CN113448071B - Optical module - Google Patents
Optical module Download PDFInfo
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- CN113448071B CN113448071B CN202010156658.7A CN202010156658A CN113448071B CN 113448071 B CN113448071 B CN 113448071B CN 202010156658 A CN202010156658 A CN 202010156658A CN 113448071 B CN113448071 B CN 113448071B
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B15/00—Optical objectives with means for varying the magnification
- G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
- G02B15/16—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group
- G02B15/163—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group having a first movable lens or lens group and a second movable lens or lens group, both in front of a fixed lens or lens group
- G02B15/167—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group having a first movable lens or lens group and a second movable lens or lens group, both in front of a fixed lens or lens group having an additional fixed front lens or group of lenses
- G02B15/173—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group having a first movable lens or lens group and a second movable lens or lens group, both in front of a fixed lens or lens group having an additional fixed front lens or group of lenses arranged +-+
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B13/00—Viewfinders; Focusing aids for cameras; Means for focusing for cameras; Autofocus systems for cameras
- G03B13/32—Means for focusing
Abstract
The invention provides an optical module. Based on the invention, the optical module comprises the first lens group for focusing, the second lens group and the third lens group for zooming adjustment, and the double lens group linkage of the second lens group and the third lens group can dynamically compensate the focusing deviation of the imaging light beam caused by the focal length change in the zooming adjustment period, so that the zooming adjustment can be carried out without refocusing of the first lens group through adaptive movement. Moreover, the whole zooming adjusting process between the wide-angle mode and the long-focus mode of the optical module can avoid the occurrence of the diffuse focusing of the imaging light beams on the imaging target surface so as to realize the whole-process clear focusing in the zooming process. In addition, the optical module can also comprise a diaphragm with a constant aperture, so that the whole-process clear focusing with a constant aperture can be realized.
Description
Technical Field
The present invention relates to an optical imaging technology, and more particularly, to an optical module capable of focusing clearly in the whole process of zooming, an optical lens using the optical module, and a camera using the optical lens.
Background
The optical module in the optical lens can comprise a group of focusing lens groups for focusing and a group of zooming lens groups for zooming, so that the imaging light beams can be focused on the imaging target surface of the photosensitive element clearly at a selected focal length.
When the zoom lens group moves to realize zoom adjustment, the change of the focal length may cause the imaging light beam to be dispersedly focused on the imaging target surface, and therefore, the focusing lens group also needs to be moved adaptively to realize refocusing under the focal length after zoom adjustment.
That is, there is a certain period of diffuse focusing during the zoom adjustment process, so that a plurality of frames of unclear images may be included in the images continuously output by the photosensitive element due to such diffuse focusing. For a security monitoring scene, if a large number of unclear images are mixed in the image output by the light-stabilizing element of the camera, the security quality is reduced.
Disclosure of Invention
In one embodiment, there is provided an optical module comprising:
the first lens group is movably arranged on the side of the imaging target surface of the photosensitive element and used for focusing the focus of the incident imaging light beam on the imaging target surface by adapting the movement of the target object distance along the optical axis direction of the optical module;
a second lens group movably arranged between the first lens group and the imaging target surface and used for carrying out zoom adjustment on the imaging of the imaging light beam on the imaging target surface by adapting to the movement of expected magnification in the optical axis direction;
a third lens group movably arranged between the second lens group and the imaging target surface and used for dynamically compensating the focusing deviation of the imaging light beam caused by the focal length change in the zooming adjusting period through linkage with the second lens group in the optical axis direction; wherein the linkage of the third lens group and the second lens group is: the second lens group and the third lens group move in the same direction so that the relative distance therebetween is variable.
Optionally, the first lens group has a first lens group focal length, and the first lens group focal length is a positive focal length; the second lens group has a second lens group focal length, and the second lens group focal length is a negative focal length; the third lens group has a third lens group focal length, and the third lens group focal length is a positive focal length.
Optionally, further comprising: a fourth lens group fixedly arranged between the third lens group and the imaging target surface; the fourth lens group has a fourth lens group focal length, and the fourth lens group focal length is a positive focal length and is used for forming convergence correction in a positive focal length direction on the imaging light beam projected by the first lens group, the second lens group and the third lens group in sequence.
Optionally, an absolute value of a ratio of the stroke range of the second lens group to the focal length of the second lens group is greater than a ratio of the stroke range of the third lens group to the focal length of the third lens group.
