Optical device

Abstract

An optical device is provided, comprising: a lens group including a plurality of lenses; a moving unit configured to move the plurality of lenses; and a control unit configured to control the moving unit to switch between a closed position state in which the plurality of lenses are closest to each other and function as a single lens, and an open position state in which the plurality of lenses are spaced apart from each other.

Description

[Technical field]

[0001] The present disclosure relates to an optical apparatus, a device, and a method for controlling the refractive power of a lens group in an optical apparatus. For example, the device may be a mobile device such as a mobile phone, a smart phone, a tablet computer, or a personal computer. Optionally, the device may be a digital still camera, a digital video camera, a security / surveillance camera, a network camera, an automotive / traffic camera, or a medical camera, etc. [Background technology]

[0002] Conventionally, as a method for realizing a zoom function or a focus function in an imaging device, there is a method in which a lens group including a plurality of lenses is changed in refractive power by relatively moving the lenses. Also, a method is known in which the refractive power is changed by changing and controlling the curvature of a single lens using a liquid lens.

[0003] On the other hand, the miniaturization of imaging devices contributes to the miniaturization of mobile devices equipped with imaging functions, such as smartphones, mobile phones, tablets, drive recorders, etc. The miniaturization also contributes to the miniaturization of imaging devices, such as web cameras, action cameras, monitoring cameras, and compact digital cameras. Furthermore, imaging devices can be further miniaturized by suppressing the increase in the overall size of the lens group that forms the imaging lens.

[0004] The present disclosure makes it possible to change the distribution of refractive power while suppressing an increase in the size of the lens group. Summary of the Invention

[0005] In the above circumstances, technical advantages are provided by the embodiments disclosed below. The embodiments provide an optical apparatus, a device, and a method for controlling the refractive power of a lens group in an optical apparatus. The device may be a mobile phone, a smartphone, a tablet computer, a personal computer, a digital still camera, a digital video camera, a security / surveillance camera, a network camera, an automotive / traffic camera, or a medical camera, etc.

[0006] A first aspect of an embodiment provides an optical device.

[0007] In a first possible implementation form of the first aspect, an optical device includes a lens group including a plurality of lenses, a moving unit configured to move the plurality of lenses, and a control unit configured to control the moving unit to switch between a closed position state in which the plurality of lenses are closest to each other and function as one lens, and an open position state in which the plurality of lenses are spaced apart from each other. Possible According to an implementation, the refractive power of the lens group can be switched between a first refractive power corresponding to a closed position state and a second refractive power corresponding to an open position state.

[0008] A second possible implementation form of the first aspect provides an apparatus according to the first possible implementation form of the first aspect.

[0009] Here, in the closed position, the lenses are configured to satisfy the condition given by the following equation (1): D min / φ<0.2 …(1) Here, D min denotes the distance between two adjacent lenses in the lens group, and φ denotes the optical effective diameter of the lens having the largest lens diameter in the lens group. Optionally, the plurality of lenses in the closed position is given by Equation (1a): R The conditions may be met. D min / φ<0.1 …(1a)

[0010] A third possible implementation of the first aspect provides a device according to the first or second possible implementation of the first aspect, wherein the plurality of lenses includes first and second aspheric lenses facing each other, and an image-side surface of the first lens and an object-side surface of the second lens facing the image-side surface of the first lens have shapes expressed by the following formulas (2) and (3): 0.5 <abs[S оb (h) / S im (h)]<2.0 …(2) Here, S оb (h) is the sag of the object side surface of the second lens at a height h from the optical axis, and S im (h) indicates the amount of sag of the image-side surface of the first lens at height h. 0.7 <R оb / R im <1.3 …(3) Here, R оb is the radius of curvature of the object-side surface of the second lens, and R im indicates the radius of curvature of the image-side surface of the first lens.

[0011] Optionally, the image-side surface of the first lens and the object-side surface of the second lens opposite the image-side surface of the first lens may have shapes represented by the following equations (2a) and (3a): 0.7 <abs[S оb (h) / S im (h)] < 1.8 … (2a) 0.8 <R оb / R im <1.2 …(3a)

[0012] Optionally, the image-side surface of the first lens and the object-side surface of the second lens opposite the image-side surface of the first lens may have a shape represented by equation (3b) below. 0.7 <abs[S оb (h) / S im (h)] < 1.6 … (3b)

[0013] A second aspect of the embodiment provides a device.

[0014] In a first possible implementation form of the second aspect, a device includes an optical device, an image sensor that receives light passing through the optical device, and a processor for generating image data based on an output signal from the image sensor, and the optical device includes a lens group including a plurality of lenses, a moving unit configured to move the plurality of lenses, and a control unit configured to control the moving unit to switch between a closed position state in which the plurality of lenses are closest to each other and function as a single lens, and an open position state in which the plurality of lenses are positioned apart from each other. Second The first aspect of the present invention Possible According to an implementation, the refractive power of the lens group can be switched between a first refractive power corresponding to a closed position state and a second refractive power corresponding to an open position state.

[0015] A second possible implementation of the second aspect provides a device according to the first possible implementation of the second aspect, where in a closed position, the plurality of lenses are configured to satisfy a condition given by the following equation (1): D min / φ<0.2 …(1) Here, D min denotes the distance between two adjacent lenses in the lens group, and φ denotes the optical effective diameter of the lens having the largest lens diameter in the lens group. Optionally, the lenses in the closed position may satisfy the condition given by equation (1a) below. D min / φ<0.1 …(1a)

[0016] A third possible implementation of the second aspect provides a device according to the first or second possible implementation of the second aspect, where the plurality of lenses includes first and second aspheric lenses facing each other, and an image-side surface of the first lens and an object-side surface of the second lens facing the image-side surface of the first lens have shapes expressed by the following formulas (2) and (3): 0.5 <abs[S оb (h) / S im (h)]<2.0 …(2) Here, S оb (h) is the sag of the object side surface of the second lens at a height h from the optical axis, and S im (h) indicates the amount of sag of the image-side surface of the first lens at height h. 0.7 <R оb / R im <1.3 …(3) Here, R оb is the radius of curvature of the object-side surface of the second lens, and R im indicates the radius of curvature of the image-side surface of the first lens.

