TWM356934U - Photographic lens and the photographic device using the same - Google Patents

Description

M356934 V. New description: [New technical field] This creation is about a photographic lens and a photographic device using the photographic lens, especially a photographic lens for imaging a subject image and using the photographic lens Photographic device. [Prior Art]

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Conventionally, there are known wide-angle lens lenses that are small, lightweight, and have high weather resistance, which are used in imaging devices such as vehicles, mobile phones, and monitors. Such an illuminating lens images an image of an object to be a subject on a light receiving surface of an photographic element such as a CCD element or a CMOS element (see Patent P. 1). Further, a wide-angle photographic lens having a four-lens structure and achieving miniaturization and lightening is also known (see Patent Documents 2 and 3). 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。. However, in recent years, photographic elements such as CCD elements or CM 〇s elements have seen the rapid development of priming. Accordingly, there is a demand for the photographic lens used for the vehicle, the mobile phone, the monitor, and the camera to be wide-angled and the small aberration is reduced. [New Content] 20 M356934 A creation was proposed in the above-mentioned contents, and its object is to provide two kinds of photographic lenses which are wide-angled and miniaturized and have improved optical performance, and a photographic apparatus using the same. The first photographic lens of the present invention, wherein a first lens having a negative refractive power, a second lens having a negative refractive power, a third lens having a positive power, and a light barrier are provided in order from the object side. And the fourth lens, the third lens, and the fourth lens having positive refractive power are lenses in which at least one lens surface of each lens is aspherical, and the following conditional expression (1) is satisfied: 2-4 < (D4) +D5)/f<5.5 (1); 10 where D4 is the air gap between the second lens and the third lens;

05 · the center wall thickness of the third lens; f: the focal length of the entire lens of the photographic lens Q, the object side lens surface of the second lens, preferably having at least one inflection point in the effective 15 diameter of the lens surface, the lens surface The central part is convex and has a effective circumference. The positive refractive power of P is weaker than the central portion, or the central portion of the lens surface is convex. The effective diameter peripheral portion is concave. The second photographic lens of the present invention includes a second 〇 lens having a negative refractive power and a meniscus lens having a concave surface facing the image side in order from the object side, and the object side lens surface is aspherical, the lens surface The central portion has a convex surface, the positive refractive power of the peripheral portion of the effective diameter is weaker than the central portion, or the central portion of the lens surface is convex, and the second lens having negative optical power at the periphery of the effective diameter has positive refractive power, the object a third lens having an aspherical surface on the side lens surface; a light barrier; and a fourth lens having a positive refractive power and an aspherical surface of the image side lens surface. 4 M356934 The second photographic lens preferably satisfies the following section 2.4<(D4+D5)/f<5.5 (1); ;* where the air between the D4j two lens and the third lens Interval D5. Center wall thickness f of the third lens: focal length of the entire system of the photographic lens. The second lens, preferably the abbe number of the d-line of the music lens, satisfies the following conditional formula (2): "d3<45 (7). The third lens of the formula (7) is preferably such that the focal length π of the third lens satisfies the following condition LO<f3/f<3.〇 (3). 15 ❿ The image side lens surface of the second lens preferably has a concave portion at a central portion of the lens surface, and a negative refractive power at a peripheral portion of the effective diameter is weaker than a central portion. . The object side lens surface of the third lens is preferably such that the central portion of the lens surface is convex and the positive refractive power of the peripheral portion of the effective diameter is weaker than the central portion. The image side lens surface of the third lens preferably has a refractive power at a peripheral portion of the effective diameter which is weaker than a central portion of the lens surface. The object side lens surface of the fourth lens preferably has a concave portion at the center portion of the lens surface and a negative refractive power at the peripheral portion of the effective diameter is stronger than the central portion. The image side lens surface of the fourth lens preferably has a convex portion at a central portion of the lens surface, and a positive refractive power at a peripheral portion of the effective diameter is weaker than a central portion. The combined focal length m of the first lens and the second lens, and the combined focal length f34 of the third lens and the fourth lens preferably satisfy the following conditional expression (sentence: 20 M356934 0.01<|fl2/f34|<0.5.. The distance L ' from the object side lens surface of the first lens to the imaging surface of the photographic lens preferably satisfies the following conditional expression (5): 7 < L / f < 16 ..... (5) The photographic apparatus of the present invention includes: a first photographic lens or a second photographic lens, and a photographic element that converts the optical image formed by the photographic lens into an electrical signal. A lens having a degree of light and a lens having a negative power are lenses that define at least the power on the paraxial axis. 1 "The effective light path of the lens surface" means effective light passing through the lens surface. The diameter of a circle drawn by the intersection of the outermost light (the position farthest from the optical axis) and the lens surface, and the 'effective light passing through the lens surface is the light used for imaging the image of the subject Here, the effective ray diameter of the lens surface and the effective diameter of the lens surface are 15 ^ Further, the effective diameter peripheral portion is a portion which is formed by a point at which the outermost light rays intersect the respective lens faces among the total rays passing through the effective diameter of each lens. "And, "the center portion of the lens surface" The convex surface is such that the positive refractive power of the peripheral portion of the effective diameter is weaker than the central portion. This means that the effective diameter peripheral portion is also convex like the central portion 2〇, and the absolute value of the radius of curvature of the effective diameter peripheral portion is larger than the radius of curvature of the central portion. In the case where the absolute value of the value of the lens surface is convex, the central portion of the lens surface has a negative refractive power, which means that the central portion of the lens surface has a convex surface, and the effective diameter peripheral portion has a concave surface. M356934 progresses, "the central portion of the lens surface is concave". The effective power of the peripheral portion of the effective diameter is weaker than the center and the portion." This means that the peripheral portion of the effective diameter is also concave like the central portion. The radius of curvature of the peripheral portion of the effective diameter. When the absolute value of the radius of curvature value of the absolute portion of the value is large, the center of the lens surface is concave, and the positive refractive power is present at the periphery of the effective diameter. i means the center of the lens surface. It is concave; is convex edge portion of the case are text Mu weeks.

