TW202028796A - Lens assembly - Google Patents

Abstract

A lens assembly includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The first lens is with positive refractive power and includes a convex surface facing an object side. The second lens is with refractive power. The third lens is with negative refractive power. The fourth lens is with positive refractive power and includes a convex surface facing the image side. The fifth lens is with negative refractive power and includes a concave surface facing the image side. The first lens, the second lens, the third lens, the fourth lens, and the fifth lens are arranged in order from the object side to the image side along an optical axis. The lens assembly satisfies: 2 < TTL/T₁ < 5; wherein TTL is an interval from an object side surface of the first lens to an image plane along the optical axis and T₁ is a thickness of the first lens along the optical axis.

Description

Imaging lens (30)

The invention relates to an imaging lens.

The current development trend of imaging lenses, in addition to the continuous development towards miniaturization, with different application requirements, it is also necessary to have high resolution and reduce the optical effective diameter of the lens closest to the object side. Conventional imaging lenses can no longer meet Today’s demands require an imaging lens with another new architecture to meet the demands of miniaturization, high resolution, and reduction of the optical effective diameter of the lens closest to the object.

In view of this, the main purpose of the present invention is to provide an imaging lens which has a shorter total lens length, higher resolution, and a smaller optical effective diameter of the lens closest to the object side, but still has good optical performance.

The imaging lens of the present invention includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The first lens has positive refractive power and includes a convex surface facing an object side. The second lens has refractive power. The third lens has negative refractive power. The fourth lens has positive refractive power and includes a convex surface facing the image side. The fifth lens has negative refractive power and includes a concave surface facing the image side. The first lens, the second lens, the third lens, the fourth lens and the fifth lens are arranged in order from the object side to the image side along an optical axis. The imaging lens satisfies the following conditions: 2<TTL/T ₁ <5; among them, TTL is the distance between an object side of the first lens and an imaging surface on the optical axis, and T ₁ is _one of the first lens on the optical axis thickness.

The second lens has positive refractive power, and the second lens includes a convex surface facing the image side.

The second lens has negative refractive power, the second lens is a biconcave lens, the third lens is a biconcave lens, and the fifth lens may further include a concave surface facing the object side.

The imaging lens satisfies the following conditions: 61×10 ^-6 /℃<CTE ₁ +CTE ₂ <81×10 ^-6 /℃; among them, CTE ₁ is one of the first lens's Coefficient of Thermal Expansion (Coefficient of Thermal Expansion), CTE ₂ It is one of the coefficient of thermal expansion of the second lens (Coefficient of Thermal Expansion).

The imaging lens satisfies the following conditions: 2<f/T ₁ <4; where f is an effective focal length of the imaging lens, and T ₁ is a thickness of the first lens on the optical axis.

The imaging lens satisfies the following conditions: 4<TTL/AAG<12; among which, TTL is the distance from one object side of the first lens to an imaging surface on the optical axis, and AAG is the distance from one image side to the most An object side of the lens close to the image side is combined with an air gap on the optical axis.

The imaging lens satisfies the following conditions: 1<T ₁ /AAG<4; where T ₁ is the thickness of the first lens on the optical axis, and AAG is the range from the image side of the first lens to the lens closest to the image side The sum of an air gap between the side of an object and the optical axis.

The imaging lens satisfies the following conditions: 0.8<(f ₄ +T ₁ )/f<2.5; among them, f ₄ is an effective focal length of the fourth lens, f is an effective focal length of the imaging lens, and T ₁ is the One thickness on the optical axis.

The imaging lens satisfies the following conditions: 0.10<D ₁ /ALD<0.15; among them, D ₁ is one of the optical effective diameters of the first lens, and ALD is the first lens, the second lens, the third lens, the fourth lens, and the fifth lens. The total optical effective diameter of one of the lenses.

The imaging lens satisfies the following conditions: 1.5<f/D ₁ <3.5; where f is an effective focal length of the imaging lens, and D ₁ is an optical effective diameter of the first lens.

In order to make the above-mentioned objects, features, and advantages of the present invention more obvious and understandable, the following specifically describes preferred embodiments in conjunction with the accompanying drawings.

