Optical device

Abstract

An optical device is provided, the device comprising: a lens group (11, 101, 102, 103, 104, 105, 106) comprising a plurality of lenses (L1, L2, L3, L4); a moving unit (120) configured to move the plurality of lenses (L1, L2, L3, L4); and a control unit (14) configured to control the moving unit (120) to change between a closed position state in which the plurality of lenses (L1, L2, L3, L4) are closest together so as to act like one lens, and an open position state in which the plurality of lenses (L1, L2, L3, L4) are positioned apart from each other.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an optical device, an apparatus, and a method for controlling a refractive power of a lens group in an optical device. For example, the apparatus can be a mobile device such as a mobile phone, a smartphone, a tablet, or a personal computer. Alternatively, the apparatus can be a digital still camera, a digital video camera, a security / surveillance camera, a webcam, a car / transport camera, a medical camera, etc. BACKGROUND

[0002] Generally, as a method of implementing a zoom function and a focusing function in an imaging device, there is a method of changing a refractive power of a lens group including a plurality of lenses by moving the lenses relative to each other. Another known method is to change the refractive power by changing and controlling the curvature of a single lens using a liquid lens.

[0003] On the other hand, miniaturization of an imaging device can contribute to miniaturization of a mobile device equipped with an imaging function such as a smartphone, a mobile phone, a tablet, and a dashcam. Miniaturization also contributes to miniaturization of an imaging device such as a webcam, an action camera, a surveillance camera, and a small digital video camera. In addition, it is also possible to miniaturize an imaging device by suppressing an increase in the size of the entire lens group that forms an imaging lens.

[0004] The present disclosure can change the refractive power distribution while suppressing an increase in the size of the lens group. SUMMARY

[0005] In the above case, the embodiments disclosed below provide technical advantages. The embodiments provide an optical device, an apparatus, and a method for controlling a refractive power of a lens group in an optical device. The apparatus can be a mobile phone, a smartphone, a tablet, a personal computer, a digital still camera, a digital video camera, a security / surveillance camera, a webcam, a car / transport camera, a medical camera, etc.

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

[0007] In a first possible implementation of the first aspect, 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 change between a closed position state in which the plurality of lenses are closest to each other so as to work like one lens and an open position state in which the plurality of lenses are placed apart from each other. According to the first implementation of the first aspect, the refractive power of the lens group can be changed between a first refractive power corresponding to the closed position state and a second refractive power corresponding to the open position state.

[0008] A second possible implementation of the first aspect provides: the apparatus according to the first possible implementation of the first aspect, wherein the plurality of lenses in the closed position state is configured to satisfy a condition provided by the following equation (1):

[0009] D min / φ < 0.2 (1),

[0010] wherein D min indicates a distance between two adjacent lenses of the lens group, and φ indicates an optically effective diameter of a lens having a largest lens diameter in the lens group. Optionally, the plurality of lenses in the closed position state can satisfy the following condition provided by the following equation (1a):

[0011] D min / φ<0.1(1a).

[0012] A third possible implementation of the first aspect provides: the apparatus according to the first or second possible implementation of the first aspect, wherein the plurality of lenses includes a first lens and a second lens of aspheric surfaces opposite to each other, wherein 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 represented by the following equations (2) and (3):

[0013] 0.5 < abs[S ob (h) / S im (h)] < 2.0 (2),

[0014] wherein S ob (h) indicates a sag amount of the object-side surface of the second lens at a height h from an optical axis, S im (h) indicates a sag amount of the image-side surface of the first lens at the height h, and

[0015] 0.7 < R ob / R im < 1.3 (3),

[0016] wherein R ob indicates a radius of curvature of the object-side surface of the second lens, and R im indicates a 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 facing the image-side surface of the first lens can have shapes represented by the following equations (2a) and (3a):

[0018] 0.7<abs[S ob (h) / S im (h)]<1.8(2a), and

[0019] 0.8 < R ob / R im <1.2 (3a).

[0020] Optionally, the image-side surface of the first lens and the object-side surface of the second lens facing the image-side surface of the first lens can have a shape represented by the following equation (3b):

[0021] 0.7 < abs[S ob (h) / S im (h)] < 1.6 (3b).

[0022] A second aspect of embodiments provides an apparatus.

[0023] In a first possible implementation form of the second aspect, the apparatus comprises: an optical device, an image sensor receiving light passing through the optical device, and a processor for generating image data based on an output signal from the image sensor, wherein the optical device comprises: a lens group comprising 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 change between a closed position state in which the plurality of lenses are closest to each other so as to work like one lens and an open position state in which the plurality of lenses are placed apart from each other. According to the first implementation form of the second aspect, the refractive power of the lens group can be changed between a first refractive power corresponding to the closed position state and a second refractive power corresponding to the open position state.

[0024] A second possible implementation form of the second aspect provides the apparatus according to the first possible implementation form of the second aspect, wherein the plurality of lenses in the closed position state are configured to satisfy a condition provided by the following equation (1):

[0025] D min / φ < 0.2 (1),

[0026] wherein D min indicates a distance between two adjacent lenses of the lens group, and φ indicates an optically effective diameter of a lens having a largest lens diameter in the lens group. Optionally, the plurality of lenses in the closed position state can satisfy the following condition provided by the following equation (1a):

[0027] D min / φ < 0.1 (1a).

