TW202210899A - Lens assembly - Google Patents

Abstract

A lens assembly includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens is with negative refractive power and includes a concave surface facing an image side. The second lens is with positive refractive power and includes a convex surface facing an object side. The third lens is with positive refractive power. The fourth lens is with negative refractive power. The fifth lens is a meniscus lens with positive refractive power. The sixth lens is with positive refractive power and includes a concave surface facing the imaget side. The first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are arranged in order from the object side to the image side along an optical axis. An air gap is between the third lens and the fourth lens.

Description

Imaging Lens(47)

The present invention relates to an imaging lens.

The development trend of today's imaging lenses, in addition to the continuous development of large apertures, with different application requirements, also needs to have the characteristics of high resolution and resistance to environmental temperature changes. There is another imaging lens with a new structure to meet the needs of large aperture, high resolution and resistance to environmental temperature changes at the same time.

In view of this, the main purpose of the present invention is to provide an imaging lens, which has a smaller aperture value, higher resolution, and is resistant to changes in ambient temperature, but still has good optical performance.

The invention provides an imaging lens including a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens. The first lens has negative refractive power and includes a concave surface facing an image side. The second lens has positive refractive power and includes a convex surface facing an object side. The third lens has positive refractive power. The fourth lens has negative refractive power. The fifth lens is a meniscus lens with positive refractive power. The sixth lens has positive refractive power and includes a concave surface facing the image side. The first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are sequentially arranged along an optical axis from the object side to the image side. An air space is included between the third lens and the fourth lens.

The first lens may further include another concave surface facing the object side, and the second lens may be more It includes another convex surface facing the image side, the third lens is a biconvex lens and includes a convex surface facing the object side and another convex surface facing the image side, the fourth lens is a biconcave lens and includes a concave surface facing the object side and another concave surface facing the image side, The fifth lens includes a concave surface facing the object side and a convex surface facing the image side, and the sixth lens can further include a convex surface facing the object side.

The first lens may further include a convex surface facing the object side, the second lens may further include a concave surface facing the image side, the third lens is a biconvex lens and includes a convex surface facing the object side and another convex surface facing the image side, and the fourth lens is The biconcave lens includes a concave surface facing the object side and another concave surface facing the image side. The fifth lens includes a concave surface facing the object side and a convex surface facing the image side. The sixth lens may further include a convex surface facing the object side.

The imaging lens of the present invention may further include a diaphragm disposed between the third lens and the fourth lens.

The first lens, the second lens and the third lens include at least one glass spherical lens, and the fourth lens, the fifth lens and the sixth lens include at least one glass spherical lens.

The imaging lens satisfies the following conditions: 120<Vd ₁ +Vd ₃ <140; wherein, Vd ₁ is the Abbe coefficient of one of the first lenses, and Vd ₃ is the Abbe coefficient of one of the third lenses.

The imaging lens satisfies the following conditions: 0.4<(f ₃ +f ₄ )/f<0.62; where f ₃ is an effective focal length of the third lens, f ₄ is an effective focal length of the fourth lens, and f is an effective focal length of the imaging lens an effective focal length.

The imaging lens satisfies the following conditions: -7<R ₂₂ /R ₂₁ <48; wherein, R ₂₁ is a curvature radius of an object side surface of the second lens, and R ₂₂ is a curvature radius of an image side surface of the second lens.

The imaging lens satisfies the following conditions: 6mm<f ₄ +f ₆ <12mm; wherein, f ₄ is the effective focal length of one of the fourth lenses, and f ₆ is the effective focal length of one of the sixth lenses.

The imaging lens satisfies the following conditions: 3.9<TTL/BFL<6; wherein, TTL is the distance between the object side of the first lens and an imaging surface on the optical axis, and BFL is the image side of the sixth lens to the imaging surface a distance on the optical axis.

The imaging lens satisfies the following conditions: 0.05<f ₁₂₃ /f ₄₅₆ <0.22; wherein, f ₁₂₃ is the combined effective focal length of one of the first lens, the second lens and the third lens, and f ₄₅₆ is the fourth lens, the fifth lens and the One of the sixth lenses combines the effective focal length.