1, 2, 3, 4, 5‧‧‧imaging lens

L11, L21, L31, L41, L51‧‧‧First lens

L12, L22, L32, L42, L52‧‧‧Second lens

L13, L23, L33, L43, L53‧‧‧third lens

L14, L24, L34, L44, L54‧‧‧Fourth lens

L15, L25, L35, L45, L55‧‧‧Fifth lens

ST1, ST2, ST3, ST4, ST5‧‧‧Aperture

OF1, OF2, OF3, OF4, OF5‧‧‧Filter

OA1, OA2, OA3, OA4, OA5‧‧‧Optical axis

IMA1, IMA2, IMA3, IMA4, IMA5‧‧‧imaging surface

S11, S21, S31, S41, S51‧‧‧Aperture surface

S12, S22, S32, S42, S52‧‧‧Object side of the first lens

S13, S23, S33, S43, S53‧‧‧The side of the first lens image

S14, S24, S34, S44, S54‧‧‧Object side of the second lens

S15, S25, S35, S45, S55‧‧‧Second lens image side

S16, S26, S36, S46, S56‧‧‧Object side of third lens

S17, S27, S37, S47, S57‧‧‧Third lens image side

S18, S28, S38, S48, S58‧‧‧Object side of the fourth lens

S19, S29, S39, S49, S59‧‧‧Fourth lens image side

S110, S210, S310, S410‧‧‧Fifth lens object side

S510‧‧‧Fifth lens object side

S111, S211, S311, S411‧‧‧Fifth lens image side

S511‧‧‧Fifth lens image side

S112, S212, S312, S412‧‧‧The side of the filter object

S512‧‧‧The side of the filter object

S113, S213, S313, S413‧‧‧ Filter image side

S513‧‧‧Filter image side

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

FIG. 2A is a field curve 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.

Figure 2C is a diagram of Modulation Transfer Function 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 curve diagram of the 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 Modulation Transfer Function of the second embodiment of the imaging lens according to the present invention.

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

FIG. 6A is a field curve diagram of the 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 the lens configuration and optical path of the fourth embodiment of the imaging lens according to the present invention.

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

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

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

FIG. 9 is a schematic diagram of the lens configuration and optical path of the fifth embodiment of the imaging lens according to the present invention.

FIG. 10A is a field curve diagram of the fifth embodiment of the imaging lens according to the present invention.

FIG. 10B is a distortion diagram of the fifth embodiment of the imaging lens according to the present invention.

FIG. 10C is a diagram of Modulation Transfer Function (Modulation Transfer Function) of the fifth embodiment of the imaging lens according to the present invention.

The present invention provides an imaging lens, including: a first lens with positive refractive power, the first lens including a convex surface facing an object side; a second lens with refractive power; a third lens with negative refractive power; a fourth lens with positive refractive power Refractive power, the fourth lens includes a convex surface facing the image side; and a fifth lens has a negative refractive power, the fifth lens includes a concave surface facing the image side; wherein the first lens, the second lens, the third lens, and the fourth lens The fifth lens is arranged in order from the object side to the image side along an optical axis; the imaging lens satisfies the following conditions: 2<TTL/T ₁ <5; where TTL is an object side of the first lens to an imaging surface one pitch axis, T ₁ is the thickness of one of the first lens on the optical axis.

Please refer to the following table 1, table 2, table 4, table 5, table 7, table 8, table 10, table 11, table 13 and table 14, among which table 1, table 4, table 7, table 10 and table Thirteen are the relevant parameter tables of the lenses of the first embodiment to the fifth embodiment of the imaging lens according to the present invention. Tables 2, Table 5, Table 8, Table 11, and Table 14 are Table 1 and Table 14 respectively. 4. The relevant parameter table of the aspheric surface of each lens in Table 7, Table 10 and Table 13.

Figures 1, 3, 5, 7, and 9 are schematic diagrams of the lens configuration and optical paths of the first, second, third, fourth, and fifth embodiments of the imaging lens of the present invention, respectively. The first lenses L11, L21, L31, L41, L51 has positive refractive power and is made of glass. Its object side surfaces S12, S22, S32, S42, S52 are convex surfaces, and the object side surfaces S12, S22, S32, S42, S52 and the image side surfaces S13, S23, S33, S43, S53 are all Aspheric surface.