[0028] A third possible implementation of the second aspect provides: the apparatus according to the first or second possible implementation of the second aspect, wherein the plurality of lenses includes first and second lenses of aspheric surfaces opposite to each other, wherein the image-side surface of the first lens and the object-side surface of the second lens facing the image-side surface of the first lens have shapes represented by the following equations (2) and (3):

[0029] 0.5 < abs[S ob (h) / S im (h)] < 2.0 (2),

[0030] wherein S ob (h) indicates a sag of the object-side surface of the second lens at a height h from the optical axis, S im (h) indicates a sag of the image-side surface of the first lens at the height h, and

[0031] 0.7 < R ob / R im < 1.3 (3),

[0032] wherein R ob indicates a radius of curvature of the object-side surface of the second lens, R im indicates a radius of curvature of the image-side surface of the first lens.

[0033] Optionally, the image-side surface of the first lens and the object-side surface of the second lens facing the image-side surface of the first lens can have shapes represented by the following equations (2a) and (3a):

[0034] 0.7<abs[S ob (h) / S im (h)]<1.8(2a), and

[0035] 0.8<R ob / R im <1.2(3a).

[0036] Optionally, the image-side surface of the first lens and the object-side surface of the second lens facing the image-side surface of the first lens can have a shape represented by the following equation (3b):

[0037] 0.7<abs[S ob (h) / S im (h)]<1.6(3b).

[0038] A third aspect of embodiments provides a method. In a first possible implementation of the third aspect, a method for controlling a dioptric power of a lens group including a plurality of lenses, the method comprising: moving the plurality of lenses between a closed position state in which the plurality of lenses are closest to act like one lens and an open position state in which the plurality of lenses are placed apart from each other. According to the first implementation of the third aspect, the dioptric power of the lens group can be changed between a first dioptric power corresponding to the closed position state and a second dioptric power corresponding to the open position state.

[0039] A second possible implementation of the third aspect provides: the method according to the first possible implementation of the third aspect, wherein the plurality of lenses in the closed position state are configured to satisfy a condition provided by the following equation (1):

[0040] D min / φ < 0.2 (1),

[0041] wherein D min indicates a distance between two adjacent lenses of the lens group, and φ indicates an optically effective diameter of a lens having a largest lens diameter in the lens group. Optionally, the plurality of lenses in the closed position state can satisfy the following condition provided by the following equation (1a):

[0042] D min / φ < 0.1 (1a).

[0043] A fourth aspect of embodiments provides a non-transitory computer-readable storage medium storing a program causing a processor to execute the method according to the first or second possible implementation of the third aspect. A fifth aspect of embodiments provides a computer-readable program causing a processor to execute the method according to the first or second possible implementation of the third aspect. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 is an external view showing a hardware configuration example of a mobile device in which an imaging lens group according to each of the first to sixth embodiments can be implemented;

[0045] Figure 2 is a cross-sectional view showing a cross section along line II-II in Figure 1

[0046] Figure 3 is a block diagram showing a hardware configuration example of a mobile device in which an imaging lens group according to each of the first to sixth embodiments can be implemented;

[0047] Figure 4 ​(a) is a configuration diagram showing an example of the imaging lens group according to the first embodiment, Figure 4 (b) is a table showing focal lengths of the respective lenses constituting the imaging lens group according to the first embodiment and conditions that the lenses satisfy;

[0048] Figure 5 is a table showing lens parameters of the respective lenses constituting the imaging lens group according to the first embodiment;

[0049] Figure 6 (a) is a configuration diagram showing an example of the imaging lens group according to the second embodiment, Figure 6 (b) is a table showing focal lengths of the respective lenses constituting the imaging lens group according to the second embodiment and conditions that the lenses satisfy;

[0050] Figure 7 is a table showing lens parameters of the respective lenses constituting the imaging lens group according to the second embodiment;

[0051] Figure 8 (a) is a configuration diagram showing an example of the imaging lens group according to the third embodiment, Figure 8 (b) is a table showing focal lengths of the respective lenses constituting the imaging lens group according to the third embodiment and conditions that the lenses satisfy;

[0052] Figure 9 is a table showing lens parameters of the respective lenses constituting the imaging lens group according to the third embodiment;

[0053] Figure 10 (a) is a configuration diagram showing an example of the imaging lens group according to the fourth embodiment, Figure 10 (b) is a table showing focal lengths of the respective lenses constituting the imaging lens group according to the fourth embodiment and conditions that the lenses satisfy;

[0054] Figure 11 is a table showing lens parameters of the respective lenses constituting the imaging lens group according to the fourth embodiment;

[0055] Figure 12 (a) is a configuration diagram showing an example of the imaging lens group according to the fifth embodiment, Figure 12 (b) is a table showing focal lengths of the respective lenses constituting the imaging lens group according to the fifth embodiment and conditions that the lenses satisfy;

[0056] Figure 13 is a table showing lens parameters of the respective lenses constituting the imaging lens group according to the fifth embodiment;

[0057] Figure 14 (a) is a configuration diagram showing an example of the imaging lens group according to the sixth embodiment, Figure 14(b) is a table showing the focal lengths of the individual lenses constituting the imaging lens group according to the sixth embodiment and the conditions satisfied by the lenses;

[0058] Figure 15 This is a table showing the lens parameters of each lens constituting the imaging lens group according to the sixth embodiment;

[0059] Figure 16 This is a table showing the lens data of each lens constituting the imaging lens group according to various embodiments. Detailed Implementation

[0060] The technical solutions of the embodiments will now be described with reference to the accompanying drawings. Obviously, the embodiments described below are not all embodiments of this disclosure, but only a part of them. It should be noted that all other embodiments obtained by those skilled in the art based on the embodiments described below without inventive effort are within the scope of protection of the embodiments of this disclosure.

[0061] The following will first describe configuration examples of the moving device in which the imaging lens group according to each embodiment can be implemented, and then describe configuration examples of the imaging lens group according to the first embodiment, second embodiment, third embodiment, fourth embodiment, fifth embodiment and sixth embodiment, as well as the characteristics of these imaging lenses.