The power of the peripheral portion of the effective diameter is weaker than the refractive power at the central portion of the lens surface. This means that the peripheral portion of the effective diameter is convex like the central portion, and the positive refractive power of the peripheral portion is weaker than the central portion. Or the effective diameter circumference = also as the center portion is concave, and the negative refractive power at the peripheral portion of the effective diameter is weaker than the central portion. The central portion of the lens surface is concave, and the negative refractive power of the effective diameter peripheral portion is stronger than that of the portion. This means that the effective diameter peripheral portion is also concave as the center portion, and the absolute value of the radius of curvature of the effective diameter peripheral portion is The case where the absolute value of the half value of the curvature of the center portion is smaller than this. The radius of curvature of the middle portion is the radius of curvature of the lens surface at the position where the lens surface intersects the optical axis. Further, the reason why the curvature radius value is expressed in absolute value is to clarify the magnitude relationship of the radius of curvature. According to the present invention, the first photographic lens and the photographic device using the photographic lens include, in order from the object side, a first-head mirror having a negative refractive power, a second lens having a negative refractive power, and having The third lens of the positive power, the light and the fourth lens having the positive power, the second lens, the third lens, and the M356934 fourth lens are lenses in which at least one lens surface of each lens is aspherical, and the condition is satisfied. Formula (1): 2.4 < (D4 + D5) / f < 5.5, so that the optical performance can be improved while widening and miniaturization can be achieved. By arranging the negative first lens and second lens on the most object side, The lens 5 can capture a light incident from a large viewing angle, and can be wide-angled. By using at least one side surface of the second lens as an aspherical surface, the aberration can be well corrected, and the lens system can be miniaturized. In the second lens, the on-axis ray and the off-axis ray are separated. Therefore, if the lens is aspherical, it is advantageous in terms of positive aberrations, and correction of the sag is relatively easy. In addition, the on-axis and off-axis rays of the first lens It is separated, but as a material of the first lens U disposed on the most object side of the lens system, a glass material as described later is preferably used. Further, the first lens becomes the largest aperture lens in the lens system. It is preferable to use a second lens which is easy to apply a plastic material as an aspherical lens, and it is preferable to perform lens correction and image aberration correction. Further, the third lens and the fourth lens are all set to at least a side surface. The lens having a positive refractive power of the aspherical surface can accurately correct the field curvature and the coma aberration while minimizing the lens system by arranging the diaphragm between the third lens and the fourth lens. According to the second photographic lens of the present invention and the photographic apparatus using the photographic lens, the first lens having a negative refractive power and a meniscus lens having a concave surface toward the image side is included in order from the object side; The mirror surface is aspherical, the central portion of the lens surface is convex, and the positive power of the effective diameter peripheral portion is weaker than the middle portion, or the central portion of the lens surface is convex, and is effective at the M356934 diameter circumference. a second lens having a negative refractive power; a third lens having a positive refractive power, an aspherical surface of the object side lens surface; a light barrier; and a fourth lens having a positive optical coke and an aspherical surface of the image side lens surface, It is possible to increase the optical performance while wide-angle and miniaturization. 5. By arranging the negative first lens and the second lens on the most object side, it is possible to capture light incident from a large angle of view and wide-angle. . towel and 'the first lens is set to have a negative power on the object side and the concave surface φ 帛 to the image side of the 'moon-shaped lens, and can be set to small and small, can be in the wide view, the full range of angles The range corrects the image plane curvature. Further, by arranging at least one side surface of the second lens as an aspherical surface, γ can well correct the aberrations, and the lens system can be miniaturized. In the first lens, the on-axis ray and the axis The external light is separated. Therefore, if the transparency is set to be aspherical, it is advantageous in correcting the aberration, and it is easier to correct. 15 In addition, the on-axis ray and the off-axis ray of the first lens are also separated, but #为为最最的眼系的系统The material of the first lens on the object side is made of a glass material as described later. Moreover, the 'first lens' becomes the largest aperture lens in the lens system. In these cases, it is preferable to use the second lens which is easy to apply the plastic material as the aspherical lens, and to make the lens and the aberration correction 20. By making the side surface of the second lens aspherical, it is easy to reduce the size and wide angle of the lens system. Further, by forming the object side surface of the second lens as a convex portion at the center of the lens surface, the positive refractive power of the effective diameter peripheral portion is weaker than the central portion or the central portion of the lens surface is convex, at the effective diameter periphery M356934 = (4) The surface of the power is easy to make the lens system compact, wide-angled, and the same, and the field curvature can be corrected well. Further, the third lens and the fourth lens are all disposed at least with a side surface that is aspherical, with a positive well order, and a Thai lens that transmits a light intercept to the third lens. The lens system can be miniaturized while accurately correcting the curvature of field and the shoe-shaped aberration between the four lenses. By making the surface on the side of the third lens object aspherical, the positive image plane can be bent. By making the surface on the fourth lens image side aspherical, it is possible to satisfactorily correct field curvature and coma aberration. [Embodiment] Hereinafter, an embodiment of an image pickup lens of the present magazine and an image pickup apparatus using the same will be described in detail with reference to the drawings. Fig. 15 is a cross-sectional view showing a schematic configuration of an image pickup apparatus using the image pickup lens of the present invention. Fig. 2 is a view in which an auxiliary line or the like for explanation is added to the figure. The illustrated photographing lens 20 is a wide-angle lens used for an in-vehicle or anti-theft photographing apparatus for photographing a surrounding situation outdoors. The image of the subject is imaged on the light-receiving surface Jk of the photographing element 1A made of CCD4CM〇s, etc. The photographing element 10 converts the optical image formed by the photographing lens 2 into an electrical signal to obtain a representation. First, the basic structure of the photographic lens 20. The photographic lens 20 includes, in order from the object side along the optical axis Z1, a first lens u, a second 10 M356934 lens L2, and a third The lens (1) aperture stop & and the fourth lens component Cg 1. Further, in the case where the lenses of the first lens L1 to the fourth lens L4 are single lenses, the lenses are not limited thereto. In the case of the single lens, it is also possible to use a light-receiving surface Jk of the image sensor 1A on the image forming surface R12 on which the object image indicating the object is imaged by the image pickup lens 20.