The second lenses L12, L22, L32, L42, L52 have refractive power and are made of plastic material, and the object side surfaces S14, S24, S34, S44, S54 and the image side surfaces S15, S25, S35, S45, S55 are all aspherical surfaces.

The third lens L13, L23, L33, L43, L53 has negative refractive power and is made of plastic material. The object side S16, S26, S36, S46, S56 and the image side S17, S27, S37, S47, S57 are all aspherical surfaces. .

The fourth lens L14, L24, L34, L44, L54 has positive refractive power and is made of plastic material. The image side surface S19, S29, S39, S49, S59 is convex, the object side surface S18, S28, S38, S48, S58 and the image side surface S19, S29, S39, S49, and S59 are all aspherical surfaces.

The fifth lens L15, L25, L35, L45, L55 has negative refractive power and is made of plastic material. The image side surfaces S111, S211, S311, S411, S511 are concave surfaces, and the object side surfaces S110, S210, S310, S410, S510 and the image side surface are concave. S111, S211, S311, S411, and S511 are all aspherical surfaces.

In addition, the imaging lenses 1, 2, 3, 4, and 5 meet at least one of the following conditions:

2<TTL/T ₁ <5 (1)

61×10 ^-6 /℃<CTE ₁ +CTE ₂ <81×10 ^-6 /℃ (2)

2<f/T ₁ <4 (3)

4<TTL/AAG<12 (4)

1<T ₁ /AAG<4 (5)

0.8<(f ₄ +T ₁ )/f<2.5 (6)

0.10<D ₁ /ALD<0.15 (7)

1.5<f/D ₁ <3.5 (8)

Wherein, f is the effective focal length of one of the imaging lenses 1, 2, 3, 4, and 5 in the first to fifth embodiments. f ₄ is the effective focal length of one of the fourth lenses L14, L24, L34, L44, and L54 in the first to fifth embodiments. TTL is from the first embodiment to the fifth embodiment, the object sides S12, S22, S32, S42, and S52 of the first lens L11, L21, L31, L41, L51 are respectively to the imaging surface IMA1, IMA2, IMA3, IMA4, IMA5 A pitch on the optical axis OA1, OA2, OA3, OA4, OA5. T ₁ is the first embodiment to the fifth embodiment, the first lens L11, L21, L31, L41, L51 on the optical axis OA1, OA2, OA3, OA4, the thickness of one of OA5. CTE ₁ is one of the coefficients of thermal expansion (Coefficient of Thermal Expansion) of the first lenses L11, L21, L31, L41, L51 in the first embodiment to the fifth embodiment. CTE ₂ is the coefficient of thermal expansion (Coefficient of Thermal Expansion) of the second lenses L12, L22, L32, L42, L52 in the first embodiment to the fifth embodiment. AAG is from the first embodiment to the fifth embodiment, one of the first lenses L11, L21, L31, L41, L51 has an image side surface S13, S23, S33, S43, S53 to a lens L15, L25 closest to the image side, respectively , L35, L45, L55, one of the object sides S110, S210, S310, S410, S510 and the total of one of the air spaces on the optical axis OA1, OA2, OA3, OA4, OA5. D ₁ is the optical effective diameter of one of the first lenses L11, L21, L31, L41, and L51 in the first to fifth embodiments. D ₂ is the optical effective diameter of one of the second lenses L12, L22, L32, L42, L52 in the first embodiment to the fifth embodiment. D ₃ is the optical effective diameter of one of the third lenses L13, L23, L33, L43, L53 in the first embodiment to the fifth embodiment. D ₄ is the optical effective diameter of one of the fourth lenses L14, L24, L34, L44, and L54 in the first to fifth embodiments. D ₅ is the optical effective diameter of one of the fifth lenses L15, L25, L35, L45, and L55 in the first to fifth embodiments. ALD is in the first to fifth embodiments, the first lens L11, L21, L31, L41, L51, the second lens L12, L22, L32, L42, L52, the third lens L13, L23, L33, L43, The sum of the optical effective diameters of one of L53, the fourth lens L14, L24, L34, L44, L54, and the fifth lens L15, L25, L35, L45, L55. The imaging lens 1, 2, 3, 4, and 5 can effectively shorten the total length of the lens, effectively improve the resolution, effectively reduce the optical effective diameter of the lens closest to the object side, and effectively correct aberrations.