[0062] (Example implementation on mobile devices)

[0063] Reference Figures 1 to 3 A movable device 10 is described on which one of the imaging lens groups 101, 102, 103, 104, 105 and 106 of the first to sixth embodiments described below can be mounted. Figure 1 and Figure 2 The mobile device 10 shown is a smartphone, but is not limiting. Mobile device 10 is an example of a device according to one embodiment of this disclosure. For example, the device may be a mobile phone, smartphone, tablet computer, personal computer, digital camera, digital camcorder, security / surveillance camera, webcam, car / transportation camera, medical camera, etc.

[0064] Figure 1 This is a perspective view showing an external configuration of a smartphone 10 on which an imaging lens assembly 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... Figure 1 Only the openings of the three imaging units arranged in the housing component 20 of the smartphone 10 are shown.

[0065] Figure 2 It is shown Figure 1A sectional view of a section along line II-II. As shown in Figure 2 The imaging unit 31 of the smartphone 10 includes, as shown in Figure 3 , 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 below, and an imaging device 16. During imaging, light rays entering through the main lens 15 as the opening pass through the respective elements in the above order and reach the imaging device 16. In addition, the imaging unit 31 includes a movement unit 120 for moving the imaging lens group 11 with respect to the imaging lens group 11, which will be described in the sections of each of the embodiments below. The movement unit 120 includes an actuator 12 Figure 3 ) as a driving source thereof.

[0066] The imaging device 16 includes an imaging element 170 such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS), and an analog to digital (AD) conversion circuit (not shown) that converts an analog electric signal output from the imaging element into a digital image signal.

[0067] The imaging element 170 of the imaging device 16 is disposed at a position of an image plane. The imaging element has a plurality of pixels. For example, the imaging element includes a pixel that generates an electric signal corresponding to the intensity of a red light component, a pixel that generates an electric signal corresponding to the intensity of a blue light component, and a pixel that generates an electric signal corresponding to the intensity of a green light component. As a modification, the imaging element can be another imaging element for monochrome shooting that includes a plurality of pixels that generate electric signals corresponding to the intensity of light.

[0068] Figure 3 is a block diagram showing a hardware configuration example of the smartphone 10 in which the imaging lens according to each of the first to sixth embodiments can be installed, and mainly shows a control configuration associated with the imaging unit 31.

[0069] As shown in Figure 3 , the control configuration of the smartphone 10 includes the actuator 12, the driver 13, and a CPU 14.

[0070] The CPU 14 executes a program stored in a memory (not shown) to control movement of the lenses in the lens group in the first to sixth embodiments described below. Specifically, the CPU 14 controls driving of the actuator 12 via the driver 13, thereby controlling movement of each lens in the imaging lens group 11. The actuator 12 and the driver 13 can be examples of a moving unit according to an embodiment of the present disclosure, and the CPU 14 can be an example of a control unit according to an embodiment of the present disclosure. Furthermore, the set of the imaging lens group 11, the actuator 12, and the driver 13 can be an example of an optical device according to an embodiment of the present disclosure. The above-described configuration makes it possible to move and arrange the lenses in the lens group of each embodiment described below.

[0071] The first to sixth embodiments of the imaging lens group 11 in the smartphone 10 will be described below.

[0072] (First Embodiment)

[0073] Figure 4 (a) and 4(b) are diagrams showing the imaging lens group 101 of the first embodiment of the present disclosure, which can be installed as the imaging lens group 11 shown in the configuration example of the smartphone 10. Figure 4 (a) shows lens positions of the imaging lens group 101 in a closed position and an open position, respectively, Figure 4 (b) shows a table showing focal lengths and the like of the imaging lens group 101 in the closed position and the open position.

[0074] As Figure 4 (a) shows, the imaging lens group 101 of the present embodiment includes three lenses L1 to L3. In addition, AX denotes an optical axis, and S1, S2, S3, S4, S5, and S6 denote surfaces of the lenses L1 to L3, respectively. For the imaging lens group 101, the closed position is a position in which the respective lenses are close to each other, and satisfies the conditional expressions (1) to (3) described later. The open position is a position in which the respective lenses of the imaging lens group 101 are separated from each other to achieve a predetermined refractive power. This makes it possible to reverse positive and negative refractive powers provided at the closed position and the open position. Furthermore, for example, the open position can be determined to achieve a refractive power corresponding to a zoom and a focus function of the imaging device. Thus, in a system of one lens group, the combination of the distances D1 and D2 between the lenses described below with reference to Figure 5 The combination of the distances D1 and D2 between the lenses described below is not limited to a single combination, and there can be multiple combinations, that is, there can be multiple open positions according to a function (such as the zoom function described above).

[0075] In Figure 4 (a), the lenses L1, L2, and L3 of the imaging lens group 101 are separated from each other from the object side on the left side of Figure 4 (a) to the image side on the right side of Figure 4The lens Ll is located closest to the object side, and the lens L3 is located closest to the image side.

[0076] As Figure 4 As shown in (a), the surfaces S l and S2 are aspherical surfaces to achieve predetermined optical characteristics. The shapes of the surfaces S l and S2 allow the lens Ll to have a positive refractive power.

[0077] The lens L2 is an aspherical lens. The shapes of the surfaces S3 and S4 allow the lens L2 to have a negative refractive power.

[0078] The object side surface S5 of the lens L3 is aspherical to have a shape similar to that of the image side surface S4 of the lens L2 adjacent thereto in the closed position and to achieve predetermined optical characteristics. The shapes of the surfaces S5 and S6 allow the lens L3 to have a negative refractive power.

