Liquid fixed focus module and lens

Abstract

The invention discloses a liquid fixed-focus module and lenses, and belongs to the technical field of robot vision imaging, and the liquid fixed-focus module sequentially comprises a first lens, a second lens, a liquid lens, a gluing sheet, a third lens, a fourth lens and a fifth lens from an object plane side to an image plane side; the surface of the object side of the first lens is a convex surface, the surface of the image side of the first lens is a concave spherical surface, the surface of the object side of the second lens is a convex spherical surface, the surface of the image side of the second lens is a plane, the surface of the object side of the gluing sheet is a concave spherical surface, and the surface of the image side of the gluing sheet is a convex spherical surface. The object side surface of the third lens is a concave spherical surface, the image side surface of the third lens is a convex spherical surface, the object side surface of the fourth lens is a convex spherical surface, the image side surface of the fourth lens is a plane, and the object side surface and the image side surface of the fifth lens are planes. The liquid focusing module is compact, light in weight and efficient in focusing response, and the visual imaging requirement of the industrial robot is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of robot vision imaging, and particularly relates to a liquid focusing module and a lens. BACKGROUND

[0002] At present, intelligent robots can realize fast and accurate image acquisition under complex working conditions for targets with different working distances, thereby providing reliable data support for autonomous decision-making. This application requirement puts forward strict requirements on the adaptation ability, flexible adjustment performance and precise imaging accuracy of the matching vision imaging system of the intelligent robots.

[0003] However, the lens modules matched with the existing robots are mostly designed with fixed focal length, which cannot adapt to the object distance change requirement of the intelligent robots in different working scenes. If the focusing distance needs to be adjusted, manual adjustment or lens replacement is often required, which seriously affects the working efficiency. In addition, some focusable lenses use mechanical structure to drive focusing, which not only has large volume and complex structure, but also is difficult to integrate into the industrial robots with strict space size requirements, and the focusing response speed is slow, which cannot match the real-time working rhythm of the intelligent robots. SUMMARY

[0004] The present application aims to overcome the problems of large volume and inflexible focusing of the lens modules for robots in the prior art, and provides a liquid focusing module and a lens.

[0005] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows: a liquid focusing module is provided, which comprises, from the object side to the image side, a first lens, a second lens, a liquid lens, a cemented plate, a third lens, a fourth lens and a fifth lens; the object side surface of the first lens is a convex surface, the image side surface of the first lens is a concave spherical surface, the object side surface of the second lens is a convex spherical surface, the image side surface of the second lens is a plane, the object side surface of the cemented plate is a concave spherical surface, the image side surface of the cemented plate is a convex spherical surface, the object side surface of the third lens is a concave spherical surface, the image side surface of the third lens is a convex spherical surface, the object side surface of the fourth lens is a convex spherical surface, the image side surface of the fourth lens is a plane, the object side surface of the fifth lens is a plane, and the image side surface of the fifth lens is a plane.

[0006] In an embodiment, the object-side radius of curvature of the first lens is 12.17 mm, the image-side radius of curvature of the first lens is 7.56 mm, the object-side radius of curvature of the second lens is 8.37 mm, the image-side radius of curvature of the second lens is ∞, the object-side radius of curvature of the cement is -7.58 mm, the image-side radius of curvature of the cement is -7.58 mm, the object-side radius of curvature of the third lens is -3.48 mm, the image-side radius of curvature of the third lens is -15.82 mm, the object-side radius of curvature of the fourth lens is 19.27 mm, the image-side radius of curvature of the fourth lens is ∞, the object-side radius of curvature of the fifth lens is ∞, and the image-side radius of curvature of the fifth lens is ∞.

[0007] In an embodiment, the optical spacing between the first lens and the second lens is 3.63 mm-3.67 mm; the optical spacing between the second lens and the liquid lens is 2.98 mm-3.02 mm; the optical spacing between the liquid lens and the cement is 2.48 mm-2.52 mm; the optical spacing between the cement and the third lens is 0.98 mm-1.02 mm; the optical spacing between the third lens and the fourth lens is 0.58 mm-0.62 mm; and the optical spacing between the fourth lens and the fifth lens is 4.98 mm-5.02 mm.

[0008] In an embodiment, the cement comprises a sixth lens and a seventh lens, the sixth lens is disposed on the object-side of the seventh lens, the object-side surface of the sixth lens is a concave spherical surface, the image-side surface of the sixth lens is a concave spherical surface, the object-side surface of the seventh lens is a convex spherical surface, and the image-side surface of the seventh lens is a convex spherical surface.

