance of the second lens group, ih is a maximum image height, TTL is a distance from an object-side surface of a lens disposed closest to the object side to an imaging surface, Fno is an F-number, t-OIS is an absolute value of a tilt driving angle of the third lens group, and Ims is an absolute value of a movement amount of the image caused by tilt driving of the third lens group. 0 <t-OIS <6.0 and Ims / t-OIS> 0.5 are satisfied.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an optical system and a camera module. [Background technology]

[0002] Patent Document 1 discloses a camera module. In the camera module, multiple imaging lenses form a subject image. A lens barrel holds the multiple imaging lenses. A lens driving device drives an optical unit consisting of the multiple imaging lenses and the lens barrel in the optical axis direction. This allows the camera module to perform an autofocus function.

[0003] Patent Document 2 discloses a foldable camera module. In the foldable camera module, a lens module holds multiple lens elements. A lens actuation subassembly moves the lens module along a Z axis parallel to the optical axis, thereby achieving an autofocus (AF) function. The lens actuation subassembly shifts the lens module in a Y direction, thereby achieving an optical image stabilization (OIS) function.

[0004] In the foldable camera module, a reflective element reflects light from a first optical path to a second optical path that converges on the optical axis of the lens module. The reflective element is a mirror or a prism. When the foldable camera module is included in a smartphone, the reflective element tilts the light propagation direction from perpendicular to the back surface of the smartphone to parallel to the back surface, thereby enabling the smartphone to be made thinner.

[0005] Patent Document 3 discloses a camera module. In this camera module, a lens barrel houses an imaging lens. A lens driving device drives the imaging lens and the lens barrel together in two axial directions perpendicular to the optical axis. This realizes an OIS function.

[0006] Patent Document 4 discloses a camera module. In the camera module, a reflecting element reflects object light traveling along a first optical axis to generate object light traveling along a second optical axis. An optical system focuses the object light traveling along the second optical axis. A lens driving device drives a second lens group of the optical system in a direction parallel to the second optical axis and a direction perpendicular to the second optical axis. This enables focusing and OIS. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 5611533 [Patent Document 2] U.S. Patent No. 10,371,928 [Patent Document 3] Patent No. 5329629 [Patent Document 4] Japanese Patent Application Publication No. 2024-27601 Summary of the Invention [Problem to be solved by the invention]

[0008] The camera module disclosed in Patent Document 1 requires a gap for the lens drive device to move the lens barrel in the optical axis direction by the amount of extension when using the full-lens extension method. This makes it difficult to make the camera module smaller and thinner. This problem becomes particularly pronounced when the camera module is equipped with a telephoto lens with a long focal length and a large amount of extension.

[0009] To solve this problem, if a camera module that performs focusing by extending the entire lens group, like the folding camera module disclosed in Patent Document 2, is equipped with a reflective element, the gap described above is required between the imaging device and the reflective element. Light rays spread in this gap. The spread of the light rays has a size that corresponds to the angle of view of the camera module. This requires a larger reflective element. This makes it difficult to make the camera module smaller and thinner.

[0010] In the camera module disclosed in Patent Document 3, it is necessary to drive the imaging lens in a direction perpendicular to the optical axis. If the camera module is equipped with a telephoto lens with a large focal length, it is necessary to increase the amount of drive of the imaging lens in a direction perpendicular to the optical axis. This makes it difficult to make the camera module smaller and thinner.

[0011] In the camera module disclosed in Patent Document 4, it is necessary to drive the second lens group in a direction perpendicular to the second optical axis. Therefore, the lens drive device that drives the second lens group must generate a large drive force. This makes the lens drive device that drives the second lens group large. This makes it difficult to make the camera module smaller and thinner.

[0012] One aspect of the present disclosure has been made in consideration of these problems. One aspect of the present disclosure aims to make optical systems and camera modules smaller and thinner, for example. [Means for solving the problem]

[0013] The optical system according to the first aspect of the present disclosure includes a first lens group including two or more lenses, having a positive power as a whole, and transmitting object light; a second lens group including at least one lens, having a negative power as a whole, disposed downstream of the first lens group, and transmitting the object light; a third lens group including at least one lens, having a positive power as a whole, disposed downstream of the second lens group, and condensing the object light onto an imaging unit; a first lens driving device that drives the second lens group to shift in a direction parallel to the optical axis of the optical system; and a second lens driving device that tilts the third lens group in a direction inclined with respect to the optical axis. When the third lens group is tilted in a direction inclined with respect to the optical axis, an image moves in a direction perpendicular to the optical axis on the image plane of the optical system. Let f be the overall effective focal length of the first lens group, the second lens group, and the third lens group; f2 be the focal length of the second lens group; ih be the maximum image height of the first lens group, the second lens group, and the third lens group as a whole; TTL be the distance from the object-side surface of the lens disposed closest to the object among the two or more lenses to the imaging surface; Fno be the F-number of the first lens group, the second lens group, and the third lens group as a whole; t-OIS be the absolute value of the tilt driving angle of the third lens group in a direction inclined with respect to the optical axis; and Ims be the absolute value of the amount of movement of the image in a direction perpendicular to the optical axis on the image plane caused by the tilt driving of the third lens group in a direction inclined with respect to the optical axis at the optical axis center of the third lens group. Then, -6.0 < f / f2 < -2.0, ih / f < 0.4, 0.7 < TTL / f < 1.0, 2.4 < Fno < 7.0, 0 < t-OIS < 6.0, and Ims / t-OIS > 0.5 are satisfied.

[0014] The camera module according to the second aspect of the present disclosure includes the optical system according to the first aspect of the present disclosure and the imaging unit. The imaging unit has an imaging surface on which the object light is condensed and photoelectrically converts the object light.

