Optical system having cemented lens including negative lens, image pickup device, vehicle-mounted system, and mobile device

Abstract

The present disclosure relates to an optical system having a cemented lens including a negative lens, an image pickup device, a vehicle-mounted system, and a mobile device. An optical system includes an aperture and a first cemented lens disposed adjacent to an object side of the aperture. The first cemented lens includes a negative lens. A predetermined condition is satisfied.

Description

Technical Field

[0001] This disclosure relates to optical systems, image pickup devices, vehicle-mounted systems, and mobile devices. Background Technology

[0002] Image acquisition devices such as vehicle-mounted cameras and surveillance cameras require low-cost, high-performance optical systems. Japanese Patent No. (“JP”) 6436787 discloses a lens barrel (optical system) for an image acquisition device.

[0003] The manufacturing cost of a lens barrel is determined by the complexity of its internal structure, thus requiring a simpler design. The outer diameter of the lenses included in the lens barrel varies depending on the specifications of the wide-angle and telephoto lenses (such as F-number, angle of view, and focal length). Therefore, as in the lens barrel disclosed in JP6436787, the internal structure of the lens barrel requires complex shapes, such as stepped structures, to hold the lenses. Summary of the Invention

[0004] This disclosure provides optical systems, image acquisition devices, vehicle-mounted systems, and mobile devices, all of which can be easily manufactured and have high performance.

[0005] An optical system according to one aspect of this disclosure includes an aperture and a first cemented lens disposed adjacent to the object side of the aperture. The first cemented lens includes a negative lens. The following inequality is satisfied:

[0006] 1.5 <D1 / D0<15.0

[0007] Where D0 is the effective diameter of the negative lens and D1 is the outer diameter of the negative lens. An image pickup device, vehicle-mounted system, and mobile device having the above optical system also constitute another aspect of this disclosure.

[0008] Other features of this disclosure will become clear from the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0009] Figure 1 It is a cross-sectional view of the optical system based on Example 1.

[0010] Figure 2 It is a lateral aberration diagram based on the optical system of Example 1.

[0011] Figure 3 It is a cross-sectional view of the optical system based on Example 2.

[0012] Figure 4 It is a lateral aberration diagram based on the optical system in Example 2.

[0013] Figure 5 This is an illustration of the optical system based on Example 1.

[0014] Figure 6 This is an illustration of the optical system based on Example 2.

[0015] Figure 7 It is a block diagram of an in-vehicle system including the optical system according to each example.

[0016] Figure 8 This is a schematic diagram of the main parts of a vehicle equipped with an optical system according to each example.

[0017] Figure 9 This is a flowchart illustrating an operational example of an in-vehicle system, including an optical system according to each example. Detailed Implementation

[0018] A detailed description of embodiments according to the present disclosure will now be given with reference to the accompanying drawings. Hereinafter, the term "unit" may refer to a software context, a hardware context, or a combination of both. In a software context, the term "unit" refers to a function, application, software module, feature, routine, instruction set, or program that can be executed by a programmable processor, such as a microprocessor, central processing unit (CPU), or specially designed programmable device or controller. Memory contains instructions or programs that, when executed by the CPU, cause the CPU to perform operations corresponding to the unit or function. In a hardware context, the term "unit" refers to a hardware element, circuit, component, physical structure, system, module, or subsystem. It may include mechanical, optical, or electrical components, or any combination thereof. It may include active (e.g., transistors) or passive (e.g., capacitors) components. It may include a semiconductor device having a substrate and other material layers having various conductivity concentrations. It may include a CPU or programmable processor capable of executing a program stored in memory to perform a specified function. It may include logic elements (e.g., AND, OR) implemented by transistor circuitry or any other switching circuitry. In the combination of software and hardware contexts, the term "cell" or "circuit" refers to any combination of software and hardware contexts as described above.