Further, when an imaging lens is applied to the imaging device, a glass cover, a low-pass chopper, an infrared ray 10 cut filter, or the like is preferably disposed in accordance with the camera-side structure of the loading lens, and it is shown in the figure that these will be performed. The example in which the rear parallel flat optical member Cgl is disposed between the lens system and the photographing element 1A is assumed. Further, instead of arranging a low-pass filter between the lens system and the imaging element, or cutting off various filters of a specific wavelength range, etc., these are disposed between adjacent lenses among the first lens I5 and the fourth lens L4. Various filters are also available. Alternatively, a coating layer having the same function as that of the various filters may be applied to any of the first lens L1 to the fourth lens [4]. Further, the symbols R1 to R12 in Fig. 1 refer to the following structural elements. That is, R1 and R2 represent the object side lens surface and the image side lens surface of the first lens L1, R3 20 and R4 represent the object side lens surface and the image side lens surface of the second lens L2, and R5 and R6 represent the third lens L3. The object side lens surface and the image side lens surface, R7 represents the position of the aperture stop Bar St, r8*R9 represents the object side lens surface and the image side lens surface of the fourth lens L4, and R10 and R11 represent the object side surface of the optical component Cgl. And the image side surface, R12 is an image plane Jk indicating the photographic lens 20. 11 M356934 The range from the center of the parent to the periphery of the effective diameter is smooth (4). The curved surface is formed by (4) mirror surface and is a lens surface that does not have a discontinuous field such as a step. In the case of the photographic lens 20, the first read error Tia*ir& L lens has a negative power, the second lens L2 has a negative power. The third lens L3 has a positive power, and the fourth lens Μ has a positive focus. degree. Further, in the photographic lens 2G, at least one lens surface of each of the second lens L2' of the third lens L3 and the first lens L4 is aspherical. Further, 'the air gap 〇4 between the second lens and the third lens, the center thickness D5 of the third lens, and the focal length f of the entire system of the photographic lens satisfy the conditional expression (1): 2.4 < (D4 + D5) / f < 5.5 . As described above, the photographic lens 2 〇 ' configured to satisfy the conditional expression (1) or the like can satisfactorily correct spherical aberration, distortion, and aberration, and can obtain a longer rear intercept. Further, the viewing angle can be set large, so that sufficient optical performance can be obtained. Further, the back intercept is the distance from the image side lens surface R9 of the fourth lens £4 to the image plane R12 (air conversion length). When the value of (D4 + D5) / f exceeds the upper limit of the conditional expression (1), the diameter of the first lens L1 disposed on the object side becomes large, and the total length of the imaging lens also becomes long, so that it is difficult to downsize. On the other hand, if the value of (D4 + D5) / f exceeds the lower limit of the conditional expression (1), spherical aberration and coma aberration are not satisfactorily corrected, and it is difficult to form a lens system which is bright (f value is small). Further, the 'photographic lens 2' is constructed as follows. 12 M356934 That is, the photographic lens 20 includes, in order from the object side along the optical axis Z1, a first lens L1, a second lens L2, a third lens L3, an aperture stop St, a fourth lens L4, and the first lens L1. It has a negative power and is a meniscus lens whose concave surface faces the image side (the arrow + Z direction side in the figure). 5 The second lens L2 has an aspherical surface on the object side (the arrow-z direction side in the drawing), and the central portion of the lens surface R3 has a convex surface, which is effective only for the circumference. The positive power of p is weaker than the central portion, or the central portion of the lens surface has a convex surface 'having a negative refractive power at the peripheral portion of the effective diameter. The third lens surface L3 has positive refractive power, and the object side lens surface R5 has an aspherical surface. The fourth mirror 10 L4 has a positive power and the image side lens surface R9 is aspherical. Further, the central portion of the lens surface is a portion on the lens surface where the lens surface and the optical axis intersect. In the following description, the description will be given of the case where the center of the lens face 3 is convex, and the positive refractive power of the peripheral portion of the effective diameter is weaker than the central portion. Specifically, when the lens surface R5 described later is described in the same manner, reference is made to Figure 2 illustrates. In addition, the symbol planes used in the description of the lens surface other than the lens surface R5 are omitted. The above-mentioned "the center of the lens surface R3 is convex, and the positive refractive power of the peripheral portion of the effective diameter is weaker than the central portion (hereinafter referred to as the lens surface R3)" is as follows. In other words, a point at which the normal surface of the lens surface having the convex portion (having a positive refractive power) at the center of the effective diameter is intersected with the optical axis Z1 at the point where the normal line H3 intersects the optical axis Z1, and the point χ3 and the intersection point p3 are connected. The length of the line segment _3_ρ3 is set to the absolute value of the radius of curvature of the lens surface R3 of the point X3. Further, the intersection of the lens surface R3 and the light 13 M356934 axis Z1 is defined as the center portion C3. In such a case, the lens surface R3 is an embodiment in which the lens surface R3 is convex on the optical axis Z1 (center portion C3) and has positive refractive power, and the center of curvature E3 and the intersection of the central portion C3 of the lens surface R3 Both sides of P3 are closer to the image side than the center portion C3, and the length of the line segment _3_ρ3 is 5 degrees (the absolute value of the radius of curvature R3X at the point X3 of the lens surface R3) is larger than the radius of curvature R3c at the center portion C3 of the lens surface R3. The absolute value is greater. Further, the central portion of the lens surface R3 has a convex surface and has a negative refractive power at the peripheral portion of the effective diameter, which means that the center of curvature E3 of the central portion C3 on the lens surface R3 is closer to the image side than the central portion C3, and the intersection point p3 is larger than the center portion. . More on the side of the object. 10, by making the second lens object side surface R3 aspherical, and the central portion of the lens surface is convex, the positive power of the effective diameter peripheral portion is weaker than the central portion, or the central portion of the lens surface R3 is convex, effective The peripheral edge portion of the diameter has a negative refractive power ′, and the lens system can be easily miniaturized and widened, and the field curvature can be satisfactorily corrected. 