In the above conditions, if the calculated value of CTE ₁ + CTE ₂ is greater than or equal to 81×10 ^-6 , it is difficult to reduce the optical effective diameter of the lens closest to the object side. Therefore, the calculated value of CTE ₁ + CTE ₂ must be less than 81 ×10 ^-6 can effectively reduce the optical effective diameter of the lens closest to the object side, when the condition is met: 61×10 ^-6 /℃<CTE ₁ +CTE ₂ <81×10 ^-6 /℃; The optical effective diameter of the lens closest to the object side.

The first embodiment of the imaging lens of the present invention will now be described in detail. Please refer to Fig. 1, the imaging lens 1 includes an aperture ST1, a first lens L11, a second lens L12, a third lens L13, and a second lens in order from an object side to an image side along an optical axis OA1. Four lenses L14, a fifth lens L15 and a filter OF1. When imaging, the light from the object side is finally imaged on an imaging surface IMA1. According to [Implementation Mode] paragraphs 1 to 7, in which: The first lens L11 can be a meniscus lens with a concave image side S13; the second lens L12 can be a biconvex lens with a convex object side S14 and a convex image side S15; the third lens L13 can be more curved For a lunar lens, the object side S16 is convex and the image side S17 is concave; the fourth lens L14 can be a meniscus lens with a concave object side S18; the fifth lens L15 can be a biconcave lens with a concave object side S110 Is concave The object side S112 and the image side S113 of the filter OF1 are both flat surfaces; using the above-mentioned lens, aperture ST1 and a design that meets at least one of the conditions (1) to (8), the imaging lens 1 can effectively shorten the total lens length It can effectively improve the resolution, effectively reduce the optical effective diameter of the lens closest to the object side, and effectively correct aberrations.

Table 1 is a table of related parameters of each lens of the imaging lens 1 in Figure 1. The data in Table 1 shows that the effective focal length of the imaging lens 1 of the first embodiment is 4.029mm and the aperture The value is equal to 2.2, the total length of the lens is equal to 5.597mm, and the field of view is equal to 77.3 degrees.

The concavity z of the aspheric surface of each lens in Table 1 is obtained by the following formula: z=ch ² /{1+[1-(k+1)c ² h ² ] ^1/2 }+Ah ⁴ +Bh ⁶ + Ch ⁸ +Dh ¹⁰ +Eh ¹² +Fh ¹⁴ +Gh ¹⁶

Among them: c: curvature; h: the vertical distance from any point on the lens surface to the optical axis; k: conic coefficient; A~G: aspherical coefficient.

Table 2 is the relevant parameter table of the aspheric surface of each lens in Table 1, where k is the Conic Constant and A~G are the aspheric coefficients.

Table 3 shows the relevant parameter values of the imaging lens 1 of the first embodiment and the calculated values of the corresponding conditions (1) to (8). From Table 3, it can be seen that the imaging lens 1 of the first embodiment can all satisfy the condition (1). ) To the requirements of condition (8).

In addition, the optical performance of the imaging lens 1 of the first embodiment can also meet the requirements, which can be seen from Figures 2A to 2C. FIG. 2A shows a field curvature diagram of the imaging lens 1 of the first embodiment. FIG. 2B shows a distortion (distortion) diagram of the imaging lens 1 of the first embodiment. Figure 2C shows the Modulation Transfer Function diagram of the imaging lens 1 of the first embodiment.

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 0.035mm.

It can be seen from FIG. 2B that the distortion (Distortion) of the imaging lens 1 of the first embodiment is between 0% and 2%.

It can be seen from FIG. 2C that the value of the Modulation Transfer Function of the imaging lens 1 of the first embodiment is between 0.30 and 1.0.