[0079] As Figure 4 As shown in the table of (b), the focal lengths of the lenses Ll, L2 and L3 of the present embodiment are 22.8, -324.27 and -19.92, respectively. The total focal lengths of the entire imaging lens group 101 in the closed position and the open position are 29.14 and 23.94, respectively. The surface condition indicating the degree of approximation of the shapes of the lens surfaces close to each other in the closed position is 0.84 for S2 / S3 and 1.04 for S4 / S5. Similarly, the radius condition indicating the degree of approximation of the shapes of the lens surfaces close to each other in the closed position is 1.19 for S2 / S3 and 0.96 for S4 / S5. Figure 4 The distance condition shown in (b) is a parameter in the condition expression (1) described later, indicating the distance between the lenses when the lenses are closest to each other in the closed position. In the imaging lens group 101 of the present embodiment, the distance condition is 0.003.

[0080] In the closed position, the lenses Ll, L2 and L3 are close to each other and satisfy the condition expressions (1) to (3) described later. Then, in this state (positional relationship), the three lenses Ll, L2 and L3 have the same refractive power as one lens in the entire lens group. On the other hand, the lenses Ll, L2 and L3 are separated from each other in the open position. In this state (positional relationship), the lenses Ll, L2 and L3 have respective refractive powers, but the imaging lens group 101 as a whole has a refractive power different from that in the closed position.

[0081] As described above, the lenses L1, L2, and L3 of the imaging lens group 101 are close to each other in the closed position, and the entire lens group has the same refractive power as that of a single lens. On the other hand, in the open position, the refractive powers of the respective lenses are combined so that the entire imaging lens group 101 has a different refractive power from that of the closed position. Then, since the lenses L1, L2, and L3 are disposed in the positional (distance) relationship of the closed position and the open position, a refractive power distribution can be generated according to the relationship.

[0082] Now, conditional expressions (1) to (3) that should be satisfied in order to cause the lenses L1, L2, and L3 of the imaging lens group 101 to generate the above-described refractive power distribution in the closed position will be described.

[0083] The lenses L1, L2, and L3 of the imaging lens group 101 satisfy

[0084] D min / φ < 0.2 conditional expression (1),

[0085] where D min is the lens distance between the respective lenses when the lenses L1, L2, and L3 are close to each other in the closed position, and φ is the optically effective diameter of the lens having the largest lens diameter among the lenses L1, L2, and L3 constituting the imaging lens group 101. In the present embodiment, the lens distance is Figure 4 the value given in the distance condition shown in (b).

[0086] Further, those of the lens surfaces of the lenses L1, L2, and L3 that are opposite to each other have similar surface shapes, and satisfy the following conditional expression (2), where S ob (h) is the surface shape (sag amount) of the object side surface at an arbitrary lens diameter height h, S im (h) is the surface shape (sag amount) of the image side surface. In the present embodiment, the surface shapes have Figure 4 the value given in the surface condition shown in (b).

[0087] 0.5 < abs[S ob (h) / S im (h)] < 2.0 conditional expression (2).

[0088] The radii of curvature R1 and R2, R3 and R4, and R5 and R6 of the lens surfaces opposite to each other satisfy the following conditional expression, where R ob is the radius of curvature of the object side surface facing the object, and R im is the radius of curvature of the image side surface. In the present embodiment, the radii of curvature have Figure 4 the value given in the radius condition shown in (b).

[0089] 0.7 < R ob / R im <1.3 Conditional Expression (3).

[0090] The following provide more preferred conditions for conditional expressions (1) to (3).

[0091] In conditional expression (1), when D min When the value of / φ becomes 0.2 or greater, the refractive power of a single lens begins to affect the overall image independently, and when all lenses are in the closed position, it is difficult to approximate the entire lens group as a single lens. Therefore, the difference between the power distribution of the refractive power in the closed position and the power distribution of the refractive power after lens separation becomes smaller, failing to achieve the desired effect. Therefore, the preferred conditional expression (1) is:

[0092] D min / φ<0.1 conditional expression (4).

[0093] Furthermore, when the lens surface shape does not satisfy conditional expressions (2) and (3), the opposing lens surfaces of lenses L1, L2, and L3 are affected by their own refraction, making it difficult to approximate the entire lens group as a single lens since each lens is in a closed position. Therefore, the difference between the power distribution of refractive power in the closed position and the change in power distribution of refractive power after lens separation becomes smaller, failing to achieve the desired effect. Therefore, more preferably, conditional expressions (2) and (3) should respectively remain as follows:

[0094] 0.7 <abs[S ob (h) / S im (h)]<1.8 conditional expression (5), and

[0095] 0.8 <R ob / R im <1.2 Conditional Expression (6).

[0096] Furthermore, more preferably, the conditional expression (5) should remain as follows:

[0097] 0.7 < abs[S ob (h) / S im (h)] < 1.6 Conditional expression (7).

[0098] Next, we will refer to Figure 5 The conditions that describe the parameters defining the optical characteristics of lenses L1, L2, and L3 included in the imaging lens group 101. Figure 5RDN in Table 1 shows parameters of respective surfaces S1 to S6 of respective lenses constituting the imaging lens group 101 according to the first embodiment, R is a radius of curvature of a lens surface, D is a distance between individual lenses, Nd is a refractive index on each surface, Vd is an Abbe number, and φ is an optically effective diameter of each lens.

[0099] Here, D1 indicates a distance between the image side (S2) of the lens L1 and the object side (S3) of the lens L2, and D2 indicates a distance between the image side (S4) of the lens L2 and the object side (S5) of the lens L3, D1 and D2 show different values when the lens group is in the closed position and the open position. Specifically, as shown in Table 2, Figure 5 D1: 0.01 and D2: 0.01 at the closed position, and D1: 1.23 and D2: 1.69 at the open position.

[0100] Figure 5 " Aspherical Coefficients" in Table 1 indicates aspherical coefficients of respective orders.