15 20 The photographic lens of this creation satisfies any of the above two basic structures, and both of the above two basic structures may be satisfied. According to the basic configuration of the photographic lens, the optical performance of the photographic lens can be improved while the photographic angle and the size of the photographic lens are improved, and the substantially further defined structural elements provided for the photographic lens 2 及其These structural elements, which are defined by the basic structure for further steps, are not essential structures in the present invention. The following conditional expressions (7) to (10) which define the basic structure of the photographic lens, and their actions and effects will be described below. In addition, the photographic lens created by the δ month may satisfy only one of the conditional expressions (2) to (丨2), or may satisfy two or more combinations of the conditional expressions (2) to (12). . Further, 'the meanings of the parameters indicated by the symbols in (2) to (12) are summarized as follows: 5 f: the focal length of the entire system of the photographing lens, that is, the combined focal length of the first lens L1 to the fourth lens L4; f2 : focal length of the second lens; ^ f 3 : focal length of the third lens; f12: composite focal length of the first lens and the second lens; 10 f34. composite focal length of the second lens and the fourth lens; D1: first lens Center thickness; D3: center thickness of the second lens; D4: air gap of the second lens and the third lens; D5: center thickness of the third lens; 15 D7. air gap of the aperture stop and the fourth lens; R4c The radius of curvature of the central portion of the image side lens surface of the second lens; _ ^d3: the Abbe number of the d-line of the third lens; L: the distance from the object-side lens surface of the first lens to the imaging surface. Here, the distance L value is a value obtained by adding a value indicated by a real length other than the post-intercept amount of the back-intercept amount by the air-converted length. Further, the back intercept Bf is a distance (length in air conversion) from the image side lens surface R9 of the fourth lens L4 to the image plane R12. N1 : refractive index of the first lens to the d line; 15 M356934 ED : effective light path of the image side lens surface R2 of the first lens l 1 , that is, light passing through the image side lens surface R2 of the first lens L1 The diameter of a circle drawn by the intersection of the outermost light ray VI and the lens surface R2 (see FIG. 2). Further, the "effective ray path of the lens surface" means the diameter of a circle drawn by the intersection of the light rays passing through the outermost side (the position farthest from the optical axis) and the lens surface among the effective rays passing through the lens surface. Moreover, the effective light passing through the above-mentioned lens surface is the light used for imaging the image of the subject. Here, the effective ray diameter of the lens surface coincides with the effective diameter of the lens surface. Further, the above-mentioned "effective diameter peripheral portion of the lens surface" is a portion which is formed by each point on the lens surface which passes through the outermost light among the effective rays passing through the lens surface, and means the circumference of the effective diameter. on. ◊ Conditional expression (2): ^ d3 < 45 is an expression relating to correction of magnification chromatic aberration and the like. When the conditional expression (2) is satisfied, the chromatic aberration of magnification is easily corrected satisfactorily. However, if it is out of the range of the conditional expression (2), it is difficult to correct the magnification color image and the magnification chromatic aberration is further corrected. As long as the Abbe number u d3 of the line of the third lens satisfies the following conditional expression (2_2) Then: 20 P <32 ......(2-2). As long as the third lens can be: In addition, in order to suppress the chromatic aberration of magnification to the minimum, the Abbe number of the d line ^ 3 satisfies the following conditional expression (2-3), that is, v d3 < 28 (2) -3). 16 M356934 Preferably, the Abbe number of the d-line forming the first lens and the second lens material is set to gamma, whereby the occurrence of the color image i can be suppressed, and good resolution performance is obtained. 5 In the third, fifth, and sixth examples to be described later, 'the _ three-lens (10) precursor material is a polycarbonate resin manufactured by Teijin Chemical Co., Ltd., panhte (registered trademark) sp, i 5丨6 (product name of the company, and (4) Calling the landing mark) is the landing mark of the company. In this material, the refractive index for the d-line is 1.60 or more', and the Abbe number for the 4-line is as small as 25 5, and the optical distortion is small. By using this material in the third lens L3, the assimilation of the chromatic aberration of magnification can be satisfactorily corrected, and the occurrence of distortion in the molding of the resin material is also suppressed to be small f. By using the photographic lens of the present invention as a photographic image of an inter-pixel photographic element of more than 10,000 megapixels, it is possible to display a good image of an object. ◊Conditional expression (3): 1.0<f3/f<3.0 is an expression regarding aberration correction or assemblability 15 or the like. When the lens system is formed by satisfying the conditional expression (3), the correction of the chromatic aberration of magnification and the lens assembly can be easily performed. When the lens system is formed by the f3/f value exceeding the upper limit of the conditional expression (3), the power of the third lens is weak, and it is difficult to correct the chromatic aberration of magnification. Further, when the f3/f value exceeds the lower limit of the conditional expression (3) to form the lens system 1', the power of the third lens becomes too strong, and the sensitivity to eccentricity becomes difficult to assemble the lens. ◊Conditional expression (4): 0.01<|fl2/f34|<0.5 is an expression regarding aberration correction or the like. 17 M356934 Correction of lens Lee bending or _ aberration if the conditional expression (4) is satisfied. Then, the value of the image surface difficulty angle::|fl2/f34i is set to exceed the upper limit of the conditional expression (4), and if the i=ization, the image plane curvature becomes large, and it is difficult to obtain a good image. When the keratinization is set to exceed the lower limit of the conditional expression (4), the coma aberration can be easily increased, and it is difficult to obtain a good image at the periphery. child. (5): 7<L/f<16 is a wide-angled conditional expression (5) of the formula 10 for miniaturization and wide-angle, etc., and the lens system is configured to achieve miniaturization. However, if L/ is When the f value is set to exceed the upper limit of the conditional expression (5), the wide angle is achieved, but the size of the photographic lens is increased. Further, when the L/f value is set to the lower limit of the conditional expression (5), the size of the photographic lens can be reduced, but it is difficult to achieve wide angle. 15 ◊Conditional expression (6): Port (4) 1々. The column is a formula for correction of aberrations. Further, N1 is a refractive index of the first lens which is four lines as described above. " When the lens system is formed by satisfying the conditional expression (6) to the right, the distortion correction can be easily performed. I and However, when the value of N1 is set to exceed the upper limit of the conditional expression (6), the Abbe number of the lens 2 system becomes small, and the chromatic aberration becomes large. Further, the formation 2 of the lens member also becomes a cause of an increase in the cost of the photographic lens. When the value of N1 is set to exceed the lower limit of the conditional expression (6), in order to achieve production, the curvature of the side surface of the object must be made large, and it is difficult to correct the distortion. 18 M356934 ◊Conditional formula (7): wwuo is a formula for machining correction, etc.丨王 and aberrations If the lens system is formed by satisfying conditional expression (7), good workability and good distortion correction can be coexisted. 5 However, if the ED/R4c value is set to exceed the upper limit of the conditional expression (7), the image side lens surface R4 of the lens is close to the hemisphere and is difficult to process, and the manufacturing cost of the photographic lens is high. It is easy to force the other two. If the r_c value is set to be lower than the conditional (7), the second lens is easily processed, but the distortion cannot be corrected well. The two-piece (8) of 1st class: the heart is about the aberration correction and the wide-angled conditional condition (8) constitutes the lens system', and the correction of the spherical aberration and the good spherical aberration can be coexisted. 15 20 . If the saki is set to exceed the upper limit of the conditional expression (8), it is difficult to correct the spherical aberration. Further, the case f2/m is set to be lower than the negative power of the conditional lens, and it is difficult to widen the angle. The younger brother has a conditional formula (9). 〇.5〇<D3/f<I.5*