[0017] Optionally, the image-side surface of the first lens and the object-side surface of the second lens opposite the image-side surface of the first lens may have shapes represented by the following equations (2a) and (3a): 0.7 <abs[S оb (h) / S im (h)] < 1.8 … (2a) 0.8 <R оb / R im <1.2 …(3a)

[0018] Optionally, the image-side surface of the first lens and the object-side surface of the second lens opposite the image-side surface of the first lens may have a shape represented by equation (3b) below. 0.7 <abs[S оb (h) / S im (h)] < 1.6 … (3b)

[0019] A third aspect of the embodiment is For controlling the refractive power of a lens group including a plurality of lenses According to a first possible implementation of the third aspect, a method is provided. 、 The method includes a step of moving the plurality of lenses by an actuator to switch between a closed position state in which the plurality of lenses are closest to each other and function as one lens, and an open position state in which the plurality of lenses are spaced apart from each other. Possible According to an implementation, the refractive power of the lens group can be switched between a first refractive power corresponding to a closed position state and a second refractive power corresponding to an open position state.

[0020] Third A second possible implementation of the aspect provides a method according to the first possible implementation of the third aspect, wherein in a closed position state, the plurality of lenses are configured to satisfy a condition given by the following formula (1): D min / φ<0.2 …(1) Here, D min denotes the distance between two adjacent lenses in the lens group, and φ denotes the optical effective diameter of the lens having the largest lens diameter in the lens group. Optionally, the lenses in the closed position may satisfy the condition given by equation (1a) below. D min / φ<0.1 …(1a)

[0021] A fourth aspect of the embodiment provides a non-transitory computer readable storage medium storing a program for causing a processor to perform a method according to the first or second possible implementation of the third aspect. A fifth aspect of the embodiment provides a computer readable program for causing a processor to perform a method according to the first or second possible implementation of the third aspect. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is an external view showing an example of the hardware configuration of a mobile device in which the imaging lens group according to each of the first to sixth embodiments can be implemented. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 2 is a block diagram showing an example of the hardware configuration of a mobile device in which the imaging lens group according to each of the first to sixth embodiments can be implemented. [Figure 4] Fig. 4(a) is a diagram showing an example of an imaging lens according to the first embodiment, and Fig. 4(b) is a table showing the focal length of each lens constituting the imaging lens group according to the first embodiment and the conditions that the lenses satisfy. [Diagram 5] 4 is a table showing lens parameters of each lens that configures the imaging lens group according to the first embodiment. [Figure 6] Fig. 6(a) is a diagram showing an example of an imaging lens group according to the second embodiment, and Fig. 6(b) is a table showing the focal length of each lens constituting the imaging lens group according to the second embodiment and the conditions that the lenses satisfy. [Figure 7] 13 is a table showing lens parameters of each lens that configures an imaging lens group according to a second embodiment. [Figure 8] Fig. 8(a) is a diagram showing an example of an imaging lens group according to the third embodiment, and Fig. 8(b) is a table showing the focal length of each lens constituting the imaging lens group according to the third embodiment and the conditions that the lenses satisfy. [Figure 9] FIG. 9 is a table showing the lens parameters of each lens constituting the imaging lens group according to the third embodiment. [Figure 10] Fig. 10(a) is a diagram showing an example of an imaging lens group according to the fourth embodiment, and Fig. 10(b) is a table showing the focal length of each lens constituting the imaging lens group according to the fourth embodiment and the conditions that the lenses satisfy. [Figure 11] 13 is a table showing lens parameters of each lens that configures an imaging lens group according to a fourth embodiment. [Figure 12] Fig. 12(a) is a diagram showing an example of an imaging lens group according to the fifth embodiment, and Fig. 12(b) is a table showing the focal length of each lens constituting the imaging lens group according to the fifth embodiment and the conditions that the lenses satisfy. [Figure 13] 13 is a table showing lens parameters of each lens that configures an imaging lens group according to a fifth embodiment. [Figure 14] Fig. 14(a) is a diagram showing an example of an imaging lens group according to the sixth embodiment, and Fig. 14(b) is a table showing the focal length of each lens constituting the imaging lens group according to the sixth embodiment and the conditions that the lenses satisfy. [Figure 15] 13 is a table showing lens parameters of each lens that configures an imaging lens group according to the sixth embodiment. [Figure 16] 4 is a table showing lens data of each lens constituting an imaging lens group according to each embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The following describes the technical solutions of the embodiments with reference to the accompanying drawings. The embodiments described below are obviously not all of the embodiments according to the present disclosure, but only some. It should be noted that based on the embodiments described below, all other embodiments that can be obtained by those skilled in the art without creative efforts should also fall within the protection scope of the embodiments of the present disclosure.

[0024] In the following, we will first explain configuration examples of mobile devices in which the imaging lens groups according to each embodiment can be implemented, and then we will explain configuration examples of the imaging lens groups according to the first, second, third, fourth, fifth and sixth embodiments and the characteristics of their imaging lenses in order.

[0025] (Example of implementation on a mobile device) With reference to FIGS. 1 to 3, one of imaging lens groups 101, 102, 103, 104, 105, and 106 according to first to sixth embodiments described later is Can be installed A mobile device 10 will be described. The mobile device 10 illustrated in Fig. 1 and Fig. 2 is a smartphone, but is not limited thereto. The mobile device 10 is an example of a device according to an embodiment of the present disclosure. For example, the device may be a mobile phone, a smartphone, a tablet computer, a personal computer, a digital still camera, a digital video camera, a security / surveillance camera, a network camera, an automobile / traffic camera, or a medical camera.