Brief Description of the Drawings

[0015] [Figure 1]FIG. 1 is a perspective view schematically illustrating a camera module according to a first embodiment. [Figure 2] 1 is a cross-sectional view schematically illustrating a camera module according to a first embodiment. [Figure 3A] FIG. 2 is a configuration diagram of an optical system provided in the camera module of the first embodiment. [Figure 3B] FIG. 2 is a configuration diagram of an optical system provided in the camera module of the first embodiment. [Figure 4A] FIG. 2 is a configuration diagram of an optical system provided in the camera module of the first embodiment. [Figure 4B] FIG. 2 is a configuration diagram of an optical system provided in the camera module of the first embodiment. [Figure 5A] FIG. 10 is a configuration diagram of an optical system provided in a camera module of a second embodiment. [Figure 5B] FIG. 10 is a configuration diagram of an optical system provided in a camera module of a second embodiment. [Figure 6A] FIG. 10 is a configuration diagram of an optical system provided in a camera module of a second embodiment. [Figure 6B] FIG. 10 is a configuration diagram of an optical system provided in a camera module of a second embodiment. [Figure 7A] FIG. 10 is a configuration diagram of an optical system provided in a camera module of a third embodiment. [Figure 7B] FIG. 10 is a configuration diagram of an optical system provided in a camera module of a third embodiment. [Figure 8A] FIG. 10 is a configuration diagram of an optical system provided in a camera module of a third embodiment. [Figure 8B] FIG. 10 is a configuration diagram of an optical system provided in a camera module of a third embodiment. [Figure 9A] FIG. 10 is a configuration diagram of an optical system provided in a camera module of a fourth embodiment. [Figure 9B] FIG. 10 is a configuration diagram of an optical system provided in a camera module of a fourth embodiment. [Figure 10A] FIG. 10 is a configuration diagram of an optical system provided in a camera module of a fourth embodiment. [Figure 10B] FIG. 10 is a configuration diagram of an optical system provided in a camera module of a fourth embodiment. [Figure 11A] FIG. 10 is a diagram illustrating the configuration of an optical system provided in a camera module according to a fifth embodiment. [Figure 11B] FIG. 10 is a diagram illustrating the configuration of an optical system provided in a camera module according to a fifth embodiment. [Figure 12A] FIG. 10 is a diagram illustrating the configuration of an optical system provided in a camera module according to a fifth embodiment. [Figure 12B] FIG. 10 is a diagram illustrating the configuration of an optical system provided in a camera module according to a fifth embodiment. [Figure 13A] FIG. 13 is a diagram illustrating the configuration of an optical system provided in a camera module according to a sixth embodiment. [Figure 13B] FIG. 13 is a diagram illustrating the configuration of an optical system provided in a camera module according to a sixth embodiment. [Figure 14A] FIG. 13 is a diagram illustrating the configuration of an optical system provided in a camera module according to a sixth embodiment. [Figure 14B] FIG. 13 is a diagram illustrating the configuration of an optical system provided in a camera module according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted.

[0017] 1. Embodiment 1 1.1 Camera module Fig. 1 is a perspective view that schematically illustrates a camera module of Embodiment 1. Fig. 2 is a cross-sectional view that schematically illustrates a camera module of Embodiment 1. Fig. 2 illustrates a cross section taken along the cutting line II-II in Fig. 1. Fig. 2 illustrates a cross section obtained by cutting the center of the camera module of Embodiment 1 in the optical axis direction of the camera module.

[0018] The camera module 1 of the first embodiment shown in Figures 1 and 2 receives object light emitted by an object and outputs an image signal corresponding to the received object light. The camera module 1 is a folding camera module equipped with a folding optical system. The camera module 1 focuses on the object using an inner focus method. The camera module 1 also performs optical image stabilization (OIS).

[0019] As shown in FIGS. 1 and 2, the camera module 1 includes a reflecting element 101, an optical system 102, an infrared cut filter 103, an imaging unit 104, and a housing 105.

[0020] The reflecting element 101 is disposed closest to the object. The reflecting element 101 reflects a first object beam emitted by an object and traveling along a first optical axis 111 to generate a second object beam traveling along a second optical axis 112. The reflecting element 101 directs the generated second object beam traveling along the second optical axis 112 toward the optical system 102. Therefore, the reflecting element 101 bends the optical paths of the light rays constituting the object beam. The angle at which the reflecting element 101 bends the light beam, i.e., the angle between the first optical axis 111 and the second optical axis 112, is preferably 90°. However, the angle may be an angle other than 90°. The reflecting element 101 is preferably a prism with high processing accuracy. However, the reflecting element 101 may also be a reflective member other than a prism. For example, the reflecting element 101 may be a reflecting plate. A reflecting plate is also called a mirror.

[0021] When camera module 1 including reflective element 101 is mounted on a smartphone, the optical axis direction can be tilted from a direction perpendicular to the back surface of the smartphone to a direction parallel to the back surface, thereby making it possible to make the smartphone thinner.

[0022] The optical system 102 is disposed after the reflecting element 101, and focuses the second object light traveling along the second optical axis 112 onto the imaging plane 104a of the imaging unit 104. As a result, the second object light is focused and an image of the object is formed on the imaging plane 104a.

[0023] The infrared cut filter 103 is disposed after the optical system 102 and cuts infrared components from the second object light focused on the image forming surface 104a of the imaging unit 104. The infrared cut filter 103 is disposed in front of the image forming surface 104a. This prevents foreign matter such as dust from directly adhering to the image forming surface 104a. This prevents the second object light focused on the image forming surface 104a from being blocked by the foreign matter. This prevents the image represented by the image signal output from the camera module 1 from being degraded by the foreign matter.

