Optical system and imaging apparatus including the same

Abstract

To provide an optical system that can maintain good optical performance even if the environmental temperature fluctuates.SOLUTION: An optical system (100) includes, in order from an object side to an image side, a first lens (L11) having negative refractive power, a second lens (L12) having negative refractive power, a third lens (L13) having negative refractive power, a fourth lens (L14) having positive refractive power, an aperture stop (S1), a fifth lens (L15) having positive refractive power, a sixth lens (L16) having negative refractive power, and a seventh lens (L17). A sign of a temperature coefficient of a refractive index for a d-line of at least one of the fourth lens and the fifth lens is negative, and a sign of a temperature coefficient of a refractive index for a d-line of at least one of the third lens and the sixth lens is positive.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an optical system, and is suitable for imaging devices such as digital still cameras, digital video cameras, in-vehicle cameras, mobile phone cameras, surveillance cameras, wearable cameras, medical cameras, and the like.

Background Art

[0002] As an optical system used in an imaging device, one having high optical performance regardless of the environmental temperature is required. Patent Document 1 discloses an optical system that corrects fluctuations in the focal position caused by changes in the environmental temperature.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the optical system disclosed in Patent Document 1, depending on the specifications of the optical system, it may be difficult to achieve both correction of fluctuations in the focal position caused by changes in the environmental temperature and correction of various aberrations.

[0005] The present invention provides an optical system capable of maintaining good optical performance even when the environmental temperature fluctuates.

Means for Solving the Problems

[0006] As an aspect of the present invention, an optical system includes a first lens with negative refractive power, a second lens with negative refractive power, a third lens with negative refractive power, a fourth lens with positive refractive power, an aperture stop, a fifth lens with positive refractive power, a sixth lens with negative refractive power, and a seventh lens, which are arranged in order from the object side to the image side. The sign of the temperature coefficient of the refractive index for the d-line at 20°C to 40°C of at least one of the fourth lens and the fifth lens is negative, and the sign of the temperature coefficient of the refractive index for the d-line at 20°C to 40°C of at least one of the third lens and the sixth lens is positive.

[0007] Other objects and features of the present invention will be described in the following embodiments.

Effects of the Invention

[0008] According to the present invention, it is possible to provide an optical system capable of maintaining good optical performance even when the environmental temperature fluctuates.

Brief Description of the Drawings

[0009]

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Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that each drawing may be drawn at a scale different from the actual one for convenience. Also, in each drawing, the same members are denoted by the same reference numerals, and redundant explanations are omitted.

[0011] The optical system according to the present embodiment includes a first lens with a negative refractive power, a second lens with a negative refractive power, a third lens with a negative refractive power, a fourth lens with a positive refractive power, an aperture stop, a fifth lens with a positive refractive power, a sixth lens with a negative refractive power, and a seventh lens, which are arranged in order from the object side to the image side. Further, the sign of the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of at least one of the fourth lens and the fifth lens is negative, and the sign of the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of at least one of the third lens and the sixth lens is positive. With such a configuration, it is possible to realize an optical system capable of maintaining high optical performance even when the temperature fluctuates.

[0012] Note that, for the optical system according to the present embodiment, the effects of the present invention can be obtained as long as at least the above-described configuration is satisfied. Also, on the image side of the lens closest to the image side (the final lens) among the lenses constituting the optical system, optical elements that do not contribute to image formation of the optical system, such as an optical filter or a cover glass, may be arranged. In the present embodiment, an optical system composed of seven lenses, i.e., the first lens to the seventh lens, will be described. However, it is also applicable to an optical system having eight or more lenses (five or more lenses in the front group or four or more lenses in the rear group), and the same effects can be obtained. However, for further miniaturization, the configuration of the present embodiment is preferable.

[0013] In the present embodiment, the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of the fifth lens is defined as dndt5 [10 -6 / °C], and the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of the sixth lens is defined as dndt6 [10 -6 / °C]. At this time, it is preferable to satisfy the following conditional expression (1).

[0014] 1.1 < dndt6 - dndt5 < 11.4 ···(1) In the present embodiment, the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of the third lens is defined as dndt3 [10 -6 / °C], and the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of the fourth lens is defined as dndt4 [10 -6 / °C]. At this time, it is preferable to satisfy the following conditional expression (2).

[0015] -3.3 < dndt3 - dndt4 < 8.0 ···(2) If neither of the conditional expressions (1) and (2) is satisfied, the effect of suppressing focus variation due to temperature fluctuation may decrease.

[0016] More preferably, the numerical ranges of the conditional expressions (1) and (2) satisfy the following conditional expressions (1a) and (2a), respectively.

[0017] 1.5 < dndt6 - dndt5 < 10.0 ···(1a) -3.0 < dndt3 - dndt4 < 7.0 ···(2a) More preferably, the numerical ranges of the conditional expressions (1) and (2) satisfy the following conditional expressions (1b) and (2b), respectively.

[0018] 1.8 < dndt6 - dndt5 < 9.1 ···(1b) -2.6 < dndt6 - dndt5 < 6.4 ···(2b) In this embodiment, when the focal length of the third lens is f3 and the focal length of the fourth lens is f4, in order to suppress the aberration of the optical system, it is preferable to satisfy the following conditional expression (3).

[0019] -1.1 < f4 / f3 < -0.6 ···(3) If the conditional expression (3) is not satisfied, the amount of aberration generated may increase and the imaging performance may deteriorate.

[0020] More preferably, the numerical range of the conditional expression (3) is set as the following conditional expression (3a).

[0021] -1.0 < f4 / f3 < -0.7 ···(3a) Even more preferably, the numerical range of the conditional expression (3) is set as the following conditional expression (3b).

[0022] -0.9 < f4 / f3 < -0.7 ···(3b) In this embodiment, when the focal length of the fifth lens is f5 and the focal length of the sixth lens is f6, in order to suppress the curvature of the image plane of the optical system, it is preferable to satisfy the following conditional expression (4).

[0023] -1.5 < f5 / f6 < -0.9 ···(4) If the conditional expression (4) is not satisfied, the amount of curvature of the image plane generated may increase and the imaging performance may deteriorate.

[0024] More preferably, the numerical range of the conditional expression (4) is set as the following conditional expression (4a). -1.4 < f5 / f6 < -0.8 ···(4a) More preferably, the numerical range of conditional expression (4) is set as in the following conditional expression (4b). -1.2 < f5 / f6 < -0.7 ···(4b) The positive lens (the fourth lens or the fifth lens) near the aperture stop S1 preferably has a large refractive power in order to suppress focus fluctuations during temperature variations. Therefore, when the focal length of the optical system (the entire system) is f, it is preferable to satisfy the following conditional expressions (5) and (6).

[0025] 0.4 < f4 / f < 2.0 ···(5) 0.5 < f5 / f < 1.9 ···(6) If neither of conditional expressions (5) and (6) is satisfied, the effect of suppressing focus fluctuations due to temperature variations may decrease.

[0026] More preferably, the numerical ranges of conditional expressions (5) and (6) respectively satisfy the following conditional expressions (5a) and (6a).

[0027] 0.5 < f4 / f < 1.8 ···(5a) 0.6 < f5 / f < 1.7 ···(6a) Even more preferably, the numerical ranges of conditional expressions (5) and (6) respectively satisfy the following conditional expressions (5b) and (6b).

[0028] 0.7 < f4 / f < 1.6 ···(5b) 0.7 < f5 / f < 1.5 ···(6b) In this embodiment, in order to cover the functions of a telephoto lens for photographing the central part with high resolution and a wide-angle lens for photographing the periphery widely with a single optical system, the distortion is controlled, and it is a wide-angle lens having a high resolution at the central part. The second lens has an aspherical shape such that the refractive power of the negative lens increases from the central part toward the periphery. When the focal length of the second lens is f2, it is preferable to satisfy the following conditional expression (7).

[0029] -4.0 < f2 / f < -1.0 ···(7) If the conditional expression (7) is not satisfied, the resolution of the central part may decrease.

[0030] More preferably, the numerical range of the conditional expression (7) is set as the following conditional expression (7a).

[0031] -3.6 < f2 / f < -1.4 ···(7a) Even more preferably, the numerical range of the conditional expression (7) is set as the following conditional expression (7b).

[0032] -3.2 < f2 / f < -1.8 ···(7b) In the case of an aspherical lens having a shape like the second lens, when the volume and diameter increase, the manufacturing cost tends to increase. Therefore, in each embodiment, the first lens has a weak refractive power, so as not to greatly affect the off-axis aberration and to have the effect of reducing the height of off-axis rays. When the focal length of the first lens is f1, it is preferable to satisfy the following conditional expression (8).

[0033] -13.7 < f1 / f < -6.8 ···(8) More preferably, the numerical range of the conditional expression (8) is set as the following conditional expression (8a).

[0034] -12.0 < f1 / f < -4.2 ···(8a) Even more preferably, the numerical range of the conditional expression (8) is set as the following conditional expression (8b).

[0035] -11.0 < f1 / f < -4.0 ···(8b) In this embodiment, when the linear expansion coefficient of the lens barrel material is α op [1 / °C] and the linear expansion coefficient of the cover material is α co [1 / °C], the effects of the invention are most obtained when the following conditional expression (9) is satisfied. If this condition is not satisfied, since the focus fluctuation amount and the correction amount by the lens when the temperature fluctuates are greatly different, focus shift may occur when the temperature fluctuates.

[0036] 1.00 < αop / α co <1.40 ···(9) More preferably, the numerical range of conditional expression (9) is set as the following conditional expression (9a).

[0037] 1.10 < α op / α co <1.35 ···(9a) Even more preferably, the numerical range of conditional expression (9) is set as the following conditional expression (9b).

[0038] 1.10 < α op / α co <1.30 ···(9b) Hereinafter, a detailed example of the optical system according to the present embodiment will be described.

Example

[0039] FIG. 1 is a schematic diagram of the main part in a cross section including the optical axis OA of the optical system 100 according to Example 1. In FIG. 1, the left side is the object side (front side), and the right side is the image side (rear side). The optical system 100 has a front group, an aperture stop S1, and a rear group, which are arranged in order from the object side to the image side. The front group is composed of a first lens L11 with negative refractive power, a second lens L12 with negative refractive power, a third lens L13 with negative refractive power, and a fourth lens L14 with positive refractive power, which are arranged in order from the object side to the image side. The rear group is composed of a cemented lens of a fifth lens L15 with positive refractive power and a sixth lens L16 with negative refractive power, which are arranged in order from the object side to the image side, and a seventh lens L17. Note that, for the cemented lens in each example, an adhesive or the like is applied between the positive lens and the negative lens and they are in close contact. Also, the presence or absence of a filter and the wavelength range do not affect the form of each example.

[0040] The optical system 100 of this embodiment is an imaging optical system used in an imaging device. The imaging surface of the imaging element is disposed at the position of the image plane IM1. The IRCF disposed on the object side of the image plane IM1 is an infrared cut filter, and the CG is a cover glass. These optical elements do not contribute to the imaging of the optical system 100. Note that the optical system 100 of this embodiment may be used as a projection optical system in a projection device such as a projector. In this case, the display surface of a display element such as a liquid crystal panel is disposed at the position of the image plane IMG.