[0009] In an embodiment, the object-side radius of curvature of the sixth lens is -7.58 mm, and the image-side radius of curvature of the sixth lens is 7.58 mm; the object-side radius of curvature of the seventh lens is 7.58 mm; and the image-side radius of curvature of the seventh lens is -7.58 mm.

[0010] In an embodiment, the focal length of the first lens is -27.355 mm; the focal length of the second lens is 9.579 mm; the focal length of the sixth lens is -4.709 mm, and the focal length of the seventh lens is 4.785 mm; the focal length of the third lens is -16.196 mm; the focal length of the fourth lens is 21.129 mm; and the focal length of the fifth lens is ∞. In an embodiment, the first lens adopts heavy flint glass, the second lens adopts lanthanum crown glass; the sixth lens adopts heavy flint glass, the seventh lens adopts lanthanum crown glass; the third lens adopts crown glass; the fourth lens adopts barium flint glass; and the fifth lens adopts heavy flint glass.

[0011] In an embodiment, the distance between the curvature center of the object side surface of the first lens and the image surface is 30.602 mm.

[0012] In an embodiment, the liquid focusing module further comprises a diaphragm, and the diaphragm and the liquid lens are located at the same position.

[0013] The application further provides a lens comprising the liquid focusing module as described above.

[0014] In summary, the application provides a liquid focusing module and a lens, wherein the liquid focusing module comprises a first lens, a second lens, a liquid lens, a diaphragm, a cemented lens, a third lens, a fourth lens and a fifth lens arranged in sequence from the object side to the image side. The liquid focusing module is compact and light in weight, small in size, and can be easily integrated into an industrial robot or a household robot, and is suitable for the narrow installation space of a robot. The liquid lens is adopted, and the layout of the optical path is optimized, so that wide-range focusing is effectively realized, the focusing response is efficient, and the real-time operation rhythm of the robot is matched. In addition, the liquid focusing module has excellent imaging quality, and can meet the accurate collection requirements of the robot positioning and detection.

[0015] In order to make the above features and advantages of the application more obvious and easy to understand, the following specific embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 FIG. 1 is a schematic diagram of the liquid focusing module in the application.

[0017] Figure 2 FIG. 4 is a light fan diagram of different field regions of the liquid focusing module in the application when the working wavelength is 486 nm, 588 nm and 656 nm.

[0018] Figure 3 FIG. 5 is a field curvature diagram of the liquid focusing module in the application when the working wavelength is 486 nm, 588 nm and 656 nm.

[0019] Figure 4 FIG. 6 is a distortion diagram of the liquid focusing module in the application when the working wavelength is 486 nm, 588 nm and 656 nm.

[0020] Figure 5The optical modulation transfer function diagram of the liquid focusing module in the application in the working waveband (486nm-656nm).

[0021] Figure 6 The relative luminance diagram of the liquid focusing module in the application when the working wavelength is 588nm.

[0022] Figure 7 The circle of confusion diagram of the liquid focusing module in the application when the working wavelength is 486nm, 588nm and 656nm.

[0023] Reference signs: The first lens-1; the second lens-2; the liquid lens-3; the diaphragm-4; the cemented plate-5; the third lens-6; the fourth lens-7; the fifth lens-8; The sixth lens-51; the seventh lens-52. DETAILED DESCRIPTION

[0024] In order to make the purpose and technical scheme of the embodiments of the application clearer, the technical scheme of the embodiments of the application will be described clearly and completely below in combination with the drawings of the embodiments of the application. Obviously, the described embodiments are part of the embodiments of the application, rather than all the embodiments. Based on the described embodiments of the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0025] In order to overcome the problems of large volume and inflexible focusing of the lens module for robots in the prior art, the application provides a liquid focusing module and a lens. Figure 1 The optical path structure schematic diagram of the liquid focusing module in the application is shown as Figure 1 The object plane A is located at the left side of the liquid focusing module, and the initial focusing object distance is 150mm; the image plane B is located at the right side of the liquid focusing module, and the image distance is 1mm. In the figure, the ideal focusing object plane and the ideal image plane are shown.

[0026] The lenses and the diaphragm 4 in the liquid focusing module are sequentially arranged and take the optical axis as the rotation center.

[0027] For the convenience of description, the surface of each lens close to the object plane A is defined as the object side surface, and the curvature of the object side surface of the lens is defined as the object plane curvature; the surface of each lens close to the image plane B is defined as the image side surface, and the curvature of the image side surface of the lens is defined as the image plane curvature; and the curvature convex surface towards the object plane A is positive, and the convex surface towards the image plane B is negative.