Formula such as processability. When the lens system is formed by satisfying the conditional expression (9), the aberration reduction can be suppressed, and the good workability and miniaturization of the second lens L2 can be coexisted. When the right value is set to exceed the upper limit of the conditional expression (9), the lens system ' cannot be miniaturized. Further, in order to prevent an increase in size of the lens system 19 M356934, the image side of the second lens L2 is restricted by the free carpel of the clock surface, and the correction of the change is insufficient. Aspherical shape - Lens L2: The right value of * is set to exceed the lower limit of the condition, and the center thickness 第 of the first telescope L2 is increased. (4) It is small and difficult to process, and the ◊ conditional expression of the photographic lens (1〇). 〇.5〇<Dl/f is an expression relating to impact resistance and the like. When the lens system and the system are configured to satisfy the conditional expression (10), the impact resistance of the first lens in the case of use in, for example, a vehicle or the like can be easily made upward. : When the 1/f value is set to exceed the lower limit of the conditional expression (10), the first lens is thinned and the valley is easily broken. ◊Conditional expression (11): 0.50<D4/f<2 〇 is an expression relating to aberration correction or the like. If the lens system is formed by satisfying the conditional expression (11), the chromatic aberration can be easily corrected. However, if the D4/f value is set to exceed the upper limit of the conditional expression (11), the size of the lens system is increased or it is difficult to correct chromatic aberration. Further, when the D4/f value is set to the lower limit of the conditional expression (11), the chromatic aberration can be satisfactorily corrected, but the image side lens surface of the second lens L2 and the object side lens surface of the third lens L3 are too close. Therefore, the aspherical shape of the image side lens surface R4 of the second lens [2] and the object side lens surface R5 of the third lens L3 are restricted, so that the aberration correction is insufficient. Moreover, it is difficult to assemble, and a ghost image due to reflection between the two lens faces also occurs. ◊Conditional expression (12): 0.05 < D7/f < 0.25 is an expression relating to the size or telecentricity of the photographic lens. 20 M356934 If the lens system is formed by satisfying conditional expression (12), it is easier to cope with the miniaturization of the lens system and good telecentricity. However, when the D7/f value is set to exceed the upper limit of the conditional expression (丨2), the size of the lens system is increased, or the interval between the aperture light 5 and the third lens is made small in order to suppress an increase in the size of the lens system. If the interval between the aperture stop and the third lens is small, the on-axis ray and the off-beam light passing through the lenses of the first lens, the second lens, and the third lens are difficult to separate, and the aberration correction is not good, and It is difficult to correct the distortion. On the other hand, when the D7/f value is set to exceed the lower limit of the conditional expression (12), it is difficult to suppress the incidence angle of the incidence of the optical imaging plane to be small, and it is difficult to form a lens system having a good telecentricity. Hereinafter, structural elements other than the above-described conditional expressions that define the photographic lens, and their actions and effects will be described. 15 20 ◊ Regarding the definition of the relevant structural elements of the first lens, the photographic lens used in the strict environment of the car-mounted lens or the surveillance camera lens is preferably used as the first lens for water resistance, acid resistance, and chemical resistance. Good material. The material of the film is formed of a material of the first lens, preferably a material having a water resistance of from 1 to 4 grades using a powder method of the Japanese optical specification. As a material for forming the first lens, it is preferable to use a powder method of the Japanese/Industry specification to have an acid resistance of m to 4 grade 21 M356934. Further, as a material for forming the first lens, a strong material is preferably used. For example, as the material for forming the first lens, a glass material is preferably used, and a transparent ceramic material may be used. By using the first lens !^ as a glass lens, it is possible to produce a photographic lens that is weather-resistant and difficult to break. Further, the present invention is not limited to the case where the first lens L1 is a glass spherical lens. The one lens surface or the side lens φ surface of the first lens L1 may be aspherical. By using the first lens L1 as an aspherical glass lens, it is possible to form an photographic lens which is excellent in water resistance, acid resistance, chemical resistance, and the like, and can more accurately correct aberrations. A glass cover having a protective lens disposed on the object side of the first lens or a hard film having improved weather resistance on the lens surface of the first lens object side may be disposed of a glazed film. When the glass cover or the like is disposed on the object side of the first lens, and the first shovel 15 is configured to be hardly affected by the external environment, the first lens 7 is a plastic aspherical surface. When the first lens is made of a plastic aspherical surface, the image surface, bending, and distortion can be corrected in a good manner. ◊ Definition of the relevant structural element of the second lens Preferably, the image side lens surface R4 of the second lens L2 is also aspherical. Preferably, the lens surface R4 has a concave portion at a central portion thereof, and a negative refractive power at a peripheral portion of the effective diameter is weaker than a central portion. The above-mentioned "the central portion of the lens surface R4 has a concave surface, and the negative refractive power at the peripheral portion of the effective diameter is weaker than the central portion" (hereinafter, also referred to as an embodiment of the lens scale 4) is as follows. 22 M356934, that is, the point at which the normal line H4 of the point X4 of the lens surface R4 having the concave portion (having a negative refractive power) at the central portion of the effective diameter intersects the optical axis Z1 is defined as the intersection point P4'. The length of the line segment X4-P4 with the intersection point P4 is set to the absolute value of the radius of curvature of the point X4 of the lens surface R4. Further, the intersection of the lens surface R4 and the light 5 axis Z1 is defined as the center portion C4. In such a case, the lens surface R4 is an embodiment in which the lens surface R4 has a concave surface (having a negative refractive power) on the optical axis Z1 (the central portion C4), and a curvature center E4 of the central portion C4 of the lens surface R4 and Both sides of the intersection point P4 are closer to the image side than the center portion C4, and the length of the line segment X4-P4 (the absolute value of the radius of curvature R4X at the point X4 of the lens surface R4) is larger than the curvature of the center portion C4 of the lens surface R4. The absolute value of the radius R4C is larger. As described above, "the lens surface R4 is formed such that the central portion C4 has a concave surface (having a negative refractive power), and the negative refractive power at the peripheral portion of the effective diameter is weaker than the central portion C4", so that the peripheral light is not sharply curved. The light is collected in the state, so that the distortion can be corrected well. Further, the object side lens surface R3 of the second lens L2 has at least i inflection points in the effective diameter of the lens surface R3, and the central portion C3 of the lens surface R3 is convex, and the positive optical focus of the effective diameter peripheral portion Χ3 The degree is weaker than the center portion, or the center portion C3 of the lens surface R3 is convex, and the effective diameter peripheral portion 乂3 is concave. Also, "5J* 〇20 transmits the second lens object side surface to be aspherical, and the lens surface R3 The effective diameter has at least one inflection point, and the central portion of the lens surface is convex. The positive refractive power of the effective diameter peripheral portion Χ4 is weaker than the central portion; or the central portion C43 of the lens surface R3 is convex φ, and the effective diameter peripheral portion The illusion is concave, and thus, the 23 M356934 can easily reduce the lens system and widen the angle, and bend the surface well. Further, the radius of curvature of the point X3 on the effective diameter peripheral edge portion of the object-side lens surface of the second lens L2 is set to R3x, and the radius of curvature of the central portion 〇 where the lens surface is intersected with the light extraction 5Z1 is set. In the case of ..., the absolute value of the curvature half position R3x is preferably a value greater than or equal to u of the absolute value of the curvature radius R3c, and the absolute value of the curvature radius R3X is set to a value of 1.2 or more of the absolute value of the curvature radius. It is easy to widen the angle of view, and the curvature of field can be corrected well. 1〇 and the radius of curvature of the effective diameter peripheral portion of the image side lens surface R4 of the first lens 1" 2 = point X4 is R4x 'the middle of the phase of the lens surface R4 and the optical axis When the radius of curvature is R4C, the absolute value of the radius of curvature R4x is preferably 15 times or more the absolute value of the radius of curvature R4c. The distortion can be satisfactorily corrected by setting the absolute value of the radius of curvature R4x to a value of 1.5 times or more of the absolute value 15 of the radius of curvature R4c. ◊ Definition of the relevant structural element of the second lens Preferably, the object side lens surface R5 of the third lens L3 is aspherical. Preferably, the lens surface R5 has a convex portion at the center portion, and the positive refractive power of the peripheral portion of the effective diameter is weaker than the central portion. As shown in FIG. 2, the center portion of the lens surface R5 has a convex surface, and the positive refractive power of the effective edge circumference σ卩 is weaker than the central portion (hereinafter, also referred to as an embodiment of the lens surface R5). . That is, the point where the normal line 55 of the point surface 5 of the lens surface 5 having the convex portion (having a positive refractive power) at the central portion of the effective control periphery intersects the optical axis 设为1 is set to 24 M356934, and the intersection point P5' will be connected to the point χ5. The length of the line segment ρ5ρ5 of the intersection point p5 is set to the absolute value of the radius of curvature of the point X5 of the lens surface R5. Further, the parent point of the lens surface R5 and the optical axis Z1 is referred to as a central portion C5. In such a case, the lens surface R5 is a lens surface R5 having a convex surface 5 (having positive refractive power) on the optical axis z 1 (center portion 匸 5), and a curvature of the central portion C5 of the lens surface R5. Both the center E5 and the intersection point P5 are closer to the image side than the center portion (^, and the length of the line segment ρ5ρ5 (the absolute value of the radius of curvature R5x at the point Χ5 of the lens surface R5) is larger than the center portion C5 of the lens surface R5. The absolute value of the radius of curvature R5c is larger. In addition, a circle Spl centering on the intersection point P5 and having a radius length of 10 as the length of the line segment X5-P5 is shown in the figure. Moreover, the center of curvature E5 is shown in the figure. The circle Sp2 whose center length is the absolute value of the radius of curvature R5c. As described above, the lens surface R5 is formed such that the central portion C5 has a convex surface (having a positive refractive power) and a positive light at the peripheral portion of the effective diameter. The power is weaker