[0024] The imaging unit 104 has an image plane 104a on which the second object light that has passed through the optical system 102 is focused. The imaging unit 104 is a sensor that photoelectrically converts the focused second object light and outputs an image signal corresponding to the second object light. The output image signal is processed by software and converted into an image. The imaging unit 104 is a complementary metal-oxide semiconductor (CMOS) image sensor, a charge-coupled device (CCD) image sensor, or the like.

[0025] The housing 105 directly or indirectly supports the reflecting element 101, the optical system 102, the infrared cut filter 103, and the imaging unit 104.

[0026] 1.2 Optical system As shown in FIG. 2, the optical system 102 includes a first lens group G1, a second lens group G2, a third lens group G3, an aperture stop St, a first lens driving device 121, and a second lens driving device 122.

[0027] The first lens group G1 receives the second object light and transmits the received second object light. The first lens group G1 includes a first set of two or more lenses including a first lens L111 and a second lens L12. The first lens group G1 has positive power as a whole. The first lens L11 is the lens of the two or more lenses that is arranged closest to the object.

[0028] A reflecting element 101 is disposed before the first lens group G1. Therefore, the object light transmitted to the optical system 102 and received by the first lens group G1 is the second object light that is reflected by the reflecting element 101 and travels along the second optical axis 112.

[0029] The second lens group G2 is disposed after the first lens group G1 and transmits the second object light that has passed through the first lens group G1. The second lens group G2 includes at least one lens including a third lens L21. The second lens group G2 has negative power as a whole.

[0030] The third lens group G3 is disposed after the second lens group G2, transmits the second object light that has passed through the second lens group G2, and focuses the transmitted second object light on the imaging unit 104. The third lens group G3 includes at least one second lens including a fourth lens L31. The third lens group G3 has positive power as a whole.

[0031] The first lens L11, the second lens L12, the third lens L21, and the fourth lens L31 are glass lenses. All or some of the first lens L11, the second lens L12, the third lens L21, and the fourth lens L31 may be plastic lenses.

[0032] The first lens group G1, the second lens group G2, and the third lens group G3 are supported directly or indirectly on the housing 105 so that the optical axes of the optical system 102, the first lens group G1, the second lens group G2, and the third lens group G3 coincide with the second optical axis 112.

[0033] The optical system 102 includes three lens groups: a first lens group G1, a second lens group G2, and a third lens group G3. The optical system 102 may include four or more lens groups.

[0034] The aperture stop St is included in the optical system 102 and limits the bundle of rays of the object light that passes through the optical system 102 .

[0035] The first lens driving device 121 drives the second lens group G2 in a direction parallel to the second optical axis 112. The first lens driving device 121 drives the second lens group G2 with a driving force generated by an actuator such as a voice coil motor (VCM), a shape memory alloy (SMA) actuator, a piezoelectric actuator, or a stepping motor, and preferably drives the second lens group G2 with a driving force generated by a VCM that is small, can generate a large driving force, and is low-cost. The first lens driving device 121 is disposed between the housing 105 and the second lens group G2.

[0036] The second lens driving device 122 tilts the third lens group G3 in a direction inclined with respect to the second optical axis 112. The second lens driving device 122 tilts the third lens group G3 using a driving force generated by an actuator such as a voice coil motor (VCM), a shape memory alloy (SMA) actuator, or a piezoelectric actuator, or a stepping motor, and preferably tilts the third lens group G3 using a driving force generated by an actuator. The second lens driving device 122 tilts the third lens group G3 by rotating the third lens group G3 about a rotation center on the second optical axis 112. The rotation center is preferably set within the second lens group G2 or the second lens driving device 122.

[0037] The first lens group G1, the first lens driving device 121, the second lens driving device 122, and the imaging unit 104 are fixed to the housing 105. Therefore, when focusing on a close-distance object that is located closer than infinity and emits object light that is received by the first lens group G1, the distance between the first lens group G1 and the imaging unit 104 in the direction parallel to the second optical axis 112 does not change.

[0038] When the second lens group G2 is driven in a direction parallel to the second optical axis 112, the focal position moves in a direction parallel to the second optical axis 112. Therefore, focusing can be performed by driving the second lens group G2 in a direction parallel to the second optical axis 112. Furthermore, when the third lens group G3 is driven in a direction tilted with respect to the second optical axis 112, the image of the object moves in a direction perpendicular to the second optical axis 112 on the image plane of the optical system 102. Therefore, OIS can be performed by tilting the third lens group G3 in a direction tilted with respect to the second optical axis 112. In this way, by separating the first lens drive device 121 that drives for focusing and the second lens drive device 122 that drives for OIS, it is possible to make each of the first lens drive device 121 that drives for focusing and the second lens drive device 122 that drives for OIS smaller and thinner. This allows the optical system 102 and the camera module 1 to be made smaller and thinner. Furthermore, when OIS is performed by second lens drive device 122 tilting third lens group G3 in a direction inclined relative to second optical axis 112, it is easier to make second lens drive device 122 smaller than when OIS is performed by second lens drive device 122 shifting third lens group G3 in a direction perpendicular to second optical axis 112. This allows optical system 102 and camera module 1 to be made smaller and thinner.

[0039] TTL: the distance from the object-side surface L11a of the first lens L11, which is arranged closest to the object side among the two or more lenses included in the first lens group G1, to the imaging plane 104a of the imaging unit 104, Fno: the overall F number of the first lens group G1, the second lens group G2, and the third lens group G3, t-OIS: absolute value of the tilt drive angle of the third lens group G3 in a direction inclined with respect to the second optical axis 112, and Ims: Absolute value of the amount of movement of the image on the image plane in a direction perpendicular to the second optical axis 112, which is caused by tilting the third lens group G3 in a direction inclined with respect to the second optical axis 112 at the optical axis center of the third lens group G3. In this case, the optical system 102 satisfies the following conditional expressions (11) to (16).