[0041] The optical specifications of this example (numerical example 1) are set to a focal length of 3.3 mm, an image-side Fno of 2.8, and a half field angle of 0 to 90 degrees. The design wavelength is 486.1 to 656.27 nm. The optical glasses of Ohara, Inc. and HOYA Corporation are used as the optical materials for each example, but other equivalent products may be used. T2 following the suffix of each optical material indicates -40°C, and T3 indicates +85°C.

[0042] Figures 2(A) to (C) are diagrams showing MTF (Modulation Transfer Function) curves at each temperature of this example. Here, three cases are shown: when the environmental temperature where the optical system is disposed is (A) normal temperature (25°C), (B) low temperature (-40°C), and (C) high temperature (85°C). In Figures 2(A) to (C), the horizontal axis indicates the spatial frequency [cycles / mm], and the vertical axis indicates the MTF value (contrast value). The MTF values at each temperature ensure 40% or more at a frequency of 83 lp / mm, which is half of the Nyquist frequency at a pixel pitch of 3.0 μm, and good imaging performance is obtained.

[0043] FIG. 3 is a configuration diagram of an imaging device including the optical system 100 of the present embodiment. The imaging device of the present embodiment includes a lens barrel OP, an imaging element having a sensor surface disposed on an image plane IM1, a sensor unit SU including base wirings, and a cover material CO connecting the lens barrel OP and the image plane IM1. Note that, depending on the imaging device, the sensor unit SU and the cover material CO may be the same as each other. Even in that case, the invention is applicable). After the positions of the lens barrel OP and the sensor surface (image plane IM1) are adjusted, they are fixed by an adhesive portion CEM.

[0044] Conventionally, the focus variation of the optical system due to temperature has been corrected by the difference in the lengths of the cover material CO and the lens barrel OP and the linear expansion coefficients of their materials. Here, the distance A from the adhesive portion CEM to the image plane IM1, the distance B from the adhesive portion CEM to the image side surface of the final lens, and the material characteristics (linear expansion coefficients) α op 、α co (α su ) are used as control parameters. At this time, the correction amount ΔL at the temperature change amount ΔT can be calculated by the following formula (A). Here, it is assumed that the materials of the cover material CO and the sensor unit SU are the same.

[0045] ΔL=(A×ΔT×α co )-(B×ΔT×α op ) …(A) If the focus variation amount due to the optical system during temperature variation and the correction amount ΔL have the same sign and the same amount, it is possible to correct the focus shift during temperature variation.

[0046] When using a high - pixel and small - pitch sensor, since it is necessary to release the heat generated by the sensor unit to the outside air side, it is useful to use a metal material for the cover material CO and the sensor unit SU. Also, the lens barrel material may use a resin material that can be manufactured at low cost. In in - vehicle lenses and surveillance cameras, materials that are resistant to heat, humidity, and ultraviolet rays are required. As a material that satisfies this condition, there is a substance (PPA / PPE) obtained by alloying a high - heat - resistant polyamide resin (PPA) with a polyphenylene ether resin (PPE). The linear expansion coefficients of painted metal cover materials (such as ADC12, ADC10, A1070, etc.) with corrosion resistance and weather resistance are about 2 - 2.5×10−5 (1 / °C), and the linear expansion coefficient of a weather - resistant resin lens barrel material (PPA / PPE) is about 2.6×10−5 (1 / °C). Thus, the difference in the linear expansion coefficients between the weather - resistant metal cover material and the resin lens barrel material (PPA / PPE) may be small.

[0047] In that case, as represented by formula (A), in order to increase the correction amount ΔL, it is necessary to increase the distance A from the adhesive part CEM to the sensor surface IM1 and decrease the distance B from the adhesive part CEM to the image - side surface of the seventh lens. However, due to optical performance and size specifications, it is difficult to significantly reduce the numerical values of the distance A or the distance B that are longer than the total lens length L1 (the length from the first lens to the sensor surface).

[0048] As described above, when there is no large difference in the linear expansion coefficients of materials such as the lens barrel OP, the cover material CO, and the sensor unit SU, it is difficult to obtain the necessary correction amount ΔL. Therefore, in each embodiment, a configuration for obtaining high optical performance while suppressing focus fluctuations due to temperature variations as much as possible by selecting the focal length of the lens and the lens material is proposed.

[0049] Here, for a single lens (simple lens) in an optical system, when the amount of change in the focal length when the environmental temperature changes is Δf, the coefficient is β, the amount of change in the environmental temperature is ΔT, and the focal length before the change in the environmental temperature is f, the following formula (B) holds.

[0050] Δf = β×ΔT×f …(B) In formula (B), when the coefficient β for a single lens has a refractive index N for the d-line (wavelength 587.56 nm), a linear expansion coefficient α, and a temperature coefficient of refractive index for the d-line dndt, it is expressed as the following formula (C).

[0051] β = α - dndt / (N - 1) …(C) Since the linear expansion coefficient of the sensor member and the lens barrel material is positive, the sensor position moves in the positive direction when the temperature rises. To match this, it is preferable to use a material with a positive temperature coefficient β for the positive lens and a negative temperature coefficient β for the negative lens. Since the linear expansion coefficient of ordinary glass materials is positive, it is preferable that the temperature coefficient dndt of the refractive index of the positive lens is negative and that of the negative lens is positive.

[0052] In this embodiment, the first lens L11, which is a negative lens, converges a wide angle of view, and by adopting an aspherical surface such that the refractive power of the negative lens increases from the central negative lens to the periphery of the second lens L12, the distortion characteristics are controlled. The third lens L13 and the fourth lens L14 correct the astigmatism, and at the same time, correct the spherical aberration due to the large refractive power of the fourth lens L14 and the fifth lens 15 near the aperture stop S1. High imaging performance can be obtained by correcting the axial chromatic aberration with the fifth lens L15 and the sixth lens L16 in the rear group and correcting the field curvature with the aspherical surface of the seventh lens L17. In particular, since the fourth lens L14 and the fifth lens L15 near the aperture stop S1 have a large positive refractive power, it is preferable that at least one of the temperature coefficients dndt of the refractive index is negative. Also, since the third lens L3 and the sixth lens L6 near the aperture stop S1 have a large negative refractive power, it is preferable that at least one of the temperature coefficients dndt of the refractive index is positive. If it deviates from each condition, the effect of suppressing the focus fluctuation due to temperature variation may decrease.

[0053] In order to suppress focus variation due to temperature variation, it is preferable that the difference in the temperature coefficients of the refractive indices of the positive lens and the negative lens near the aperture stop S1 is large. Further, in terms of the relationship between the focal lengths and glass material characteristics of each of the above-described lenses and the linear expansion coefficients of the lens barrel material and the cover material, it is preferable that the distance A from the adhesive portion CEM to the sensor surface (image plane IM1) is small compared to the overall lens length (the distance from the first lens to the sensor surface).

Example

[0054] FIG. 4 is a schematic diagram of a main part in a cross section including the optical axis OA of the optical system 200 according to Example 2. The optical system 200 includes a front group, an aperture stop S2, and a rear group, which are arranged in order from the object side to the image side. The front group is composed of a first lens L21 with negative refractive power, a second lens L22 with negative refractive power, a third lens L23 with negative refractive power, and a fourth lens L24 with positive refractive power, which are arranged in order from the object side to the image side. The rear group is composed of a cemented lens of a fifth lens L25 with positive refractive power and a sixth lens L26 with negative refractive power, and a seventh lens L27, which are arranged in order from the object side to the image side.

[0055] The optical specifications of this example (numerical example 2) are set with a focal length of 3.3 mm, an image-side Fno of 2.8, and a semi-field angle of 0 to 90 degrees. The design wavelengths are 486.1 to 656.27 nm. T2 following the suffix of each glass material indicates -40°C, and T3 indicates +85°C.

[0056] FIGS. 5(A) to (C) are diagrams showing the MTF (Modulation Transfer Function) curves at each temperature of this example. Here, three cases are shown: when the environmental temperature where the optical system is arranged is (A) normal temperature (25°C), (B) low temperature (-40°C), and (C) high temperature (85°C). In FIGS. 5(A) to (C), the horizontal axis represents the spatial frequency [cycles / mm], and the vertical axis represents the MTF value (contrast value). The MTF values at each temperature ensure 40% or more at a frequency of 83 lp / mm, which is half of the Nyquist frequency for a 3.0 μm pixel pitch, and good imaging performance is obtained.

Example

[0057] FIG. 6 is a schematic diagram of the main part in a cross section including the optical axis OA of the optical system 300 according to Embodiment 3. The optical system 300 includes a front group, an aperture stop S3, and a rear group, which are arranged in order from the object side to the image side. The front group is composed of a cemented lens of a first lens L31 with a negative refractive power, a second lens L32 with a negative refractive power, a third lens L33 with a negative refractive power, and a fourth lens L34 with a positive refractive power, which are arranged in order from the object side to the image side. The rear group is composed of a cemented lens of a fifth lens L35 with a positive refractive power and a sixth lens L36 with a negative refractive power, and a seventh lens L37, which are arranged in order from the object side to the image side.

[0058] The optical specifications of this embodiment (numerical example 3) are set with a focal length of 4.5 mm, an image-side Fno of 2.8, and a half field angle of 0 to 90 degrees. The design wavelength is 486.1 to 656.27 nm. T2 following the suffix of each optical material indicates -40°C, and T3 indicates +85°C.

[0059] FIGS. 7(A) to 7(C) are diagrams showing the MTF (Modulation Transfer Function) curves at each temperature of this embodiment. Here, three cases are shown: when the environmental temperature where the optical system is arranged is (A) normal temperature (25°C), (B) low temperature (-40°C), and (C) high temperature (85°C). In FIGS. 7(A) to 7(C), the horizontal axis represents the spatial frequency [cycles / mm], and the vertical axis represents the MTF value (contrast value). The MTF value at each temperature ensures 40% or more at a frequency of 83 lp / mm, which is half of the Nyquist frequency at a pixel pitch of 3.0 μm, and good imaging performance is obtained.

Embodiment

[0060] FIG. 8 is a schematic diagram of a main part in a cross section including the optical axis OA of the optical system 400 according to Example 4. The optical system 400 has a front group, an aperture stop S4, and a rear group, which are arranged in order from the object side to the image side. The front group is composed of a cemented lens of a first lens L41 with negative refractive power, a second lens L42 with negative refractive power, and a third lens L43 with negative refractive power, and a fourth lens L44 with positive refractive power, which are arranged in order from the object side to the image side. The rear group is composed of a cemented lens of a fifth lens L45 with positive refractive power and a sixth lens L46 with negative refractive power, and a seventh lens L47, which are arranged in order from the object side to the image side.

[0061] The optical specifications of this example (numerical example 4) are set with a focal length of 4.6 mm, an image-side Fno of 2.8, and a half field angle of 0 to 90 degrees. The design wavelength is 486.1 to 656.27 nm. T2 at the end of each optical material indicates -40°C, and T3 indicates +85°C.