[0026] 1 is a perspective view showing an external configuration of a smartphone 10 on which the imaging lens group according to each of the first to sixth embodiments can be mounted. In this configuration example, the smartphone includes three imaging units 31, 32, and 33. It should be noted that FIG. 1 merely shows the openings of the three imaging units arranged in the case member 20 of the smartphone 10.

[0027] 2 is a cross-sectional view showing a cross section taken along line II-II in FIG. 1. As shown in FIG. 2, the imaging unit 31 of the smartphone 10 includes a main lens 15 forming an opening of the imaging unit 31, an imaging lens group (lens unit) 11 according to any one of the first to sixth embodiments described later, and an imaging device 16. Light entering through the main lens 15 as an opening during imaging passes through each element in the above order and reaches the imaging device 16. The imaging unit 31 also includes a moving unit 120 for moving the lens group described later in the sections of the respective embodiments for the imaging lens group 11, and the moving unit 120 includes an actuator 12 (FIG. 3) as its driving source.

[0028] The imaging device 16 includes an imaging element 170 such as a CCD or CMOS, and an AD conversion circuit (not shown) that converts an analog electrical signal output from the imaging element into a digital imaging signal.

[0029] The imaging element 170 of the imaging device 16 is disposed at the position of the image forming plane. The imaging element has a plurality of pixels. For example, the imaging element includes a pixel that generates an electrical signal corresponding to the intensity of a red light component, a pixel that generates an electrical signal corresponding to the intensity of a blue light component, and a pixel that generates an electrical signal corresponding to the intensity of a green light component. As a modification, the imaging element may be another imaging element for monochrome photography that includes a plurality of pixels that generate an electrical signal corresponding to the intensity of light.

[0030] FIG. 3 is a block diagram showing an example of the hardware configuration of a smartphone 10 in which the imaging lens according to each of the first to sixth embodiments can be mounted, and mainly shows a control configuration related to the imaging unit 31.

[0031] As shown in FIG. 3, the control configuration of the smartphone 10 includes an actuator 12, a driver 13, and a CPU 14.

[0032] The CPU 14 executes a program stored in a memory (not shown) to control the movement of the lenses in the lens group described later in the first to sixth embodiments. Specifically, the CPU 14 controls the driving of the actuator 12 via the driver 13, thereby controlling the movement of each lens in the imaging lens group 11. The actuator 12 and the driver 13 may be examples of a moving unit according to an embodiment of the present disclosure, and the CPU 14 may be an example of a control unit according to an embodiment of the present disclosure. Furthermore, a set of the imaging lens group 11, the actuator 12, and the driver 13 may be an example of an optical device according to an embodiment of the present disclosure. The above-mentioned configuration makes it possible to move and position the lenses in the lens group of each embodiment described below.

[0033] In the following, first to sixth embodiments of the imaging lens group 11 in the smartphone 10 will be described.

[0034] (First embodiment)

[0035] Figure 4(a) and Figure 4(b) 1 is a diagram showing an imaging lens group 101 according to a first embodiment of the present disclosure that can be mounted as the imaging lens group 11 shown in the configuration example of the smartphone 10. Figure 4(a) indicate the lens positions of the imaging lens group 101 in the closed position and the open position, respectively, Figure 4(b) 1 shows a table showing the focal length and the like of the imaging lens group 101 in the closed and open positions. Figure 4(a)As shown in FIG. 1, the imaging lens group 101 of this embodiment includes three lenses L1 to L3. AX indicates the optical axis, and S1, S2, S3, S4, S5, and S6 indicate the surfaces of the lenses L1 to L3, respectively. The closed position of the imaging lens group 101 is a position where the lenses are close to each other and the conditional expressions (1) to (3) described later are satisfied. The open position is a position where the lenses of the imaging lens group 101 are separated from each other so as to realize a predetermined refractive power. This makes it possible to reverse the positive and negative refractive powers given at the closed and open positions. In addition, the open position can be determined so as to realize, for example, a refractive power corresponding to the zoom and focus functions of the imaging device. Therefore, in a system of one lens group, the combination of the distances D1 and D2 between the lenses, which will be described later with reference to FIG. 5, is not limited to one combination, and there may be a plurality of combinations, that is, a plurality of open positions according to functions such as the zoom function described above.

[0036] Figure 4(a) Then, the lenses L1, L2, and L3 of the imaging lens group 101 are as follows: Figure 4(a) From the object side, which is the left side of Figure 4(a) That is, lens L1 is located closest to the object side, and lens L3 is located closest to the image side.

[0037] Figure 4(a) As shown in Figure 1, surfaces S1 and S2 are aspheric to achieve the desired optical properties. The shape of surfaces S1 and S2 allows lens L1 to have positive refractive power.

[0038] Lens L2 is an aspheric lens. The shape of surfaces S3 and S4 allows lens L2 to have negative refractive power.

[0039] The object-side surface S5 of lens L3 is aspheric so that in the closed position it has a shape that is similar to the shape of the image-side surface S4 of the adjacent lens L2, and provides the desired optical properties. The shapes of surfaces S5 and S6 allow lens L3 to have negative refractive power.

[0040] Figure 4(b)As shown in the table, the focal lengths of the lenses L1, L2, and L3 in this embodiment are 22.8, -324.27, and -19.92, respectively. The total focal lengths of the entire imaging lens group 101 in the closed and open positions are 29.14 and 23.94, respectively. The surface conditions indicating the degree of similarity of the lens surface shapes adjacent to each other in the closed position are S2 / S3 of 0.84 and S4 / S5 of 1.04. Similarly, the radius conditions indicating the degree of similarity of the lens surface shapes adjacent to each other in the closed position are S2 / S3 of 1.19 and S4 / S5 of 0.96. Figure 4(b) The distance condition shown in is a parameter of conditional expression (1) described later, and indicates the distance between the lenses when they are closest to each other in the closed position. In the imaging lens group 101 of this embodiment, the distance condition is 0.003.