[0040] -6.0 <f / f2<-2.0 (11) ih / f<0.4 (12) 0.7 <TTL / f<1.0 (13) 2.4 <Fno<7.0 (14) 0 <t-OIS<6.0 (15) Ims / t-OIS>0.5 (16)

[0041] Conditional expression (11) defines a desirable range for the ratio of the focal length f of the optical system 102 to the focal length f2 of the second lens group G2. When this ratio is equal to or less than the lower limit of −6.0, the refractive power of the second lens group G2 becomes large. This results in large fluctuations in aberrations of the optical system 102 when focusing on close objects. In particular, fluctuations in the curvature of field and coma of the optical system 102 become large. On the other hand, when this ratio is equal to or greater than the upper limit of −2.0, the refractive power of the second lens group G2 becomes small. This results in large amounts of movement of the second lens group G2 when focusing on close objects. For these reasons, it is undesirable for this ratio to be equal to or less than −6.0 or equal to or greater than −2.0.

[0042] Conditional expression (12) defines a desirable range of the ratio of the maximum image height ih to the focal length f of the optical system 102, which determines the focal length of the optical system 102 in 35 mm equivalent.

[0043] Conditional expression (13) defines a desirable range for the telephoto ratio of the optical system 102. If the telephoto ratio is equal to or less than the lower limit of 0.7, the optical system 102 will be small. However, the aberration of the optical system 102 will be large. Also, the aberration of the optical system 102 will fluctuate greatly when focusing on a close-up object. In particular, the fluctuation of the curvature of field of the optical system 102 will be large. On the other hand, if the telephoto ratio is equal to or greater than the upper limit of 1.0, the optical system 102 will be large. For these reasons, it is not desirable for the telephoto ratio to be equal to or less than 0.7 or equal to or greater than 1.0.

[0044] Conditional expression (14) defines the F-number Fno of the optical system 102. If the F-number Fno is equal to or less than the lower limit of 2.4, the thickness of the optical system 102 increases. Furthermore, the spherical aberration and coma of the optical system 102 increase. On the other hand, if the F-number Fno is equal to or greater than the upper limit of 7.0, the amount of light that the optical system 102 can receive decreases. Furthermore, the resolution performance of the optical system 102 decreases due to the diffraction limit. For these reasons, it is undesirable for the F-number Fno to be equal to or less than 2.4 or equal to or greater than 7.0.

[0045] Conditional expression (15) defines a desirable range for the absolute value t-OIS of the tilt drive angle of the third lens group G3. If the absolute value t-OIS of the tilt drive angle is equal to or greater than the upper limit of 6.0, the resolution performance of the optical system 102 will be reduced, causing the optical system 102 to fail. For this reason, it is not desirable for the absolute value t-OIS of the tilt drive angle to be equal to or greater than 6.0.

[0046] Conditional expression (16) defines a desirable range for the ratio of the absolute value Ims of the image movement amount to the absolute value t-OIS of the tilt drive angle of the third lens group G3, which determines the performance of the OIS of the optical system 102 achieved by tilting the third lens group G3 in a direction inclined relative to the second optical axis 112. When this ratio is greater than the lower limit of 0.5, the drive amount of the third lens group G3 required to move the image when tilting only the third lens group G3 is smaller than the drive amount of the first lens group G1, the second lens group G2, and the third lens group G3 as a whole required to move the image the same amount when driving the first lens group G1, the second lens group G2, and the third lens group G3 as a whole. This allows for efficient OIS operation. Furthermore, the second lens drive device 122 can be made smaller.

[0047] 1.4 Lenses in the lens group The two or more lenses included in the first lens group G1 include a first lens L11 having positive power and a second lens L12 having negative power. The first lens L11 is the lens located closest to the reflecting element 101 among the two or more lenses.

[0048] The first at least one lens 132 provided in the second lens group G2 includes a third lens L21 having negative power.

[0049] The second at least one lens 133 provided in the third lens group G3 includes a fourth lens L31 having positive power.

[0050] The optical performance of the optical system 102 can be adjusted by the configuration of each of the first lens L11, second lens L12, third lens L21, and fourth lens L31. Specific examples thereof will be described later.

[0051] The camera module 1 includes a sensor and a controller (not shown). The sensor detects the state of camera shake and outputs a signal indicating the state of camera shake. Based on the output signal, the controller causes the second lens driving device 122 to tilt the third lens group G3.

[0052] The camera module 1 may include a reflective element driving device that drives the reflective element 101 to rotate. The reflective element driving device drives the reflective element 101 to rotate by rotating the reflective element 101 around a rotation axis. When the reflective element 101 is driven to rotate, the image of the object moves in a direction perpendicular to the second optical axis 112 on the image plane of the optical system 102. Therefore, OIS can be performed by driving the reflective element 101 to rotate. The reflective element driving device is disposed between the housing 105 and the second lens group G2. When the camera module 1 includes a reflective element driving device, a driving device selected from the second lens driving device 122 and the reflective element driving device depending on the situation may drive the reflective element, or both the second lens driving device 122 and the reflective element driving device may drive the reflective element.

[0053] 1.5 Configuration diagram and lens data 3A and 3B are diagrams illustrating the configuration of an optical system provided in the camera module of Embodiment 1. Fig. 3A is a diagram illustrating the configuration when focusing at infinity, and Fig. 3B is a diagram illustrating the configuration when focusing at 1m.

[0054] 4A and 4B are diagrams illustrating the configuration of an optical system provided in the camera module of Embodiment 1. Fig. 4A is a diagram illustrating the configuration when in the normal position, and Fig. 4B is a diagram illustrating the configuration when image stabilization is performed.