[0028] The liquid focusing module is provided with the first lens 1, the second lens 2, the liquid lens 3, the diaphragm 4, the cemented plate 5, the third lens 6, the fourth lens 7 and the fifth lens 8 from the object plane side to the image plane side. The cemented plate 5 comprises the sixth lens 51 and the seventh lens 52, the sixth lens is arranged on the object plane side of the seventh lens, and the image side surface of the sixth lens is cemented with the object side surface of the seventh lens. The liquid lens 3 and the diaphragm 4 are located at the same position.

[0029] The object side surface of the first lens 1 is a convex surface, the object plane curvature radius of the first lens 1 is 12.17mm, the image side surface of the first lens 1 is a concave spherical surface, and the image plane curvature radius of the first lens 1 is 7.56mm; The object side surface of the second lens 2 is a convex spherical surface, the object plane curvature radius of the second lens 2 is 8.37mm, the image side surface of the second lens 2 is a plane, and the image plane curvature radius of the second lens 2 is ∞; The object side surface of the sixth lens 51 in the cemented plate 5 is a concave spherical surface, the object plane curvature radius of the sixth lens 51 in the cemented plate 5 is -7.58mm, the image side surface of the sixth lens 51 in the cemented plate 5 is a concave spherical surface, and the image plane curvature radius of the sixth lens 51 in the cemented plate 5 is 7.58mm; The object side surface of the seventh lens 52 in the cemented plate 5 is a convex spherical surface, the object plane curvature of the seventh lens 52 in the cemented plate 5 is consistent with the image plane curvature of the sixth lens 51 in the cemented plate 5, and the curvature radius is 7.58mm; the image side surface of the seventh lens 52 in the cemented plate 5 is a convex spherical surface, and the image plane curvature radius of the seventh lens 52 in the cemented plate 5 is -7.58mm; The object side surface of the third lens 6 is a concave spherical surface, the object plane curvature radius of the third lens 6 is -3.48mm, the image side surface of the third lens 6 is a convex spherical surface, and the image plane curvature radius of the third lens 6 is -15.82mm; The object side surface of the fourth lens 7 is a convex spherical surface, the object plane curvature radius of the fourth lens 7 is 19.27mm, the image side surface of the fourth lens 7 is a plane, and the image plane curvature radius of the fourth lens 7 is ∞; The object side surface of the fifth lens 8 is a plane, the object plane curvature radius of the fifth lens 8 is ∞, the image side surface of the fifth lens 8 is a plane, and the image plane curvature radius of the fifth lens 8 is ∞.

[0030] The surface type tolerance of all curvatures is 3-5 apertures, and the local aperture is 0.3-0.5 (interferometer is used for detection).

[0031] The focal length of the liquid fixed-focus module is 16 mm; the focal length of the first lens 1 is -27.355 mm; the focal length of the second lens 2 is 9.579 mm; the focal length of the sixth lens 51 in the cemented plate 5 is -4.709 mm, and the focal length of the seventh lens 52 in the cemented plate 5 is 4.785 mm; the focal length of the third lens 6 is -16.196 mm; the focal length of the fourth lens 7 is 21.129 mm; and the focal length of the fifth lens 8 is infinite.

[0032] The lenses are all glass lenses, wherein the liquid lens 3 adopts Corning A25N0 liquid lens 3, the first lens 1, the second lens 2, the third lens 6, the fourth lens 7 and the fifth lens 8 all adopt Chengdu Guangming colorless glass, and the model of Chengdu Guangming is used for representation. The first lens 1 adopts heavy flint glass (H-ZF7LA); the second lens 2 adopts lanthanum flint glass (H-LaF2); the sixth lens 51 in the cemented plate 5 adopts heavy flint glass (H-ZF4A), and the seventh lens 52 in the cemented plate 5 adopts lanthanum crown glass (H-LaK3); the third lens 6 adopts crown glass (H-K51); the fourth lens 7 adopts barium flint glass (H-BaF8); and the fifth lens 8 adopts heavy flint glass (H-ZF52).

[0033] The total optical length of the liquid fixed-focus module is 30.602 mm, that is, the distance between the curvature center of the object side surface of the first lens 1 and the image surface B is 30.602 mm. The optical interval between the first lens 1 and the second lens 2 is 3.63 mm-3.67 mm, preferably 3.65 mm; the optical interval between the second lens 2 and the liquid lens 3 is 2.98 mm-3.02 mm, preferably 3.00 mm; the surface of the liquid lens 3 is adjacent to the diaphragm 4; the optical interval between the diaphragm 4 and the cemented plate 5 is 2.48 mm-2.52 mm, preferably 2.50 mm; the optical interval between the cemented plate 5 and the third lens 6 is 0.98 mm-1.02 mm, preferably 1.00 mm; the optical interval between the third lens 6 and the fourth lens 7 is 0.58 mm-0.62 mm, preferably 0.600 mm; and the optical interval between the fourth lens 7 and the fifth lens 8 is 4.98 mm-5.02 mm, preferably 5.00 mm.