In order to make the above objects, features, and advantages of the present invention more clearly understood, preferred embodiments are hereinafter described in detail with the accompanying drawings.

1, 2, 3, 4: Imaging lens

L11, L21, L31, L41: The first lens

L12, L22, L32, L42: Second lens

L13, L23, L33, L43: Third lens

L14, L24, L34, L44: Fourth lens

L15, L25, L35, L45: Fifth lens

L16, L26, L36, L46: Sixth lens

ST1, ST2, ST3, ST4: Aperture

OA1, OA2, OA3, OA4: Optical axis

OF1, OF2, OF3, OF4: Filters

CG1, CG2, CG3, CG4: Protective glass

IMA1, IMA2, IMA3, IMA4: Imaging plane

S11, S21, S31, S41: the object side of the first lens

S12, S22, S32, S42: the image side of the first lens

S13, S23, S33, S43: the object side of the second lens

S14, S24, S34, S44: second lens image side

S15, S25, S35, S45: the object side of the third lens

S16, S26, S36, S46: third lens image side

S17, S27, S37, S47: Aperture surface

S18, S28, S38, S48: the object side of the fourth lens

S19, S29, S39, S49: image side of the fourth lens

S110, S210, S310, S410: the object side of the fifth lens

S111, S211, S311, S411: image side of the fifth lens

S112, S212, S312, S412: object side of sixth lens

S113, S213, S313, S413: the image side of the sixth lens

S114, S214, S314, S414: Side of filter object

S115, S215, S315, S415: Filter image side

S116, S216, S316, S416: Protect the side of the glass

S117, S217, S317, S417: Protective glass image side

FIG. 1 is a schematic diagram of a lens configuration and an optical path of a first embodiment of an imaging lens according to the present invention.

FIG. 2A is a field curvature diagram of the first embodiment of the imaging lens according to the present invention.

FIG. 2B is a distortion diagram of the first embodiment of the imaging lens according to the present invention.

FIG. 2C is a Modulation Transfer Function diagram of the first embodiment of the imaging lens according to the present invention.

FIG. 3 is a schematic diagram of the lens configuration and optical path of the second embodiment of the imaging lens according to the present invention.

FIG. 4A is a field curvature diagram of a second embodiment of the imaging lens according to the present invention.

FIG. 4B is a distortion diagram of the second embodiment of the imaging lens according to the present invention.

FIG. 4C is a diagram of the modulation transfer function of the second embodiment of the imaging lens according to the present invention.

FIG. 5 is a schematic diagram of a lens configuration and an optical path of a third embodiment of the imaging lens according to the present invention.

6A is a field curvature diagram of a third embodiment of the imaging lens according to the present invention.

FIG. 6B is a distortion diagram of the third embodiment of the imaging lens according to the present invention.

FIG. 6C is a modulation transfer function diagram of the third embodiment of the imaging lens according to the present invention.

FIG. 7 is a schematic diagram of a lens configuration of a fourth embodiment of the imaging lens according to the present invention.

FIG. 8A is a longitudinal aberration (Longitudinal Aberration) diagram of the fourth embodiment of the imaging lens according to the present invention

FIG. 8B is a field curvature diagram of the fourth embodiment of the imaging lens according to the present invention.

FIG. 8C is a distortion diagram of the fourth embodiment of the imaging lens according to the present invention.

FIG. 8D is a lateral chromatic aberration (Lateral Color) diagram of the fourth embodiment of the imaging lens according to the present invention.

FIG. 8E is a relative illuminance diagram of the fourth embodiment of the imaging lens according to the present invention.

FIG. 8F is a modulation transfer function diagram of the fourth embodiment of the imaging lens according to the present invention.

FIG. 8G is a diagram of a Through Focus Modulation Transfer Function of the fourth embodiment of the imaging lens according to the present invention.