[0041] In the closed position, the lenses L1, L2, and L3 are close to each other and satisfy the conditional expressions (1) to (3) described below. In this state (positional relationship), the three lenses L1, L2, and L3 have the same refractive power as one lens in the lens group as a whole. On the other hand, in the open position, the lenses L1, L2, and L3 are separated from each other. In this state (positional relationship), the lenses L1, L2, and L3 have their own refractive power, but the imaging lens group 101 as a whole has a refractive power different from the refractive power in the open position.

[0042] As described above, in the closed position, the lenses L1, L2, and L3 of the imaging lens group 101 are close to each other, and the entire lens group has the same refractive power as a single lens. On the other hand, in the open position, the refractive powers of the lenses are combined, and thus the entire imaging lens group 101 has a refractive power different from that in the closed position. Then, when the lenses L1, L2, and L3 are set to the closed position and the open position in terms of the position (distance) relationship, it is possible to generate a refractive power distribution according to the relationship.

[0043] Here, the conditional expressions (1) to (3) that should be satisfied in order for the lenses L1, L2, and L3 of the imaging lens group 101 to produce the above-mentioned refractive power distribution in the closed position will be described.

[0044] The lenses L1, L2, and L3 of the imaging lens group 10 are D min / φ < 0.2 …Conditional expression (1) D min is the lens distance between the lenses L1, L2, and L3 when they are close to each other in the closed position, and φ is the optical effective diameter of the lens having the largest lens diameter among the lenses L1, L2, and L3 that constitute the imaging lens group 101. In this embodiment, the lens distance is expressed as follows: Figure 4(b) This is the value given by the distance condition shown in. The lens surfaces of the lenses L1, L2, and L3 facing each other have similar surface shapes that satisfy the following conditional formula (2): оb (h) is the surface shape (sag amount) of the object side surface at an arbitrary lens diameter height h, and S im (h) is the surface shape (sag amount) of the image side surface. In this embodiment, the surface shape is Figure 4(b) It has a value given by the surface condition shown in FIG. 0.5 < abs[S оb (h) / S im (h)] < 2.0 …Conditional formula (2) The radii of curvature of the opposing lens surfaces R1 and R2, R3 and R4, and R5 and R6 satisfy the following conditions: оb is the radius of curvature of the surface facing the object, and R im is the radius of curvature of the image-side surface. In this embodiment, the radii of curvature are Figure 4(b) The radius of the radii is given by the radius condition shown in FIG. 0.7 < R оb / R im < 1.3 …Conditional expression (3)

[0045] In the following, more preferable conditions for the conditional expressions (1) to (3) will be presented. In the conditional expression (1), D min When the value of / φ is 0.2 or more, the refractive power of each lens starts to have an individual effect, and it becomes difficult to treat the entire lens group approximately as a single lens even when each lens is in the closed position. As a result, the difference when switching between the refractive power arrangement in the closed position and the refractive power arrangement after the lenses are separated becomes smaller, and the expected effect cannot be obtained. Therefore, conditional formula (1) is D min / φ < 0.1 …Conditional expression (4) It is preferable that:

[0046] Furthermore, when the lens surface shapes do not satisfy conditional expressions (2) and (3), the lens surfaces of the mutually facing lenses L1, L2, and L3 are affected by their own refractive actions, making it difficult to treat the entire lens group approximately as a single lens even when each lens is in the closed position. As a result, the difference when switching between the refractive power arrangement in the closed position and the refractive power arrangement after the lenses are separated becomes smaller, and the expected effect cannot be obtained. Therefore, it is more preferable that conditional expressions (2) and (3) are respectively as follows: 0.7 < abs[S оb (h) / S im (h)] < 1.8 …Conditional formula (5) And, 0.8 < R оb / R im < 1.2…Conditional expression (6) It should be.

[0047] Furthermore, condition (5) should more preferably be 0.7 < abs[S оb (h) / S im (h)] < 1.6 …Conditional formula (7) It should be.

[0048] Next, conditions for parameters that define the optical characteristics of lenses L1, L2, and L3 included in imaging lens group 101 will be described with reference to Fig. 5. RDN in Fig. 5 indicates parameters such as the surfaces S1 to S6 of each lens that constitutes imaging lens group 101 according to the first embodiment, R is the radius of curvature of the lens surface, D is the distance between each lens, Nd is the refractive index at each surface, Vd is the Abbe number, and φ is the effective optical diameter of each lens. Here, D1 represents the distance between the image side (S2) of lens L1 and the object side (S3) of lens L2, D2 represents the distance between the image side (S4) of lens L2 and the object side (S5) of lens L3, and D1 and D2 show different values ​​when the lens group is in the closed position and when it is in the open position. Specifically, as shown in FIG. 5, in the closed position, D1 is 0.01 and D2 is 0.01, and in the open position, D1 is 1.23 and D2 is 1.69.

[0049] "Aspherical Coefficients" in FIG. 5 indicates the aspherical coefficients of the corresponding orders.

[0050] Among the parameters shown in the RDN table in Fig. 5, R, D, Nd, and φ are designed to satisfy all of the above-mentioned conditional expressions (1) to (3). The Abbe number Vd is a value that provides well-balanced correction of axial chromatic aberration and lateral chromatic aberration.

[0051] The shape of an aspheric lens is given by the aspheric shape formula shown in the following formula (8), where Z represents the depth of the aspheric surface, Y represents the distance (height) from the optical axis to the lens surface, R represents the paraxial radius of curvature, K represents the conic constant, and C4, C6, C8, C 10 represent the 4th, 6th, 8th, and 10th order aspheric coefficients, respectively.