[0062] FIGS. 9(A) to (C) are diagrams showing MTF (Modulation Transfer Function) curves at each temperature of this example. Here, three cases are shown: when the environmental temperature where the optical system is arranged is (A) normal temperature (25°C), (B) low temperature (-40°C), and (C) high temperature (85°C). In FIGS. 9(A) to (C), the horizontal axis represents the spatial frequency [cycles / mm], and the vertical axis represents the MTF value (contrast value). The MTF value at each temperature ensures 40% or more at a frequency of 83 lp / mm, which is half of the Nyquist frequency at a pixel pitch of 3.0 μm, and good imaging performance is obtained.

Example

[0063] FIG. 10 is a schematic diagram of the main part in a cross section including the optical axis OA of the optical system 500 according to Example 5. The optical system 500 has a front group, an aperture stop S5, and a rear group, which are arranged in order from the object side to the image side. The front group is composed of a first lens L51 with negative refractive power, a second lens L52 with negative refractive power, a third lens L53 with negative refractive power, and a fourth lens L54 with positive refractive power, which are arranged in order from the object side to the image side. The rear group is composed of a cemented lens of a fifth lens L55 with positive refractive power and a sixth lens L56 with negative refractive power, and a seventh lens L57, which are arranged in order from the object side to the image side.

[0064] The optical specifications of this example (numerical example 5) are set with a focal length of 3.3 mm, an image-side Fno of 2.8, and a half field angle of 0 to 60 degrees. The design wavelength is 486.1 to 656.27 nm. T2 at the end of each optical material indicates -40°C, and T3 indicates +85°C.

[0065] FIGS. 11(A) to (C) are diagrams showing the MTF (Modulation Transfer Function) curves at each temperature of this example. Here, three cases are shown: when the environmental temperature where the optical system is arranged is (A) normal temperature (25°C), (B) low temperature (-40°C), and (C) high temperature (85°C). In FIGS. 11(A) to (C), the horizontal axis represents the spatial frequency [cycles / mm], and the vertical axis represents the MTF value (contrast value). The MTF value at each temperature ensures 40% or more at a frequency of 83 lp / mm, which is half of the Nyquist frequency at a pixel pitch of 3.0 μm, and good imaging performance is obtained.

[0066] Hereinafter, numerical examples 1 to 5 corresponding to the above-described Examples 1 to 5 are shown. In each numerical example, the surface number is the order of each optical surface when counted from the object surface. r [mm] represents the curvature radius of the i-th optical surface, and d [mm] represents the distance between the i-th optical surface and the (i + 1)-th optical surface. Note that other materials having equivalent physical properties may be used for the material (optical material) of each lens in each numerical example.

[0067] Also, "E±P" in each numerical value means "×10 ±PIt means "」". Here, when the aspherical shape of each embodiment has the z-axis in the optical axis direction, the h-axis perpendicular to the optical axis, the direction of light propagation is positive, R is the paraxial curvature radius, k is the conic coefficient, and A to I are the aspherical coefficients of the 4th to 20th order, it is represented by the following formula (D).

[0068] [Number]