Obviously, 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, which is a schematic diagram of the lens configuration and optical path of the second embodiment of the imaging lens according to the present invention. The imaging lens 2 includes an aperture ST2, a first lens L21, a second lens L22, a third lens L23, a fourth lens L24, and a second lens in order from an object side to an image side along an optical axis OA2. Five lenses L25 and one filter OF2. When imaging, the light from the object side is finally imaged on an imaging surface IMA2. According to paragraphs 1 to 7 of the [Embodiment Mode], the first lens L21 may be a biconvex lens, and the image side surface S23 is convex; The second lens L22 can be a meniscus lens, the object side S24 is concave, and the image side S25 is convex; the third lens L23 can be more biconcave, the object side S26 is concave, and the image side S27 is concave; the fourth lens The surface shape of L24 is the same as that of the fourth lens L14 in the first embodiment, and will not be repeated here; the fifth lens L25 can be a biconcave lens, and its surface shape is the same as that of the fifth lens L15 in the first embodiment The same is not repeated here; the object side S212 and the image side S213 of the filter OF2 are both flat surfaces; the above-mentioned lens, the aperture ST2, and the design satisfying at least one of the conditions (1) to (8) are used to make The imaging lens 2 can effectively shorten the total length of the lens, effectively improve the resolution, effectively reduce the optical effective diameter of the lens closest to the object side, and effectively correct aberrations.

Table 4 is a table of related parameters of each lens of the imaging lens 2 in Figure 3. The data in Table 4 shows that the effective focal length of the imaging lens 2 of the second embodiment is equal to 4.029mm, the aperture value is equal to 2.2, and the total lens length is equal to 5.442mm, The field of view is equal to 77.25 degrees.

The definition of the aspheric surface concavity z of each lens in Table 4 is the same as the definition of the aspheric surface concavity z of each lens in Table 1 in the first embodiment, and will not be repeated here.

Table 5 is the relevant parameter table of the aspheric surface of each lens in Table 4, where k is the Conic Constant and A~G are the aspheric coefficients.

Table 6 shows the relevant parameter values of the imaging lens 2 of the second embodiment and the calculated values of the corresponding conditions (1) to (8). From Table 6, it can be seen that the imaging lens 2 of the second embodiment can meet the condition (1). ) To the requirements of condition (8).

In addition, the optical performance of the imaging lens 2 of the second embodiment can also meet the requirements, which can be seen from Figures 4A to 4C. Figure 4A shows the field curvature of the imaging lens 2 of the second embodiment. Figure 4B shows a distortion (distortion) diagram of the imaging lens 2 of the second embodiment. Fig. 4C shows a Modulation Transfer Function diagram of the imaging lens 2 of the second embodiment.

It can be seen from FIG. 4A that the field curvature of the imaging lens 2 of the second embodiment is between -0.035mm and 0.04mm.

It can be seen from FIG. 4B that the distortion (Distortion) of the imaging lens 2 of the second embodiment is between 0% and 1.4%.

It can be seen from FIG. 4C that the value of the Modulation Transfer Function of the imaging lens 2 of the second embodiment is between 0.23 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 Figure 5. Figure 5 is a third example of the imaging lens according to the present invention. Schematic diagram of the lens configuration and optical path of the embodiment. The imaging lens 3 includes an aperture ST3, a first lens L31, a second lens L32, a third lens L33, a fourth lens L34, and a second lens in order from an object side to an image side along an optical axis OA3. Five lenses L35 and one filter OF3. When imaging, the light from the object side is finally imaged on an imaging surface IMA3. According to the first to seventh paragraphs of [Embodiment], wherein: the surface shape of the first lens L31 is the same as that of the first lens L11 in the first embodiment, and will not be repeated here; the second lens L32 can be a biconcave lens , The object side surface S34 is concave, and the image side surface S35 is concave; the third lens L33 can be more biconcave, the object side S36 is concave, and the image side S37 is concave; the fourth lens L34 can be more biconvex, and its object side S38 is a convex surface; the fifth lens L35 can be a double-concave lens, and its surface shape is the same as that of the fifth lens L15 in the first embodiment, which will not be repeated here; the filter OF3 has its object side surface S312 and an image side surface S313 All are flat surfaces; using the above-mentioned lens, aperture ST3 and a design that meets at least one of the conditions (1) to (8), the imaging lens 3 can effectively shorten the total length of the lens, effectively improve the resolution, and effectively reduce the maximum The optical effective diameter of the lens near the object side effectively corrects aberrations.

Table 7 is a table of related parameters of each lens of the imaging lens 3 in Figure 5. The data in Table 7 shows that the effective focal length of the imaging lens 3 of the third embodiment is equal to 4.597mm, the aperture value is equal to 2.2, and the total lens length is equal to 4.958mm, The field of view is equal to 69 degrees.