[0019] The process of this embodiment will now be described. Since the manufacturing cost of the lens barrel depends on the complexity of its internal structure, a simple structure is needed to attempt to reduce costs. A lathe is used as a machining tool that can provide relatively low-cost machining. The simplest structure that a lathe can machine is a cylindrical (tubular) structure. However, it is difficult to make the outer diameters of the lenses inside a cylindrical lens barrel equal because the difference between the maximum and minimum outer diameters of the lenses inside the lens barrel depends on the specifications of wide-angle and telephoto lenses. Especially in the case of wide-angle lenses, the outer diameter of the lens near the aperture (aperture stop) is often smaller than the outer diameter of the lens on the object or image plane side.

[0020] In lens aberration correction, cementing positive and negative lenses near the aperture is very useful for correcting chromatic aberration. A positive lens is a lens whose thickness at the center cross-section is greater than its thickness at the edges. A negative lens is a lens whose thickness at the center cross-section is thinner than its thickness at the edges. Arranging the positive and negative lenses via an air layer between them, instead of cementing them, is also effective for aberration correction. However, when the outer diameter of a positive lens with a small radius of curvature extends radially, it is difficult to make the lens diameter equal to that of the other lens because the edge will shrink, potentially causing damage during manufacturing, and it is difficult to hold the lens in place within the lens barrel. Furthermore, to ensure edge thickness and make the outer diameter of the positive lens equal to that of the other lens, the radius of curvature of the positive lens needs to be restricted, resulting in a loss of freedom in lens design.

[0021] On the other hand, while maintaining the radius of curvature and edge thickness, the outer diameter of the negative lens can be expanded radially, or the lens diameter can be expanded in a direction orthogonal to the optical axis, and from the perspective of lens manufacturing, the difficulty is not too high.

[0022] Each example can be achieved by extending the negative lens of the cemented lens radially near the aperture while maintaining the radius of curvature of the negative lens, or by extending the negative lens in a direction orthogonal to the optical axis, so that the outer diameter of the cemented lens is equal to the outer diameter of the other lens. Therefore, an optical system using a low-cost cylindrical lens barrel can be constructed. A description of each example will now be given below.

[0023] Figure 1 It is a cross-sectional view of the optical system 1a according to Example 1. Figure 3 It is a cross-sectional view of the optical system 1b according to Example 2. Figure 5 It is an explanatory diagram of the optical system 1a according to Example 1. Figure 6 This is an illustrative diagram of optical system 1b according to Example 2. The optical system according to each example is an imaging optical system for image acquisition devices such as digital video cameras, digital still cameras, broadcast cameras, film-based cameras, and surveillance cameras. In each cross-sectional view, the left side is the object side (front), and the right side is the image side (rear). In each cross-sectional view, IM1 and IM2 are image planes, and image sensors such as complementary metal-oxide-semiconductor (CMOS) sensors and charge-coupled device (CCD) sensors are placed there.

[0024] The optical system according to each example includes an aperture (aperture stop) S1 or S2 that determines the F-number (aperture value) of the optical system, and a cemented lens disposed adjacent to at least one of the object side or image side of the aperture S1 or S2. The term "cemented lens" here refers to a plurality (two or more) of lenses joined together. The cemented lens includes at least one negative lens. In each example, the following inequality (1) is satisfied:

[0025] 1.5 <D1 / D0<15.0...(1)

[0026] Where D0 is the effective diameter of at least one negative lens, and D1 is the outer diameter of at least one negative lens. Here, the effective diameter is the diameter (effective area) through which the effective light rays that contribute to imaging pass on the optical surface. In inequality (1), the ratio of the outer diameter D1 to the effective diameter D0 is greater than the lower limit of 1.5 and less than the upper limit of 15.0.

[0027] When this value is below the lower limit of inequality (1), it becomes difficult to make the outer diameter of the cemented lens equal to the outer diameter of the other lens and a more complex lens barrel structure is required, which increases the cost of the optical system. On the other hand, when this value is above the upper limit of inequality (1), the material cost of the negative lens used to make the outer diameter of the cemented lens equal to the outer diameter of the other lens increases.

[0028] The numerical range of inequality (1) can be replaced by the numerical range of the following inequality (1a).