[0069] (Numerical Example 1) Numerical data at room temperature (+25 °C) r d optical material Object surface -2000.0 AIR L11 spherical surface 20.189 1.578 SLAL21_OHARA Spherical surface 9.042 0.585 AIR L12 aspherical surface 11 4.155 1.219 MBACD12_HOYA Aspherical surface 12 2.025 1.555 AIR L13 spherical surface 1000.000 1.000 LBSL7_OHARA Spherical surface 2.938 0.533 AIR Plane plane 0.220 AIR L14 spherical surface 4.491 3.085 SBAL3_OHARA Spherical surface -4.033 0.200 AIR S1 plane plane 0.244 AIR L15 spherical surface 5.825 3.620 SFPM2_OHARA Spherical surface -3.125 0.002 Adhesive L16 spherical surface -3.125 0.892 STIH53W_OHARA Spherical surface -52.818 0.545 AIR L17 aspherical surface 13 6.318 2.431 MBACD12_HOYA Aspherical surface 14 -35.344 0.794 AIR IRCF plane, plane 0.400 IRCF plane, plane 0.540 AIR CG plane, plane 0.400 CG plane, plane 0.150 AIR IM1 plane, plane - - Numerical data at low temperature (-40°C) r d optical material Object surface - 2000.0 'AIRT2' L11 spherical surface, 20.183, 1.577, SLAL21_OHARA spherical surface, 9.039, 0.581, 'AIRT2' L12 aspherical surface 11, 4.153, 1.219, 'BACD12T2' aspherical surface 12, 2.025, 1.554, 'AIRT2' L13 spherical surface, -999.653, 1.000, 'LBSL7T2' spherical surface, 2.937, 0.533, 'AIRT2' plane, plane 0.218, 'AIRT2' L14 spherical surface, 4.488, 3.083, 'SBAL3T2' spherical surface, -4.031, 0.198, 'AIRT2' S1 plane, plane 0.241, 'AIRT2' L15 spherical surface, 5.819, 3.617, 'SFPM2T2' spherical surface, -3.123, 0.002, adhesive L16 spherical surface, -3.124, 0.892, 'TIH53WT2' spherical surface, -52.836, 0.545, 'AIRT2' L17 aspherical surface 13, 6.315, 2.430, 'BACD12T2' aspherical surface 14, -35.330, 0.789, 'AIRT2' IRCF plane, plane 0.400 IRCF plane, plane 0.538, 'AIRT2' CG plane, plane 0.400 CG plane, plane 0.150, 'AIRT2' IM1 Plane Plane - - Numerical data at high temperature (+85°C) rd optical material Object surface - 2000.0 'AIRT3' L11 Spherical surface 20.196 1.578 SLAL21_OHARA Spherical surface 9.045 0.589 'AIRT3' L12 Aspherical surface 11 4.157 1.220 'BACD12T3' Aspherical surface 12 2.026 1.556 'AIRT3' L13 Spherical surface -1000.381 1.000 'LBSL7T3' Spherical surface 2.939 0.534 'AIRT3' Plane Plane 0.222 'AIRT3' L14 Spherical surface 4.494 3.087 'SBAL3T3' Spherical surface -4.035 0.202 Adhesive S1 Plane Plane 0.247 'AIRT3' L15 Spherical surface 5.830 3.623 'SFPM2T3' Spherical surface -3.127 0.002 Adhesive L16 Spherical surface -3.127 0.893 'TIH53WT3' Spherical surface -52.799 0.548 'AIRT3' L17 Aspherical surface 13 6.321 2.432 'BACD12T3' Aspherical surface 14 -35.360 0.799 'AIRT3' IRCF Plane Plane 0.400 IRCF Plane Plane 0.542 'AIRT3' CG Plane Plane 0.400 CG Plane Plane 0.150 'AIRT3' IM1 Plane Plane - - Aspherical coefficients during temperature variation +25°C Asphere 11, Asphere 12, Asphere 13, Asphere 14 R 4.155, 2.025, 6.318, -35.344 k -0.957, -0.636, -0.536, 10.000 A 4.3931E-03, 8.6115E-03, 5.3875E-03, 2.2435E-02 B -1.8805E-03, 9.0907E-03, -5.4839E-03, -1.2124E-02 C 3.9279E-04, -2.1284E-02, 2.0343E-03, 3.0039E-03 D -2.1186E-04, 1.9096E-02, -4.5133E-04, -4.6812E-04 E 5.5462E-05, -1.0925E-02, 5.7732E-05, 4.5314E-05 F -7.3440E-06, 3.9210E-03, -3.9963E-06, -2.5333E-06 G 5.3183E-07, -8.3569E-04, 1.1794E-07, 6.3810E-08 H -2.02338E-08, 9.63085E-05, 0, 0 I 3.17496E-10, -4.61118E-06, 0, 0 -40 °C Asphere 11, Asphere 12, Asphere 13, Asphere 14 R 4.153, 2.025, 6.315, -35.330 k -0.957, -0.636, -0.536, 10.000 A 4.3985E-03, 8.6221E-03, 5.3941E-03, 9.6362E+00 B -1.8843E-03, 9.1092E-03, -5.4951E-03, -1.4712E+01 C 3.9391E-04, -2.1345E-02, 2.0401E-03, 8.5169E+00 D -2.1263E-04, 1.9166E-02, -4.5299E-04, -2.4425E+00 E 5.5711E-05 -1.0974E-02 5.7991E-05 3.7133E-01 F -7.3830E-06 3.9418E-03 -4.0175E-06 -2.8675E-02 G 5.3509E-07 -8.40802E-04 1.1866E-07 8.8574E-04 H -2.03743E-08 9.69768E-05 0 0 I 3.19960E-10 -4.64696E-06 0 0 +85 °C Aspherical surface 11, Aspherical surface 12, Aspherical surface 13, Aspherical surface 14 R 4.157 2.026 6.321 -35.360 k -0.957 -0.636 -0.536 10.000 A 4.3871E-03 8.5997E-03 5.3801E-03 2.2405E-02 B -1.8762E-03 9.0698E-03 -5.4714E-03 -1.2097E-02 C 3.9153E-04 -2.1216E-02 2.0278E-03 2.9942E-03 D -2.1098E-04 1.9017E-02 -4.4947E-04 -4.6619E-04 E 5.5183E-05 -1.0870E-02 5.7441E-05 4.5085E-05 F -7.3003E-06 3.8977E-03 -3.9725E-06 -2.5182E-06 G 5.2818E-07 -8.29949E-04 1.1713E-07 6.3372E-08 H -2.00765E-08 9.55594E-05 0 0 I 3.14738E-10 -4.57111E-06 0 0 Refractive index during temperature variation Wavelength (nm) Glass Name 680 587.56 470 SLAL21_OHARA 1.697817 1.703 1.714471 MBACD12_HOYA 1.579291 1.58313 1.591455 STIH53W_OHARA 1.833727 1.84666 1.878166 SFPM2_OHARA 1.591805 1.59522 1.602703 LBSL7_OHARA 1.513136 1.51633 1.523132 SBAL3_OHARA 1.567194 1.571351 1.58059 NBK7_SCHOTT 1.513615 1.5168 1.523605 'AIRT2' 1.000341 1.000343 1.000346 'AIRT3' 1.000222 1.000223 1.000225 'SLAL21T2' 1.69792 1.703087 1.714517 'SLAL21T3' 1.698647 1.703853 1.715381 'BACD12T2' 1.579607 1.583436 1.591738 'BACD12T3' 1.579872 1.583729 1.592094 'LBSL7T2' 1.51337 1.516557 1.523341 'LBSL7T3' 1.513749 1.516957 1.523792 'SBAL3T2' 1.56778 1.571927 1.581138 'SBAL3T3' 1.567501 1.571674 1.580958 'SFPM2T2' 1.592724 1.596133 1.6036 'SFPM2T3' 1.591787 1.595214 1.602726 'NBK7T2' 1.513971 1.517149 1.523937 'NBK7T3' 1.514125 1.517324 1.524162 'TIH53WT2' 1.834336 1.847225 1.87859 'TIH53WT3' 1.83417 1.847165 1.878857 (Numerical Example 2) Numerical data at room temperature (+25°C) r d optical material Object surface - 2000.000 AIR L21 Spherical surface 20.282 1.581 SLAL21_OHARA Spherical surface 9.062 0.580 AIR L22 Aspherical surface 21 4.155 1.219 MBACD12_HOYA Aspherical surface 22 2.031 1.554 AIR L23 Spherical surface -3033.208 1.000 LBSL7_OHARA Spherical surface 2.876 0.513 AIR Plane Plane 0.200 AIR L24 Spherical surface 4.502 3.071 SBAL14_OHARA Spherical surface -3.918 0.254 AIR S2 Plane Plane 0.418 AIR L25 Spherical surface 5.782 3.648 SFPM2_OHARA Spherical surface -3.257 0.002 Adhesive L26 Spherical surface -3.257 0.800 STIH53W_OHARA Spherical surface -51.774 0.521 AIR L27 Aspherical surface 23 6.553 2.349 AIR Aspherical surface 24 -34.987 0.794 AIR IRCF Plane Plane 0.400 IRCF Plane Plane 0.540 AIR CG Plane Plane 0.400 CG Plane Plane 0.150 AIR IM2 Plane Plane - - Numerical data at low temperature (-40°C) r d optical material Object surface - 2000.000 'AIRT2' L21 Spherical surface 20.275 1.580 SLAL21_OHARA Spherical surface 9.059 0.576 'AIRT2' L22 Aspherical surface 21 4.153 1.219 'BACD12T2' Aspherical surface 22 2.030 1.553 'AIRT2' L23 Spherical surface -3032.157 1.000 'LBSL7T2' Spherical surface 2.875 0.513 'AIRT2' Plane Plane 0.198 'AIRT2' L24 Spherical surface 4.500 3.069 'SBAL14T2' Spherical surface -3.916 0.252 'AIRT2' S2 Plane Plane 0.418 'AIRT2' L25 Spherical surface 5.777 3.646 'SFPM2T2' Spherical surface -3.255 0.002 Adhesive L26 Spherical surface -3.255 0.800 'TIH53WT2' Spherical surface -51.790 0.518 'AIRT2' L27 Aspherical surface 23 6.551 2.348 'BACD12T2' Aspherical surface 24 -34.972 0.793 'AIRT2' IRCF Plane Plane 0.400 IRCF Plane Plane 0.539 'AIRT2' CG Plane Plane 0.400 CG Plane Plane 0.150 'AIRT2' IM2 Plane Plane - - Numerical data at high temperature (+85°C) r d optical material Object surface - 2000.000 'AIRT3' L21 Spherical surface 20.288 1.581 SLAL21_OHARA Spherical surface 9.065 0.584 'AIRT3' L22 Aspherical surface 21 4.157 1.220 'BACD12T3' Aspherical surface 22 2.032 1.555 'AIRT3' L23 Spherical surface -3034.363 1.000 'LBSL7T3' Spherical surface 2.877 0.514 'AIRT3' Plane Flat 0.202 'AIRT3' L24 Spherical surface 4.504 3.072 'SBAL14T3' Spherical surface -3.920 0.255 'AIRT3' S2 Plane Flat 0.418 'AIRT3' L25 Spherical surface 5.788 3.651 'SFPM2T3' Spherical surface -3.259 0.002 Adhesive L26 Spherical surface -3.259 0.800 'TIH53WT3' Spherical surface -51.759 0.524 'AIRT3' L27 Aspherical surface 23 6.556 2.350 'BACD12T3' Aspherical surface 24 -35.003 0.795 'AIRT3' IRCF Plane Flat 0.400 IRCF Plane Flat 0.541 'AIRT3' CG Plane Flat 0.400 CG Plane Flat 0.150 'AIRT3' IM2 Plane Flat - - Aspherical coefficients during temperature variation +25°C Aspherical surface 21 Aspherical surface 22 Aspherical surface 23 Aspherical surface 24 R 4.155 2.031 6.553 -34.987 k -0.958 -0.630 -0.520 10.000 A 4.3922E-03 8.4604E-03 5.2762E-03 2.2519E-02 B -1.8806E-03 9.1282E-03 -5.1181E-03 -1.2083E-02 C 3.9285E-04 -2.1303E-02 1.7707E-03 2.9640E-03 D -2.1189E-04 1.9124E-02 -3.6287E-04 -4.5868E-04 E 5.5470E-05 -1.0947E-02 4.2095E-05 4.4454E-05 F -7.3453E-06 3.9307E-03 -2.5927E-06 -2.5180E-06 G 5.3196E-07 -8.3829E-04 6.7731E-08 6.5063E-08 H -2.02410E-08 9.66860E-05 0 0 I 3.17658E-10 -4.63383E-06 0 0 -40 °C Asphere 21 Asphere 22 Asphere 23 Asphere 24 R 4.153 2.030 6.551 -34.972 k -0.958 -0.630 -0.520 10.000 A 4.3975E-03 8.4707E-03 5.2827E-03 2.2546E-02 B -1.8844E-03 9.1467E-03 -5.1285E-03 -1.2107E-02 C 3.9397E-04 -2.1363E-02 1.7757E-03 2.9725E-03 D -2.1266E-04 1.9194E-02 -3.6420E-04 -4.6036E-04 E 5.5719E-05 -1.0996E-02 4.2284E-05 4.4654E-05 F -7.3843E-06 3.9516E-03 -2.6065E-06 -2.5313E-06 G 5.3522E-07 -8.43419E-04 6.8146E-08 6.5461E-08 H -2.03815E-08 9.73570E-05 0 0 I 3.20123E-10 -4.66979E-06 0 0 +85 °C Asphere 21 Asphere 22 Asphere 23 Asphere 24 R 4.157 2.032 6.556 -35.003 k -0.958 -0.630 -0.520 10.000 A 4.3861E-03 8.4487E-03 5.2690E-03 2.2488E-02 B -1.8763E-03 9.1072E-03 -5.1064E-03 -1.2055E-02 C 3.9159E-04 -2.1234E-02 1.7650E-03 2.9545E-03 D -2.1101E-04 1.9045E-02 -3.6138E-04 -4.5678E-04 E 5.5190E-05 -1.0891E-02 4.1883E-05 4.4230E-05 F -7.3016E-06 3.9073E-03 -2.5773E-06 -2.5030E-06 G 5.2831E-07 -8.32532E-04 6.7266E-08 6.4616E-08 H -2.00836E-08 9.59340E-05 0 0 I 3.14898E-10 -4.59357E-06 0 0 Refractive Index at Temperature Variation Wavelength (nm) Glass Name 680 587.56 470 SLAL21_OHARA 1.697817 1.703 1.714471 MBACD12_HOYA 1.579291 1.58313 1.591455 STIH53W_OHARA 1.833727 1.84666 1.878166 SFPM2_OHARA 1.591805 1.59522 1.602703 LBSL7_OHARA 1.513136 1.51633 1.523132 SBAL14_OHARA 1.564913 1.568832 1.577438 NBK7_SCHOTT 1.513615 1.5168 1.523605 'AIRT2' 1.000341 1.000343 1.000346 'AIRT3' 1.000222 1.000223 1.000225 'SLAL21T2' 1.69792 1.703087 1.714517 'SLAL21T3' 1.698647 1.703853 1.715381 'BACD12T2' 1.579607 1.583436 1.591738 'BACD12T3' 1.579872 1.583729 1.592094 'LBSL7T2' 1.51337 1.516557 1.523341 'LBSL7T3' 1.513749 1.516957 1.523792 'SBAL14T2' 1.56535 1.56926 1.57784 'SBAL14T3' 1.565361 1.569295 1.577943 'SFPM2T2' 1.592724 1.596133 1.6036 'SFPM2T3' 1.591787 1.595214 1.602726 'NBK7T2' 1.513971 1.517149 1.523937 'NBK7T3' 1.514125 1.517324 1.524162 'TIH53WT2' 1.834336 1.847225 1.87859 'TIH53WT3' 1.83417 1.847165 1.878857 (Numerical Example 3) Numerical data at room temperature (+25°C) r d optical material Object surface - 2000.000 AIR L31 Spherical surface 35.117 2.000 SLAL21_OHARA Spherical surface 9.996 0.825 AIR L32 Aspherical surface 31 4.854 1.796 MBACD12_HOYA Aspherical surface 32 2.290 2.584 AIR L33 Spherical surface -19.216 2.008 STIM2_OHARA Spherical surface 4.136 0.002 Adhesive L34 Plane 4.136 2.124 SLAH60MQ_OHARA Spherical surface -9.984 1.000 AIR S3 Spherical surface Plane 1.000 AIR L35 Plane 7.606 2.997 SPHM52Q_OHARA Spherical surface -3.348 0.002 Adhesive L36 Spherical surface -3.348 0.600 STIH53W_OHARA Spherical surface -7.851 2.202 AIR L37 Aspherical surface 33 -197.087 3.547 MBACD12_HOYA Aspherical surface 34 -33.493 0.571 AIR IRCF Plane Plane 0.400 IRCF Plane Plane 0.410 AIR CG Plane Plane 0.500 CG Plane Plane 0.435 AIR IM3 Plane Plane 0.000 - Numerical data at low temperature (-40°C) r d optical material Object surface - 2000.000 'AIRT2' L31 Spherical surface 35.107 2.000 'SLAL21T2' Spherical surface 9.993 0.825 'AIRT2' L32 Aspherical surface 31 4.852 1.796 'BACD12T2' Aspherical surface 32 2.289 2.584 'AIRT2' L33 Spherical surface -19.207 2.008 'STIM2T2' Spherical surface 4.134 0.002 Adhesive L34 Plane 4.134 2.124 'AH60MQT2' Spherical surface -9.978 1.000 'AIRT2' S3 Spherical surface to plane 1.000 'AIRT2' L35 Plane 7.602 2.997 'PHM52QT2' Spherical surface -3.347 0.002 Adhesive L36 Spherical surface -3.347 0.600 'TIH53WT2' Spherical surface -7.847 2.202 'AIRT2' L37 Aspherical surface 33 -197.006 3.547 'BACD12T2' Aspherical surface 34 -33.479 0.571 'AIRT2' IRCF Plane to plane 0.400 IRCF Plane to plane 0.410 'AIRT2' CG Plane to plane 0.500 CG Plane to plane 0.435 'AIRT2' IM3 Plane to plane 0.000 - Numerical data at high temperature (+85°C) r d optical material Object surface - 2000.000 'AIRT3' L31 Spherical surface 35.129 2.001 'SLAL21T3' Spherical surface 9.999 0.832 'AIRT3' Aspherical surface L32 31 4.857 1.797 'BACD12T3' Aspherical surface 32 2.291 2.585 'AIRT3' Spherical surface L33 -19.225 2.009 'STIM2T3' Spherical surface 4.138 0.002 Adhesive Flat surface L34 4.138 2.125 'AH60MQT3' Spherical surface -9.990 1.003 'AIRT3' Spherical surface to flat surface S3 1.004 'AIRT3' Flat surface L35 7.610 2.999 'PHM52QT3' Spherical surface -3.350 0.002 Adhesive Spherical surface L36 -3.350 0.600 'TIH53WT3' Spherical surface -7.856 2.206 'AIRT3' Aspherical surface L37 33 -197.177 3.549 'BACD12T3' Aspherical surface 34 -33.508 0.574 'AIRT3' IRCF Flat surface to flat surface 0.400 IRCF Flat surface to flat surface 0.411 'AIRT3' CG Flat surface to flat surface 0.500 CG Flat surface to flat surface 0.436 'AIRT3' IM3 Flat surface to flat surface 0.000 - Aspherical coefficients during temperature variation +25 °C Aspherical surface 31, Aspherical surface 32, Aspherical surface 33, Aspherical surface 34 R 4.854 2.290 -197.087 -33.493 k -2.055 -0.585 0.000 0.000 A 2.9797E-03 4.3897E-03 -4.3508E-04 7.2846E-03 