[0052] Z=(Y 2 / R) / [1-{1-(1+K)(Y 2 / R 2 )} 1 / 2 ]+C4Y 4 +C6Y 6 +C8Y 8 +C 10 Y 10…Conditional expression (8)

[0053] In the example shown in Fig. 5, the lens L2 is an aspheric lens. The lenses L1 and L3 have an aspheric surface on one side and a spherical surface on the other side. At least one of the lenses L1, L2, and L3 may be a resin lens. For example, when the aspheric lens is made of a resin lens that is easily processed, the manufacturing cost of the imaging lens group 101 can be reduced.

[0054] Figure 4(b) Comparing the total focal length of the lens group in the closed position and the open position in the table shown in Fig. 1, it is 29.14 mm in the closed position and 23.94 mm in the open position. Therefore, by transitioning the state from the closed position to the open position and changing the refractive power distribution, it is possible for the three lenses L1, L2, and L3 to have a zoom lens function.

[0055] In addition, the values ​​of the conditional expressions (1) to (3) are expressed as Figure 4(b) It is understood that the lenses in the table shown in satisfy the conditional expressions (4) to (6) which provide more preferable conditions, and also satisfy the conditional expression (7) which provides more preferable conditions. As a result, the lenses L1, L2, and L3 in this embodiment behave as a single lens in the entire lens group in the closed position, and while separating to the open position, the lenses can change the refractive power distribution of the entire lens group from the value in the closed position due to the refractive power of each lens. As described above, when a plurality of lenses are arranged to form a lens group and the arrangement relationship thereof does not satisfy conditional expressions (1) to (3), the plurality of lenses exist individually and merely realize their respective optical characteristics. On the other hand, according to the first embodiment of the present disclosure, the arrangement relationship of the plurality of lenses is set so that the conditional expressions (1) to (3) are satisfied in the closed position, and the lenses have a predetermined refractive power in the open position. This makes it possible for the lenses, as a lens group, to generate a refractive power distribution according to the positional relationship of the lenses. As a result, it is possible to prevent the size of the imaging device from increasing when the refractive power distribution is realized.

[0056] Second embodiment Next, a second embodiment will be described below, and detailed descriptions of contents overlapping with the first embodiment will be omitted.

[0057] Figure 6(a) and Figure 6(b) 1 is a diagram showing an imaging lens group 102 according to a second embodiment of the present disclosure that can be implemented as the imaging lens group 11 shown in the configuration example of the smartphone 10. Figure 6(a) indicates the lens positions of the imaging lens group 102 in the closed position and the open position, respectively, Figure 6(b) 1 shows a table showing the focal length and the like of the imaging lens group 102 in the closed and open positions.

[0058] Figure 6(a) In the second embodiment, the lenses L1, L2, L3, and L4 of the imaging lens group 102 are: Figure 6(a) From the object side, which is the left side of Figure 6(a) That is, lens L1 is located closest to the object side, and lens L4 is located closest to the image side.

[0059] The shapes of lenses L1, L2, L3, and L4 are Figure 6(a) In the imaging lens group 102, the lenses L1 and L2 have negative refractive power. The lenses L3 and L4 have positive refractive power. The lens L3 is an aspheric lens.

[0060] Each lens of the imaging lens group 102 is Figure 6(b) The shape of the lens is defined by the lens parameters shown in FIG.

[0061] FIG. 7 is a table showing the lens parameters of each lens constituting the imaging lens group 102 according to the second embodiment. Figure 6(b) is a table showing the focal lengths of the lenses that make up the imaging lens group 102 according to the second embodiment, the total focal length of the entire lens group in the open and closed positions, and the values ​​of conditional expressions (1) to (3) for lenses L1, L2, L3, and L4.

[0062] Figure 6(b)By setting the lens parameters of each lens according to the above conditions, various aberrations can be corrected. Also, since the Abbe number of each lens is set as shown in FIG. 7, chromatic aberration can be corrected. Also, comparing the total focal length at the closed position and the open position, the total focal length at the open position is 58.82 mm, and the total focal length at the closed position is 341.42 mm, which is about 5.8 times the total focal length at the open position. Therefore, the four lenses L1, L2, L3, and L4 of the imaging lens group 102 can have a zoom lens function by transitioning the state from the closed position to the open position and changing the refractive power distribution.

[0063] Figure 6(a) As shown in Fig. 1, lenses L1 and L2, lenses L2 and L3, and lenses L3 and L4 have similar shapes at least near the optical axis on opposing sides S2 and S3, S4 and S5, and S6 and S7, respectively. As a result, the lenses in the closed position can approach each other so as to satisfy conditional expressions (1) to (3), and have the same refractive power as a single lens.

[0064] Third embodiment Next, a third embodiment will be described. In the following, detailed description of the contents overlapping with the first embodiment will be omitted.

[0065] Figure 8(a) and Figure 8(b) 10 is a diagram showing an imaging lens group 103 according to a third embodiment of the present disclosure that can be implemented as the imaging lens group 11 shown in the configuration example of the smartphone 10. Figure 8(a) indicates the lens positions of the imaging lens group 103 in the closed position and the open position, Figure 8(b) 1 shows a table showing the focal length of the imaging lens group 103 in the closed position and the open position. The lens configuration of the imaging lens group 103 will be described later. Figure 8(b) This corresponds to the conditions and the lens parameters in FIG.

[0066] Figure 8(a) As shown in FIG. 1, the imaging lens group 103 of this embodiment includes two lenses L1 and L2. The lenses L1 and L2 are: Figure 8(a)From the object side, which is the left side of Figure 8(a) Lens L1 is located closest to the object side, and lens L2 is located closest to the image side.

[0067] The shapes of lenses L1 and L2 are Figure 8(a) In the imaging lens group 103, the lens L1 has a negative refractive power. The lens L2 has a positive refractive power. The lenses L1 and L2 are aspheric lenses.

[0068] Each lens of the imaging lens group 103 is Figure 8(b) The shape of the lens is defined by the lens parameters shown in FIG.