The invention provides an imaging lens, comprising: a first lens with negative refractive power, the first lens includes a concave surface facing an image side; a second lens with positive refractive power, the second lens includes a convex surface facing an object side; a The third lens has positive refractive power; a fourth lens has negative refractive power; a fifth lens with positive refractive power, the fifth lens is a meniscus lens; and a sixth lens with positive refractive power, the sixth lens includes a concave surface facing the image side; wherein the first lens, the second lens , the third lens, the fourth lens, the fifth lens and the sixth lens are sequentially arranged along an optical axis from the object side to the image side; wherein an air space is included between the third lens and the fourth lens.

Among the first lens, second lens, third lens, fourth lens, fifth lens and sixth lens of the aforementioned imaging lens, any two adjacent lenses may have an air gap on the optical axis; that is, , the imaging lens may have six single non-cemented lenses. Since the manufacturing process of the cemented lens is more complicated than that of the non-cemented lens, especially the cemented surface of the two lenses needs to have a high-precision curved surface in order to achieve a high degree of closeness when the two lenses are cemented. Poor adhesion affects the overall optical imaging quality. Therefore, in the imaging lens of the present invention, any two adjacent lenses can have an air gap on the optical axis, which can effectively avoid the problems caused by the cemented lens.

Please refer to Table 1, Table 3, Table 5 and Table 7 below, among which Table 1, Table 3, Table 5 and Table 7 are the correlation of each lens of the first embodiment to the fourth embodiment of the imaging lens according to the present invention, respectively Parameters Table.

Figures 1, 3, 5, and 7 are schematic diagrams of lens configurations of the first, second, third, and fourth embodiments of the imaging lens of the present invention, respectively, wherein the first lenses L11, L21, L31, and L41 have negative refractive power and are made of glass material. The image sides S12, S22, S32, and S42 are concave, and the object sides S11, S21, S31, and S41 and the image sides S12, S22, S32, and S42 are spherical surfaces.

The second lenses L12, L22, L32, and L42 have positive refractive power and are made of glass. The object sides S13, S23, S33, and S43 are convex, and the object sides S13, S23, S33, and S43 and the image sides S14, S24, and S34 , S44 are spherical surfaces.

The third lenses L13, L23, L33, and L43 are biconvex lenses with positive refractive power and are made of glass. The object sides S15, S25, S35, and S45 are convex, and the image sides S16, S26, S36, and S46 are convex, and the object sides are convex. S15, S25, S35, and S45 and the image side surfaces S16, S26, S36, and S46 are all spherical surfaces.

Four lenses L14, L24, L34, L44 are double concave lenses with negative refractive power, made of glass material, the object side S18, S28, S38, S48 are concave, the image side S19, S29, S39, S49 are concave, the object side S18 , S28, S38, S48 and the image sides S19, S29, S39, and S49 are all spherical surfaces.

The fifth lens L15, L25, L35, and L45 are meniscus lenses with positive refractive power and are made of glass material. The object sides S110, S210, S310, and S410 are concave, and the image sides S111, S211, S311, and S411 are convex. The object side surfaces S110 , S210 , S310 and S410 and the image side surfaces S111 , S211 , S311 and S411 are all spherical surfaces.

The sixth lens L16, L26, L36, and L46 are meniscus lenses with positive refractive power and are made of glass material. The object sides S112, S212, S312, and S412 are convex, and the image sides S113, S213, S313, and S413 are concave. The object side surfaces S112, S212, S312, and S412 and the image side surfaces S113, S213, S313, and S413 are all spherical surfaces.