than the center portion 15, and the field curvature can be corrected well. Preferably, the image side lens surface R6 of the third lens L3 is also aspherical. β For the lens surface R6, preferably, The power of the peripheral portion of the effective diameter of the mirror surface R6 is larger than the central portion of the lens surface R6. The above-mentioned "the refractive power of the peripheral portion of the effective surface of the lens surface R6 is weaker than the refractive power of the central portion of the lens surface 20 R6 (hereinafter, also referred to as an embodiment of the lens surface R6)" The configuration is such that the point at which the normal line H6 of the point X6 on the effective diameter peripheral edge portion of the lens surface R6 intersects the optical axis Z1 is defined as the intersection point P6', and the length of the line segment X6-P6 of the joint point X6 and the intersection point P6 is set. The absolute value of the radius of curvature of the point X6 of the lens surface R6 is 25 M356934. The intersection of the lens surface R6 and the optical axis Z丨 is defined as the center portion c6. In the case of the above, the lens surface R6 is an embodiment of the lens surface. Both the center of curvature E6 and the intersection point P6 of the center portion C6 of R6 are located on the object side or the image side with respect to the center portion C6, and the length of the line segment χ6_ρ6 (the absolute value of the radius of curvature R6x at the point 5 X6 of the lens surface R6) The absolute value of the radius of curvature R6c is larger than the central portion C6 of the lens surface R6. As described above, the image side lens surface R6 of the third lens L3 is set as the power of the effective diameter peripheral portion of the lens surface R6. Better than the power of the central portion of the lens surface R6' Spherical aberration and field curvature. 10 Further, the curvature radius of the point X5 on the effective diameter peripheral edge portion of the object side lens surface R5 of the third lens L3 is R5x, and the lens surface R5 intersects with the optical axis Z1. When the radius of curvature of the center portion C5 is r5c, the absolute value of the radius of curvature R5x is preferably a value equal to or greater than twice the absolute value of the radius of curvature R5c. The absolute value of the radius of curvature R5x is set to the absolute value of the radius of curvature R5c. The image-side curvature can be well corrected by a value of 12 times or more. ◊ Regarding the definition of the structural element of the fourth lens, the object-side lens scale 8 of the fourth lens L4 is preferably aspherical. Preferably, the lens surface R8 has a concave portion at the center portion, and the negative refractive power of the peripheral portion of the effective diameter is weaker than the central portion. In the above-mentioned "the central portion of the lens surface R8 is concave", the structure in which the negative refractive power of the effective diameter peripheral portion is weaker than the central portion (hereinafter, also referred to as an embodiment of the lens scale 8) is as follows. That is, the point F A at which the normal line H8 of the point X8 on the effective diameter peripheral edge portion of the lens surface R8 having the concave portion (having a negative refractive power) intersects the optical axis Z1 is 26 M356934 point P8, and the joint point X8 is connected. The length of the line segment X8-P8 of the intersection point P8 is set to the absolute value of the radius of curvature of the point X8 of the lens surface R8. Further, the intersection of the lens surface r8 and the optical axis Z1 is referred to as a central portion C8. In such a case, the embodiment of the lens surface R8 is such that the lens surface Rg has a concave surface 5 (having a negative refractive power) on the optical axis z 1 (the central portion c8), and a curvature of the central portion C8 of the lens surface R8. Both the center E8 and the intersection point P8 are closer to the object side than the center portion C8, and the length of the line segment X8_P8 (the absolute value of the radius of curvature R8X at the point X8 of the lens surface R8) is larger than the curvature at the center portion C8 of the lens surface R8. The absolute value of the radius R8c is smaller. As described above, "the lens surface R8 has a concave portion (having a 10-negative power) as the central portion c 8 and the negative refractive power at the peripheral portion of the effective diameter is stronger than the central portion C8, so that the 彗 image can be satisfactorily corrected. difference. Preferably, the image side lens surface R9 of the fourth lens L4 is also aspherical. Preferably, the lens surface R9 has a convex portion at the center portion, and the positive refractive power of the peripheral portion of the effective diameter is weaker than the central portion. In the above-mentioned structure, the center portion of the lens surface R9 is convex, and the positive refractive power of the peripheral portion of the effective diameter is weaker than the central portion (hereinafter, also referred to as the lens surface R9). That is, the point at which the normal line H9 of the point X9 on the effective diameter peripheral edge portion of the lens surface R9 having the convex portion (having the positive refractive power) intersects the optical axis 21 is referred to as the intersection point P9, and the joint point X9 and The length of the line segment _9_ρ9 of the intersection point P9 is set to the absolute value of the radius of curvature of the point X9 of the lens surface R9. Further, the intersection of the lens surface R9 and the optical axis Z1 is defined as the center portion C9. In such a case, the lens surface R9 is an embodiment in which the lens surface R9 has a convex surface (having a positive refractive power) on the optical axis Z1 (the central portion C9), and a curvature center E9 of the central portion C9 of the lens surface R9 and the intersection 27 M356934 Both points P9 are closer to the object side than the center portion C9, and the length of the line segment _9_ρΜ々 (the absolute value of the radius of curvature Rx9 at the point χ9 of the lens surface R9) is larger than the radius of curvature of the center portion C9 of the lens surface R9. The absolute value of Rc9 is larger. As described above, "the lens surface R9 has a convex portion as the center portion C9, and the positive refractive power at the peripheral portion of the effective axis is weaker than the central portion C9, so that the field curvature and the coma aberration can be satisfactorily corrected. Further, the radius of curvature of the point X9 on the edge portion of the effective-diameter circumference of the image-side lens surface R9 of the fourth lens [4] is set to R9x, and the center portion C9 where the lens surface R9 and the light-axis 21 intersect When the radius of curvature is set to R9c, the absolute value of the curvature radius R9x is preferably 丄2 times or more of the absolute value of the curvature radius R9c. By setting the absolute value of the curvature radius R9x to a value of 1_2 times or more of the absolute value of the curvature radius R9c, the spherical aberration and the image plane curvature can be satisfactorily corrected. In this way, each lens surface from the object side lens surface 3 of the second lens L2 to the image side lens surface R9 of the fourth I5 lens L4 is set to have the aspherical shape as described above, and the spherical aberration and the image plane curvature are removed. In addition to 彗 像 aberration, it can also be good _ to correct distortion. ◊ Definition of other structural elements The aperture stop St is preferably disposed between the third lens 匕3 and the fourth lens M20. The aperture stop St is arranged in the third lens. The entire lens system can be miniaturized with the fourth lens ’. 28 M356934 In the photographic lens _, when the glass cover or the like is not disposed on the object side of the first lens, the first lens L1 is preferably set as a glass lens, and the second lens L2 and the third lens are £3, The four lenses are set as plastic lenses. By setting the material of the second lens L2 to the fourth lens L4 to plastic, the aspherical shape can be accurately reproduced. Moreover, the lens system can be produced at low cost. As a material for forming each of the plastic lenses from the second lens L2 to the fourth lens L4, a so-called nanocomposite in which particles smaller than the wavelength of light are mixed with respect to the resin material may be used. Each of the lenses of the first lens L1 to the fourth lens L4 is not limited to being made of a material having a refractive index of 10 Å, and any one or more of the four lenses may be a refractive index distribution type lens. The respective lenses of the first lens L2 to the fourth lens L4 are not limited to the case where one or both surfaces are aspherical, and may be formed as a diffractive optical surface. In other words, the diffractive optical element may be formed on any one or more lenses 15 from the first lens L2 to the fourth lens L4. When the light beam passing through the effective light path of the first lens L1 or the second lens L2 becomes stray light and reaches the imaging surface, there is a phenomenon of ghost image, but it is preferably effective on the first lens L1 or the second lens L2. The light-shielding plates Sk 1 and Sk 2 (see FIGS. 1 and 2 ) of the light-shielding means are provided in the field outside the light-diameter, and the stray light is blocked. The shading means may be configured by disposing a sheet which blocks light in an area outside the effective light path of the lens, or a structure of a film made of a light-shielding paint on an area outside the effective light path of the lens. 29 M356934 Further, a space between the first lens 匕丨 and the second lens L2 may be disposed depending on the need for the light shielding means. Further, the light shielding means may be disposed in the field outside the effective light path on the second lens L2 to the fourth lens, or between these lenses. 5, the transmission from the second lens L2 to the fourth lens L4 is as described above, and when the ideal image height is 2fxtan ( Θ /2), the distortion can be made within ± 10%. . As described above, according to the photographic lens of the present invention, the optical performance can be improved as compared with the conventional wide-angle lens, and the size can be reduced. Next, the numerical data relating to each of the imaging lenses according to the first to sixth embodiments of the present invention will be described with reference to Figs. 3 to 2. 3 to 8 are diagrams respectively showing an embodiment! ~ The schematic structure of the photographic lens of the sixth embodiment. j view. The symbols in Figs. 3 to 8 which coincide with the symbols in Figs. 1 and 2 indicate mutually corresponding structures. 15 to FIG. 14 to FIG. 14A are diagrams showing four data of the imaging lenses of the first to sixth embodiments, respectively. The upper left portion (indicated by the symbol (4) in the drawing) in each of the figures: lens data, in the upper center The part (indicated by the symbol (8) in the figure) indicates the photography penetration = the outline specification. Further, in the lower left portion (the figure is indicated by symbol (4)), each coefficient of the aspherical shape indicating the lens surface shape (aspherical shape) is shown. Lower = (indicated by symbol (4) in the figure) indicates the absolute value of the radius of curvature of the effective peripheral portion of each lens surface. In the respective diagrams of Figs. 9 to 14, the upper left side of F' is taken. The 卩 lens data 1f7 is expressed by the face number of the first ", 2, 3, . . . . . . . . in which the face number of the lens and the like are sequentially increased from the object side toward the image side. In addition, the number of these lenses 30 M356934 also includes the surface number (i=7) on which the aperture control light rest St is loaded, and the surface of the object and the side surface of the image side of the optical component cgi of the parallel plane plate (i) =1〇, 11), the face number of the imaging surface (i=12), etc. Further, the lens surface is aspherical, and the surface number is accompanied by an *. 5 Ri represents the paraxial radius of curvature of the i-th (i=l, 2, 3, ...) plane,