[0034] The aperture of the liquid fixed-focus module is F / 6, the image surface B size diameter is 9.6 mm, the diagonal field of view angle is 30.76°, and the object side numerical aperture is 0.009. The working environment of the liquid fixed-focus module is a visible light environment, and the working waveband is 486 nm-650 nm. The liquid fixed-focus module is suitable for a board module camera and an intelligent built-in module camera with an effective photosensitive diagonal line size of 9.6 mm or less, and can be applied to a robot imaging module or an intelligent camera module. The theoretical focusing distance of the liquid fixed-focus module is 30 mm to 10,000 mm.

[0035] The application further provides a lens, which comprises the liquid fixed-focus module as described above, and the specific structure of the liquid fixed-focus module can be referred to the description above.

[0036] Figure 2 The light fan diagram of the liquid fixed-focus module in different field of view regions when the working wavelengths are 486 nm, 588 nm and 656 nm is shown. In the light fan diagram, the X axis is the position of the entrance pupil, and the Y axis is the deviation of the chief ray transmission on the image surface position. Figure 2 The aberration set generated in different field of view regions is shown, and the meridional plane and sagittal plane aberrations in each field of view region can be seen.

[0037] Figure 3 The field curvature diagram of the liquid fixed-focus module in the application when the working wavelengths are 486.1 nm, 587.6 nm and 656.3 nm. Figure 3 Different curves in the figure represent different wavelengths, and it can be seen that the image surface curvature is controlled within 0.0461 mm, the image surface curvature can be ignored, and it is indicated that the field curvature correction of the optical system in the embodiment is good.

[0038] Figure 4 The distortion diagram of the liquid fixed-focus module in the application when the working wavelengths are 486.1 nm, 587.6 nm and 656.3 nm. The abscissa in the figure represents the distortion size, the ordinate represents the field of view, and the curve represents the F-Tan(θ) distortion corresponding to the light rays of different wavelengths on the image surface in different fields of view. Figure 4 It can be seen from the figure that, within the full field of view of the liquid fixed-focus module, the distortion is controlled to be less than 0.652%, and the maximum distortion position appears in the edge field of view of the whole image, and it is indicated that the distortion of the optical system is well corrected.

[0039] Figure 5The optical modulation transfer function diagram of the liquid fixed-focus module in the application in the working waveband (486.0 nm-656.0 nm). The lens imaging modulation degree of different spatial frequencies of the meridian or sagittal plane under each field of view, the horizontal coordinate is the spatial frequency, and the vertical coordinate is the OTF module value (optical transfer function). Different lines represent different fields of view and differences in meridian or sagittal. Figure 5 It is shown that, in the range of 0-350 cycles / mm, the optical modulation transfer function curves from the center to the edge field are concentrated and uniformly smooth, and the liquid fixed-focus module has good imaging quality and good detail resolution ability in the case of high frequency and low frequency.

[0040] Figure 6 The relative luminance diagram of the liquid fixed-focus module in the application when the working wavelength is 588 nm. The horizontal coordinate represents the field of view, and the vertical coordinate represents the relative luminance. Figure 6 It represents the light distribution in different areas of the image plane after the light passes through the optical system, reflecting the attenuation of the illumination of different fields of view. It can be seen from Figure 6 that the image illumination of the edge can reach more than 90% of the center illumination, and the image illumination almost does not decay.

[0041] Figure 7 The liquid fixed-focus module in the application is a liquid fixed-focus module in the application when the working wavelength is 486 nm, 588 nm and 656 nm. Figure 7 It is the diffusion of all pupil rays converging to the image plane in different field of view regions, and different curves represent different wavelengths. From Figure 7 it can be seen that the geometric spot radius of almost all fields of view in the design wavelength range can reach within 4.316 μm, indicating that the aberration correction of the liquid fixed-focus module is good.