[0101] In the RDN table of Table 1, Figure 5 R, D, Nd, and φ are designed to satisfy all of the above condition expressions (1) to (3). The Abbe number Vd is a value that corrects axial chromatic aberration and magnification chromatic aberration in a well-balanced manner.

[0102] The shape of the aspherical lens is given by an expression of an aspherical shape shown in the following expression (8), where Z indicates a depth of an aspherical surface, Y indicates a distance (height) from an optical axis to a lens surface, R indicates a paraxial radius of curvature, K indicates a conic constant, C4, C6, C8, and C10 indicate aspherical coefficients of fourth, sixth, eighth, and tenth orders, respectively. 10

[0103] Z = (Y 2 / R) / [1-{1-(1+K)(Y 2 / R 2 )} 1 / 2 +C4Y 4 +C6Y 6 +C8Y 8 +C 10 Y 10

[0104] In the example shown in Table 1, Figure 5 The lens L2 is an aspherical lens. The lenses L1 and L3 have an aspherical surface on one side and a spherical surface on the other side. At least one of the lenses L1, L2, and L3 can be a resin lens. For example, when the aspherical lens is constituted by a resin lens that is easy to process, the manufacturing cost of the imaging lens group 101 can be reduced.​​

[0105] Comparison Figure 4 The total focal lengths of the lens group in the table shown in (b) are 29.14 mm in the closed position and 23.94 mm in the open position. Thus, by changing the state from the closed position to the open position and changing the power distribution, the three lenses L1, L2, and L3 are allowed to have the function of a zoom lens.

[0106] Further, it should be understood that Figure 4 (b) those representing the values of the conditional expressions (1) to (3) satisfy the conditional expressions (4) to (6) that provide more preferable conditions, and the conditional expression (7) that provides the most preferable condition. Thus, the lenses L1, L2, and L3 in the present embodiment behave as a single lens in the entire lens group at the closed position, and as the lenses separate toward the open position, the lenses can change the power distribution of the entire lens group to be more than the value at the closed position due to the power of each lens.

[0107] As described above, when a plurality of lenses are arranged to form a lens group and the arrangement relationship thereof does not satisfy the conditional expressions (1) to (3), the plurality of lenses exist only individually to achieve 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 at the closed position, and the lenses have predetermined powers at the open position. This allows the lenses as a lens group to generate a power distribution according to the positional relationship of the lenses. Thus, in achieving the power distribution, it is possible to prevent the size of the imaging device from increasing.

[0108] (Second Embodiment)

[0109] Next, the second embodiment will be described. The detailed description of the content repeated with the first embodiment will be omitted hereinafter.

[0110] Figure 6 (a) and 6(b) are diagrams showing an imaging lens group 102 according to the second embodiment of the present disclosure, which can be implemented as the imaging lens group 11 shown in the configuration example of the smartphone 10. Figure 6 (a) shows the lens positions of the imaging lens group 102 in the closed position and the open position, respectively, Figure 6 (b) shows a table showing the focal lengths and the like of the imaging lens group 102 in the closed position and the open position.

[0111] In Figure 6 In (a), the lenses L1, L2, L3, and L4 of the imaging lens group 102 according to the second embodiment are arranged from Figure 6 The left side from the object side in (a) is Figure 6In (a), the image sides on the right are arranged sequentially. That is, lens L1 is located closest to the object side, and lens L4 is located closest to the image side.

[0112] The shapes of lenses L1, L2, L3, and L4 are as follows: Figure 6 As shown in (a). In the imaging lens group 102, lenses L1 and L2 have negative refractive power. Lenses L3 and L4 have positive refractive power. Lens L3 is an aspherical lens.

[0113] Each lens of the imaging lens group 102 satisfies Figure 6 (b) shows the condition, the shape is determined by Figure 7 The lens parameters are defined as shown.

[0114] Figure 7 This 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 length of the lens constituting 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 the conditional expressions (1) to (3) for lenses L1, L2, L3 and L4.

[0115] By according to Figure 6 (b) sets the lens parameters for each lens, which can correct various aberrations. Furthermore, since the Abbe number of each lens is... Figure 7 As shown in the settings, chromatic aberration can be corrected. Furthermore, comparing the total focal length in the closed and open positions, the total focal length in the open position is 58.82 mm, while the total focal length in the closed position is 341.42 mm, approximately 5.8 times the total focal length in the open position. Therefore, by changing the state from the closed to the open position and altering the refractive power distribution, the four lenses L1, L2, L3, and L4 of the imaging lens group 102 can function as zoom lenses.

[0116] like Figure 6 As shown in (a), lenses L1 and L2, lenses L2 and L3, and lenses L3 and L4 have approximate shapes on opposite sides S2 and S3, S4 and S5, and S6 and S7, respectively, at least near the optical axis. Therefore, the lenses in the closed position can approach each other to satisfy conditional expressions (1) to (3) and have the same refractive power as a single lens.

[0117] (Third Embodiment)

[0118] Next, the third embodiment will be described. Detailed descriptions of content that is repeated in the first embodiment will be omitted below.

[0119] Figure 8Figs. 8(a) and 8(b) are diagrams showing an imaging lens group 103 according to a third embodiment of the present disclosure, which can be implemented as the imaging lens group 11 shown in the configuration example of the smartphone 10. Figure 8 (a) shows the lens positions of the imaging lens group 103 in the closed position and the open position, respectively, Figure 8 (b) shows a table showing the focal length and the like of the imaging lens group 103 in the closed position and the open position. The lens configuration of the imaging lens group 103 corresponds to Figure 8 the conditions in (b) and Figure 9 the lens parameters in (c), which will be described later.