Di(i-1, 2, 3, ...) represents the interplanar spacing on the optical axis zi of the i-th face and the i+1th face. Further, the symbol Ri of the lens data corresponds to the symbol Ri (i = 1, 2, 3, ...) representing the lens surface in Fig. i, and Ndj in each lens data is oriented from the object side. The refractive index of the jth (j = 1, 2, 3, ...) optical element of the image side 10 which is sequentially increased by the side 10 (wavelength 587.6 nm), and Vdj represents the pair of the jth optical element. Abbe number of the d line. Further, the paraxial radius of curvature and the surface spacing of the soap are mm, and the paraxial radius of curvature is positive when the convex surface is toward the object side, and negative when the convex surface is toward the image side. In addition, each aspherical surface is defined by the following aspherical type. [Math 1]

7- Y2/R ϊΐ(Γ^.72/^2)ι/2 +Σ^ζΓ Ζ : aspherical depth (the point on the aspheric surface from the height γ is perpendicular to the optical axis that is in contact with the vertex of the non-2-spherical surface The vertical length of the plane; γ: height (distance from the optical axis) (mm); R: paraxial radius of curvature (mm);

Ai : aspherical coefficient (i = 3 to 2 〇); 31 M356934 κ: conical number. In the outline specifications of the upper center portion in each of Figs. 9 to 14, the following values are shown. Table F values are respectively: Fno., half angle of view: ω, image height: m, back intercept:

Bf (two gas conversion length / m Air), the distance from the object side lens surface of the first lens to the imaging surface: L, the effective ray diameter of the first lens image side: ED, the focal length of the entire lens of the lens (first lens ~ The combined focal length of the fourth lens: f, the focal length of the first lens: fl, the focal length of the second lens: f2, the focal length of the third lens: f3, the focal length of the fourth lens: f4, the first lens, the second lens Synthetic focal length: fl2, composite focal length of the third lens and the fourth lens: the value of f34. The distance L value is a value represented by the air-converted length of the back-intercept amount and a value added by the real length other than the post-intercept amount in the distance L value. 0° 15 20 Further, FIG. 9 to FIG. The lower left portion of each of the graphs 14 indicates that each of the coefficients κ, A3, A4, A 5 ... of the aspherical surface representing each aspherical surface Ri (i = 3, 4) is represented by a significant number of 3 The value after the number of digits is summarized. In the lower right part of each of FIGS. 9 to 14 , IX3-P3 丨, |Χ4-Ρ4|, ... in the "mark" column of the description are corresponding to those described in the specification. The symbol "the length of the line segment Χ3_ρ3 connecting the point X3 and the point p3" and the "length of the line segment X4-P4 of the joint point X4 and the intersection point P4". Fig. 15 is a diagram showing the values of the respective conditional values (丨) to (丨2) in each of the embodiments 1 to 6. 32 M356934 Figs. 16 to 21 are diagrams showing aberrations of the imaging lenses of the embodiment ～ to the sixth embodiment, respectively. Fig. 16 to Fig. 21 show aberrations of the photographic lens of each example for the d line (wavelength 587.6 nm), the plant line (wavelength 486 lnm), and the c line (wavelength 65 6.3 nm), respectively. In addition, in terms of the distortion map, the angle of view of the entire system of the lens is used (using the variable 〇$ 0 $ ω), and the ideal image height is set to 2f>< tan((9 /2), indicating the distance from it Further, the peripheral surface of the effective surface of the lens surface of the lens having the shape of the rotating object is usually a circular shape having a constant distance from the optical axis of the lens. The field of the circular shape becomes an effective field on the lens surface. From the basic data and the aberrations of the examples i to 6, it is understood that the wide-angle imaging lens of the present invention can improve the optical performance by optimizing the shape or material of each of the four lenses. In addition, the gamma creation is not limited to the above-described embodiments and the respective embodiments, and various changes can be made. For example, the curvature radius, the surface interval, and the refractive index value of each lens component are not limited to those shown in the above figures. The value of the photographic lens of the present invention can be made inexpensively by miniaturizing the lens system by using the aspherical surface after the second lens, and the image surface can be corrected step by step. Distortion aberrations, etc. 7 Fig. 22 is a photographing device with the photographic lens of the present invention and the photographic element of the photographic element formed by the photographic lens formed by the photographic lens, φ P & __ The car's picture of the car photographic lens. 5〇2~Γ= 'The car's face lens for the photographic camera is used in the car 501. This car 501 includes: 33 M356934 shadow assistant side The car lens 502 of the exterior photographic lens of the side dead angle range, the car photographic lens of the exterior lens for the rear corner of the car W, and the back of the shirt and the same front as the driver Fig. 1 is a view showing a schematic configuration of an imaging lens of the present invention. Fig. 2 is a view showing an auxiliary line for explaining the same as that of Fig. 1. Fig. 3 is a cross-sectional view showing a schematic configuration of an imaging lens of the first embodiment. Fig. 4 is a cross-sectional view showing a schematic configuration of an imaging lens of the second embodiment. Fig. 5 is a view showing a schematic configuration of an imaging lens of the third embodiment. Sectional view of Figure 6. Figure 6 is a representation Fig. 7 is a cross-sectional view showing a schematic configuration of an imaging lens of Example 5. Fig. 8 is a cross-sectional view showing a schematic configuration of an imaging lens of Example 6. Fig. 9 is a view showing an embodiment of the imaging lens of the embodiment. Fig. 1A is a view showing basic data of the imaging lens of the embodiment 2. Fig. 11 is a view showing basic data of the imaging lens of the embodiment 3. Fig. 12 is a view showing an embodiment. Fig. 13 is a view showing basic data of the imaging lens of the embodiment 5. Fig. 14 is a view showing basic data of the imaging lens of the sixth embodiment. Fig. 15 is a diagram showing the basic data of the imaging lens of the sixth embodiment. The example shows a map corresponding to each parameter value in the conditional expressions (1) to (12). Fig. 16 is a view showing aberrations of the imaging lens of the first embodiment. 34 M356934 FIG. 17A is a view showing aberrations of the imaging lens of Example 2. Fig. 18 is a view showing aberrations of the imaging lens of the third embodiment. Fig. 19 is a view showing aberrations of the imaging lens of Example 4; Fig. 20 is a view showing aberrations of the imaging lens of Example 5; Fig. 21 is a view showing aberrations of the imaging lens of the sixth embodiment. Fig. 22 is a view showing a car on which an in-vehicle photographing lens is mounted.