The definition of the aspheric surface concavity z of each lens in Table 7 is the same as the definition of the aspheric surface concavity z of each lens in Table 1 in the first embodiment, and will not be repeated here.

Table 8 is a table of related parameters of the aspheric surface of each lens in Table 7, where k is the Conic Constant and A~G are the aspheric coefficients.

Table 9 shows the relevant parameter values of the imaging lens 3 of the third embodiment and the calculated values corresponding to conditions (1) to (8). From Table 9, it can be seen that the imaging lens 3 of the third embodiment can all meet the condition (1) ) To the requirements of condition (8).

In addition, the optical performance of the imaging lens 3 of the third embodiment can also meet the requirements, which can be seen from Figures 6A to 6C. FIG. 6A shows a field curvature diagram of the imaging lens 3 of the third embodiment. Fig. 6B shows a distortion (distortion) diagram of the imaging lens 3 of the third embodiment. FIG. 6C shows a Modulation Transfer Function diagram of the imaging lens 3 of the third embodiment.

It can be seen from FIG. 6A that the field curvature of the imaging lens 3 of the third embodiment is between -0.06mm and 0.07mm.

It can be seen from Figure 6B that the distortion of the imaging lens 3 of the third embodiment (Distortion) is between 0% and 2%.

It can be seen from FIG. 6C that the imaging lens 3 of the third embodiment has a Modulation Transfer Function value between 0.30 and 1.0.

Obviously, 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, which is a schematic diagram of the lens configuration and optical path of the fourth embodiment of the imaging lens according to the present invention. The imaging lens 4 includes an aperture ST4, a first lens L41, a second lens L42, a third lens L43, a fourth lens L44, and a second lens in order from an object side to an image side along an optical axis OA4. Five lenses L45 and one filter OF4. When imaging, the light from the object side is finally imaged on an imaging surface IMA4. According to the first to seventh paragraphs of [Embodiment], wherein: the surface shape of the first lens L41 is the same as that of the first lens L11 in the first embodiment, and will not be repeated here; the second lens L42 can be a biconcave lens , The object side surface S44 is concave, and the image side surface S45 is concave; the third lens L43 can be more biconcave, the object side S46 is concave, and the image side S47 is concave; the fourth lens L44 can be more biconvex, and its object side S48 is a convex surface; the fifth lens L45 can be a double-concave lens, and its surface shape is the same as that of the fifth lens L15 in the first embodiment, which will not be repeated here; the filter OF4 has the object side S412 and the image side S413 All are flat surfaces; using the above-mentioned lens, aperture ST4, and a design that meets at least one of the conditions (1) to (8), the imaging lens 4 can effectively shorten the total length of the lens, effectively improve the resolution, and effectively reduce the maximum The optical effective diameter of the lens near the object side effectively corrects aberrations.

Table 10 is a table of related parameters of each lens of the imaging lens 4 in Figure 7. The data in Table 10 shows that the effective focal length of the imaging lens 4 of the fourth embodiment is equal to 4.113mm, the aperture value is equal to 2.2, and the total lens length is equal to 4.59mm, The field of view is equal to 75.5 degrees.

The definition of the aspheric surface concavity z of each lens in Table 10 is the same as the definition of the aspheric surface concavity z of each lens in Table 1 of the first embodiment, and will not be repeated here.

Table 11 is a table of related parameters of the aspheric surface of each lens in Table 10, where k is the Conic Constant and A~G are the aspheric coefficients.

Table 12 shows the relevant parameter values of the imaging lens 4 of the fourth embodiment and the calculated values corresponding to conditions (1) to (8). From Table 12, it can be seen that the imaging lens 4 of the fourth embodiment can all meet the conditions (1) to the requirements of condition (8).

In addition, the optical performance of the imaging lens 4 of the fourth embodiment can also meet the requirements. This can be seen from Figures 8A to 8C. FIG. 8A shows a field curvature diagram of the imaging lens 4 of the fourth embodiment. FIG. 8B shows a distortion (distortion) diagram of the imaging lens 4 of the fourth embodiment. FIG. 8C shows a Modulation Transfer Function (Modulation Transfer Function) diagram of the imaging lens 4 of the fourth embodiment.