[0120] As shown in Figure 8 (a), the imaging lens group 103 of the present embodiment includes two lenses L1 and L2. The lenses L1 and L2 are arranged in order from Figure 8 the object side on the left side of Figure 8 (a) to the image side on the right side of (a). The lens L1 is located closest to the object side, and the lens L2 is located closest to the image side.

[0121] Figure 8 The shapes of the lenses L1 and L2 are as shown in (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 aspherical lenses.

[0122] Figure 8 Each lens of the imaging lens group 103 satisfies the conditions shown in Figure 9 (b), and the shape is defined by the lens parameters shown in

[0123] Figure 8 (b) is a table showing the respective values of the focal length 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 position and the closed position, and the conditional expressions (1) to (3) of the lenses L1 and L2. Figure 9 (c) is a table showing the lens parameters of the respective lenses constituting the imaging lens group 103 according to the third embodiment.

[0124] By setting the lens parameters of the respective lenses in accordance with the conditions in Figure 8 (b), various aberrations can be corrected. Further, since the Abbe number of each lens is set as shown in Figure 9 , chromatic aberration can be corrected. In addition, comparing the total focal lengths of the closed position and the open position, the total focal length of the open position is 13.48 mm, and the total focal length of the closed position is 89.97 mm, which is about 6.7 times the total focal length of the open position. Therefore, by changing the refractive power distribution by changing the state from the closed position to the open position, the two lenses L1 and L2 of the imaging lens group 103 can have the function of a zoom lens.

[0125] As Figure 8 (a) shows, the lenses L1 and L2 have an approximate shape at least near the optical axis on the opposite sides S2 and S3. Therefore, the lenses in the closed position can be brought close to each other to satisfy the conditional expressions (1) to (3) and have the same power as a single lens.

[0126] (Fourth Embodiment)

[0127] Next, the fourth embodiment will be described. The detailed description of the contents repeated with the first embodiment will be omitted hereinafter.

[0128] Figure 10 (a) and 10(b) are diagrams showing an imaging lens group 104 according to the fourth embodiment of the present disclosure, which can be implemented as the imaging lens group 11 shown in the configuration example of the smartphone 10. Figure 10 (a) shows the lens positions of the imaging lens group 104 in the closed position and the open position, respectively, Figure 10 (b) shows a table showing the focal length and the like of the imaging lens group 104 in the closed position and the open position.

[0129] As Figure 10 (a) shows, the imaging lens group 104 of the present embodiment includes two lenses L1 and L2. The lenses L1 and L2 are arranged in order from Figure 10 (a) the object side on the left side Figure 10 (a) the image side on the right side. The lens L1 is located closest to the object side, and the lens L2 is located closest to the image side.

[0130] The shapes of the lenses L1 and L2 are as shown in Figure 10 (a). In the imaging lens group 104, the lens L1 has a negative power. The lens L2 has a positive power. The lens L1 is an aspheric lens.

[0131] Each lens of the imaging lens group 104 satisfies the condition shown in Figure 10 (b), the shape is defined by the lens parameters shown in Figure 11 .

[0132] Figure 10 (b) is a table showing the respective values of the focal length 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 position and the closed position, and the conditional expressions (1) to (3) of the lenses L1 and L2. Figure 11 is a table showing the lens parameters of each lens constituting the imaging lens group 104 according to the fourth embodiment.

[0133] By virtue of the conditional expressions (1) to (3) according to the fourth embodiment, the imaging lens group 104 can be implemented as the imaging lens group 11 shown in the configuration example of the smartphone 10. Figure 10The conditions in (b) set the lens parameters of the individual lenses, and various aberrations can be corrected. In addition, since the Abbe number of each lens is set as shown in Figure 11 , chromatic aberration can be corrected. In addition, comparing the total focal length in the closed position and the total focal length in the open position, the total focal length in the closed position takes a negative value of -60.40 mm, and the total focal length in the open position takes a positive value of 50.20 mm. Thus, by changing the state from the closed position to the open position and changing the power distribution from negative to positive, the two lenses L1 and L2 of the imaging lens group 104 can have the function of a zoom lens.

[0134] As shown in Figure 10 (a), the opposite sides S2 and S3 of the lenses L1 and L2 are close to each other, and there is a slight gap between them at the closed position. However, even in this case, the lenses L1 and L2 satisfy the condition expressions (1) to (3) so that the lenses in the closed position have the same power as a single lens.

[0135] (Fifth Embodiment)

[0136] Next, a fifth embodiment will be described. The detailed description of the contents repeated with the first embodiment will be omitted hereinafter.

[0137] Figure 12 (a) and Figure 12 (b) are diagrams showing an imaging lens group 105 according to the fifth embodiment of the present disclosure, which can be realized as the imaging lens group 11 shown in the configuration example of the smartphone 10. Figure 12 (a) show the lens positions of the imaging lens group 105 in the closed position and the open position, respectively, Figure 12 (b) shows a table showing the focal length and the like of the imaging lens group 105 in the closed position and the open position.

[0138] As shown in Figure 12 (a), the imaging lens group 105 of the present embodiment includes three lenses L1 to L3. The lenses L1, L2, and L3 are arranged in order from Figure 12 (a) the object side on the left side Figure 12 (a) the image side on the right side. The lens L1 is located closest to the object side, and the lens L3 is located closest to the image side.

[0139] The shapes of the lenses L1, L2, and L3 are as shown in Figure 12 (a). In the imaging lens group 105, the lenses L1 and L3 have negative power. The lens L3 is an aspherical lens. The lens L2 has positive power.

[0140] Each lens of the imaging lens group 105 satisfies the conditions shown in Figure 12 (b), and the shape is defined by the lens parameters shown in Figure 13 .