B -1.4630E-04 1.0111E-03 -1.2523E-03 -2.5525E-03 C -5.6253E-05 -1.2289E-03 3.1940E-04 2.9193E-04 D 5.5854E-06 2.7508E-04 -4.6867E-05 -1.9271E-05 E -2.1591E-07 -2.9317E-05 3.3157E-06 6.8799E-07 F 3.2717E-09 1.2539E-06 -9.3447E-08 -1.0252E-08 G 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 H 0.00000E+00 0.00000E+00 0.0000E+00 0.0000E+00 I 0.00000E+00 0.00000E+00 0.0000E+00 0.0000E+00 -40 °C Asphere 31 Asphere 32 Asphere 33 Asphere 34 R 4.852 2.289 -197.006 -33.479 k -2.055 -0.585 0.000 0.000 A 2.9833E-03 4.3951E-03 -4.3561E-04 7.2935E-03 B -1.4660E-04 1.0131E-03 -1.2548E-03 -2.5577E-03 C -5.6413E-05 -1.2324E-03 3.2031E-04 2.9276E-04 D 5.6059E-06 2.7609E-04 -4.7039E-05 -1.9342E-05 E -2.1688E-07 -2.9448E-05 3.3306E-06 6.9108E-07 F 3.2891E-09 1.2605E-06 -9.3942E-08 -1.0306E-08 G 0.0000E+00 0.00000E+00 0.0000E+00 0.0000E+00 H 0.00000E+00 0.00000E+00 0.0000E+00 0.0000E+00 I 0.00000E+00 0.00000E+00 0.0000E+00 0.0000E+00 +85 °C Asphere 31 Asphere 32 Asphere 33 Asphere 34 R 4.857 2.291 -197.177 -33.508 k -2.055 -0.585 0.000 0.000 A 2.9756E-03 4.3836E-03 -4.3448E-04 7.2746E-03 B -1.4596E-04 1.0088E-03 -1.2494E-03 -2.5466E-03 C -5.6072E-05 -1.2250E-03 3.1837E-04 2.9099E-04 D 5.5624E-06 2.7394E-04 -4.6674E-05 -1.9192E-05 E -2.1483E-07 -2.9169E-05 3.2990E-06 6.8453E-07 F 3.2523E-09 1.2464E-06 -9.2890E-08 -1.0191E-08 G 0.0000E+00 0.00000E+00 0.0000E+00 0.0000E+00 H 0.00000E+00 0.00000E+00 0.0000E+00 0.0000E+00 I 0.00000E+00 0.00000E+00 0.0000E+00 0.0000E+00 Refractive Index at Temperature Variation Wavelength (nm) Glass Name 680 587.56 470 SLAL21_OHARA 1.697817 1.703 1.714471 MBACD12_HOYA 1.579291 1.58313 1.591455 STIM2_OHARA 1.613638 1.620041 1.634924 SLAH60MQ_OHARA 1.825568 1.834 1.853466 SPHM52Q_OHARA 1.614189 1.618 1.626295 STIH53W_OHARA 1.833727 1.84666 1.878166 SBSL7_OHARA 1.513149 1.51633 1.523134 'AIRT2' 1.000341 1.000343 1.000346 'AIRT3' 1.000222 1.000223 1.000225 'SLAL21T2' 1.69792 1.703087 1.714517 'SLAL21T3' 1.698647 1.703853 1.715381 'BACD12T2' 1.579607 1.583436 1.591738 'BACD12T3' 1.579872 1.583729 1.592094 'STIM2T2' 1.614043 1.620426 1.635246 'STIM2T3' 1.614147 1.620579 1.635547 'AH60MQT2' 1.826238 1.834643 1.854038 'AH60MQT3' 1.825939 1.834407 1.853972 'PHM52QT2' 1.614789 1.618592 1.626866 'PHM52QT3' 1.614498 1.618324 1.626656 'TIH53WT2' 1.834336 1.847225 1.87859 'TIH53WT3' 1.83417 1.847165 1.878857 'SBSL7T2' 1.513513 1.516687 1.523472 'SBSL7T3' 1.513642 1.516836 1.523673 (Numerical Example 4) Numerical data at room temperature (+25°C) r d optical material Object surface - 2000.000 AIR L41 Spherical surface 34.161 2.000 SLAL21_OHARA Spherical surface 10.122 0.845 AIR L42 Aspherical surface 41 4.943 1.585 MBACD12_HOYA Aspherical surface 42 2.398 2.643 AIR L43 Spherical surface -10.939 2.162 SNSL36_OHARA Spherical surface 5.025 0.002 Adhesive L44 Plane 5.025 1.976 SLAH66_OHARA Spherical surface -8.036 0.700 AIR S4 Spherical surface Plane 0.800 AIR L45 Plane 7.369 4.242 SFPM2_OHARA Spherical surface -3.322 0.002 Adhesive L46 Spherical surface -3.322 0.600 STIH53W_OHARA Spherical surface -8.357 1.707 AIR L47 Aspherical surface 43 -200.010 3.422 MBACD12_HOYA Aspherical surface 44 -26.619 0.571 AIR IRCF Plane Plane 0.400 IRCF Plane Plane 0.410 AIR CG Plane Plane 0.500 CG Plane Plane 0.435 AIR IM4 Plane Plane 0.000 - Numerical data at low temperature (-40°C) r d optical material Object Surface - 2000.000 'AIRT2' L41 Spherical Surface 34.151 1.999 'SLAL21T2' Spherical Surface 10.119 0.841 'AIRT2' L42 Aspherical Surface 41 4.941 1.584 'BACD12T2' Aspherical Surface 42 2.397 2.642 'AIRT2' L43 Spherical Surface -10.933 2.161 'SNSL36T2' Spherical Surface 5.023 0.002 Adhesive L44 Plane 5.023 1.975 'SLAH66T2' Spherical Surface -8.034 0.697 'AIRT2' S4 Spherical Surface Plane 0.796 'AIRT2' L45 Plane 7.362 4.239 'SFPM2T2' Spherical Surface -3.320 0.002 Adhesive L46 Spherical Surface -3.320 0.600 'TIH53WT2' Spherical Surface -8.351 1.703 'AIRT2' L47 Aspherical Surface 43 -199.929 3.421 'BACD12T2' Aspherical Surface 44 -26.608 0.573 'AIRT2' IRCF Plane Plane 0.400 IRCF Plane Plane 0.409 'AIRT2' CG Plane Plane 0.500 CG Plane Plane 0.434 'AIRT2' IM4 Plane Plane 0.000 - Numerical Data at High Temperature (+85°C) r d Optical Material Object Surface - 2000.000 'AIRT3' L41 Spherical Surface 34.172 2.001 'SLAL21T3' Spherical Surface 10.125 0.849 'AIRT3' L42 Aspherical Surface 41 4.945 1.585 'BACD12T3' Aspherical surface 42 2.399 2.644 'AIRT3' L43 Spherical surface -10.946 2.163 'SNSL36T3' Spherical surface 5.027 0.002 Adhesive L44 Plane 5.027 1.977 'SLAH66T3' Spherical surface -8.039 0.703 'AIRT3' S4 Spherical surface Plane 0.804 'AIRT3' L45 Plane 7.376 4.245 'SFPM2T3' Spherical surface -3.324 0.002 Adhesive L46 Spherical surface -3.324 0.600 'TIH53WT3' Spherical surface -8.364 1.711 'AIRT3' L47 Aspherical surface 43 -200.102 3.424 'BACD12T3' Aspherical surface 44 -26.631 0.569 'AIRT3' IRCF Plane Plane 0.400 IRCF Plane Plane 0.411 'AIRT3' CG Plane Plane 0.500 CG Plane Plane 0.436 'AIRT3' IM4 Plane Plane 0.000 - Aspherical coefficients during temperature variation +25 °C Aspherical surface 41 Aspherical surface 42 Aspherical surface 43 Aspherical surface 44 R 4.943 2.398 -200.010 -26.619 k -1.911 -0.524 0.000 0.000 A 3.4299E-03 4.7376E-03 1.7904E-04 7.9926E-03 B -1.3523E-04 1.9464E-03 -1.3490E-03 -2.8155E-03 C -8.7971E-05 -1.7053E-03 3.2178E-04 3.1889E-04 D 9.5122E-06 3.8057E-04 -4.5069E-05 -2.0386E-05 E -4.0146E-07 -4.0090E-05 3.1559E-06 7.0575E-07 F 6.4620E-09 1.6863E-06 -8.8137E-08 -1.0266E-08 G 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 H 0.00000E+00 0.00000E+00 0.0000E+00 0.0000E+00 I 0.00000E+00 0.00000E+00 0.0000E+00 0.0000E+00 -40 °C Aspherical 41 Aspherical 42 Aspherical 43 Aspherical 44 R 4.941 2.397 -199.929 -26.608 k -1.911 -0.524 0.000 0.000 A 3.4341E-03 4.7434E-03 1.7926E-04 8.0023E-03 B -1.3551E-04 1.9504E-03 -1.3517E-03 -2.8213E-03 C -8.8222E-05 -1.7102E-03 3.2270E-04 3.1980E-04 D 9.5471E-06 3.8197E-04 -4.5234E-05 -2.0460E-05 E -4.0326E-07 -4.0270E-05 3.1701E-06 7.0891E-07 F 6.4963E-09 1.6952E-06 -8.8604E-08 -1.0320E-08 G 0.0000E+00 0.00000E+00 0.0000E+00 0.0000E+00 H 0.00000E+00 0.00000E+00 0.0000E+00 0.0000E+00 I 0.00000E+00 0.00000E+00 0.0000E+00 0.0000E+00 +85 °C Aspherical surface 41, Aspherical surface 42, Aspherical surface 43, Aspherical surface 44 R 4.945 2.399 -200.102 -26.631 k -1.911 -0.524 0.000 0.000 A 3.4252E-03 4.7311E-03 1.7879E-04 7.9815E-03 B -1.3492E-04 1.9419E-03 -1.3459E-03 -2.8091E-03 C -8.7688E-05 -1.6999E-03 3.2075E-04 3.1787E-04 D 9.4730E-06 3.7900E-04 -4.4883E-05 -2.0302E-05 E -3.9944E-07 -3.9888E-05 3.1400E-06 7.0219E-07 F 6.4236E-09 1.6762E-06 -8.7612E-08 -1.0205E-08 G 0.0000E+00 0.00000E+00 0.0000E+00 0.0000E+00 H 0.00000E+00 0.00000E+00 0.0000E+00 0.0000E+00 I 0.00000E+00 0.00000E+00 0.0000E+00 0.0000E+00 Refractive index during temperature variation Wavelength (nm) Glass name 680 587.56 470 SLAL21_OHARA 1.697817 1.703 1.714471 MBACD12_HOYA 1.579291 1.58313 1.591455 SNSL36_OHARA 1.513609 1.517417 1.525865 SLAH66_OHARA 1.766477 1.772499 1.78581 SFPM2_OHARA 1.591805 1.59522 1.602703 STIH53W_OHARA 1.833727 1.84666 1.878166 SBSL7_OHARA 1.513149 1.51633 1.523134 'AIRT2' 1.000341 1.000343 1.000346 'AIRT3' 1.000222 1.000223 1.000225 'SLAL21T2' 1.69792 1.703087 1.714517 'SLAL21T3' 1.698647 1.703853 1.715381 'BACD12T2' 1.579607 1.583436 1.591738 'BACD12T3' 1.579872 1.583729 1.592094 'SNSL36T2' 1.513987 1.517784 1.526201 'SNSL36T3' 1.514079 1.517905 1.526398 'SLAH66T2' 1.766827 1.772834 1.786108 'SLAH66T3' 1.76713 1.773175 1.786544 'SFPM2T2' 1.592724 1.596133 1.6036 'SFPM2T3' 1.591787 1.595214 1.602726 'TIH53WT2' 1.834336 1.847225 1.87859 'TIH53WT3' 1.83417 1.847165 1.878857 'SBSL7T2' 1.513513 1.516687 1.523472 'SBSL7T3' 1.513642 1.516836 1.523673 (Numerical Example 5) Numerical data at normal temperature (+25°C) r d optical material Object surface - 2000.000 AIR L51 Spherical surface 17.980 1.546 SLAL21_OHARA Spherical surface 9.400 0.500 AIR L52 Aspherical surface 21 4.236 1.262 MBACD12_HOYA Aspherical surface 22 1.768 1.452 AIR L53 Spherical surface Plane 1.000 LBSL7_OHARA Spherical surface 3.210 0.443 AIR Plane Plane 0.200 AIR L54 Spherical surface 4.699 2.698 SBAL3_OHARA Spherical surface -3.767 0.200 AIR S5 Plane Plane 0.348 AIR L55 Spherical surface 6.128 3.664 SPHM52_OHARA Spherical surface -3.082 0.000 Adhesive L56 Spherical surface -3.082 1.129 STIH53W_OHARA Spherical surface -75.031 0.503 AIR L57 Aspherical surface 23 5.826 2.536 MBACD12_HOYA Aspherical surface -64.896 0.777 AIR IRCF Plane Plane 0.400 IRCF Plane Plane 0.540 AIR CG Plane Plane 0.400 CG Plane Plane 0.150 AIR IM5 Plane Plane - - Numerical data at low temperature (-40°C) r d optical material Object surface - 2000.000 AIRT2' L51 Spherical surface 17.975 1.546 SLAL21_OHARA Spherical surface 9.397 0.495 AIRT2' L52 Aspherical surface 21 4.234 1.262 'BACD12T2' Aspherical surface 22 1.767 1.451 AIRT2' L53 Spherical surface Plane 1.000 'LBSL7T2' Spherical surface 3.208 0.443 'AIRT2' Plane Plane 0.198 'AIRT2' L54 Spherical surface 4.696 2.696 'SBAL3T2' Spherical surface -3.765 0.198 'AIRT2' S5 Plane Plane 0.345 'AIRT2' L55 Spherical surface 6.123 3.661 'SPHM52T2' Spherical surface -3.080 0.002 Adhesive L56 Spherical surface -3.080 1.128 'TIH53WT2' Spherical surface -75.086 0.503 'AIRT2' L57 Aspherical surface 23 5.823 2.535 'BACD12T2' Aspherical surface 24 -64.869 0.774 AIRT2' IRCF Plane Plane 0.400 IRCF Plane Plane 0.538 'AIRT2' CG Plane Plane 0.400 CG Plane Plane 0.150 'AIRT2' IM5 Plane Plane - - Numerical data at high temperature (+85°C) r d Optical material Object surface - 2000.000 AIRT3' L51 Spherical surface 17.986 1.547 SLAL21_OHARA Spherical surface 9.403 0.504 AIRT3' L52 Aspherical surface 21 4.238 1.263 'BACD12T3' Aspherical surface 22 1.769 1.453 AIRT3' L53 Spherical surface Plane 1.000 'LBSL7T3' Spherical surface 3.211 0.443 AIRT3' Plane Plane 0.202 AIRT3' L54 Spherical surface 4.702 2.699 'SBAL3T3' Spherical surface -3.769 0.202 AIRT3' S5 Plane Plane 0.351 AIRT3' L55 Spherical surface 6.133 3.666 'SPHM52T3' Spherical surface -3.083 0.002 Adhesive L56 Spherical surface -3.083 1.130 'TIH53WT3' Spherical surface -74.975 0.507 AIRT3' L57 Aspherical surface 23 5.828 2.537 'BACD12T3' Aspherical surface 24 -64.925 0.780 AIRT3' IRCF Plane Plane 0.400 IRCF Plane Plane 0.542 AIRT3' CG Plane Plane 0.400 CG Plane Plane 0.150 AIRT3' IM5 Plane Plane - - Aspherical coefficients during temperature variation +25 °C Aspherical surface 51 Aspherical surface 52 Aspherical surface 53 Aspherical surface 54 R 4.236 1.768 5.826 -64.896 k -0.961 -0.529 -0.757 10.000 A 4.8671E-03 5.0100E-03 3.8494E-03 2.0469E-02 B -1.0868E-03 4.5665E-02 -4.7676E-03 -1.1495E-02 C -4.5531E-04 -1.0320E-01 1.8831E-03 2.6378E-03 D 6.0879E-05 1.1146E-01 -4.2097E-04 -3.2048E-04 E 1.3044E-05 -7.3820E-02 5.2532E-05 1.7533E-05 F -3.8438E-06 3.0498E-02 -3.4575E-06 -8.7253E-08 G 3.8771E-07 -7.5943E-03 9.2852E-08 -1.9319E-08 H -1.82186E-08 1.03919E-03 0.0000E+00 0.0000E+00 I 3.35082E-10 -5.98857E-05 0.0000E+00 0.0000E+00 -40 °C Aspherical surface 51, Aspherical surface 52, Aspherical surface 53, Aspherical surface 54 R 4.234 1.767 5.823 -64.869 k -0.961 -0.529 -0.757 10.000 A 4.8731E-03 5.0161E-03 3.8542E-03 2.0494E-02 B -1.0890E-03 4.5758E-02 -4.7773E-03 -1.1518E-02 C -4.5661E-04 -1.0349E-01 1.8884E-03 2.6454E-03 D 6.1102E-05 1.1186E-01 -4.2251E-04 -3.2166E-04 E 1.3103E-05 -7.4151E-02 5.2768E-05 1.7612E-05 F -3.8642E-06 3.0660E-02 -3.4759E-06 -8.7715E-08 G 3.9009E-07 -7.64075E-03 9.3420E-08 -1.9437E-08 H -1.83450E-08 1.04641E-03 0.0000E+00 0.0000E+00 I 3.37682E-10 -6.03504E-05 0.0000E+00 0.0000E+00 +85 °C Aspherical surface 51 Aspherical surface 52 Aspherical surface 53 Aspherical surface 54 R 4.238 1.769 5.828 -64.925 k -0.961 -0.529 -0.757 10.000 A 4.8604E-03 5.0031E-03 3.8441E-03 2.0441E-02 B -1.0843E-03 4.5560E-02 -4.7566E-03 -1.1469E-02 C -4.5385E-04 -1.0287E-01 1.8770E-03 2.6294E-03 D 6.0627E-05 1.1100E-01 -4.1923E-04 -3.1916E-04 E 1.2978E-05 -7.3448E-02 5.2268E-05 1.7445E-05 F -3.8209E-06 3.0317E-02 -3.4370E-06 -8.6733E-08 G 3.8505E-07 -7.54212E-03 9.2214E-08 -1.9186E-08 H -1.80769E-08 1.03111E-03 0.0000E+00 0.0000E+00 I 3.32170E-10 -5.93653E-05 0.0000E+00 0.0000E+00 Refractive index during temperature variation Wavelength (nm) Glass name 680 587.56 470 SLAL21_OHARA 1.697817 1.703 1.714471 MBACD12_HOYA 1.579291 1.58313 1.591455 STIH53W_OHARA 1.833727 1.84666 1.878166 LBSL7_OHARA 1.513136 1.51633 1.523132 SBAL3_OHARA 1.567194 1.571351 1.58059 SPHM52_OHARA 1.6142 1.618 1.626304 NBK7_SCHOTT 1.513615 1.5168 1.523605 'AIRT2' 1.000341 1.000343 1.000346 'AIRT3' 1.000222 1.000223 1.000225 'SLAL21T2' 1.69792 1.703087 1.714517 'SLAL21T3' 1.698647 1.703853 1.715381 'BACD12T2' 1.579607 1.583436 1.591738 'BACD12T3' 1.579872 1.583729 1.592094 'LBSL7T2' 1.51337 1.516557 1.523341 'LBSL7T3' 1.513749 1.516957 1.523792 'SBAL3T2' 1.56778 1.571927 1.581138 'SBAL3T3' 1.567501 1.571674 1.580958 'SPHM52T2' 1.614991 1.618785 1.627074 'SPHM52T3' 1.614328 1.618141 1.626479 'NBK7T2' 1.513971 1.517149 1.523937 'NBK7T3' 1.514125 1.517324 1.524162 'TIH53WT2' 1.834336 1.847225 1.87859 'TIH53WT3' 1.83417 1.847165 1.878857 Table 1 shows the numerical values of the conditional expressions in Examples 1 to 5. By satisfying each conditional expression, it is possible to realize an optical system that suppresses focus fluctuations due to temperature variations even when the linear expansion difference between the lens barrel and the cover material is small.