[0029] 2.0 <D1 / D0<14.5...(1a)

[0030] In inequality (1a), the ratio of outer diameter D1 to effective diameter D0 is greater than the lower limit of 2.0 and less than the upper limit of 14.5. The numerical range of inequality (1) can be replaced by the numerical range of the following inequality (1b).

[0031] 2.5 <D1 / D0<14.0...(1b)

[0032] In inequality (1b), the ratio of outer diameter D1 to effective diameter D0 is greater than the lower limit of 2.5 and less than the upper limit of 14.0. The cemented lens may include a first cemented lens (cemented lens CE11 or CE21) disposed adjacent to the object side of aperture S1 or S2, and a second cemented lens (cemented lens CE12 or CE22) disposed adjacent to the image side of aperture S1 or S2. Each of the first and second cemented lenses may consist of two or three lenses. Thus, for example, the cemented lens can be easily manufactured. The first cemented lens may have negative refractive power, and the second cemented lens may have positive refractive power. The negative lens may be the negative lens L12 or L22 constituting the first cemented lens. The negative lens may be the negative lens with the smallest effective diameter among the negative lenses constituting the optical system.

[0033] The following inequality (2) can be satisfied:

[0034] 1.05≤D2max / D1≤1.30...(2)

[0035] Where D2max is the outer diameter of the lens with the largest outer diameter among the lenses constituting optical system 1a or 1b. In inequality (2), the ratio of the outer diameter D2max of the lens with the largest outer diameter to the outer diameter D1 is greater than or equal to the lower limit of 1.05 and less than or equal to the upper limit of 1.30.

[0036] The following inequality (3) can be satisfied:

[0037] 0.80≤Dmax / D1≤1.20...(3)

[0038] Where Dmax is the effective diameter of the lens with the largest effective diameter among the lenses constituting optical system 1a or 1b. In inequality (3), the ratio of the effective diameter Dmax of the lens with the largest effective diameter to the outer diameter D1 is greater than or equal to the lower limit of 0.80 and less than or equal to the upper limit of 1.20.

[0039] When the value is higher than the upper limit or lower than the lower limit of each of inequalities (2) and (3), it becomes difficult to make the outer diameter of the cemented lens equal to the outer diameter of the other lens, requiring a more complex lens barrel structure and increasing the cost.

[0040] The numerical ranges of inequalities (2) and (3) can be replaced by the numerical ranges of the following inequalities (2a) and (3a), respectively:

[0041] 1.08≤D2max / D1≤1.28..(2a)

[0042] 0.83≤Dmax / D1≤1.18...(3a)

[0043] In inequality (2a), the ratio of the outer diameter D2max to the outer diameter D1 of the lens with the largest outer diameter is greater than or equal to the lower limit of 1.08 and less than or equal to the upper limit of 1.28. In inequality (3a), the ratio of the effective diameter Dmax to the outer diameter D1 of the lens with the largest effective diameter is greater than or equal to the lower limit of 0.83 and less than or equal to the upper limit of 1.18. The numerical ranges of inequalities (2) and (3) can be replaced by the numerical ranges of the following inequalities (2b) and (3b), respectively:

[0044] 1.10≤D2max / D1≤1.25...(2b)

[0045] 0.87≤Dmax / D1≤1.16...(3b)

[0046] In inequality (2b), the ratio of the outer diameter D2max of the lens with the largest outer diameter to its outer diameter D1 is greater than or equal to the lower limit of 1.10 and less than or equal to the upper limit of 1.25. In inequality (3b), the ratio of the effective diameter Dmax of the lens with the largest effective diameter to its outer diameter D1 is greater than or equal to the lower limit of 0.87 and less than or equal to the upper limit of 1.16. The lower and upper limits in the above inequalities are predetermined values. A description of the construction of the optical system according to each example will now be given.

[0047] Example 1

[0048] A description of the optical system 1a according to Example 1 will be given. Figure 1 As shown, the optical system 1a, from the object side to the image side, includes a negative lens L11, a cemented lens CE11, an aperture S1, a cemented lens CE12, a positive lens L17, and a negative lens L18. The cemented lens CE11 includes a negative lens L12 and a positive lens L13. The cemented lens CE12 includes a positive lens L14, a negative lens L15, and a positive lens L16.