[0055] As shown in Figures 3A, 3B, 4A, and 4B, the optical system 102 includes an aperture stop St, a first lens group G1 having overall positive power, a second lens group G2 having overall negative power, and a third lens group G3 having overall positive power. In the optical system 102, the aperture stop St, the first lens group G1, the second lens group G2, and the third lens group G3 are arranged in this order from the object side. The first lens group G1 is made up of a first lens L11 having positive power and a second lens L12 having negative power. The second lens group G2 is made up of a third lens L21 having negative power. The third lens group G3 is made up of a fourth lens L31 having positive power.

[0056] Table 1 shows lens data of the optical system 102 provided in the camera module 1 of the first embodiment.

[0057] [Table 1]

[0058] In Table 1, f denotes the focal length of the entire optical system 102, Fno denotes the F-number of the entire optical system 102, ω denotes the half angle of view (degrees) of the entire optical system 102, ih denotes the maximum image height of the entire optical system 102, and TTL denotes the distance from the object-side surface L11a of the first lens L11, which is the closest to the reflecting element 101 among the two or more lenses provided in the first lens group G1, to the imaging unit 104. Also, i denotes the surface number of the lens surface counted from the object side, r denotes the radius of curvature of the lens surface, t denotes the distance between the lens surfaces on the second optical axis 112, Nd denotes the refractive index for the d-line, and vd denotes the Abbe number for the d-line. In Table 1, an asterisk (*) is added after the surface number of an aspherical lens surface.

[0059] The aspherical shape of an aspherical lens surface is expressed by formula (1), where z is the position in the optical axis direction, h is the height in the direction perpendicular to the optical axis, k is the cone number, and A4, A6, A8, A10, and A12 are aspherical coefficients. This also applies to Tables 2 to 6 below.

[0060]

number

[0061] When the optical system 102 has the lens data shown in Table 1, the actual focal length f of the optical system 102 is 38.0 mm. Furthermore, when the imaging unit 104 is a 1 / 4.4-inch sensor, the 35mm equivalent focal length of the optical system 102 is approximately 400 mm. Therefore, when the telephoto side camera of the twin-lens camera is equipped with the camera module 1 and the wide-angle side camera of the twin-lens camera is equipped with a camera module having an optical system with a 35mm equivalent focal length of 24 mm, the zoom ratio of the twin-lens camera can be increased to approximately 17 times.

[0062] When the optical system 102 has the lens data shown in Table 1, the actual focal length f is 38 mm, and the focal length f2 is -8.59 mm. The maximum image height ih is 2.050 mm, the distance TTL is 30.87 mm, and the F-number Fno is 5.0. When the absolute value of the tilt drive angle t-OIS is 3.045 deg, the absolute value of the movement amount Ims is 0.402 mm.

[0063] Therefore, the optical system 102 satisfies the above-mentioned conditional expressions (11) to (16).

[0064] In the optical system 102, focusing can be performed from infinity to close-up photography by driving the second lens group G2 toward the image side. When the optical system 102 has the lens data shown in Table 1, the amount of drive of the second lens group G2 required to focus at a shooting distance of 1 meter is 0.15 mm, as shown in Figures 3A and 3B. This drive amount is smaller than the 1.51 mm of lens extension required to focus at a shooting distance of 1 meter using the all-group extension method.

[0065] 4A and 4B, in the optical system 102, the intersection of the object-side surface of the third lens group G3 and the second optical axis 112 is used as the rotation center O1, and the third lens group G3 is tilted in a direction inclined with respect to the second optical axis 112 to move the image, thereby enabling OIS. If the imaging unit 104 is a 1 / 4.4-inch sensor and the 35mm equivalent focal length of the optical system 102 is 400 mm, the amount of image movement required to correct a shake of 1 degree is 0.402 mm. If the optical system 102 has the lens data shown in Table 1, as shown in FIGS. 4A and 4B, tilting the third lens group G3 by 3.045 degrees is sufficient to achieve the image movement of 0.402 mm required to correct a shake of 1 degree.

[0066] 2. Embodiment 2 The following describes the differences between the second embodiment and the first embodiment. For points that are not described, the second embodiment also employs the same configuration as that employed in the first embodiment.

[0067] 5A and 5B are diagrams illustrating the configuration of an optical system provided in a camera module of embodiment 2. Fig. 5A is a diagram illustrating the configuration when focusing at infinity, and Fig. 5B is a diagram illustrating the configuration when focusing at 1m.

[0068] 6A and 6B are diagrams illustrating the configuration of an optical system provided in a camera module of embodiment 2. Fig. 6A is a diagram illustrating the configuration when in the normal position, and Fig. 6B is a diagram illustrating the configuration when image stabilization is performed.

[0069] Table 2 shows lens data of the optical system 102 provided in the camera module 1 of the second embodiment.

[0070] [Table 2]

[0071] When optical system 102 has the lens data shown in Table 2, the actual focal length f of optical system 102 is 55.4 mm. Furthermore, when imaging unit 104 is a 1 / 3-inch sensor, the 35 mm equivalent focal length of optical system 102 is approximately 400 mm. Therefore, when the telephoto side camera of a twin-lens camera is equipped with camera module 1 and the wide-angle side camera of the twin-lens camera is equipped with a camera module having an optical system with a 35 mm equivalent focal length of 24 mm, the zoom ratio of the twin-lens camera can be increased to approximately 17 times.

[0072] When the optical system 102 has the lens data shown in Table 2, the actual focal length f is 55.4 mm. The focal length f2 is -12.4 mm. The maximum image height ih is 2.980 mm. The distance TTL is 44.85 mm. The F-number Fno is 5.0. When the absolute value t-OIS of the tilt drive angle is 3.045 deg, the absolute value Ims of the movement amount is 0.585 mm.