[0070] [Table 1]

[0071] [Imaging device] FIG. 12 is a schematic diagram of the main part of an imaging device 70 according to an embodiment of the present invention. The imaging device 70 according to the present embodiment includes an optical system (imaging optical system) 71 according to any one of the above-described examples, a light receiving element 72 that photoelectrically converts an image of an object formed by the optical system 71, and a camera body (housing) 73 that holds the light receiving element 72. The optical system 71 is held by a lens barrel (holding member) and is connected to the camera body 73. As shown in FIG. 7, a display unit 74 that displays an image acquired by the light receiving element 72 may be connected to the camera body 73. As the light receiving element 72, an imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor can be used.

[0072] When the imaging device 70 is used as a distance measuring device, for example, an imaging element (imaging surface phase difference sensor) having pixels capable of splitting a light beam from an object into two and performing photoelectric conversion can be adopted as the light receiving element 72. When the subject is on the front focal plane of the optical system 71, no positional deviation occurs in each image corresponding to the two split light beams on the image plane of the optical system 71. However, when the subject is at a position other than the front focal plane of the optical system 71, a positional deviation occurs in each image. At this time, since the positional deviation of each image corresponds to the displacement amount from the front focal plane of the subject, the distance to the subject can be measured by acquiring the positional deviation amount and the direction of the positional deviation of each image using the imaging surface phase difference sensor.