[0049] In this example, each cemented lens is manufactured by applying an adhesive or similar substance between the positive and negative lenses to ensure close contact between each lens. In this example, the presence or absence of a filter and the wavelength range are not limited. These points also apply to Example 2 below.

[0050] Table 1 summarizes the numerical data for the optical system 1a according to this example. The optical specifications for this example are set as a focal length of 6 mm, an image-side F-number (Fno) of 2.0, and a half-angle of 0 to 60 degrees. The design wavelength is 486.1 to 656.27 nm. Optical glass manufactured by OHARA or HOYA is used in each example, but other equivalent products may also be used.

[0051] Table 1

[0052]

[0053]

[0054] Table 2 summarizes the aspherical shape data for optical system 1a. The aspherical shape for each example is represented as follows:

[0055]

[0056] The Z-axis is set to the optical axis, the h-axis is set to the direction orthogonal to the optical axis, and the direction of light propagation is set to positive. R is the paraxial radius of curvature, k is the conic coefficient, and A to D are the fourth, sixth, eighth, and tenth order aspherical coefficients. Furthermore, "e±XX" in each aspherical coefficient means "x10". ±XX".

[0057] Table 2

[0058]

[0059]

[0060] like Figure 5 As shown, the effective diameter D0 is the effective diameter of the concave portion of the cemented part of the negative lens L12. The outer diameter D1 is the outer diameter of the negative lens L12. The effective diameter Dmax of the lens constituting the optical system 1a with the largest effective diameter is the effective diameter of the image-side surface of the positive lens L17. The outer diameter D2max of the lens constituting the optical system 1a with the largest outer diameter is the outer diameter of the image-side surface of the positive lens L17.

[0061] Figure 2 This is the lateral aberration diagram of optical system 1a. Figure 2 The diagram illustrates the lateral aberrations for the C-line (wavelength 656.3 nm), d-line (wavelength 587.6 nm), and F-line (wavelength 486.1 nm) at three viewing angles of optical system 1a. The values ​​are expressed in millimeters (mm). Figure 2 It can be seen that field curvature, chromatic aberration, and other issues have been satisfactorily corrected.

[0062] Example 2

[0063] A description of the optical system 1b according to Example 1 will now be given. Figure 3 As shown, the optical system 1b, from the object side to the image side, includes a negative lens L21, a cemented lens CE21, an aperture S2, a cemented lens CE22, a negative lens L27, a positive lens L28, and a positive lens L29. The cemented lens CE21 includes a negative lens L22 and a positive lens L23. The cemented lens CE22 includes a positive lens L24, a negative lens L25, and a positive lens L26. Each of the cemented lenses CE21 and CE22 is manufactured by applying an adhesive or similar bonding agent between the positive and negative lenses to ensure close contact between them. In this example, the presence or absence of a filter and the wavelength range are not limited.

[0064] Table 3 summarizes the numerical data for the optical system 1b according to this example. The optical specifications of this example are set as follows: focal length of 3 mm, image-side Fno of 4, and half-angle of 0 to 70 degrees. The design wavelength is 486.1 to 656.27 nm.

[0065] Table 3

[0066]

[0067]

[0068] Table 4 summarizes the aspherical shape data of optical system 1b.

[0069] Table 4

[0070] Paraxial radius of curvature R 4.764 14.440 -16.208 Conic coefficient k 0 0.00 0.00 Fourth-order aspherical coefficient A -0.00975 -2.86E-04 1.05E-04 Sixth-order aspherical coefficient B 0.0004195 3.43E-07 -9.48E-07 Eighth-order aspherical coefficient C -1.20E-05 0.00E+00 0.00E+00 The tenth-order aspherical coefficient D 3.75E-08 0.00E+00 0.00E+00

[0071] like Figure 6 As shown, the effective diameter D0 is the effective diameter of the concave portion of the cemented part of the negative lens L22. The outer diameter D1 is the outer diameter of the negative lens L22. The effective diameter Dmax of the lens constituting the optical system 1b with the largest effective diameter is the effective diameter of the image-side surface of the positive lens L28. The outer diameter D2max of the lens constituting the optical system 1b with the largest outer diameter is the outer diameter of the image-side surface of the positive lens L28.