[0042] In summary, the application provides a liquid fixed-focus module and a lens liquid fixed-focus module and lens. The application sequentially sets a first lens, a second lens, a liquid lens, a diaphragm, a cemented plate, a third lens, a fourth lens and a fifth lens from the object plane side to the image plane side, constructs a compact and lightweight liquid fixed-focus module, is small in size and can be easily integrated into an industrial robot or a household robot, and is suitable for the narrow installation space of a robot. By adopting a liquid lens and optimizing the light path layout, a wide range of focusing is effectively realized, the focusing response is efficient, and the real-time operation rhythm of a robot is matched. In addition, the liquid fixed-focus module has excellent imaging quality and can meet the accurate collection requirements of robot positioning and detection.

[0043] Although the present application has been disclosed with reference to the embodiments above, it is not intended to limit the present application and any person skilled in the art can make some changes and modifications without departing from the spirit and scope of the present application, and the scope of protection of the present application is defined by the following claims.

Claims

1. A liquid focus module, characterized in that, From the object plane side to the image plane side successively include a first lens, a second lens, a liquid lens, a cemented lens, a third lens, a fourth lens and a fifth lens; the object side surface of the first lens is a convex surface, the image side surface of the first lens is a concave spherical surface, the object side surface of the second lens is a convex spherical surface, the image side surface of the second lens is a plane, the object side surface of the cemented lens is a concave spherical surface, the image side surface of the cemented lens is a convex spherical surface, the object side surface of the third lens is a concave spherical surface, the image side surface of the third lens is a convex spherical surface, the object side surface of the fourth lens is a convex spherical surface, the image side surface of the fourth lens is a plane, the object side surface of the fifth lens is a plane, and the image side surface of the fifth lens is a plane.

2. A liquid focus module as claimed in claim 1, characterized in that The object plane curvature radius of the first lens is 12.17mm, the image plane curvature radius of the first lens is 7.56mm, the object plane curvature radius of the second lens is 8.37mm, the image plane curvature radius of the second lens is ∞, the object plane curvature radius of the cemented lens is -7.58mm, the image plane curvature radius of the cemented lens is -7.58mm, the object plane curvature radius of the third lens is -3.48mm, the image plane curvature radius of the third lens is -15.82mm, the object plane curvature radius of the fourth lens is 19.27mm, the image plane curvature radius of the fourth lens is ∞, the object plane curvature radius of the fifth lens is ∞, and the image plane curvature radius of the fifth lens is ∞.

3. A liquid focus module as described in claim 2, characterized in that, The optical spacing between the first lens and the second lens is 3.63mm-3.67mm; the optical spacing between the second lens and the liquid lens is 2.98mm-3.02mm; the optical spacing between the liquid lens and the cemented lens is 2.48mm-2.52mm; the optical spacing between the cemented lens and the third lens is 0.98mm-1.02mm; the optical spacing between the third lens and the fourth lens is 0.58mm-0.62mm; and the optical spacing between the fourth lens and the fifth lens is 4.98mm-5.02mm.

4. The liquid focus module of claim 1, wherein: The cemented lens comprises a sixth lens and a seventh lens, the sixth lens is arranged on the object plane side of the seventh lens, the object side surface of the sixth lens is a concave spherical surface, the image side surface of the sixth lens is a concave spherical surface, the object side surface of the seventh lens is a convex spherical surface, and the image side surface of the seventh lens is a convex spherical surface.

5. A liquid focus module as described in claim 4, characterized in that, The object plane curvature radius of the sixth lens is -7.58mm, and the image plane curvature radius of the sixth lens is 7.58mm; the object plane curvature radius of the seventh lens is 7.58mm; and the image plane curvature radius of the seventh lens is -7.58mm.

6. A liquid focus module as described in claim 4, characterized in that, The focal length of the first lens is -27.355mm; the focal length of the second lens is 9.579mm; the focal length of the sixth lens is -4.709mm, the focal length of the seventh lens is 4.785mm; the focal length of the third lens is -16.196mm; the focal length of the fourth lens is 21.129mm; and the focal length of the fifth lens is ∞.

7. A liquid focus module as described in claim 4, characterized in that, The first lens adopts heavy flint glass, the second lens adopts lanthanum flint glass; the sixth lens adopts heavy flint glass, the seventh lens adopts lanthanum crown glass; the third lens adopts crown glass; the fourth lens adopts barium flint glass; the fifth lens adopts heavy flint glass.

8. The liquid focus module of claim 1, wherein: The distance between the curvature center of the object side surface of the first lens and the image surface is 30.602 mm.

9. The liquid focus module of claim 1, wherein, The liquid focusing module further comprises a diaphragm, and the diaphragm and the liquid lens are located at the same position.

10. A lens characterized by comprising: The lens comprises the liquid focusing module as claimed in any one of claims 1-9.

Images