20 photographic lens L3 third lens S t aperture light shelf Cgl optical component C3, C5 center Spl, Sp2 circle 5 〇 1 car H5 normal X3, X4, X5, X6 point 502, 5 〇 3, 504 car photographic lens [main components Explanation of symbols] 1 〇 photographic element L2 second lens Z1 optical axis

Ski, Sk2 visor P5 intersection L1 first lens L4 fourth lens Jk light receiving surface R5c, R5x radius of curvature E5 center of curvature VI light

The effective ray diameter R1 of the image side lens surface R2 of the ED first lens L1, the object side lens surface R2 of the first lens L1, the image side lens surface R3 of the first lens L1, the object side lens surface R4 of the second lens L2, the second lens L2 Image side lens surface R5 Object side lens surface R6 of third lens L3 Image side lens surface R7 of third lens L3 Position 35 of aperture stop St. M356934 R8 Object side lens surface R9 of fourth lens L4 Fourth lens L4 Image side surface R11 of the side lens surface R10 optical part Cgl Image side surface R12 of the optical part Cgl of the image side Jk

36

Claims (1)

M356934 6. Patent application scope: L—a photographic lens comprising, in order from the object side, a first lens having a negative power; a second lens having a negative power; a third lens having a positive power; a light beam; and a fourth lens having a positive power, 'is a conditional expression of each lens: the second lens, the third lens, and at least one lens surface of the fourth lens are aspherical lenses, and Satisfy with 10 2.4 < (D4 + D5) / f < 5.5, (1); w RJ king rolling interval; D5. #海三第一的第一壁厚; f: the focal length of the entire system of the photographic lens. 15 20 2_ The object-side lens surface of the photographic lens as described in the patent application scope is less convex in the central portion of the lens surface of the lens, and the power is weaker than the center portion, or The surface of the lens. The circumference of the positive 4th diameter is concave. The 卩 卩 凸 凸 凸 凸 凸 凸 凸 凸 凸 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如Lunar lens; 37 M356934 Second lens 'the object side lens surface is aspherical, the central portion of the lens surface is convex, the positive power of the effective diameter peripheral portion is weaker than the central portion, or the central portion of the lens surface is convex 'There is a negative power at the periphery of the effective diameter. The third lens has positive refractive power, and the object side lens surface is aspherical 5; the light shed; and the fourth lens, which has positive power and image side The lens surface is aspherical. 4. The photographic lens according to claim 3, wherein the following conditional expression (1) is satisfied: 10 2.4 < (D4 + D5) / f < 5.5 (1); Medium, D4: an air gap between the second lens and the third lens; D5: a center wall thickness of the third lens; f: a focal length of the entire system of the photographic lens. The photographic lens according to any one of claims 1 to 4, wherein the Abbe number of the d-line of the third lens>d3 satisfies the following conditional expression (2): v d3< The photographic lens of any one of the above-mentioned claims, wherein the third lens has a focal length of £3, which satisfies the following: Conditional formula (3): 1.0 <f3/f<3.〇...(3). 7. The photographic lens according to any one of claims 1 to 4, wherein the image side lens surface of the second lens has a concave portion at a central portion of the effective diameter periphery portion. The negative power is weaker than the center portion. 38 M356934, 8. 纟t-month Patent Range No. 4 to 4, wherein the object-side lens surface of the second lens is convex, and the central portion of the lens surface is convex. The positive power of the peripheral portion of the effective diameter is weaker than the central portion. . 9. The photo lens of claim 3, wherein the image side lens surface of the third lens is: the power of the peripheral portion of the effective diameter is greater than the lens surface The photographic lens according to any one of the items of the fourth aspect, wherein the object side lens surface of the fourth lens is: the lens surface The photographic lens according to any one of the first to fourth aspects of the present invention, wherein the photographic lens is the same as the photographic lens of any one of the above-mentioned items. The image side lens surface of the four lens is: "in the middle of the lens surface." The positive power of the peripheral portion of the effective surface of the main convex surface of the crucible is weaker than the central portion. 12. The photographic lens of any one of claims 1 to 4, wherein the composite focal length fi2 of the first lens and the second lens and the synthesis of the second lens and the fourth lens are The focal length f34 satisfies the following conditional expression (4): 八0.010.01<|fl2/f34|<〇.5 (4). The photographic lens according to any one of claims 1 to 4, wherein a distance L from an object side lens surface of the first lens to an imaging surface of the photographic lens 20 satisfies the following condition Equation (5): 7<L/f<16 (5). A photographic apparatus, comprising: a photographic lens according to any one of claims 1 to 4; and 39 M356934 a photographic element that converts an optical image formed by the photographic lens into an electrical signal.