[0072] Figure 4 This is the lateral aberration diagram of optical system 1b. Figure 4 The diagram illustrates the lateral aberrations for the C-line (wavelength 656.3 nm), d-line (wavelength 587.6 nm), and F-line (wavelength 486.1 nm) at three viewing angles of optical system 1b. The values ​​are expressed in millimeters (mm). Figure 4 It can be seen that field curvature, chromatic aberration, and other issues have been satisfactorily corrected.

[0073] Table 5 summarizes the numerical data for each inequality in each example.

[0074] Table 5

[0075] Example 1 10.0 8.00 3.25 9.00 2.77 0.89 1.11 Example 2 26.0 24.00 1.60 21.00 13.13 1.14 1.24

[0076] Now for reference Figures 7 to 9 The following will be a description of an in-vehicle camera 100 including an optical system (optical device) according to each example and an in-vehicle system (driving support device) 600 including the in-vehicle camera 100. Figure 7 This is a configuration diagram of an in-vehicle camera 100 and an in-vehicle system 600 having the in-vehicle camera 100. The in-vehicle system 600 is maintained by a movable mobile body (mobile device) such as a car (vehicle) and is configured to support the driving (steering) of the vehicle based on image information of the vehicle's surroundings acquired by the in-vehicle camera 100. Figure 8 This is a schematic diagram of a vehicle 700, which includes an onboard system 600, as a mobile device. Figure 8 The illustration shows the imaging range 500 of the vehicle camera 100 being set in front of the vehicle 700, but the imaging range 500 can also be set behind or to the side of the vehicle 700.

[0077] like Figure 7As shown, the vehicle system 600 includes a vehicle camera 100, a vehicle information acquisition device 200, a control device (ECU: Electronic Control Unit) 300, and a warning device 400. The vehicle camera 100 includes an image acquisition unit (image acquisition device or circuit) 101, an image processing unit or circuit 102, a parallax calculation unit 103, a distance acquisition unit (acquisition unit) 104, and a conflict determination unit 105. The image processing unit 102, parallax calculation unit 103, distance acquisition unit 104, and conflict determination unit 105 constitute a processing unit. The image acquisition unit 101 includes an optical system and an image sensor (imaging plane phase difference sensor) according to any of the above examples. The image processing unit or circuit 102 may include a central processing unit (CPU) or a programmable processor that can execute instructions to perform specified operations. Other devices, such as random access memory (RAM), read-only memory (ROM), electrically erasable read-only memory (EEROM) memory devices or circuits, may also be included. The memory (RAM, ROM, or EEPROM) can store programs or instructions that, when executed by the CPU or processor, cause the CPU or processor to perform specified operations, such as calculating disparity (in the disparity calculation unit 103), acquiring distance (in the distance acquisition unit 104), and determining conflict (in the conflict determination unit 105). These operations include... Figure 9 As shown in the image.

[0078] Figure 9 This is a flowchart illustrating an example of the operation of the in-vehicle system 600 according to this example. A description of the operation of the in-vehicle system 600 will now be given with reference to this flowchart.

[0079] First, in step S1, the image acquisition circuit 101 is used to image objects such as obstacles or pedestrians around a vehicle and acquire multiple image data (parallax image data).

[0080] In step S2, the vehicle information acquisition device 200 acquires vehicle information. The vehicle information includes information such as the vehicle's speed, yaw rate, and steering angle.

[0081] In step S3, the image processing unit 102 performs image processing on the multiple image data acquired by the image picking unit 101. More specifically, it performs image feature analysis to analyze feature quantities in the image data, such as edge quantity, orientation, and density values. Here, image feature analysis can be performed on each of the multiple image data, or it can be performed on only a portion of the multiple image data.