Optionally, an absolute value of a ratio of the focal length of the first lens group to the focal length of the second lens group is greater than a ratio of the focal length of the first lens group to the focal length of the third lens group; and the ratio of the focal length of the first lens group to the focal length of the fourth lens group is larger than the ratio of the focal length of the first lens group to the focal length of the third lens group.
Optionally, the first lens group includes a first lens, a second lens and a third lens that are sequentially arranged at a fixed relative distance in a direction toward the imaging target surface, where the first lens is a meniscus spherical lens with a negative focal length, the second lens is a double-convex spherical lens, and the third lens is a single-convex spherical lens with a positive focal length; the second lens group comprises a fourth lens, a fifth lens and a sixth lens which are sequentially arranged in a direction facing the imaging target surface at fixed relative intervals, wherein the fourth lens is a biconcave aspheric lens with a negative focal length, the fifth lens is a biconcave spherical lens with a negative focal length, and the sixth lens is a biconvex spherical lens with a positive focal length; the third lens group comprises a seventh lens and an eighth lens which are sequentially arranged in a direction facing the imaging target surface at a fixed relative distance, wherein the seventh lens is a biconcave spherical lens with a negative focal length, and the eighth lens is a biconvex spherical lens with a positive focal length; the fourth lens group comprises at least four of a ninth lens, a tenth lens, an eleventh lens, a twelfth lens and a thirteenth lens which are sequentially arranged in a direction facing the imaging target surface at fixed relative intervals, wherein the ninth lens is an aspheric lens with a positive focal length, the tenth lens is a biconcave spherical lens with a negative focal length, the eleventh lens is a biconvex spherical lens with a positive focal length, the twelfth lens is a meniscus spherical lens with a negative focal length, and the thirteenth lens is a meniscus spherical lens with a negative focal length.
Optionally, the first lens and the second lens are further formed by bonding as a first cemented lens; and/or the fifth lens and the sixth lens are further formed into a second cemented lens by bonding.
Optionally, further comprising: a diaphragm fixedly disposed between the third lens group and the imaging target surface, and having a constant aperture diameter.
Optionally, a span dimension of the optical module in the optical axis direction is greater than an upper focal length limit of the optical module and is not more than three times of the upper focal length limit; the span size is the distance between the light entrance mirror surface of the first lens group, which faces away from the imaging target surface, and the imaging target surface; and the upper limit of the focal length is the total focal length of the optical module when the second lens group is located at the limit position close to the imaging target surface.
In another embodiment, an optical lens is provided, which includes the optical module according to the foregoing embodiments.
In another embodiment, there is provided a camera comprising a light sensing element, and an optical lens as described in the previous embodiments.
Based on the above embodiment, the optical module includes the first lens group for focusing, and the second lens group and the third lens group for zoom adjustment, and the dual lens group linkage of the second lens group and the third lens group can dynamically compensate the focus deviation of the imaging beam caused by the focal length change during the zoom adjustment period, so that the zoom adjustment can be performed without refocusing by adaptively moving the first lens group. Moreover, the whole zooming adjusting process between the wide-angle mode and the long-focus mode of the optical module can avoid the occurrence of the diffuse focusing of the imaging light beam on the imaging target surface so as to realize the whole clear focusing in the zooming process.
In addition, based on the above-mentioned embodiment, the optical module may further include a diaphragm having a constant aperture, so that full-range clear focusing with a constant aperture size may be achieved.
Drawings
The following drawings are only schematic illustrations and explanations of the present invention, and do not limit the scope of the present invention:
FIGS. 1 a-1 c are schematic diagrams illustrating exemplary structures of an optical module in one embodiment;
FIG. 2 is a schematic diagram illustrating a zoom adjustment process of the optical module shown in FIGS. 1a to 1 c;
FIG. 3 is a schematic diagram illustrating an optical path effect of the optical module in the wide-angle mode shown in FIG. 1 a;
FIG. 4 is a schematic diagram illustrating the optical path effect of the optical module in the tele mode shown in FIG. 1 b;
fig. 5a to 5d are schematic diagrams illustrating optical path effects of the optical module in the intermediate mode shown in fig. 1 c.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and examples.
Fig. 1a to 1c are schematic structural diagrams of an optical module according to an embodiment. Fig. 2 is a schematic diagram illustrating a zoom adjustment process of the optical module shown in fig. 1a to 1 c. Wherein fig. 1a shows the state of the optical module in the wide mode, fig. 1b shows the state of the optical module in the tele mode, and fig. 1c shows the state of the optical module in an intermediate mode between the wide mode as shown in fig. 1a and the tele mode as shown in fig. 1 b.
