A high-resolution, short-focal-length machine vision lens and camera device

Abstract

The present invention provides a high-resolution, short-focal-length machine vision lens and a camera device, wherein the lens comprises an optical system, the optical system comprises a focusing group, a fixed group and an aperture stop, the focusing group comprises a first lens having a negative focal power and a meniscus structure, a second lens having a negative focal power, a third lens having a negative focal power and a biconcave structure, a fourth lens having a positive focal power and a biconvex structure, a fifth lens having a negative focal power and a meniscus structure, a sixth lens having a positive focal power and a biconvex structure, and a seventh lens having a negative focal power and a meniscus structure, the fixed group comprises an eighth lens having a positive focal power and a biconvex structure, a ninth lens having a positive focal power and a biconvex structure, a tenth lens having a negative focal power and a meniscus structure, and an eleventh lens having a positive focal power, and the aperture stop is arranged between the sixth lens and the seventh lens. The lens of the present invention has the characteristics of short focal length, high resolution and multiple object distances.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial lenses, and in particular to a high-resolution, short-focal-length machine vision lens and a camera device. Background Art

[0002] With the rapid development of machine vision, a series of lenses with megapixels and 10 million pixels of various focal lengths have been launched on the market to adapt to 2 / 3-inch cameras. However, due to the increasing demand, the performance of 10 million pixel lenses has gradually begun to fail to meet the needs of machine vision image acquisition, and the resolution needs to be further improved. Summary of the invention

[0003] In order to solve the above problems in the prior art, the present invention provides a high-resolution, short-focal-length machine vision lens and a camera device, which have the characteristics of short focal length, high resolution, multiple object distances and compatibility with small aperture.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] In a first aspect, the present invention provides a high-resolution, short-focal-length machine vision lens, comprising an optical system, wherein the optical system comprises a focusing group, a fixed group and an aperture stop, wherein the focusing group comprises a first lens having negative focal power and a meniscus structure, a second lens having negative focal power, a third lens having negative focal power and a biconcave structure, a fourth lens having positive focal power and a biconvex structure, a fifth lens having negative focal power and a meniscus structure, a sixth lens having positive focal power and a biconvex structure, and a seventh lens having negative focal power and a meniscus structure, which are arranged on the same optical axis from the object side to the image side, wherein the fixed group comprises an eighth lens having positive focal power and a biconvex structure, a ninth lens having positive focal power and a biconvex structure, a tenth lens having negative focal power and a meniscus structure, and an eleventh lens having positive focal power, which are arranged on the same optical axis from the object side to the image side, wherein the aperture stop is arranged between the sixth lens and the seventh lens;

[0006] The fourth lens and the fifth lens form a first cemented lens group, and the ratio of the focal length fu1 of the first cemented lens group to the total focal length f of the optical system satisfies the relationship:

[0007] 5<|fu1 / f|<10;

[0008] The ninth lens and the tenth lens form a second cemented lens group, and the ratio of the focal length fu2 of the second cemented lens group to the total focal length f of the optical system satisfies the relationship:

[0009] 3.5<|fu2 / f|<7;

[0010] The aperture diaphragm is a circular aperture, and the aperture diaphragm is adjustable between F2.8 and F22.

[0011] The beneficial effects of the present invention are as follows: the effective focal length of the machine vision lens provided by the present invention is 6 mm, and it adopts eleven lenses. It can adapt to 2 / 3-inch cameras with object distances of 250 mm to infinity through floating focus, and the resolution can reach up to 15 million pixels; and the aperture can be flexibly adjusted to be compatible with small apertures, thereby having the characteristics of short focal length, high resolution, multiple object distances and compatibility with small apertures.

[0012] Optionally, the first lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens and the tenth lens are spherical lenses made of glass, and the second lens and the eleventh lens are aspherical lenses made of glass.

[0013] Optionally, the aspheric lens surfaces of the second lens and the eleventh lens both satisfy the following equation:

[0014] + + + + + + + ;

[0015] Among them, z is the position along the optical axis, y is the height in the vertical direction relative to the optical axis, R is the radius of curvature, K is the cone coefficient, and A, B, C, D, E, F, G, H and J are aspherical coefficients.

[0016] Optionally, a distance L from a front surface vertex of the first lens to a back surface vertex of the eleventh lens and a total focal length f of the optical system satisfy the following relationship:

[0017] |L / f|<10.

[0018] Optionally, an optical back intercept BFL from the vertex of the rear surface of the eleventh lens to the image plane and a total focal length f of the optical system satisfy the following relationship:

[0019] |BFL / f|<3.

[0020] Optionally, the focal length ft1 of the focusing group and the total focal length f of the optical system satisfy the following relationship:

[0021] |ft1 / f|<3.