In addition, imaging lenses 1, 2, 3, and 4 satisfy at least one of the following conditions:

120<Vd ₁ +Vd ₃ <140 (1)

0.4<(f ₃ +f ₄ )/f<0.62 (2)

-7<R ₂₂ /R ₂₁ <48 (3)

6mm<f ₄ +f ₆ <12mm (4)

3.9<TTL/BFL<6 (5)

0.05<f ₁₂₃ /f ₄₅₆ <0.22 (6)

Wherein, Vd ₁ is the Abbe coefficient of the first lenses L11, L21, L31, L41 in the first to fourth embodiments, and Vd ₃ is the third lens L13 in the first to fourth embodiments , one of the Abbe coefficients of L23, L33, and L43, _f3 is an effective focal length of the third lens L13, L23, L33, and L43 in the first to fourth embodiments, and _f4 is the first to fourth embodiments In the fourth embodiment, one of the effective focal lengths of the fourth lenses L14, L24, L34, and L44, f6 is one of the effective focal lengths of the _sixth lenses L16, L26, L36, and L46 in the first to fourth embodiments, and f is one of the effective focal lengths of the imaging lenses 1, 2, 3, and 4 in the first to fourth embodiments, and f ₁₂₃ is the first to fourth embodiments, the first lenses L11, L21, L31, L41 , the second lens L12, L22, L32, L42 and the third lens L13, L23, L33, L43 one combined effective focal length, f ₄₅₆ is the first embodiment to the fourth embodiment, the fourth lens L14, L24, L34 , L44, the fifth lens L15, L25, L35, L45 and the combined effective focal length of one of the sixth lenses L16, L26, L36, L46, R ₂₁ is the first embodiment to the fourth embodiment, the second lens L12, L22 , a radius of curvature of the side surfaces S13, S23, S33 and S43 of the objects of L32 and L42, and R ₂₂ is the image side surfaces S14, S24, S14, S24, A radius of curvature of S34, S44, TTL is the first embodiment to the fourth embodiment, the side surfaces S11, S21, S31, S41 of the first lens L11, L21, L31, L41 are respectively to the imaging planes IMA1, IMA2, IMA3 , IMA4 is a distance on the optical axis OA1, OA2, OA3, OA4, BFL is the image side S113, S213, S313, S413 of the sixth lens L16, L26, L36, L46 in the first embodiment to the fourth embodiment A distance between the imaging planes IMA1, IMA2, IMA3, and IMA4 on the optical axes OA1, OA2, OA3, and OA4, respectively. The imaging lenses 1, 2, 3, and 4 can effectively reduce the aperture value, effectively improve the resolution, effectively resist environmental temperature changes, effectively correct aberrations, and effectively correct chromatic aberration.

When the condition (1) is satisfied: 120<Vd ₁ +Vd ₃ <140, the chromatic aberration can be effectively reduced and the image quality can be improved.

When the condition (2) is satisfied: 0.4<(f ₃ +f ₄ )/f<0.62, the processing sensitivity can be effectively reduced and the quality can be improved.

When the condition (3) is satisfied: -7<R ₂₂ /R ₂₁ <48, the sensitivity of the second lens can be effectively reduced and the quality can be improved.

When the condition (5) is satisfied: 3.9<TTL/BFL<6, a longer back focal length is available, which is beneficial to the assembly of the imaging lens.

The first embodiment of the imaging lens of the present invention will now be described in detail. Referring to FIG. 1, the imaging lens 1 includes a first lens L11, a second lens L12, a third lens L13, an aperture ST1, a first lens L11, a second lens L12, a third lens L13, an aperture ST1, and a first lens in sequence from an object side to an image side along an optical axis OA1. Four lenses L14, a fifth lens L15, a sixth lens L16, a filter OF1 and a protective glass CG1. During imaging, the light from the object side is finally imaged on an imaging plane IMA1. According to the first to eighth paragraphs of [Embodiment], wherein:

The first lens L11 is a biconcave lens, and its object side surface S11 is a concave surface;

The second lens L12 is a biconvex lens, and its image side surface S14 is a convex surface;

The object side S114 and the image side S115 of the filter OF1 are both planes;

The object side S116 and the image side S117 of the protective glass CG1 are both flat surfaces;

Using the above-mentioned lens, aperture ST1 and the design that satisfies at least one of the conditions (1) to (6), the imaging lens 1 can effectively reduce the aperture value, effectively improve the resolution, effectively resist environmental temperature changes, and effectively Correction of aberration, effective correction of chromatic aberration.

Table 1 is a table of relevant parameters of each lens of the imaging lens 1 in the first figure.