Referring to fig. 1a to fig. 1c in conjunction with fig. 2, an optical axis of the optical module in this embodiment passes through a photosensitive element 70, wherein the photosensitive element may be a photosensitive imaging Device such as a CCD (Charge Coupled Device). The optical module may include a first lens group 10, a second lens group 20, and a third lens group 30.
The first lens group 10 is movably (for example, the maximum moving stroke may be 0.6 mm) disposed on the side of the imaging target surface of the photosensitive element 70, and is configured to focus the focus of the incident imaging light beam on the imaging target surface of the photosensitive element 70 by moving in the optical axis direction to adapt the target object distance;
the second lens group 20 is movably arranged between the first lens group 10 and the imaging target surface of the photosensitive element 70, and is used for carrying out zoom adjustment on the imaging of the imaging light beams on the imaging target surface of the photosensitive element 70 by adapting to the movement of a desired magnification in the optical axis direction;
the third lens group 30 is movably disposed between the second lens group and the imaging target surface of the photosensitive element 70, and is configured to dynamically compensate for a focus deviation of the imaging light beam due to a focal length change during zoom adjustment by interlocking with the second lens group in the optical axis direction. The linkage between the third lens group 30 and the second lens group 20 may be: the second lens group 20 and the third lens group 30 move in the same direction with a variable relative distance therebetween.
Based on the above structure, the dual lens group linkage of the second lens group 20 and the third lens group 30 can dynamically compensate the focus deviation of the imaging light beam due to the focal length change during the zoom adjustment, so that the zoom adjustment can be performed without refocusing the first lens group 10 by adaptive movement. Moreover, during the whole zoom adjusting process of the optical module between the wide-angle mode shown in fig. 1a and the telephoto mode shown in fig. 1b, the occurrence of diffuse focusing of the imaging light beam on the imaging target surface of the photosensitive element 70 can be avoided, so as to achieve the whole-process clear focusing during the zooming process.
The optical module in the above embodiment may further include a filter 60 for shielding the imaging target surface of the photosensitive element 70. If the imaging target surface of the photosensitive element 70 is shielded by the filter 60 which cuts off infrared light and transmits visible light, clear infrared imaging with full-range focusing can be realized; if the imaging target surface of the photosensitive element 70 is shielded by the filter 60 that is transparent to both visible light and infrared light, visible light imaging and infrared imaging (for obtaining a fused image) with clear overall focusing can also be achieved.
As a preferable solution for meeting both imaging requirements, the filter 60 may include two filter sectors that are arranged in a staggered manner, that is, the filter 60 may include a first filter sector that is transparent to infrared light and visible light, and a second filter sector that is transparent to both visible light and infrared light, and the first filter sector and the second filter sector are arranged in a staggered manner.
Therefore, in the daylight mode with sufficient sunlight, the optical filter 60 can be switched to a phase posture in which the first filter sector shields the imaging target surface of the photosensitive element 70 and the second filter sector avoids the imaging target surface of the photosensitive element 70, so as to realize visible light imaging of the photosensitive element 70; in the dark mode with weak sunlight, the filter 60 can be switched to a phase posture in which the second filter sector shields the imaging target surface of the photosensitive element 70 and the first filter sector avoids the imaging target surface of the photosensitive element 70, so as to realize visible light imaging and infrared imaging of the photosensitive element 70.
For the above switching manner, although the light transmitted by the optical filter 60 in different phase positions has different wavelength ranges, the light has the same optical path, so that refocusing is not required, the whole focusing process is clear, and the infrared confocal system can be considered.
Taking the example that the imaging element is a 1/1.8' type CCD with the diagonal size of 9.2mm, the measured imaging image can reach the resolution of 400 ten thousand pixels, the central resolution can be higher than 250lp/mm (line pair/mm), and the peripheral 0.8H (80% diagonal position) resolution can be higher than 160lp/mm.
As a preferable scheme, the first lens group 10 has a first lens group focal length f1, and the first lens group focal length f1 may be a positive focal length; the second lens group 20 has a second lens group focal length f2, and the second lens group focal length f2 can be a negative focal length; the third lens group 30 has a third lens group focal length f3, and the third lens group focal length f3 can be a positive focal length.