[0073] Therefore, the optical system 102 satisfies the above-mentioned conditional expressions (11) to (16).

[0074] In the optical system 102, focusing can be performed from infinity to close-up photography by driving the second lens group G2 toward the image side. When the optical system 102 has the lens data shown in Table 2, the amount of drive of the second lens group G2 required to focus at a shooting distance of 1 meter is 0.327 mm, as shown in Figures 5A and 5B. This drive amount is smaller than the 3.263 mm of lens extension required to focus at a shooting distance of 1 meter using the all-group extension method.

[0075] Furthermore, in the optical system 102, OIS can be performed by tilting the third lens group G3 in a direction inclined relative to the second optical axis 112 to move the image. If the imaging unit 104 is a 1 / 3-inch sensor and the 35mm equivalent focal length of the optical system 102 is 400 mm, the amount of image movement required to correct a shake of 1 degree is 0.585 mm. If the optical system 102 has the lens data shown in Table 2, as shown in FIGS. 6A and 6B, tilting the third lens group G3 by 3.026 degrees is sufficient to achieve the image movement of 0.585 mm required to correct a shake of 1 degree.

[0076] 3. Embodiment 3 The following describes the differences between the third embodiment and the first embodiment. For points that are not described, the same configurations as those employed in the first embodiment are also employed in the third embodiment.

[0077] 7A and 7B are diagrams illustrating the configuration of an optical system provided in a camera module of embodiment 3. Fig. 7A is a diagram illustrating the configuration when focusing at infinity, and Fig. 7B is a diagram illustrating the configuration when focusing at 1m.

[0078] 8A and 8B are diagrams illustrating the configuration of an optical system provided in a camera module of embodiment 3. Fig. 8A is a diagram illustrating the configuration when in the normal position, and Fig. 8B is a diagram illustrating the configuration when image stabilization is performed.

[0079] Table 3 shows lens data of the optical system 102 provided in the camera module 1 of the third embodiment.

[0080] [Table 3]

[0081] When optical system 102 has the lens data shown in Table 3, the actual focal length f of optical system 102 is 21.7 mm. Furthermore, when imaging unit 104 is a 1 / 4.4-inch sensor, the 35 mm equivalent focal length of optical system 102 is approximately 220 mm. Therefore, when the telephoto side camera of a twin-lens camera is equipped with camera module 1 and the wide-angle side camera of the twin-lens camera is equipped with a camera module having an optical system with a 35 mm equivalent focal length of 24 mm, the zoom ratio of the twin-lens camera can be increased to approximately 9 times.

[0082] When the optical system 102 has the lens data shown in Table 3, the actual focal length f is 21.7 mm. The focal length f2 is -8.5 mm. The maximum image height ih is 2.050 mm. The distance TTL is 20.02 mm. The F-number Fno is 3.6. When the absolute value t-OIS of the tilt drive angle is 2.790 deg, the absolute value Ims of the movement amount is 0.207 mm.

[0083] Therefore, the optical system 102 satisfies the above-mentioned conditional expressions (11) to (16).

[0084] In the optical system 102, focusing can be performed from infinity to close-up photography by driving the second lens group G2 toward the image side. When the optical system 102 has the lens data shown in Table 3, the amount of drive of the second lens group G2 required to focus at a shooting distance of 1 meter is 0.167 mm, as shown in Figures 7A and 7B. This drive amount is smaller than the 0.480 mm of lens extension required to focus at a shooting distance of 1 meter using the all-group extension method.

[0085] Furthermore, in the optical system 102, OIS can be performed by tilting the third lens group G3 in a direction inclined relative to the second optical axis 112 to move the image. If the imaging unit 104 is a 1 / 4.4-inch sensor and the 35mm equivalent focal length of the optical system 102 is 220 mm, the amount of image movement required to correct a shake of 1 degree is 0.207 mm. If the optical system 102 has the lens data shown in Table 3, as shown in FIGS. 8A and 8B, tilting the third lens group G3 by 2.790 degrees is sufficient to achieve the image movement of 0.207 mm required to correct a shake of 1 degree.

[0086] 4. Embodiment 4 The following describes the differences between the fourth embodiment and the first embodiment. For points that are not described, the same configurations as those employed in the first embodiment are also employed in the fourth embodiment.

[0087] 9A and 9B are diagrams illustrating the configuration of an optical system provided in a camera module of embodiment 4. Fig. 9A is a diagram illustrating the configuration when focusing at infinity, and Fig. 9B is a diagram illustrating the configuration when focusing at 1m.

[0088] 10A and 10B are diagrams illustrating the configuration of an optical system provided in a camera module according to embodiment 4. Fig. 10A is a diagram illustrating the configuration when in the normal position, and Fig. 10B is a diagram illustrating the configuration when image stabilization is performed.

[0089] In the fourth embodiment, the second lens L12, the third lens L21, and the fourth lens L31 are plastic lenses.

[0090] Table 4 shows lens data of the optical system 102 provided in the camera module 1 of the fourth embodiment.

[0091] [Table 4]

[0092] When optical system 102 has the lens data shown in Table 4, the actual focal length f of optical system 102 is 38.1 mm. Furthermore, when imaging unit 104 is a 1 / 4.4-inch sensor, the 35mm equivalent focal length of optical system 102 is approximately 400 mm. Therefore, when the telephoto side camera of a twin-lens camera is equipped with camera module 1 and the wide-angle side camera of the twin-lens camera is equipped with a camera module having an optical system with a 35mm equivalent focal length of 24 mm, the zoom ratio of the twin-lens camera can be increased to approximately 16x.