[0082] In step S4, the disparity calculation unit 103 calculates the disparity (image offset) information between multiple image data acquired by the image picking unit 101. The method used to calculate the disparity information can be a known method such as the Sequential Similarity Detection Algorithm (SSDA) or the Region Correlation Method, and therefore its description will be omitted in this example. Steps S2, S3, and S4 can be executed in the order described above or in parallel with each other.

[0083] In step S5, the distance acquisition unit 104 acquires (or calculates) the distance information to the object imaged by the image pickup unit 101. The distance information can be calculated based on the disparity information calculated by the disparity calculation unit 103 and the internal and external parameters of the image pickup unit 101. Here, the distance information is about the relative position to the object, such as the distance to the object, the amount of defocus, the image offset, etc., and can directly represent the distance value of the object in the image or indirectly represent the information corresponding to the distance value.

[0084] Next, in step S6, using the vehicle information acquired by the vehicle information acquisition device 200 and the distance information calculated by the distance acquisition unit 104, the conflict determination unit 105 determines whether the distance to the object is included in a preset distance range. This configuration can determine whether the object exists within a set distance range around the vehicle and determine the probability of a conflict between the vehicle and the object. The conflict determination unit 105 determines "there is a possibility of conflict" (step S7) if the object exists within the set distance range, and determines "there is no possibility of conflict" (step S8) if the object does not exist within the set distance range.

[0085] Next, if the conflict determination unit 105 determines that there is a "possibility of conflict," the conflict determination unit 105 notifies (sends) the determination result to the control device 300 and the warning device 400. At this time, the control device 300 controls the vehicle based on the determination result of the conflict determination unit 105 (step S6), and the warning device 400 warns the vehicle user (vehicle driver, passenger) based on the determination result of the conflict determination unit 105 (step S7). The determination result can be notified to at least one of the control device 300 and the warning device 400.

[0086] The control device 300 can control the movement of the vehicle by outputting control signals to the vehicle's drive unit (engine, motor, etc.). For example, it can control actions within the vehicle such as applying the brakes, releasing the accelerator, turning the steering wheel, generating control signals to produce braking force on each wheel, and suppressing the output of the engine or motor. The warning device 400 warns the user, for example, by emitting a warning sound (alarm), displaying a warning message on the screen of the car navigation system, or by vibrating the seatbelt or steering wheel.

[0087] Therefore, the vehicle system 600 according to this example can effectively detect objects and avoid collisions between the vehicle and the objects through the above-described process. In particular, applying the optical system according to the above example to the vehicle system 600 can detect objects and determine the probability of collisions over a wide field of view while reducing the overall size of the vehicle camera 100 and maintaining arrangement freedom.

[0088] In this example, the vehicle-mounted camera 100 includes a single image acquisition unit 101 with an imaging plane phase difference sensor; however, this disclosure is not limited to this example, and the vehicle-mounted camera 100 can use a stereo camera with two image acquisition units. In this case, instead of an imaging plane phase difference sensor, image data is acquired simultaneously by two synchronized image acquisition units, and the two image data are used for processing similar to that described above. However, the two image acquisition units can be desynchronized as long as the image acquisition time difference between the two image acquisition units is known.

[0089] Various examples are applicable to the calculation of distance information. One example is using a pupil-segmented image sensor (light receiving unit) with multiple pixel portions arranged in a regular two-dimensional array as the image sensor for image pickup unit 101. In the pupil-segmented image sensor, a pixel portion includes a microlens and multiple photoelectric converters, receives a pair of light beams passing through different regions of the pupil in the optical system, and can output paired image data from the photoelectric converters.

[0090] Next, the image offset for each region is calculated by correlation calculation between paired image data, and image offset map data representing the distribution of the image offset is calculated by the distance acquisition unit 104. Alternatively, the distance acquisition unit 104 can also convert the image offset into defocus amount and generate defocus map data representing the distribution of the defocus amount (distribution on a two-dimensional plane of the captured image). The distance acquisition unit 104 can acquire distance map data representing the distance to the object converted from the defocus amount.