[0022] Optionally, the focal length ft2 of the fixed group and the total focal length f of the optical system satisfy the following relationship:

[0023] |ft2 / f|<3.

[0024] Optionally, the air gap D between the focusing group and the fixed group is floating, and the ratio of the air gap D to the total focal length f of the optical system satisfies the following relationship:

[0025] |D / f|<1.

[0026] Optionally, the focal length fg1 of the first lens, the focal length fg2 of the second lens, the focal length fg3 of the third lens, the focal length fg4 of the fourth lens, the focal length fg5 of the fifth lens, the focal length fg6 of the sixth lens, the focal length fg7 of the seventh lens, the focal length fg8 of the eighth lens, the focal length fg9 of the ninth lens, the focal length fg10 of the tenth lens and the focal length fg11 of the eleventh lens satisfy the following focal length relationship with the total focal length f of the optical system:

[0027] 5<|fg1 / f|<8;

[0028] 2<|fg2 / f|<4;

[0029] 2<|fg3 / f|<4;

[0030] 1<|fg4 / f|<3;

[0031] 2<|fg5 / f|<4;

[0032] 1<|fg6 / f|<4;

[0033] 1<|fg7 / f|<4;

[0034] 1<|fg8 / f|<4;

[0035] 1<|fg9 / f|<4;

[0036] 1<|fg10 / f|<4;

[0037] 1<|fg11 / f|<4.

[0038] In a second aspect, the present invention provides a camera device, including a photosensitive component and the machine vision lens of the first aspect;

[0039] The machine vision lens is mounted on the photosensitive component so that the photosensitive component is suitable for receiving light passing through the optical system and outputting imaging data.

[0040] Among them, the technical effect corresponding to the camera device provided in the second aspect refers to the relevant description of the high-resolution, short-focal-length machine vision lens provided in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of the optical structure of a high-resolution, short-focal-length machine vision lens according to an embodiment of the present invention;

[0042] Figure 2 A modulation transfer function curve diagram of a high-resolution, short-focal-length machine vision lens according to an embodiment of the present invention;

[0043] Figure 3 is a distortion curve diagram of a high-resolution, short-focal-length machine vision lens according to an embodiment of the present invention;

[0044] Figure 4 It is a relative illumination curve of a high-resolution, short-focal-length machine vision lens according to an embodiment of the present invention.

[0045] Description of reference numerals:

[0046] T1, focusing group; T2, fixed group; A1, aperture diaphragm;

[0047] G1, first lens; G2, second lens; G3, third lens; G4, fourth lens; G5, fifth lens; G6, sixth lens; G7, seventh lens; G8, eighth lens; G9, ninth lens; G10, tenth lens; G11, eleventh lens;

[0048] U1, the first cemented lens group; U2, the second cemented lens group. DETAILED DESCRIPTION

[0049] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0050] Embodiment 1

[0051] Please refer to Figure 1A high-resolution, short-focal-length machine vision lens comprises an optical system, the optical system comprises a focusing group T1, a fixed group T2 and an aperture stop A1, the focusing group T1 comprises a first lens G1 with negative focal power and a meniscus structure, a second lens G2 with negative focal power, a third lens G3 with negative focal power and a biconcave structure, a fourth lens G4 with positive focal power and a biconvex structure, a fifth lens G5 with negative focal power and a meniscus structure, a sixth lens G6 with positive focal power and a biconvex structure, and a seventh lens G7 with negative focal power and a meniscus structure, and the fixed group T2 comprises an eighth lens G8 with positive focal power and a biconvex structure, a ninth lens G9 with positive focal power and a biconvex structure, a tenth lens G10 with negative focal power and a meniscus structure, and an eleventh lens G11 with positive focal power, which are arranged on the same optical axis from the object to the image. The aperture stop A1 is arranged between the sixth lens G6 and the seventh lens G7.

[0052] The fourth lens G4 and the fifth lens G5 form a first cemented lens group U1, and the ratio of the focal length fu1 of the first cemented lens group U1 to the total focal length f of the optical system satisfies the relationship:

[0053] 5<|fu1 / f∣<10.

[0054] The ninth lens G9 and the tenth lens G10 form a second cemented lens group U2. The ratio of the focal length fu2 of the second cemented lens group U2 to the total focal length f of the optical system satisfies the relationship:

[0055] 3.5<|fu2 / f∣<7.

[0056] As a result, a high-resolution, low-distortion machine vision lens with a focal length of 6mm can be realized. Its image square F number is 2.8, which can match a 2 / 3-inch camera. The highest resolution can reach 250lp / mm and can match a 2um pixel chip. When the chip size is the largest, its pixels can reach 15 million pixels. Figure 3 It can be seen that the maximum optical distortion of the entire field of view is less than 2%.