[0069] Figure 8(b) Fig. 9 is a table showing the focal lengths of the lenses constituting the imaging lens group 103 according to the third embodiment, the total focal length of the entire lens group in the open and closed positions, and the values ​​of conditional expressions (1) to (3) for lenses L1 and L2. Fig. 9 is a table showing lens parameters of each lens constituting the imaging lens group 103 according to the third embodiment.

[0070] Figure 8(b) By setting the lens parameters of each lens according to the above conditions, various aberrations can be corrected. Also, since the Abbe number of each lens is set as shown in FIG. 9, chromatic aberration can be corrected. Also, comparing the total focal length at the closed position and the open position, the total focal length at the open position is 13.48 mm, and the total focal length at the closed position is 89.97 mm, which is about 6.7 times the total focal length at the open position. Therefore, the two lenses L1 and L2 of the imaging lens group 103 can have a zoom lens function by transitioning the state from the closed position to the open position and changing the refractive power distribution.

[0071] Figure 8(a)As shown in Fig. 1, the lenses L1 and L2 have similar shapes at least near the optical axis for the opposing surfaces S2 and S3. As a result, the lenses in the closed position can approach each other so as to satisfy conditional expressions (1) to (3), and have the same refractive power as a single lens.

[0072] (Fourth embodiment) Next, a fourth embodiment will be described. In the following, detailed description of the contents overlapping with the first embodiment will be omitted.

[0073] Figure 10(a) and Figure 10(b) 13 is a diagram showing an imaging lens group 104 according to a fourth embodiment of the present disclosure that can be implemented as the imaging lens group 11 shown in the configuration example of the smartphone 10. FIG. Figure 10(a) indicates the lens positions of the imaging lens group 104 in the closed position and the open position, respectively, Figure 10(b) 1 shows a table showing the focal length of the imaging lens group 104 in the closed and open positions.

[0074] Figure 10(a) As shown in FIG. 1, the imaging lens group 104 of this embodiment includes two lenses L1 and L2. The lenses L1 and L2 are: Figure 10(a) From the object side, which is the left side of Figure 10(a) Lens L1 is located closest to the object side, and lens L2 is located closest to the image side.

[0075] The shapes of lenses L1 and L2 are Figure 10(a) In the imaging lens group 104, the lens L1 has a negative refractive power. The lens L2 has a positive refractive power. The lens L1 is an aspheric lens.

[0076] Each lens of the imaging lens group 104 is Figure 10(b) The shape of the lens is defined by the lens parameters shown in FIG.

[0077] Figure 10(b)11 is a table showing the focal lengths of the lenses constituting the imaging lens group 104 according to the fourth embodiment, the total focal length of the entire lens group in the open and closed positions, and the values ​​of conditional expressions (1) to (3) for lenses L1 and L2. Fig. 11 is a table showing lens parameters of each lens constituting the imaging lens group 104 according to the fourth embodiment.

[0078] Figure 10(b) By setting the lens parameters of each lens according to the above conditions, various aberrations can be corrected. Furthermore, since the Abbe number of each lens is set as shown in FIG. 11, chromatic aberration can be corrected. Furthermore, when comparing the total focal length at the closed position and the open position, the total focal length at the closed position has a negative value of −60.40 mm, and the total focal length at the open position has a positive value of 50.20 mm. Therefore, the two lenses L1 and L2 of the imaging lens group 104 can have a zoom lens function by transitioning the state from the closed position to the open position and changing the refractive power distribution from negative to positive.

[0079] Figure 10(a) As shown in Fig. 1, the opposing sides S2 and S3 of the lenses L1 and L2 are close to each other with a small gap between them in the closed position. However, even in this case, the lenses L1 and L2 satisfy the conditions (1) to (3), so that in the closed position the lenses have the same refractive power as a single lens.

[0080] Fifth embodiment Next, a fifth embodiment will be described. In the following, detailed description of the contents that overlap with the first embodiment will be omitted.

[0081] Figure 12(a) and Figure 12(b) 13 is a diagram showing an imaging lens group 105 according to a fifth embodiment of the present disclosure that can be implemented as the imaging lens group 11 shown in the configuration example of the smartphone 10. FIG. Figure 12(a) indicates the lens positions of the imaging lens group 105 in the closed position and the open position, respectively, Figure 12(b) 1 shows a table showing the focal length of the imaging lens group 105 in the closed position and the open position.

[0082] Figure 12(a) As shown in FIG. 1, the imaging lens group 105 of this embodiment includes three lenses L1 to L3. The lenses L1, L2, and L3 are Figure 12(a) From the object side, which is the left side of Figure 12(a) Lens L1 is located closest to the object side, and lens L3 is located closest to the image side.

[0083] The shapes of lenses L1, L2, and L3 are Figure 12(a) In the imaging lens group 105, the lenses L1 and L3 have negative refractive power. The lens L3 is an aspheric lens. The lens L2 has positive refractive power.

[0084] Each lens of the imaging lens group 105 is Figure 12(b) The shape of the lens is defined by the lens parameters shown in FIG.

[0085] Figure 12(b) Fig. 13 is a table showing the focal lengths of the lenses constituting the imaging lens group 105 according to the fifth embodiment, the total focal length of the entire lens group in the open and closed positions, and the values ​​of conditional expressions (1) to (3) for lenses L1, L2, and L3. Fig. 13 is a table showing lens parameters of each lens constituting the imaging lens group 105 according to the fifth embodiment.

[0086] Figure 12(b) By setting the lens parameters of each lens according to the above conditions, various aberrations can be corrected. Furthermore, since the Abbe number of each lens is set as shown in FIG. 13, chromatic aberration can be corrected. Furthermore, when comparing the total focal length at the closed position and the open position, the total focal length at the closed position has a negative value of −60.40 mm, and the total focal length at the open position has a positive value of 50.20 mm. Therefore, the three lenses L1, L2, and L3 of the imaging lens group 105 can have a zoom lens function by transitioning the state from the closed position to the open position and changing the refractive power distribution from negative to positive.