[0091] At least one of the in-vehicle system 600 and the vehicle 700 may include a notification device (notification unit) for notifying the manufacturer of the in-vehicle system, the seller (dealer) of the mobile device, etc., of any conflict between the vehicle 700 and an obstacle. For example, the notification unit may be a unit that sends information about the conflict between the vehicle 700 and the obstacle (conflict information) to a preset external notification destination via email or the like.

[0092] Therefore, configuring the notification unit to automatically notify of conflict information can facilitate post-conflict procedures such as inspection and repair. The notification destination can be an insurance company, medical institution, police, or any other destination set by the user. The notification unit can notify the destination not only of the conflict information but also fault information for each component and information regarding consumable consumption. The presence or absence of a conflict can be detected based on distance information obtained from the output of the aforementioned optical receiving unit or through another detection unit (sensor).

[0093] In this example, the vehicle system 600 is applied to driving support (conflict damage mitigation), but the vehicle system 600 is not limited to this example and can be applied to cruise control (including adaptive cruise control) and autonomous driving. The vehicle system 600 is not only applicable to vehicles such as automobiles, but also to mobile bodies such as ships, aircraft, and industrial robots. Furthermore, the vehicle system 600 is applicable not only to mobile bodies, but also to various units that utilize object recognition, such as intelligent transportation systems (ITS).

[0094] In this example, the optical system is applied to the image acquisition unit of the vehicle system, but this disclosure is not limited to this example. For example, the optical system can be applied to image acquisition devices such as digital still cameras, digital video cameras, or film-based cameras, or it can be applied to optical devices such as telescopes or projection devices such as projectors.

[0095] Each example can provide an optical system, an image pickup device, an in-vehicle system, and a mobile device, each of which can be easily manufactured and has high performance.

[0096] While this disclosure has been described with reference to exemplary embodiments, it should be understood that this disclosure is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. An optical system, comprising: An aperture; A first cemented lens disposed adjacent to the object side of the aperture; And A second cemented lens disposed adjacent to the image side of the aperture, Characterized in that the first cemented lens includes a first negative lens, The cemented lenses included in the optical system are composed of the first cemented lens and the second cemented lens, Wherein the first negative lens is a negative lens satisfying the following inequalities: 1.5 < D1 / D0 < 15.0, and 0.80 ≤ Dmax / D1 ≤ 1.20, Where D0 is the effective diameter of the negative lens, D1 is the outer diameter of the negative lens, and Dmax is the effective diameter of the lens having the largest outer diameter among the lenses constituting the optical system.

2. The optical system according to claim 1, characterized in that, The first cemented lens includes a positive lens.

3. The optical system according to claim 2, characterized in that, The first cemented lens has a negative refractive power.

4. The optical system according to claim 2, wherein the outer diameter of the first negative lens is larger than the outer diameter of the positive lens.

5. The optical system according to claim 1, characterized in that, The second cemented lens includes a second negative lens, Wherein the second negative lens of the second cemented lens also satisfies the following inequality: 1.5 < D1 / D0 < 15.

0.

6. The optical system according to claim 5, characterized in that, The second cemented lens includes two positive lenses.

7. The optical system according to claim 1, characterized in that, The second cemented lens has a positive refractive power.

8. The optical system according to claim 1, characterized in that, The first negative lens has the smallest effective diameter among the negative lenses included in the optical system.

9. The optical system according to claim 1, characterized in that, The first negative lens satisfies the following inequality: 1.05 ≤ D2max / D1 ≤ 1.30 Where D2max is the outer diameter of the lens having the largest outer diameter.

10. The optical system according to claim 2, characterized in that, The positive lens has the smallest effective diameter among the positive lenses included in the optical system.

11. An image pickup device, comprising: The optical system according to any one of claims 1 to 10; And An image sensor configured to capture an object via the optical system.

12. A vehicle-mounted system, comprising: The image pickup device according to claim 11; And A determination unit configured to determine the possibility of conflict between the vehicle and the object based on the distance information about the object acquired by the image pickup device.

13. A mobile device, comprising the image pickup device according to claim 11, Wherein the mobile device can be moved while holding the image pickup device.

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