Table 2 shows the relevant parameter values of the imaging lens 1 of the first embodiment and the calculated values of the corresponding conditions (1) to (6). It can be seen from Table 2 that the imaging lens 1 of the first embodiment can meet the conditions (1). ) to the requirements of condition (6).

In addition, the optical performance of the imaging lens 1 of the first embodiment can also meet the requirements. It can be seen from FIG. 2A that the field curvature of the imaging lens 1 of the first embodiment is between -0.035mm and 0.04mm. It can be seen from FIG. 2B that the distortion of the imaging lens 1 of the first embodiment is between -10% and 0%. It can be seen from FIG. 2C that the modulation transfer function value of the imaging lens 1 of the first embodiment is between 0.27 and 1.0.

It is obvious that the field curvature and distortion of the imaging lens 1 of the first embodiment can be effectively corrected, and the resolution of the lens can also meet the requirements, thereby obtaining better optical performance.

Please refer to FIG. 3. FIG. 3 is a schematic diagram of the lens configuration of the imaging lens according to the second embodiment of the present invention. The imaging lens 2 includes a first lens L21, a second lens L22, a third lens L23, an aperture ST2, a fourth lens L24, a first lens L24, a first lens Five lenses L25, a sixth lens L26, a filter OF2 and a protective glass CG2. During imaging, the light from the object side is finally imaged on an imaging plane IMA2. According to the first to eighth paragraphs of [Embodiment], wherein:

The first lens L21 is a double concave lens, and its object side surface S21 is a concave surface;

The second lens L22 is a biconvex lens, and its image side surface S24 is a convex surface;

The object side S214 and the image side S215 of the filter OF2 are both planes;

The object side S216 and the image side S217 of the protective glass CG2 are both flat surfaces;

Using the above-mentioned lens, aperture ST2 and the design that satisfies at least one of the conditions (1) to (6), the imaging lens 2 can effectively reduce the aperture value, effectively improve the resolution, effectively resist environmental temperature changes, and effectively Correction of aberration, effective correction of chromatic aberration.

Table 3 is a table of relevant parameters of each lens of the imaging lens 2 in Figure 3.

Table 4 shows the relevant parameter values of the imaging lens 2 of the second embodiment and the calculated values of the corresponding conditions (1) to (6). It can be seen from Table 4 that the imaging lens 2 of the second embodiment can meet the conditions (1). ) to the requirements of condition (6).

In addition, the optical performance of the imaging lens 2 of the second embodiment can also meet the requirements. It can be seen from FIG. 4A that the field curvature of the imaging lens 2 of the second embodiment is between -0.04mm and 0.06mm. It can be seen from FIG. 4B that the distortion of the imaging lens 2 of the second embodiment is between -10% and 0%. It can be seen from FIG. 4C that the modulation transfer function value of the imaging lens 2 of the second embodiment is between 0.54 and 1.0.

It is obvious that the field curvature and distortion of the imaging lens 2 of the second embodiment can be effectively corrected, and the resolution of the lens can also meet the requirements, thereby obtaining better optical performance.

Please refer to FIG. 5. FIG. 5 is a schematic diagram of a lens configuration of a third embodiment of an imaging lens according to the present invention. The imaging lens 3 includes a first lens L31, a second lens L32, a third lens L33, an aperture ST3, a fourth lens L34, a first lens L34, a first lens Five lenses L35, a sixth lens L36, a filter OF3 and a Cover glass CG3. During imaging, the light from the object side is finally imaged on an imaging plane IMA3. According to the first to eighth paragraphs of [Embodiment], wherein:

The first lens L31 is a double concave lens, and its object side surface S31 is a concave surface;

The second lens L32 is a biconvex lens, and its image side surface S34 is a convex surface;

The object side S314 and the image side S315 of the filter OF3 are both planes;

The object side S316 and the image side S317 of the protective glass CG3 are both flat surfaces;

Using the above-mentioned lens, aperture ST3 and the design that satisfies at least one of the conditions (1) to (6), the imaging lens 3 can effectively reduce the aperture value, effectively improve the resolution, effectively resist environmental temperature changes, and effectively Correction of aberration, effective correction of chromatic aberration.