[0087] Figure 12(a)As shown in Fig. 1, the lenses L1 and L2 have similar shapes at least near the optical axis on the opposing sides S2 and S3, respectively. The same is true for L2 and L3. As a result, the lenses in the closed position can approach each other so as to satisfy conditional expressions (1) to (3), and have the same refractive power as a single lens.

[0088] Sixth embodiment Next, a sixth embodiment will be described. In the following, detailed description of the contents that overlap with the first embodiment will be omitted.

[0089] Figure 14(a) and Figure 14(b) 13 is a diagram showing an imaging lens group 106 according to a sixth embodiment of the present disclosure, which can be implemented as the imaging lens group 11 shown in the configuration example of the smartphone 10. FIG. Figure 14(a) indicates the lens positions of the imaging lens group 106 in the closed position and the open position, respectively, Figure 14(b) 1 shows a table showing the focal length of the imaging lens group 106 in the closed and open positions.

[0090] Figure 14(a) As shown in FIG. 1, the imaging lens group 106 of this embodiment includes three lenses L1 to L3. The lenses L1, L2, and L3 are Figure 14(a) From the object side, which is the left side of Figure 14(a) Lens L1 is located closest to the object side, and lens L3 is located closest to the image side.

[0091] The shapes of lenses L1, L2, and L3 are Figure 14(a) In the imaging lens group 106, the lenses L1 and L2 have negative refractive power. The lenses L1, L2, and L3 are aspheric lenses. The lens L3 has positive refractive power.

[0092] Each lens of the imaging lens group 106 is Figure 14(b) The shape of the lens is defined by the lens parameters shown in FIG.

[0093] Figure 14(b)Fig. 15 is a table showing the focal lengths of the lenses constituting the imaging lens group 106 according to the sixth embodiment, the total focal length of the entire lens group in the open and closed positions, and the values ​​of conditional expressions (1) to (3) for lenses L1, L2, and L3. Fig. 15 is a table showing lens parameters of each lens constituting the imaging lens group 106 according to the sixth embodiment.

[0094] Figure 14(b) By setting the lens parameters of each lens according to the above conditions, various aberrations can be corrected. Furthermore, since the Abbe number of each lens is set as shown in FIG. 15, chromatic aberration can be corrected. Furthermore, when comparing the total focal length at the closed position and the open position, the total focal length at the closed position has a negative value of −60.40 mm, and the total focal length at the open position has a positive value of 50.20 mm. Therefore, the three lenses L1, L2, and L3 of the imaging lens group 106 can have a zoom lens function by transitioning the state from the closed position to the open position and changing the refractive power distribution from negative to positive.

[0095] Figure 14(a) As shown in Fig. 1, the opposing sides S3, S4, S5 of the lenses L1, L2, L3 have a small gap between them in the closed position. However, the lenses L1, L2, L3 still satisfy the conditions (1) to (3), so that in the closed position the lenses have the same refractive power as a single lens.

[0096] 16 summarizes the values ​​of conditional expressions (1) to (3) for each example. As can be seen from the values ​​in the table, conditional expressions (1) to (3) are satisfied in each example. Furthermore, in Examples 1, 2, and 3, conditional expressions (4) to (6), and (7) are satisfied, so the imaging lenses constituting Examples 1, 2, and 3 have more suitable parameters.

[0097] The above disclosure merely discloses exemplary embodiments and is not intended to limit the scope of protection of the present invention. Those skilled in the art will understand that the above-mentioned embodiments and all or part of other embodiments and modifications that can be derived based on the claims of the present invention naturally fall within the scope of the present invention.

Claims

1. a lens group having a plurality of lenses including a first aspherical lens, a second aspherical lens, and a third aspherical lens; a moving unit configured to move the plurality of lenses; a control unit configured to control the moving unit to switch between a closed position state in which the plurality of lenses are closest to each other and have the same refractive power as one lens as a whole, and an open position state in which the plurality of lenses are spaced apart from each other, wherein an aspheric surface on the image side of the first aspheric lens and an aspheric surface on the object side of the second aspheric lens face each other and have shapes that are similar to each other, and an aspheric surface on the image side of the second aspheric lens and an aspheric surface on the object side of the third aspheric lens face each other and have shapes that are similar to each other, The image-side aspheric surface of the first aspheric lens and the object-side aspheric surface of the second aspheric lens have shapes expressed by the following formulas (1a) and (2a), 0.5<abs[S ob2 (h) / S im1 (h)]<2.0 …(1a)、 0.7<R ob2 / R im1 <1.3 …(2a)、 Here, S im1 (h) represents the sag amount of the image-side aspheric surface of the first aspheric lens at a height h from the optical axis, and S ob2 (h) represents the sag amount of the object-side aspheric surface of the second aspheric lens at the height h, and R im1 denotes the radius of curvature of the image-side aspheric surface of the first aspheric lens, and R ob2 represents the radius of curvature of the object-side aspheric surface of the second aspheric lens, The image-side aspheric surface of the second aspheric lens and the object-side aspheric surface of the third aspheric lens have shapes expressed by the following formulas (1b) and (2b), 0.5<abs[S ob3 (h) / S im2 (h)]<2.0 …(1b)、 0.7<R ob3 / R im2 <1.3 …(2ｬ), Here, S im2 (h) denotes the sag amount of the image-side aspheric surface of the second aspheric lens at the height h, and S ob3 (h) represents the sag amount of the object-side aspheric surface of the third aspheric lens at the height h, and R im2 denotes the radius of curvature of the image-side aspheric surface of the second aspheric lens, and R ob3 denotes the radius of curvature of the object-side aspheric surface of the third aspheric lens, optical equipment.