[0141] Figure 12 (b) is a table showing respective values of conditional expressions (1) to (3) of focal lengths of lenses constituting the imaging lens group 105 according to the fifth embodiment, total focal length of the entire lens group in the open position and the closed position, and lenses L1, L2 and L3. Figure 13 is a table showing lens parameters of each lens constituting the imaging lens group 105 according to the fifth embodiment.

[0142] By setting the lens parameters of each lens in the conditions according to Figure 12 (b), various aberrations can be corrected. Further, since the Abbe number of each lens is set as shown in Figure 13 , chromatic aberration can be corrected. In addition, comparing the total focal lengths of the closed position and the open position, the total focal length of the closed position takes a negative value -876.50 mm, and the total focal length of the open position takes a positive value 83.70 mm. Therefore, by changing the state from the closed position to the open position and changing the power distribution from negative to positive, the three lenses L1, L2 and L3 of the imaging lens group 105 can have the function of a zoom lens.

[0143] As shown in Figure 12 (a), the lenses L1 and L2 have an approximate shape at least near the optical axis on the opposite sides S2 and S3. The same applies to the lenses L2 and L3. Therefore, the lenses in the closed position can be brought close to each other to satisfy the conditional expressions (1) to (3) and have the same power as a single lens.

[0144] (Sixth Embodiment)

[0145] Next, the sixth embodiment will be described. The detailed description of the contents repeated with the first embodiment will be omitted hereinafter.

[0146] Figure 14 (a) and Figure 14 (b) is a diagram showing an imaging lens group 106 according to the 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. Figure 14 (a) shows the lens positions of the imaging lens group 106 in the closed position and the open position, respectively, Figure 14 (b) shows a table showing the focal lengths and the like of the imaging lens group 106 in the closed position and the open position.

[0147] As shown in Figure 14 (a), the imaging lens group 106 of the present embodiment includes three lenses L1 to L3. The lenses L1, L2 and L3 are arranged from Figure 14 (a) the object side on the left side to Figure 14(a) the image side is arranged in order from the right. The lens LI is located closest to the object side, and the lens L3 is located closest to the image side.

[0148] The shapes of the lenses LI, L2, and L3 are as shown in Figure 14 (a). In the imaging lens group 106, the lenses LI and L2 have negative refractive power. The lenses LI, L2, and L3 are aspherical lenses. The lens L3 has positive refractive power.

[0149] Each lens of the imaging lens group 106 satisfies the conditions shown in Figure 14 (b), and the shapes are defined by the lens parameters shown in Figure 15 .

[0150] Figure 14 (b) is a table showing the respective values of the conditional expressions (1) to (3) for the lenses constituting the imaging lens group 106 according to the sixth embodiment, the focal length of each lens, the total focal length of the entire lens group in the open position and the closed position, and the lens LI, L2, and L3. Figure 15 is a table showing the lens parameters of each lens constituting the imaging lens group 106 according to the sixth embodiment.

[0151] By setting the lens parameters of each lens in accordance with the conditions in Figure 14 (b), various aberrations can be corrected. Furthermore, since the Abbe number of each lens is set as shown in Figure 15 , chromatic aberration can be corrected. In addition, comparing the total focal lengths of the closed position and the open position, the total focal length of the closed position is 87.38 mm, and the total focal length of the open position is 14.28 mm. Thus, by changing the state from the closed position to the open position and changing the refractive power distribution from negative to positive, the three lenses LI, L2, and L3 of the imaging lens group 106 can have the function of a zoom lens.

[0152] As shown in Figure 14 (a), the opposite sides S3, S4, and S5 of the lenses LI, L2, and L3 have a slight gap therebetween at the closed position. However, even in this case, the lenses LI, L2, and L3 satisfy the conditional expressions (1) to (3) so that the lenses in the closed position have the same refractive power as a single lens.

[0153] Figure 16 The values of the conditional expressions (1) to (3) for each example are summarized. As can be seen from the values in the table, each example satisfies the conditional expressions (1) to (3). Furthermore, since the conditional expressions (4) to (6) and (7) are satisfied in Examples 1, 2, and 3, the imaging lenses constituting Examples 1, 2, and 3 have more preferable parameters.

[0154] The above disclosure only discloses exemplary embodiments and is not intended to limit the protection scope of the present application. It can be understood by those skilled in the art that all or part of the above-mentioned embodiments and other embodiments and modifications derived based on the scope of the claims of the present application certainly belong to the scope of the present application.

Claims

1. An optical device, characterized in that, include: A lens group, comprising multiple lenses; A moving unit is configured to move the plurality of lenses; as well as The control unit is configured to control the moving unit to move the plurality of lenses between a closed position and an open position, wherein in the closed position the plurality of lenses are closest together to function as a single lens, and in the open position the plurality of lenses are spaced apart from each other. The plurality of lenses in the closed position are configured to satisfy the condition provided by the following equation (1): （1）， Among them, D min Indicates the distance between two adjacent lenses in the lens group. Indicates the optically effective diameter of the lens with the largest lens diameter in the lens group; The plurality of lenses includes a first lens and a second lens, both aspherical surfaces facing each other, wherein the image-side surface of the first lens and the object-side surface of the second lens facing the image-side surface of the first lens have shapes represented by the following equations (2) and (3): （2）， Among them, S ob (h) indicates the amount of sag of the object-side surface of the second lens at any lens diameter height h from the optical axis, S im (h) indicates the amount of sag of the image-side surface of the first lens at the lens diameter height h, and （3）， Among them, R ob The radius of curvature R of the object-side surface of the second lens is indicated. im Indicates the radius of curvature of the image-side surface of the first lens.