Table 5 is a table of relevant parameters of each lens of the imaging lens 3 in Fig. 5 .

Table 6 shows the relevant parameter values of the imaging lens 3 of the third embodiment and the calculated values of the corresponding conditions (1) to (6). It can be seen from Table 6 that the imaging lens 3 of the third embodiment can meet the conditions (1). ) to the requirements of condition (6).

In addition, the optical performance of the imaging lens 3 of the third embodiment can also meet the requirements. It can be seen from FIG. 6A that the field curvature of the imaging lens 3 of the third embodiment is between -0.04mm and 0.05mm. It can be seen from FIG. 6B that the distortion of the imaging lens 3 of the third embodiment is between -12% and 0%. It can be seen from FIG. 6C that the modulation transfer function value of the imaging lens 3 of the third embodiment is between 0.52 and 1.0.

It is obvious that the field curvature and distortion of the imaging lens 3 of the third embodiment can be effectively corrected, and the resolution of the lens can also meet the requirements, thereby obtaining better optical performance.

Please refer to FIG. 7. FIG. 7 is a schematic diagram of the lens configuration of the fourth embodiment of the imaging lens according to the present invention. The imaging lens 4 sequentially includes a first lens L41, a second lens L42, a third lens L43, an aperture ST4, a fourth lens L44, a first lens L44, a first lens Five lenses L45, a sixth lens L46, a filter OF4 and a protective glass CG4. During imaging, the light from the object side is finally imaged on an imaging plane IMA4. According to the first to eighth paragraphs of [Embodiment], wherein:

The first lens L41 is a meniscus lens, and its object side surface S41 is a convex surface;

The second lens L42 is a meniscus lens, and its image side surface S44 is a concave surface;

The object side S414 and the image side S415 of the filter OF4 are both planes;

The object side S416 and the image side S417 of the protective glass CG4 are both flat surfaces;

Using the above-mentioned lens, aperture ST4 and the design that satisfies at least one of the conditions (1) to (6), the imaging lens 4 can effectively reduce the aperture value, effectively improve the resolution, effectively resist environmental temperature changes, and effectively Correction of aberration, effective correction of chromatic aberration.

Table 7 is a table of relevant parameters of each lens of the imaging lens 4 in Fig. 7 .

Table 8 shows the relevant parameter values of the imaging lens 4 of the fourth embodiment and the calculated values of the corresponding conditions (1) to (6). It can be seen from Table 8 that the imaging lens 4 of the fourth embodiment can meet the conditions (1). ) to the requirements of condition (6).

In addition, the optical performance of the imaging lens 4 of the fourth embodiment can also meet the requirements. It can be seen from FIG. 8A that the longitudinal aberration of the imaging lens 4 of the fourth embodiment is between -0.01 mm and 0.035 mm. It can be seen from FIG. 8B that the field curvature of the imaging lens 4 of the fourth embodiment is between -0.025mm and 0.035mm. It can be seen from FIG. 8C that the distortion of the imaging lens 4 of the fourth embodiment is between -2% and 0%. It can be seen from FIG. 8D that the lateral chromatic aberration of the imaging lens 4 of the fourth embodiment is between -1.0 μm and 2.5 μm. It can be seen from FIG. 8E that the relative illuminance of the imaging lens 4 of the fourth embodiment is between 0.85 and 1.0. It can be seen from FIG. 8F that the modulation transfer function value of the imaging lens 4 of the fourth embodiment is between 0.51 and 1.0. It can be seen from FIG. 8G that the imaging lens 4 of the fourth embodiment has a modulation transfer function value between 0.0 and 0.90 when the focus shift is between -0.05mm and 0.05mm.

It is obvious that the longitudinal aberration, field curvature, distortion, and lateral chromatic aberration of the imaging lens 4 of the fourth embodiment can be effectively corrected, and the relative illuminance, lens resolution, and focal depth can also meet the requirements, thereby obtaining better optical performance.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone familiar with the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention The scope shall be determined by the scope of the appended patent application.