[0057] In this embodiment, the first lens G1, the third lens G3, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, the ninth lens G9 and the tenth lens G10 are all spherical lenses made of glass, and the second lens G2 and the eleventh lens G11 are aspherical lenses made of glass.

[0058] The distance L from the front surface vertex of the first lens G1 to the back surface vertex of the eleventh lens G11 and the total focal length f of the optical system satisfy the following relationship:

[0059] |L / f|<10.

[0060] The optical back intercept BFL from the back surface vertex of the eleventh lens G11 to the image plane and the total focal length f of the optical system satisfy the following relationship:

[0061] |BFL / f|<3.

[0062] The focal length ft1 of the focusing group T1 and the total focal length f of the optical system satisfy the following relationship:

[0063] |ft1 / f|<3.

[0064] Among them, the focal length ft2 of the fixed group T2 and the total focal length f of the optical system satisfy the following relationship:

[0065] |ft2 / f|<3.

[0066] The air gap D between the focusing group T1 and the fixed group T2 is floating, and the ratio of the air gap D to the total focal length f of the optical system satisfies the following relationship:

[0067] |D / f|<1.

[0068] The aperture stop A1 is a circular aperture, and the aperture stop A1 is adjustable between F2.8 and F22. It should be noted that this embodiment adopts a floating focus method, and its aperture can be flexibly adjusted, so the machine vision lens of this embodiment is compatible with small apertures.

[0069] Among them, the focal length fg1 of the first lens G1, the focal length fg2 of the second lens G2, the focal length fg3 of the third lens G3, the focal length fg4 of the fourth lens G4, the focal length fg5 of the fifth lens G5, the focal length fg6 of the sixth lens G6, the focal length fg7 of the seventh lens G7, the focal length fg8 of the eighth lens G8, the focal length fg9 of the ninth lens G9, the focal length fg10 of the tenth lens G10 and the focal length fg11 of the eleventh lens G11 satisfy the following focal length relationship with the total focal length f of the optical system:

[0070] 5<|fg1 / f|<8;

[0071] 2<|fg2 / f|<4;

[0072] 2<|fg3 / f|<4;

[0073] 1<|fg4 / f|<3;

[0074] 2<|fg5 / f|<4;

[0075] 1<|fg6 / f|<4;

[0076] 1<|fg7 / f|<4;

[0077] 1<|fg8 / f|<4;

[0078] 1<|fg9 / f|<4;

[0079] 1<|fg10 / f|<4;

[0080] 1<|fg11 / f|<4.

[0081] Therefore, a high-resolution, short-focal-length machine vision lens in the present embodiment has an effective focal length of 6 mm, a relative numerical aperture of F / 2.8, a full field angle of 43°, a diagonal size of the image plane of 11 mm, a total optical length from the first lens G1 to the image plane of 70.6 mm, an operating band of 400 nm-700 nm, and a working distance of 250 mm.

[0082] The optical parameters of each lens are shown in Table 1. The surface numbers in Table 1 are arranged from the object side to the image side. When the surface is a plane, the radius is infinite. The air gap between the fourth lens G4 and the fifth lens G5 and the air gap between the ninth lens G9 and the tenth lens G10 are both 0 mm, that is, the two are attached, so there is only one surface here, and there are 21 surfaces in total.

[0083] Table 1

[0084]

[0085] In this embodiment, the aspheric lens surfaces of the second lens G2 and the eleventh lens G11 both satisfy the following equation:

[0086] + + + + + + + ;

[0087] Among them, z is the position in the direction of the optical axis, y is the height in the vertical direction relative to the optical axis, R is the radius of curvature, K is the cone coefficient, and A, B, C, D, E, F, G, H and J are aspheric coefficients. The aspheric coefficients are shown in Table 2.

[0088] Table 2

[0089]

[0090] Among them, 8.4E-4 means 8.4×10 -4 , and the same applies to the rest.

[0091] thus, Figure 2The OTF in the figure is the optical transfer function. It can be seen that the machine vision lens of this embodiment is greater than 0.3 at the full field of view of 250lp / mm, which has a very high resolution. Figure 3 It can be seen that the maximum distortion of the machine vision lens of this embodiment is less than 1.2%, indicating that the lens can correct field curvature and distortion very well. Figure 4 It can be seen that the relative illumination of the machine vision lens of this embodiment at the edge is greater than 90%, indicating that the lens has good brightness.

[0092] Embodiment 2

[0093] This embodiment provides a camera device, including a photosensitive component and the machine vision lens of Embodiment 1. The machine vision lens is installed on the photosensitive component, so that the photosensitive component is suitable for receiving light passing through the optical system and outputting imaging data.

[0094] In summary, the machine vision lens of this embodiment is a high-resolution short-focus lens that is compatible with multiple object distances and a small aperture.