[0073] Note that the optical system 71 and the camera body 73 may be configured to be detachable from each other. That is, the optical system 71 and the lens barrel may be configured as an interchangeable lens (lens device). Further, the optical systems according to the above-described embodiments are not limited to imaging devices such as digital still cameras, silver halide film cameras, video cameras, in-vehicle cameras, and surveillance cameras, and can be applied to various optical devices such as telescopes, binoculars, projectors (projection devices), and digital copiers.

[0074] [In-vehicle system] FIG. 13(A) is a schematic view of a mobile device 10 and an imaging device 20 (in-vehicle camera) held by the mobile device 10 according to an embodiment of the present invention. FIG. 13(A) shows a case where the mobile device 10 is an automobile (vehicle). The mobile device 10 includes an in-vehicle system (driving support device) (not shown) for assisting a user 40 (such as a driver or a passenger) of the mobile device 10 using an image acquired by the imaging device 20. In the present embodiment, a case where the imaging device 20 is installed so as to image the rear of the mobile device 10 is shown, but the imaging device 20 may be installed so as to image the front, side, etc. of the mobile device 10. Further, two or more imaging devices 20 may be installed at two or more locations on the mobile device 10.

[0075] The imaging device 20 includes an optical system 201 and an imaging unit 210 according to any of the above-described embodiments. The optical system 201 is an optical system (variable-angle lens) having different imaging magnifications for a first angle of view (first field of view) 30 and a second angle of view (second field of view) 31 larger than the first angle of view 30. The imaging surface (light-receiving surface) of the imaging unit 210 includes a first region that images an object included in the first angle of view 30 and a second region that images an object included in the second angle of view 31. At this time, the number of pixels per unit angle of view in the first region is larger than the number of pixels per unit angle of view in the second region excluding the first region. In other words, the resolution of the imaging device 20 in the first angle of view (first region) is higher than the resolution in the second angle of view (second region).

[0076] The optical characteristics of the optical system 201 will be described in detail below. The left diagram in FIG. 13(B) shows the image height y [mm] at each half field angle θ [deg.] on the imaging surface of the imaging unit 210 in the form of contour lines. The right diagram in FIG. 13(B) shows, in a graph, the relationship between each half field angle θ and the image height y (the projection characteristics of the optical system 201) in the first quadrant of the left diagram.

[0077] As shown in FIG. 13(B), the optical system 201 is configured such that the projection characteristics y(θ) are different from each other for an angle of view less than a predetermined half field angle θa and an angle of view greater than or equal to the half field angle θa. Therefore, the increase amount (resolution) of the image height y with respect to the half field angle θ per unit also differs for each angle of view. The local resolution of the optical system 201 is represented by the differential value dy(θ) / dθ of the projection characteristics y(θ) with respect to the half field angle θ. In the left diagram of FIG. 13(B), it shows that the higher the resolution, the larger the interval between the contour lines of the image height y for each half field angle θ. Also, in the right diagram of FIG. 13(B), it shows that the higher the resolution, the larger the slope of the graph of the projection characteristics y(θ).

[0078] In the left diagram of FIG. 13(B), the first region 201a, which is the central region, corresponds to an angle of view less than the half field angle θa, and the second region 201b, which is the peripheral region, corresponds to an angle of view greater than or equal to the half field angle θa. The angle of view less than the half field angle θa corresponds to the first angle of view 30 in FIG. 13(A), and the combined angle of view of the angle of view less than the half field angle θa and the angle of view greater than or equal to the half field angle θa corresponds to the second angle of view 31 in FIG. 13(A). As described above, the first region 201a is a region of high resolution and low distortion, and the second region 201b is a region of low resolution and high distortion.

[0079] Incidentally, the ratio value θa / θmax of the half angle θa to the maximum half angle θmax is preferably 0.15 or more and 0.35 or less, and more preferably 0.16 or more and 0.25 or less. In each of the above-described embodiments, since the maximum half angle θmax = 90° or 60°, for example, the value of the half angle θa is preferably 13.5° or more and 31.5° or less, or 9.0 or more and 21.0° or less. More preferably, the value of the half angle θa is 14.4° or more and 22.5° or less, or 9.6 or more and 15.0° or less.

[0080] When the half angle of the optical system is θ [deg.], the projection characteristic representing the relationship between the half angle θ and the image height y is y(θ), the maximum half angle of the optical system is θmax, and the focal length of the optical system (entire system) is f, the optical system of the present embodiment satisfies the following conditional expression (10).

[0081] 1.0 < f×sin(θmax) / y(θmax) ≦ 1.9 ···(10) By configuring the optical system so as to satisfy the conditional expression (10), it is possible to increase the resolution of the subject image of the angle of view near the optical axis OA while having a wide angle of view.

[0082] More preferably, the numerical range of the conditional expression (10) is set as the following conditional expression (10a).

[0083] 1.0 < f×sin(θmax) / y(θmax) ≦ 1.7 ···(10a) Even more preferably, the numerical range of the conditional expression (10) is set as the following conditional expression (10b).

[0084] 1.0 < f×sin(θmax) / y(θmax) ≦ 1.4 ···(10b) Also, the optical system in the present embodiment preferably satisfies the following conditional expression (11).

[0085] 0.65 < y(θmax / 2) / y(θmax) < 0.85 ···(11) The conditional expression (11) defines the ratio between the image height y(θmax) at the maximum half field angle θmax and the image height y(θmax / 2) at half of the maximum half field angle θmax / 2. By satisfying the conditional expression (11), it is possible to increase the resolution of the subject image in the field angle near the optical axis OA while maintaining a wide field angle.

[0086] More preferably, the numerical range of the conditional expression (11) is set as in the following conditional expression (11a).

[0087] 0.65 < y(θmax / 2) / y(θmax) < 0.83 ···(11a) Even more preferably, the numerical range of the conditional expression (11) is set as in the following conditional expression (11b).

[0088] 0.65 < y(θmax / 2) / y(θmax) < 0.81 ···(11b) As described above, in the first region 201a, the distortion of the optical system 201 is small and the resolution is high. Therefore, a high-definition image can be obtained compared to the second region 201b. Thus, good visibility can be obtained by setting the first region 201a (the first field angle 30) as the area of interest of the user 40. For example, when the imaging device 20 is arranged at the rear part of the moving device 10 as shown in Fig. 13(A), by displaying the image corresponding to the first field angle 30 on the electronic rearview mirror, the user 40 can obtain a natural sense of perspective when gazing at a vehicle behind. On the other hand, for the second region 201b (the second field angle 31), it corresponds to a wide field angle including the first field angle 30. Therefore, for example, when the moving device 10 is reversing, by displaying the image corresponding to the second field angle 31 on the in-vehicle display, the driving support for the user 40 can be performed.

[0089] FIG. 14 is a functional block diagram for explaining a configuration example of the in-vehicle system 2 according to the present embodiment. The in-vehicle system 2 is a system for displaying an image obtained by an imaging device 20 installed behind the moving device 10 to the user 40. The in-vehicle system 2 includes an imaging device 20, a processing device 220, and a display device (display unit) 230. The imaging device 20 has an optical system 201 and an imaging unit 210 as described above. The imaging unit 210 includes an imaging element such as a CCD sensor or a CMOS sensor, generates imaging data by photoelectrically converting the optical image formed by the optical system 201, and outputs it to the processing device 220.

[0090] The processing device 220 includes an image processing unit 221, a display angle determination unit 224 (determination unit), a user setting change unit 226 (first change unit), a rear vehicle distance detection unit 223 (first detection unit), a reverse gear detection unit 225 (second detection unit), and a display angle change unit 222 (second change unit). The processing device 220 is a computer such as a CPU (Central Processing Unit) microcomputer, for example, and functions as a control unit that controls the operations of the respective components based on a computer program. At least one component in the processing device 220 may be realized by hardware such as an ASIC (Application Specific Integrated Circuit) or a PLA (Programmable Logic Array).

[0091] The image processing unit 221 generates image data by performing image processing such as WDR (Wide Dynamic Range) correction, gamma correction, LUT (Look Up Table) processing, and distortion correction on the imaging data acquired from the imaging unit 210. Note that the distortion correction is performed on at least the imaging data corresponding to the second region 201b. This makes it easier for the user 40 to visually recognize the image when it is displayed on the display device 230, and also improves the detection rate of the rear vehicle in the rear vehicle distance detection unit 223. Note that it is not necessary to perform distortion correction on the imaging data corresponding to the first region 201a. The image processing unit 221 outputs the image data generated by executing the above-described image processing to the display angle change unit 222 and the rear vehicle distance detection unit 223.

[0092] The rear vehicle distance detection unit 223 uses the image data output from the image processing unit 221 to acquire information regarding the distance to a rear vehicle included in the image data corresponding to a range that does not include the first viewing angle 30 in the second viewing angle 31. For example, the rear vehicle distance detection unit 223 can detect a rear vehicle based on the image data corresponding to the second region 201b in the image data, and calculate the distance to the host vehicle from changes in the position and size of the detected rear vehicle. The rear vehicle distance detection unit 223 outputs the calculated distance information to the display angle determination unit 224.

[0093] Furthermore, the rear vehicle distance detection unit 223 may determine the vehicle type of the rear vehicle based on data regarding feature information such as the shape and color for each vehicle type, which is output as a result of machine learning (deep learning) based on images of a large number of vehicles. At this time, the rear vehicle distance detection unit 223 may output information regarding the vehicle type of the rear vehicle to the display angle determination unit 224. The reverse gear detection unit 225 detects whether the transmission of the moving device 10 (host vehicle) is in the reverse gear, and outputs the detection result to the display angle determination unit 224.

[0094] The display angle determination unit 224 determines whether to set the angle of view (display angle of view) of the image to be displayed on the display device 230 to the first angle of view 30 or the second angle of view 31 based on the output from at least one of the rear vehicle distance detection unit 223 or the reverse gear detection unit 225. Then, the display angle determination unit 224 outputs to the display angle change unit 222 according to the determination result. For example, when the distance value in the distance information is equal to or less than a certain threshold value (for example, 3 m), the display angle determination unit 224 can determine that the display angle is set to the second angle of view 31, and when it is greater than the threshold value, it can determine that the display angle is set to the first angle of view 30. Alternatively, when the display angle determination unit 224 receives a notification from the reverse gear detection unit 225 that the transmission of the moving device 10 has entered the reverse gear, it can determine that the display angle is set to the second angle of view 31. Also, when the reverse gear is not engaged, the display angle determination unit 224 can determine that the display angle is set to the first angle of view 30.

[0095] Furthermore, when the transmission of the moving device 10 is in the reverse gear, the display angle determination unit 224 can determine that the display angle is set to the second angle of view 31 regardless of the result of the rear vehicle distance detection unit 223. Also, when the transmission of the moving device 10 is not in the reverse gear, the display angle determination unit 224 can determine that the display angle is determined according to the detection result of the rear vehicle distance detection unit 223. Note that the display angle determination unit 224 may change the determination criterion for changing the angle of view according to the vehicle type of the moving device 10 by receiving vehicle type information from the rear vehicle distance detection unit 223. For example, when the moving device 10 is a large vehicle such as a truck, since the braking distance is longer than that of a normal vehicle, it is desirable to set the aforementioned threshold value longer (for example, 10 m) than that of a normal vehicle.