It can be seen from FIG. 8A that the field curvature of the imaging lens 4 of the fourth embodiment is between -0.045mm and 0.045mm.

It can be seen from FIG. 8B that the distortion (Distortion) of the imaging lens 4 of the fourth embodiment is between -0.2% and 2%.

It can be seen from FIG. 8C that the value of the Modulation Transfer Function (Modulation Transfer Function) of the imaging lens 4 of the fourth embodiment is between 0.29 and 1.0.

Obviously, the Field Curvature and Distortion of the imaging lens 4 of the fourth 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. 9, which is a schematic diagram of the lens configuration and optical path of the fifth embodiment of the imaging lens according to the present invention. The imaging lens 5 includes an aperture ST5, a first lens L51, a second lens L52, a third lens L53, a fourth lens L54, and a second lens in order from an object side to an image side along an optical axis OA5. Five lenses L55 and one filter OF5. When imaging, the light from the object side is finally imaged on an imaging surface IMA5. According to paragraphs 1 to 7 of the [Embodiment], wherein: the surface shape of the first lens L51 is the same as that of the first lens L11 in the first embodiment, and will not be repeated here; the surface shape of the second lens L52 is similar to The second lens L12 in the first embodiment is the same, and will not be repeated here; the third lens L53 can be a meniscus lens, The object side surface S56 is concave and the image side surface S57 is convex; the fourth lens L54 can be a biconvex lens, and the object side S58 is convex; the fifth lens L55 can be a meniscus lens, and the object side S510 is convex; The object side S512 and the image side S513 of the optical sheet OF5 are both flat surfaces; the use of the above-mentioned lens, the aperture ST5 and the design that meets at least one of the conditions (1) to (8), the imaging lens 5 can effectively shorten the total lens length , Effectively improve the resolution, effectively reduce the optical effective diameter of the lens closest to the object side, and effectively correct aberrations.

Table 13 is a table of related parameters of each lens of the imaging lens 5 in Figure 9. The data in Table 13 shows that the effective focal length of the imaging lens 5 of the fifth embodiment is equal to 3.165mm, the aperture value is equal to 2.25, and the total lens length is equal to 4.32 mm, the field of view is equal to 76.7 degrees.

The concavity z of the aspheric surface of each lens in Table 13 is obtained by the following formula: z=ch ² /{1+[1-(k+1)c ² h ² ] ^1/2 }+Ah ⁴ +Bh ⁶ +Ch ⁸ +Dh ¹⁰ +Eh ¹² +Fh ¹⁴ +Gh ¹⁶ +Hh ¹⁸ +Ih ²⁰

Among them: c: curvature; h: the vertical distance from any point on the lens surface to the optical axis; k: conic coefficient; A~I: aspherical coefficient.

Table 14 is a table of related parameters of the aspheric surface of each lens in Table 13, where k is the Conic Constant and A~I are the aspheric coefficients.

Table 15 shows the relevant parameter values of the imaging lens 5 of the fifth embodiment and the calculated values corresponding to conditions (1) to (8). From Table 15 we can see that the imaging lens 5 of the fifth embodiment can all meet the conditions (1) to the requirements of condition (8).

In addition, the optical performance of the imaging lens 5 of the fifth embodiment can also meet the requirements, which can be seen from Figures 10A to 10C. FIG. 10A shows a field curvature diagram of the imaging lens 5 of the fifth embodiment. FIG. 10B shows a distortion (distortion) diagram of the imaging lens 5 of the fifth embodiment. FIG. 10C shows a Modulation Transfer Function diagram of the imaging lens 5 of the fifth embodiment.

It can be seen from FIG. 10A that the field curvature of the imaging lens 5 of the fifth embodiment is between -0.05 mm and 0.20 mm.

It can be seen from FIG. 10B that the distortion (Distortion) of the imaging lens 5 of the fifth embodiment is between 0% and 2%.

It can be seen from FIG. 10C that the imaging lens 5 of the fifth embodiment has a Modulation Transfer Function value between 0.18 and 1.0.

It is obvious that the Field Curvature and Distortion of the imaging lens 5 of the fifth embodiment can be effectively corrected, and the resolution of the lens 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 subject to the scope of the attached patent application.