1: Imaging lens

L11: The first lens

L12: Second lens

L13: Third lens

L14: Fourth lens

L15: Fifth lens

L16: Sixth lens

ST1: Aperture

OA1: Optical axis

OF1: filter

CG1: Protective glass

IMA1: Imaging plane

S11: Object side of the first lens

S12: The first lens image side

S13: Object side of the second lens

S14: The second lens is like the side

S15: Object side of the third lens

S16: The third lens is like the side

S17: Aperture Surface

S18: Fourth lens object side

S19: Fourth lens like side

S110: Object side of fifth lens

S111: Fifth lens image side

S112: Object side of sixth lens

S113: The sixth lens image side

S114: Side of filter object

S115: Filter like side

S116: Protect the side of glass

S117: Protective glass like side

Claims (10)

An imaging lens, comprising: a first lens having negative refractive power, the first lens includes a concave surface facing an image side; a second lens with positive refractive power, the second lens includes a convex surface facing an object side; a third lens having positive refractive power; a fourth lens having negative refractive power; a fifth lens having positive refractive power, the fifth lens is a meniscus lens; and A sixth lens has positive refractive power, and the sixth lens includes a concave surface facing the image side; wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are sequentially arranged along an optical axis from the object side to the image side; Wherein an air space is included between the third lens and the fourth lens. The imaging lens as described in item 1 of the claimed scope, wherein: The first lens further includes another concave surface facing the object side; and The second lens further includes another convex surface facing the image side. The imaging lens as described in item 1 of the claimed scope, wherein: The first lens further includes a convex surface facing the object side; and The second lens further includes a concave surface facing the image side. The imaging lens according to any one of claims 1 to 3 of the claimed scope, wherein the third lens is a biconvex lens and includes a convex surface facing the object side and another convex surface facing the image side. The imaging lens according to any one of claims 1 to 3 of the claimed scope, wherein the fourth lens is a biconcave lens and includes a concave surface facing the object side and another concave surface facing the image side. The imaging lens according to any one of claims 1 to 3 of the claimed scope, wherein the fifth lens comprises a concave surface facing the object side and a convex surface facing the image side. The imaging lens according to any one of claims 1 to 3 of the claimed scope, wherein the sixth lens further comprises a convex surface facing the object side. The imaging lens according to any one of claims 1 to 3 of the scope of the application, further comprising an aperture disposed between the third lens and the fourth lens. The imaging lens according to any one of claims 1 to 3 of the claimed scope, wherein the first lens, the second lens and the third lens comprise at least one glass spherical lens, the fourth lens, the The fifth lens and the sixth lens include at least one glass spherical lens. The imaging lens according to any one of claims 1 to 3 of the scope of the application, wherein the imaging lens satisfies the following conditions: 0.4<(f ₃ +f ₄ )/f<0.62; 6mm<f ₄ +f ₆ <12mm; 0.05<f ₁₂₃ /f ₄₅₆ <0.22; 3.9<TTL/BFL<6; -7< _R22 / _R21 <48; 120<Vd ₁ +Vd ₃ <140; Wherein, f is an effective focal length of the imaging lens, f ₃ is an effective focal length of the third lens, f ₄ is an effective focal length of the fourth lens, f ₆ is an effective focal length of the sixth lens, f ₁₂₃ is the combined effective focal length of one of the first lens, the second lens and the third lens, f ₄₅₆ is the combined effective focal length of one of the fourth lens, the fifth lens and the sixth lens, and TTL is the first lens A distance from an object side to an imaging surface on the optical axis, BFL is a distance from an image side of the sixth lens to the imaging surface on the optical axis, R ₂₁ is an object of the second lens A curvature radius of a side surface, R ₂₂ is a curvature radius of an image side surface of the second lens, Vd ₁ is an Abbe coefficient of the first lens, and Vd ₃ is an Abbe coefficient of the third lens.

Images