2. The apparatus according to claim 1, characterized in that, The plurality of lenses in the closed position state are specifically configured to satisfy the conditions provided by the following equation (4): （4）。 3. The apparatus according to claim 1, characterized in that, The image-side surface of the first lens and the object-side surface of the second lens facing the image-side surface of the first lens are specifically configured to have shapes represented by the following equations (5) and (6): (5), and （6）。 4. The apparatus according to claim 1, characterized in that, The image-side surface of the first lens and the object-side surface of the second lens facing the image-side surface of the first lens are specifically configured to have a shape represented by the following equation (7): （7）。 5. The apparatus according to any one of claims 1 to 4, characterized in that, At least one of the aspherical first lens and the second lens is configured to have an aspherical shape as represented by the following equation (8): （8）， Where Z represents the depth of the aspherical surface, Y represents the distance from the optical axis to the lens surface, R represents the paraxial radius of curvature, K represents the conic constant, and C4, C6, C8, and C... 10 These represent the aspheric coefficients of the fourth, sixth, eighth, and tenth orders, respectively.

6. The apparatus according to any one of claims 1 to 4, characterized in that, At least one of the plurality of lenses is a resin lens.

7. An optical device, characterized in that, include: 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, wherein the optical device includes: A lens group, comprising multiple lenses; The moving unit is configured to move the plurality of lenses; and The control unit is configured to control the moving unit to move the plurality of lenses between a closed position and an open position, wherein in the closed position the plurality of lenses are closest together to function as a single lens, and in the open position the plurality of lenses are spaced apart from each other. The plurality of lenses in the closed position are configured to satisfy the condition provided by the following equation (9): （9）， Among them, D min Indicates the distance between two adjacent lenses in the lens group. Indicates the optically effective diameter of the lens with the largest lens diameter in the lens group; The plurality of lenses includes a first lens and a second lens, both aspherical surfaces facing each other, wherein the image-side surface of the first lens and the object-side surface of the second lens facing the image-side surface of the first lens have shapes represented by the following equations (10) and (11): （10）， Among them, S ob (h) indicates the amount of sag of the object-side surface of the second lens at any lens diameter height h from the optical axis, S im (h) indicates the amount of sag of the image-side surface of the first lens at the lens diameter height h, and （11）， Among them, R ob The radius of curvature R of the object-side surface of the second lens is indicated. im Indicates the radius of curvature of the image-side surface of the first lens.

8. The device according to claim 7, characterized in that, The plurality of lenses in the closed position state are specifically configured to satisfy the conditions provided by the following equation (12): （12）。 9. The device according to claim 7, characterized in that, The image-side surface of the first lens and the object-side surface of the second lens facing the image-side surface of the first lens are specifically configured to have shapes represented by the following equations (13) and (14): （13）， （14）。 10. The device according to claim 7, characterized in that, The image-side surface of the first lens and the object-side surface of the second lens facing the image-side surface of the first lens are specifically configured to have a shape represented by the following equation (15): （15）。 11. The device according to any one of claims 7 to 10, characterized in that, At least one of the aspherical first lens and the second lens is configured to have an aspherical shape as represented by the following equation (16): （16）， Where Z represents the depth of the aspherical surface, Y represents the distance from the optical axis to the lens surface, R represents the paraxial radius of curvature, K represents the conic constant, and C4, C6, C8, and C... 10 These represent the aspheric coefficients of the fourth, sixth, eighth, and tenth orders, respectively.

12. The device according to any one of claims 7 to 10, characterized in that, At least one of the plurality of lenses is a resin lens.

13. A method for controlling the refractive power of a lens group comprising multiple lenses, characterized in that, include: The actuator moves the plurality of lenses between a closed position and an open position. In the closed position, the plurality of lenses are closest together to function as a single lens. In the open position, the plurality of lenses are spaced apart from each other. The plurality of lenses in the closed position are configured to satisfy the condition provided by the following equation (17): （17）， Among them, D min Indicates the distance between two adjacent lenses in the lens group. Indicates the optically effective diameter of the lens with the largest lens diameter in the lens group; The plurality of lenses includes a first lens and a second lens, both aspherical surfaces facing each other, wherein the image-side surface of the first lens and the object-side surface of the second lens facing the image-side surface of the first lens have shapes represented by the following equations (18) and (19): （18）， Among them, S ob (h) indicates the amount of sag of the object-side surface of the second lens at any lens diameter height h from the optical axis, S im (h) indicates the amount of sag of the image-side surface of the first lens at the lens diameter height h, and （19）， Among them, R ob The radius of curvature R of the object-side surface of the second lens is indicated. im Indicates the radius of curvature of the image-side surface of the first lens.

14. The method according to claim 13, characterized in that, The plurality of lenses in the closed position state are specifically configured to satisfy the conditions provided by the following equation (20): （20）。 15. The method according to claim 13, characterized in that, The image-side surface of the first lens and the object-side surface of the second lens facing the image-side surface of the first lens are specifically configured to have shapes represented by the following equations (21) and (22): (21), and （22）。 16. The method according to claim 13, characterized in that, The image-side surface of the first lens and the object-side surface of the second lens facing the image-side surface of the first lens are specifically configured to have a shape represented by the following equation (23): （23）。 17. The method according to any one of claims 13 to 16, characterized in that, At least one of the aspherical first lens and the second lens is configured to have an aspherical shape as represented by the following equation (24): （24）， Where Z represents the depth of the aspherical surface, Y represents the distance from the optical axis to the lens surface, R represents the paraxial radius of curvature, K represents the conic constant, and C4, C6, C8, and C... 10 These represent the aspheric coefficients of the fourth, sixth, eighth, and tenth orders, respectively.

18. The method according to any one of claims 13 to 16, characterized in that, At least one of the plurality of lenses is a resin lens.

19. A non-transitory computer-readable storage medium, characterized in that, It stores a program that causes the processor to execute the method according to any one of claims 13 to 18.

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