1‧‧‧Imaging lens

L11‧‧‧First lens

L12‧‧‧Second lens

L13‧‧‧Third lens

L14‧‧‧Fourth lens

L15‧‧‧Fifth lens

ST1‧‧‧Aperture

OF1‧‧‧Filter

OA1‧‧‧Optical axis

IMA1‧‧‧Image surface

S11‧‧‧Aperture surface

S12‧‧‧Object side of the first lens

S13‧‧‧First lens image side

S14‧‧‧Second lens object side

S15‧‧‧Second lens image side

S16‧‧‧Third lens object side

S17‧‧‧Third lens image side

S18‧‧‧Fourth lens object side

S19‧‧‧Fourth lens image side

S110‧‧‧Fifth lens object side

S111‧‧‧Fifth lens image side

S112‧‧‧The side of the filter object

S113‧‧‧Filter image side

Claims (10)

An imaging lens comprising: a first lens with positive refractive power, the first lens including a convex surface facing an object side; a second lens with refractive power; a third lens with negative refractive power; a fourth lens with positive refractive power, the The fourth lens includes a convex surface facing the image side; and a fifth lens has a negative refractive power, the fifth lens includes a concave surface facing the image side; wherein the first lens, the second lens, the third lens, and the second lens The four lenses and the fifth lens are arranged in sequence from the object side to the image side along an optical axis; wherein the imaging lens satisfies the following conditions: 2<TTL/T ₁ <5; wherein, TTL is the first lens an object side surface to an imaging plane of the optical axis to one pitch, T ₁ is the first one of the lens thickness on the optical axis. According to the imaging lens described in claim 1, wherein the second lens has a positive refractive power, and the second lens includes a convex surface facing the image side. The imaging lens according to claim 1, wherein the second lens has negative refractive power, the second lens is a biconcave lens, the third lens is a biconcave lens, and the fifth lens further includes a concave surface facing the object side . The imaging lens described in any one of claims 1 to 3 in the scope of patent application, wherein the imaging lens meets the following conditions: 61×10 ^-6 /℃<CTE ₁ +CTE ₂ <81×10 ^-6 / ℃; Wherein, CTE _{1 is a} coefficient of thermal expansion of the first lens (Coefficient of Thermal Expansion), and CTE _{2 is a} coefficient of thermal expansion of the second lens (Coefficient of Thermal Expansion). The imaging lens described in any one of claims 1 to 3 of the scope of patent application, wherein the imaging lens satisfies the following conditions: 2<f/T ₁ <4; where f is an effective focal length of the imaging lens , T ₁ is the first one of the lens thickness on the optical axis. The imaging lens described in any one of claims 1 to 3 in the scope of the patent application, wherein the imaging lens satisfies the following conditions: 4<TTL/AAG<12; wherein, TTL is an object side of the first lens A distance from an imaging surface on the optical axis, AAG is the sum of an air distance on the optical axis from an image side surface of the first lens to an object side surface of the lens closest to the image side. For the imaging lens described in any one of claims 1 to 3 in the scope of the patent application, the imaging lens satisfies the following conditions: 1<T ₁ /AAG<4; where T _{1 is} the first lens in the A thickness on the optical axis, AAG is the sum of an air distance on the optical axis from an image side surface of the first lens to an object side surface of the lens closest to the image side. For example, the imaging lens described in any one of claims 1 to 3 of the scope of patent application, wherein the imaging lens satisfies the following conditions: 0.8<(f ₄ +T ₁ )/f<2.5; where f _{4 is} the one effective focal length of the fourth lens, f for the effective focal length of one of the imaging lens, T ₁ is the first one of the lens thickness on the optical axis. The imaging lens described in any one of claims 1 to 3 in the scope of the patent application, wherein the imaging lens satisfies the following conditions: 0.10<D ₁ /ALD<0.15; where D _{1 is one of} the first lenses Optical effective diameter, ALD is the sum of one optical effective diameter of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens. The imaging lens described in any one of claims 1 to 3 of the scope of patent application, wherein the imaging lens satisfies the following conditions: 1.5<f/D ₁ <3.5; where f is an effective focal length of the imaging lens , D _{1 is} an optical effective diameter of the first lens.

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