2. In the closed position, the lenses are configured to satisfy a condition given by the following equation (3): D min / φ<0.2 …(3) Here, D min represents the distance between two adjacent lenses of the lens group on the optical axis, and φ represents the optical effective diameter of the lens having the largest lens diameter in the lens group.

2. The apparatus of claim 1.

3. In the closed position, the lenses are configured in particular to satisfy the condition given by the following equation (4): D min / φ<0.1 …(4) 3. The apparatus of claim 2.

4. The image-side aspheric surface of the first aspheric lens and the object-side aspheric surface of the second aspheric lens are particularly configured to have shapes expressed by the following formulas (5a) and (6a): 0.7<abs[S ob2 (h) / S im1 (h)]<1.8 …(5a) 0.8<R ob2 / R im1 <1.2 …(6a) 4. The apparatus of claim 3.

5. The image-side aspheric surface of the second aspheric lens and the object-side aspheric surface of the third aspheric lens are particularly configured to have shapes expressed by the following formulas (5b) and (6b): 0.7<abs[S ob3 (h) / S im2 (h)]<1.8 …(5b) 0.8<R ob3 / R im2 <1.2 …(6b) 4. The apparatus of claim 3.

6. In particular, the image-side aspheric surface of the first aspheric lens and the object-side aspheric surface of the second aspheric lens are configured to have a shape expressed by the following formula (7a): 0.7<abs[S ob2 (h) / S im1 (h)]<1.6 …(7a) 5. The apparatus of claim 4.

7. The image-side aspheric surface of the second aspheric lens and the object-side aspheric surface of the third aspheric lens are particularly configured to have a shape expressed by the following formula (7b): 0.7<abs[S ob3 (h) / S im2 (h)]<1.6 …(7b) 6. The apparatus of claim 5.

8. A device comprising an optical arrangement according to any one of claims 1 to 7, an image sensor receiving light passing through the optical arrangement, and a processor for generating image data based on an output signal from the image sensor.

9. 1. A method for controlling the refractive power of a lens group including a plurality of lenses, the method comprising: a step of moving the plurality of lenses by an actuator so as to switch between a closed position state in which the plurality of lenses are closest to each other and the plurality of lenses collectively have the same refractive power as one lens, and an open position state in which the plurality of lenses are spaced apart from each other, the plurality of lenses including a first aspherical lens, a second aspherical lens, and a third aspherical lens; an aspheric surface on an image side of the first aspheric lens and an aspheric surface on an object side of the second aspheric lens face each other and have shapes that approximate each other, and an aspheric surface on an image side of the second aspheric lens and an aspheric surface on an object side of the third aspheric lens face each other and have shapes that approximate each other, The image-side aspheric surface of the first aspheric lens and the object-side aspheric surface of the second aspheric lens have shapes expressed by the following formulas (8a) and (9a), 0.5<abs[S ob2 (h) / S im1 (h)]<2.0 …(8a)、 0.7<R ob2 / R im1 <1.3 …(9a), Here, S im1 (h) represents the sag amount of the image-side aspheric surface of the first aspheric lens at a height h from the optical axis, and S ob2 (h) represents the sag amount of the object-side aspheric surface of the second aspheric lens at the height h, and R im1 denotes the radius of curvature of the image-side aspheric surface of the first aspheric lens, and R ob2 represents the radius of curvature of the object-side aspheric surface of the second aspheric lens, The image-side aspheric surface of the second aspheric lens and the object-side aspheric surface of the third aspheric lens have shapes expressed by the following formulas (8b) and (9b), 0.5<abs[S ob3 (h) / S im2 (h)]<2.0 …(8b)、 0.7<R ob3 / R im2 <1.3 …(9q) Here, S im2 (h) denotes the sag amount of the image-side aspheric surface of the second aspheric lens at the height h, and S ob3 (h) represents the sag amount of the object-side aspheric surface of the third aspheric lens at the height h, and R im2 denotes the radius of curvature of the image-side aspheric surface of the second aspheric lens, and R ob3 denotes the radius of curvature of the object-side aspheric surface of the third aspheric lens, method.

10. The closed position state is configured such that the lenses satisfy a condition given by the following equation (10): D min / φ<0.2 …(10) Here, D min represents the distance between two adjacent lenses of the lens group on the optical axis, and φ represents the optical effective diameter of the lens having the largest lens diameter in the lens group.

10. The method of claim 9.

11. The closed position state is particularly configured such that the lenses satisfy the condition given by the following equation (11): D min / φ<0.1 …(11) The method of claim 10.

12. In particular, the image-side aspheric surface of the first aspheric lens and the object-side aspheric surface of the second aspheric lens are configured to have shapes expressed by the following formulas (12a) and (13a): 0.7<abs[S ob2 (h) / S im1 (h)]<1.8 …(12a) 0.8<R ob2 / R im1 <1.2 …(13a) 10. The method of claim 9.

13. The image-side aspheric surface of the second aspheric lens and the object-side aspheric surface of the third aspheric lens are particularly configured to have shapes expressed by the following formulas (12b) and (13b): 0.7<abs[S ob3 (h) / S im2 (h)]<1.8 …(12b) 0.8<R ob3 / R im2 <1.2 …(13b) 10. The method of claim 9.

14. In particular, the image-side aspheric surface of the first aspheric lens and the object-side aspheric surface of the second aspheric lens are configured to have a shape expressed by the following formula (14a): 0.7<abs[S ob2 (h) / S im1 (h)]<1.6 …(14a) The method of claim 12.

15. The image-side aspheric surface of the second aspheric lens and the object-side aspheric surface of the third aspheric lens are particularly configured to have a shape expressed by the following formula (14b): 0.7<abs[S ob3 (h) / S im2 (h)]<1.6 …(14b) The method of claim 13.

16. A non-transitory computer readable storage medium storing a program for causing a computer to carry out the method according to any one of claims 9 to 15.

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