[0095] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0096] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0097] In the present invention, unless otherwise clearly specified and limited, when a first feature is “on” or “below” a second feature, it may be that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, when a first feature is “above”, “above” or “above” a second feature, it may be that the first feature is directly above or obliquely above the second feature, or it may simply mean that the first feature is higher in level than the second feature. When a first feature is “below”, “below” or “below” a second feature, it may be that the first feature is directly below or obliquely below the second feature, or it may simply mean that the first feature is lower in level than the second feature.

[0098] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0099] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A high-resolution, short-focal-length machine vision lens, characterized in that: An optical system is provided, wherein the optical system comprises a focusing group, a fixed group and an aperture stop, wherein the focusing group comprises only a first lens with negative focal power and a meniscus structure, a second lens with negative focal power, a third lens with negative focal power and a biconcave structure, a fourth lens with positive focal power and a biconvex structure, a fifth lens with negative focal power and a meniscus structure, a sixth lens with positive focal power and a biconvex structure, and a seventh lens with negative focal power and a meniscus structure, and wherein the fixed group comprises only an eighth lens with positive focal power and a biconvex structure, a ninth lens with positive focal power and a biconvex structure, a tenth lens with negative focal power and a meniscus structure, and an eleventh lens with positive focal power, and wherein the aperture stop is provided between the sixth lens and the seventh lens; The fourth lens and the fifth lens form a first cemented lens group, and the ratio of the focal length fu1 of the first cemented lens group to the total focal length f of the optical system satisfies the relationship: 5<|fu1 / f|<10; The ninth lens and the tenth lens form a second cemented lens group, and the ratio of the focal length fu2 of the second cemented lens group to the total focal length f of the optical system satisfies the relationship: 3.5<|fu2 / f|<7; The aperture diaphragm is a circular aperture, and the aperture diaphragm is adjustable between F2.8 and F22; The focal length fg1 of the first lens, the focal length fg2 of the second lens, the focal length fg3 of the third lens, the focal length fg4 of the fourth lens, the focal length fg5 of the fifth lens, the focal length fg6 of the sixth lens, the focal length fg7 of the seventh lens, the focal length fg8 of the eighth lens, the focal length fg9 of the ninth lens, the focal length fg10 of the tenth lens and the focal length fg11 of the eleventh lens satisfy the following focal length relationship with the total focal length f of the optical system: 5<|fg1 / f|<8; 2<|fg2 / f|<4; 2<|fg3 / f|<4; 1<|fg4 / f|<3; 2<|fg5 / f|<4; 1<|fg6 / f|<4; 1<|fg7 / f|<4; 1<|fg8 / f|<4; 1<|fg9 / f|<4; 1<|fg10 / f|<4; 1<|fg11 / f|<4.

2. A high-resolution, short-focal-length machine vision lens according to claim 1, characterized in that: The first lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens and the tenth lens are all spherical lenses made of glass, and the second lens and the eleventh lens are aspherical lenses made of glass.

3. A high-resolution, short-focal-length machine vision lens according to claim 2, characterized in that: The aspheric lens surfaces of the second lens and the eleventh lens both satisfy the following equation: + + + + + + + ; Among them, z is the position along the optical axis, y is the height in the vertical direction relative to the optical axis, R is the radius of curvature, K is the cone coefficient, and A, B, C, D, E, F, G, H and J are aspherical coefficients.

4. The high-resolution, short-focal-length machine vision lens according to claim 1, characterized in that: The distance L from the front surface vertex of the first lens to the back surface vertex of the eleventh lens and the total focal length f of the optical system satisfy the following relationship: |L / f|<10.

5. The high-resolution, short-focal-length machine vision lens according to claim 1, characterized in that: The optical back focus BFL from the back surface vertex of the eleventh lens to the image plane and the total focal length f of the optical system satisfy the following relationship: |BFL / f|<3.

6. The high-resolution, short-focal-length machine vision lens according to claim 1, characterized in that: The focal length ft1 of the focusing group and the total focal length f of the optical system satisfy the following relationship: |ft1 / f|<3.

7. The high-resolution, short-focal-length machine vision lens according to claim 1, characterized in that: The focal length ft2 of the fixed group and the total focal length f of the optical system satisfy the following relationship: |ft2 / f|<3.

8. The high-resolution, short-focal-length machine vision lens according to claim 1, characterized in that: The air gap D between the focusing group and the fixed group is floating, and the ratio of the air gap D to the total focal length f of the optical system satisfies the following relationship: |D / f|<1.

9. A camera device, characterized in that: Comprising a photosensitive component and a machine vision lens as described in any one of claims 1 to 8; The machine vision lens is mounted on the photosensitive component so that the photosensitive component is suitable for receiving light passing through the optical system and outputting imaging data.

Images