[0093] When the optical system 102 has the lens data shown in Table 4, the actual focal length f is 38.1 mm. The focal length f2 is -7.69 mm. The maximum image height ih is 2.050 mm. The distance TTL is 32.4 mm. The F-number Fno is 5.0. When the absolute value t-OIS of the tilt drive angle is 3.020 deg, the absolute value Ims of the movement amount is 0.404 mm.

[0094] Therefore, the optical system 102 satisfies the above-mentioned conditional expressions (11) to (16).

[0095] In the optical system 102, focusing can be performed from infinity to close-up photography by driving the second lens group G2 toward the image side. When the optical system 102 has the lens data shown in Table 4, the amount of drive of the second lens group G2 required to focus at a shooting distance of 1 meter is 0.131 mm, as shown in Figures 9A and 9B. This drive amount is smaller than the 1.489 mm of lens extension required to focus at a shooting distance of 1 meter using the all-group extension method.

[0096] Furthermore, in the optical system 102, OIS can be performed by tilting the third lens group G3 in a direction inclined relative to the second optical axis 112 to move the image. If the imaging unit 104 is a 1 / 4.4-inch sensor and the 35mm equivalent focal length of the optical system 102 is 400 mm, the amount of image movement required to correct a shake of 1 degree is 0.404 mm. If the optical system 102 has the lens data shown in Table 4, as shown in FIGS. 10A and 10B, tilting the third lens group G3 by 3.020 degrees is sufficient to achieve the image movement of 0.404 mm required to correct a shake of 1 degree.

[0097] 5. Embodiment 5 The following describes the differences between the fifth embodiment and the first embodiment. For points that are not described, the same configurations as those employed in the first embodiment are also employed in the fifth embodiment.

[0098] 11A and 11B are diagrams illustrating the configuration of an optical system provided in a camera module of embodiment 5. Fig. 11A is a diagram illustrating the configuration when focusing at infinity, and Fig. 11B is a diagram illustrating the configuration when focusing at 1m.

[0099] 12A and 12B are diagrams illustrating the configuration of an optical system provided in a camera module of embodiment 5. Fig. 12A is a diagram illustrating the configuration when in the normal position, and Fig. 12B is a diagram illustrating the configuration when image stabilization is performed.

[0100] In the fifth embodiment, the two or more lenses provided in the first lens group G1 include three lenses: a first lens L11, a second lens L12, and a lens L13.

[0101] Table 5 shows lens data of the optical system 102 provided in the camera module 1 of the fifth embodiment.

[0102] [Table 5]

[0103] When optical system 102 has the lens data shown in Table 5, the actual focal length f of optical system 102 is 38.1 mm. Furthermore, when imaging unit 104 is a 1 / 4.4-inch sensor, the 35mm equivalent focal length of optical system 102 is approximately 400 mm. Therefore, when the telephoto side camera of a twin-lens camera is equipped with camera module 1 and the wide-angle side camera of the twin-lens camera is equipped with a camera module having an optical system with a 35mm equivalent focal length of 24 mm, the zoom ratio of the twin-lens camera can be increased to approximately 17x.

[0104] When the optical system 102 has the lens data shown in Table 5, the actual focal length f is 38.1 mm. The focal length f2 is -10.46 mm. The maximum image height ih is 2.050 mm. The distance TTL is 30.8 mm. The F-number Fno is 5.0. When the absolute value t-OIS of the tilt drive angle is 2.966 deg, the absolute value Ims of the movement amount is 0.400 mm.

[0105] Therefore, the optical system 102 satisfies the above-mentioned conditional expressions (11) to (16).

[0106] In optical system 102, focusing can be performed from infinity to close-up photography by driving second lens group G2 toward the image side. When optical system 102 has the lens data shown in Table 5, the amount of drive of second lens group G2 required to focus at a shooting distance of 1 meter is 0.177 mm, as shown in Figures 11A and 11B. This drive amount is smaller than the 1.527 mm of lens extension required to focus at a shooting distance of 1 meter using the all-group extension method.

[0107] Furthermore, in the optical system 102, OIS can be performed by tilting the third lens group G3 in a direction inclined relative to the second optical axis 112 to move the image. If the imaging unit 104 is a 1 / 4.4-inch sensor and the 35mm equivalent focal length of the optical system 102 is 400 mm, the amount of image movement required to correct a shake of 1 degree is 0.400 mm. If the optical system 102 has the lens data shown in Table 5, as shown in FIGS. 12A and 12B, tilting the third lens group G3 by 2.966 degrees is sufficient to achieve the amount of image movement of 0.400 mm required to correct a shake of 1 degree.

[0108] 6. Embodiment 6 The following describes the differences between the sixth embodiment and the first embodiment. For points that are not described, the sixth embodiment also employs the same configuration as that employed in the first embodiment.

[0109] 13A and 13B are diagrams illustrating the configuration of an optical system provided in a camera module of embodiment 6. Fig. 13A is a diagram illustrating the configuration when focusing at infinity, and Fig. 13B is a diagram illustrating the configuration when focusing at 1m.

[0110] 14A and 14B are diagrams illustrating the configuration of an optical system provided in a camera module according to embodiment 6. Fig. 14A is a diagram illustrating the configuration when in the normal position, and Fig. 14B is a diagram illustrating the configuration when image stabilization is performed.

[0111] In the sixth embodiment, the third lens group G3 is tilted in a direction inclined with respect to the second optical axis 112 around the intersection of the image side surface of the third lens group G3 and the second optical axis 112 as the rotation center O6.

[0112] Table 6 shows lens data of the optical system 102 provided in the camera module 1 of the sixth embodiment.