[0096] The user setting change unit 226 is for allowing the user 40 to change the determination criterion for whether to change the display angle to the second angle of view 31 by the display angle determination unit 224. The determination criterion set (changed) by the user 40 is input from the user setting change unit 226 to the display angle determination unit 224.

[0097] The display angle change unit 222 generates a display image to be displayed on the display device 230 according to the determination result of the display angle determination unit 224. For example, when it is determined that the first display angle is 30°, the display angle change unit 222 cuts out a rectangular included angle image (the first image) from the image data corresponding to the first display angle 30° and outputs it to the display device 230. Further, when there is a rear vehicle that satisfies a predetermined condition in the image data corresponding to the second display angle 31°, the display angle change unit 222 outputs an image (the second image) including the rear vehicle to the display device 230. Note that the second image may include an image corresponding to the first region 201a. The display angle change unit 222 functions as a display control unit that performs display control to switch between a first display state in which the display device 230 displays the first image and a second display state in which the display device 230 displays the second image.

[0098] The cutting out of the image by the display angle change unit 222 is executed by storing the image data output from the image processing unit 221 in a storage unit (memory) such as a RAM and then reading out the image to be cut out therefrom. Note that the region corresponding to the first image in the image data is a rectangular region at the first display angle 30° corresponding to the first region 201a. Further, the region corresponding to the second image in the image data is a rectangular region including the rear vehicle at the second display angle 31° corresponding to the second region 201b.

[0099] The display device 230 has a display unit such as a liquid crystal display or an organic EL, and displays the display image output from the display angle change unit 222. For example, the display device 230 includes a first display unit as an electronic rearview mirror disposed above the windshield (front glass) of the mobile device 10, and a second display unit as an operation panel (monitor) disposed below the windshield of the mobile device 10. According to this configuration, the first image and the second image generated from the above-described image data can be respectively displayed on the first display unit and the second display unit. The first display unit may be configured to be able to be used as a mirror when not used as a display, for example, by including a half mirror or the like. The second display unit may also serve as a display of a navigation system or an audio system, for example.

[0100] Note that the mobile device 10 is not limited to a vehicle such as an automobile, and may be a moving body such as a ship, an aircraft, an industrial robot, or a drone. Further, although the in-vehicle system 2 according to the present embodiment is used for displaying an image to the user 40, it is not limited thereto, and may be used for driving support such as cruise control (including a function of following the entire vehicle speed) and automatic driving. Furthermore, the in-vehicle system 2 can be applied not only to mobile devices but also to various devices that utilize object recognition such as an advanced road traffic system (ITS).

[0101] As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist thereof.

[0102] The disclosure of each example includes the following configurations and methods. (Configuration 1) Having a first lens with a negative refractive power, a second lens with a negative refractive power, a third lens with a negative refractive power, a fourth lens with a positive refractive power, an aperture stop, a fifth lens with a positive refractive power, a sixth lens with a negative refractive power, and a seventh lens arranged in order from the object side to the image side, The sign of the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of at least one of the fourth lens and the fifth lens is negative, An optical system, characterized in that the sign of the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of at least one of the third lens and the sixth lens is positive. (Configuration 2) When the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of the fifth lens is dndt5 [10 -6 / °C], and the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of the sixth lens is dndt6 [10 -6 / °C], 1.1 < dndt6 - dndt5 < 11.4 The optical system according to Configuration 1, characterized by satisfying the conditional expression. (Configuration 3) When the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of the third lens is dndt3, and the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of the fourth lens is dndt4, -3.3 < dndt3 - dndt4 < 8.0 The optical system according to Configuration 1 or 2, characterized by satisfying the conditional expression. (Configuration 4) When the focal length of the fifth lens is f5 and the focal length of the sixth lens is f6, -1.5 < f5 / f6 < -0.9 The optical system according to any one of Configurations 1 to 3, characterized by satisfying the conditional expression. (Configuration 5) When the focal length of the third lens is f3 and the focal length of the fourth lens is f4, -1.1 < f4 / f3 < -0.6 The optical system according to any one of Configurations 1 to 4, characterized by satisfying the conditional expression. (Configuration 6) When the focal length of the fourth lens is f4 and the focal length of the optical system is f, 0.4 < f4 / f < 2.0 The optical system according to any one of Configurations 1 to 5, characterized by satisfying the conditional expression. (Configuration 7) When the focal length of the fifth lens is f5 and the focal length of the optical system is f, 0.5 < f5 / f < 1.9 The optical system according to any one of Configurations 1 to 6, characterized by satisfying the conditional expression. (Configuration 8) The second lens is an aspherical lens, When the focal length of the second lens is f2 and the focal length of the optical system is f, -4.0 < f2 / f < -1.0 The optical system according to any one of Configurations 1 to 7, characterized by satisfying the conditional expression. (Configuration 9) When the focal length of the first lens is f1 and the focal length of the optical system is f, -13.7 < f1 / f < -6.8 The optical system according to any one of Configurations 1 to 8, characterized by satisfying the conditional expression. (Configuration 10) The optical system according to any one of Configurations 1 to 9, characterized in that the second lens is an aspherical lens. (Configuration 11) Let the linear expansion coefficient of the lens barrel be α op [10 -6 / °C], and the linear expansion coefficient of the cover material connecting the lens barrel and the imaging device be α co [10 -6 / °C], then 1.00 < α op / α co < 1.40 The optical system according to any one of Configurations 1 to 10, characterized by satisfying the conditional expression. (Configuration 12) The optical system according to Configuration 11, characterized in that the distance from the adhesion part of the cover material and the lens barrel to the imaging surface is smaller than the distance from the first lens to the imaging surface of the imaging device. (Configuration 13) When the half field angle of the optical system is θ [deg.], the projection characteristic representing the relationship between the half field angle θ and the image height y is y(θ), and the maximum half field angle of the optical system is θmax, 1.0 < f × sin(θmax) / y(θmax) ≤ 1.9 The optical system according to any one of Configurations 1 to 12, characterized by satisfying the conditional expression. (Configuration 14) When the half field angle of the optical system is θ [deg.], the projection characteristic representing the relationship between the half field angle θ and the image height y is y(θ), and the maximum half field angle of the optical system is θmax, 0.65 < y(θmax / 2) / y(θmax) < 0.85 The optical system according to any one of Configurations 1 to 13, characterized by satisfying the conditional expression. (Configuration 15) An imaging device comprising the optical system according to any one of Configurations 1 to 14 and an imaging element that images an object through the optical system. (Configuration 16) An in-vehicle system comprising the imaging device according to Configuration 15 and a display device that displays an image obtained based on the output of the imaging device. (Configuration 17) The in-vehicle system according to Configuration 16, wherein the display device has a first display unit that displays a first image corresponding to a first field angle among the images and a second display unit that displays a second image corresponding to a second field angle including the first field angle. (Configuration 18) A mobile device comprising the imaging device according to Configuration 15 and being movable while holding the imaging device.

Explanation of Reference Numerals

[0103] 100 Optical system L11 First lens L12 Second lens L13 Third lens L14 Fourth lens L15 Fifth lens L16 Sixth lens L17 Seventh lens S1 Aperture stop

Claims

1. A first lens with negative refractive power, a second lens with negative refractive power, a third lens with negative refractive power, a fourth lens with positive refractive power, an aperture stop, a fifth lens with positive refractive power, a sixth lens with negative refractive power, and a seventh lens, which are arranged in order from the object side to the image side, The sign of the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of at least one of the fourth lens and the fifth lens is negative, An optical system, wherein the sign of the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of at least one of the third lens and the sixth lens is positive.

2. When the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of the fifth lens is dndt5 [10 －６ / °C] and the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of the sixth lens is dndt6 [10 －６ / °C], 1.1 < dndt6 - dndt5 < 11.4 The optical system according to claim 1, which satisfies the conditional expression.

3. When the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of the third lens is dndt3 and the temperature coefficient of the refractive index with respect to the d-line at 20°C to 40°C of the fourth lens is dndt4, -3.3 < dndt3 - dndt4 < 8.0 The optical system according to claim 1, which satisfies the conditional expression.

4. When the focal length of the fifth lens is f5 and the focal length of the sixth lens is f6, -1.5 < f5 / f6 < -0.9 The optical system according to claim 1, which satisfies the conditional expression.

5. When the focal length of the third lens is f3 and the focal length of the fourth lens is f4, -1.1 < f4 / f3 < -0.6 The optical system according to claim 1, characterized by satisfying the following conditional expression.

6. When the focal length of the fourth lens is f4 and the focal length of the optical system is f, 0.4 < f4 / f < 2.0 The optical system according to claim 1, characterized by satisfying the following conditional expression.

7. When the focal length of the fifth lens is f5 and the focal length of the optical system is f, 0.5 < f5 / f < 1.9 The optical system according to claim 1, characterized by satisfying the following conditional expression.

8. The second lens is an aspherical lens, When the focal length of the second lens is f2 and the focal length of the optical system is f, -4.0 < f2 / f < -1.0 The optical system according to claim 1, characterized by satisfying the following conditional expression.

9. When the focal length of the first lens is f1 and the focal length of the optical system is f, -13.7 < f1 / f < -6.8 The optical system according to claim 1, characterized by satisfying the following conditional expression.

10. The optical system according to claim 1, characterized in that the second lens is an aspherical lens.

11. Let the linear expansion coefficient of the lens barrel be α ｏｐ [10 －６ / °C], and the linear expansion coefficient of the cover material connecting the lens barrel and the imaging element be α ｃｏ [10 －６ / °C], then 1.00 < α ｏｐ / α ｃｏ < 1.40 The optical system according to any one of claims 1 to 10, characterized by satisfying the following conditional expression.

12. The optical system according to claim 11, wherein the distance from the bonding portion between the cover material and the lens barrel to the imaging surface is smaller than the distance from the first lens to the imaging surface of the imaging device.

13. When the half field angle of the optical system is θ [deg.], the projection characteristic representing the relationship between the half field angle θ and the image height y is y(θ), and the maximum half field angle of the optical system is θmax, 1.0 < f × sin(θmax) / y(θmax) ≤ 1.9 The optical system according to any one of claims 1 to 10, characterized in that it satisfies the conditional expression.

14. When the half field angle of the optical system is θ [deg.], the projection characteristic representing the relationship between the half field angle θ and the image height y is y(θ), and the maximum half field angle of the optical system is θmax, 0.65 < y(θmax / 2) / y(θmax) < 0.85 The optical system according to any one of claims 1 to 10, characterized in that it satisfies the conditional expression.

15. An imaging device comprising the optical system according to any one of claims 1 to 10 and an imaging device that images an object through the optical system.

16. An in-vehicle system comprising the imaging device according to claim 15 and a display device that displays an image obtained based on the output of the imaging device.

17. The in-vehicle system according to claim 16, wherein the display device has a first display unit that displays a first image corresponding to a first field angle among the images and a second display unit that displays a second image corresponding to a second field angle including the first field angle.

18. A mobile device comprising the imaging device according to claim 15 and being movable while holding the imaging device.

Images