[0113] [Table 6]

[0114] When optical system 102 has the lens data shown in Table 6, the actual focal length f of optical system 102 is 38.1 mm. Furthermore, when imaging unit 104 is a 1 / 4.4-inch sensor, the 35mm equivalent focal length of optical system 102 is approximately 400 mm. Therefore, when the telephoto side camera of a twin-lens camera is equipped with camera module 1 and the wide-angle side camera of the twin-lens camera is equipped with a camera module having an optical system with a 35mm equivalent focal length of 24 mm, the zoom ratio of the twin-lens camera can be increased to approximately 17x.

[0115] When the optical system 102 has the lens data shown in Table 6, the actual focal length f is 38.1 mm. The focal length f2 is -8.62 mm. The maximum image height ih is 2.050 mm. The distance TTL is 30.9 mm. The F-number Fno is 5.0. When the absolute value t-OIS of the tilt drive angle is 3.057 deg, the absolute value Ims of the movement amount is 0.402 mm.

[0116] Therefore, the optical system 102 satisfies the above-mentioned conditional expressions (11) to (16).

[0117] In optical system 102, focusing can be performed from infinity to close-up photography by driving second lens group G2 toward the image side. When optical system 102 has the lens data shown in Table 6, the amount of drive of second lens group G2 required to focus at a shooting distance of 1 meter is 0.152 mm, as shown in Figures 13A and 13B. This drive amount is smaller than the 1.512 mm of lens extension required to focus at a shooting distance of 1 meter using the all-group extension method.

[0118] Furthermore, in the optical system 102, OIS can be performed by tilting the third lens group G3 in a direction inclined relative to the second optical axis 112 to move the image. If the imaging unit 104 is a 1 / 4.4-inch sensor and the 35mm equivalent focal length of the optical system 102 is 400 mm, the amount of image movement required to correct a shake of 1 degree is 0.402 mm. If the optical system 102 has the lens data shown in Table 6, as shown in FIGS. 14A and 14B, tilting the third lens group G3 by 3.057 degrees is sufficient to achieve the image movement of 0.402 mm required to correct a shake of 1 degree.

[0119] In this way, even if the rotation center O6 is changed from the intersection of the object-side surface of the third lens group G3 and the second optical axis 112 to the intersection of the image-side surface of the third lens group G3 and the second optical axis 112, OIS can be performed appropriately. This also applies if the rotation center O6 is changed to a point other than the intersection of the image-side surface of the third lens group G3 and the second optical axis 112. However, the design of the optical system 102 must be changed depending on the position of the rotation center O6. The rotation center O6 is also preferably located within the third lens group G3 or the second lens drive device 122.

[0120] The present disclosure is not limited to the above-described embodiments, and may be replaced with a configuration that is substantially the same as the configuration shown in the above-described embodiments, a configuration that has the same effect, or a configuration that can achieve the same purpose. [Explanation of symbols]

[0121] 1 camera module 101 Reflective element 102 Optical system 103 Infrared cut filter 104 Imaging unit 104a Image plane 105 Case 111 1st optical axis 112 2nd optical axis 121 first lens driving device 122 second lens driving device 132,133 Lenses G1 First lens group G2 Second lens group G3 3rd lens group L11 First lens L11a side L12 Second lens L13 lens L21 Third lens L31 4th lens O1 Rotation Center O6 Rotation center

Claims

1. An optical system comprising: a first lens group including two or more lenses, having a positive power as a whole, and transmitting object light; a second lens group including at least one first lens, having a negative power as a whole, and disposed after the first lens group to transmit the object light; a third lens group including at least one second lens, having a positive power as a whole, and disposed after the second lens group to focus the object light onto an imaging unit; a first lens driving device that drives and shifts the second lens group in a direction parallel to the optical axis of the optical system; a second lens driving device that tilts the third lens group in a direction inclined with respect to the optical axis; Equipped with When the third lens group is tilted in a direction inclined with respect to the optical axis, an image moves on an image plane of the optical system in a direction perpendicular to the optical axis, f: the actual focal length of the first lens group, the second lens group, and the third lens group as a whole, f2: the focal length of the second lens group, ih: the maximum image height of the first lens group, the second lens group, and the third lens group as a whole, TTL: the distance from the object-side surface of the lens positioned closest to the object side among the two or more lenses to the image plane, Fno: the overall F-number of the first lens group, the second lens group, and the third lens group, t-OIS: the absolute value of the tilt drive angle of the third lens group in a direction inclined with respect to the optical axis, and Ims: absolute value of the amount of movement of the image on the image plane in a direction perpendicular to the optical axis, which is caused by tilt driving of the third lens group in a direction inclined with respect to the optical axis at the optical axis center of the third lens group In this case, -6.0<f / f2<-2.0, ih / f<0.4, 0.7<TTL / f<1.0, 2.4<Fno<7.0, 0<t-OIS<6.0 and Ims / t-OIS>0.5 An optical system that satisfies the above.

2. the two or more lenses include a first lens having a positive power and a second lens having a negative power; the first at least one lens includes a third lens having negative power; The second at least one lens includes a fourth lens having a positive power. The optical system of claim 1 .

3. The first lens driving device drives the second lens group by a driving force generated by a voice coil motor.

3. The optical system according to claim 1 or 2.

4. The second lens driving device tilts the third lens group using a driving force generated by an actuator.

3. The optical system according to claim 1 or 2.

5. The optical system according to claim 1 or 2; the imaging unit; Equipped with The imaging unit has an image forming surface on which the object light is condensed, and performs photoelectric conversion on the object light. Camera module.

6. a reflecting element disposed in front of the first lens group, which reflects a first object light beam traveling along a first optical axis to generate a second object light beam traveling along a second optical axis; the optical axis is the second optical axis, The object beam is the second object beam. The camera module according to claim 5 .

Images