Based on the positive and negative focal length configuration described above, in the process of switching between the wide mode shown in fig. 1a and the telephoto mode shown in fig. 1b, the third lens group 30 moves in the same direction as the second lens group 20, and the distance between the third lens group 30 and the second lens group 20 changes in a tendency of first becoming larger and second becoming smaller over the entire movement stroke of the second lens group 20.
As can be seen from fig. 2, the third lens group 30 and the second lens group 20 have a first distance D _ WA therebetween in the wide-angle mode, the third lens group 30 and the second lens group 20 have a second distance D _ LF therebetween in the telephoto mode, the third lens group 30 and the second lens group 20 have a third distance D _ S (variable) therebetween in the intermediate mode, and the third distance D _ S is greater than each of the first distance D _ WA and the second distance D _ LF.
In actual lens fitting, an absolute value of a ratio of the first lens group focal length f1 of the first lens group 10 to the second lens group focal length f2 of the second lens group 20 may be greater than a ratio of the first lens group focal length f1 of the first lens group 10 to the third lens group focal length f3 of the third lens group 30, that is, | f1/f2| > f1/f3.
That is, p1 ≧ f1/f2 ≧ p2, p3 ≧ f1/f3 ≧ p4, where the first focal length ratio p1 (e.g., a value may be 6) is greater than the second focal length ratio p2 (e.g., a value may be 4), the second focal length ratio p2 is greater than the third focal length ratio p3 (e.g., a value may be 1.5), and the third focal length ratio p3 is greater than the fourth focal length ratio p4 (e.g., a value may be 0.7).
Further, an absolute value of a ratio of a stroke range m2 of the second lens group 20 (a full stroke of movement, for example, 25.8mm, for switching between the wide-angle mode shown in fig. 1a and the telephoto mode shown in fig. 1 b) to the second lens group focal length f may be larger than a ratio of a stroke range of the third lens group 30 (a full stroke of movement, for example, 4.6mm, for switching between the wide-angle mode shown in fig. 1a and the telephoto mode shown in fig. 1 b) to the third lens group focal length f3, that is, | m2/f2| > m3/f3.
That is, q1 ≧ m2/f2 ≧ q2, q3 ≧ m3/f3> q4, where the first distance ratio q1 (e.g., may be 3) is greater than the second distance ratio q2 (e.g., may be 1.5), the second distance ratio q2 is greater than the third distance ratio q3 (e.g., may be 0.1), and the third distance ratio q3 is greater than the fourth distance ratio q4 (e.g., may be 0).
If | f1/f2| > f1/f3 and/or | m2/f2| > m3/f3, the zoom capability of the second lens group 20 having a negative focal length may be stronger than that of the third lens group 30 having a positive focal length, and a larger zoom (magnification-varying) space, for example, a zoom space of 9.7mm to 47mm, may thereby be provided.
However, if the range of | f1/f2| exceeding f1/f3 is too large and/or the range of | m2/f2| exceeding m3/f3 is too large, the total focal length of the first lens group focal length f1 (positive), the second lens group focal length f2 (negative) and the third lens group focal length f3 (positive) may be negative, so that the imaging light beam cannot be focused on the imaging target surface of the photosensitive element 70. At this time, the optical module may further include a fourth lens group 40.
The fourth lens group 40 may be fixedly disposed between the third lens group 30 and the imaging target surface of the photosensitive element 70, wherein the fourth lens group 40 may have a fourth lens group focal length f4, and the fourth lens group focal length f4 is a positive focal length, and is used for forming convergence correction in a positive focal length direction on the imaging light beams projected by the first lens group 10, the second lens group 20 and the third lens group 30 in sequence.
For example, the ratio of the first lens group focal length f1 of the first lens group 10 to the fourth lens group focal length f4 of the fourth lens group 40 may be greater than the ratio of the first lens group focal length f of the first lens group 10 to the third lens group focal length f3 of the third lens group 30, i.e., f1/f4> f1/f3.
That is, p5 is greater than or equal to f1/f4 and greater than or equal to p6, p3 is greater than or equal to f1/f3 and greater than or equal to p4, wherein the fifth focal length ratio p5 (for example, 5) is greater than the sixth focal length ratio p6 (for example, 2.5), the sixth focal length ratio p6 is greater than the third focal length ratio p3 (for example, 1.5), and the third focal length ratio p3 is greater than the fourth focal length ratio p4 (for example, 0.7).
In order to provide a physical space satisfying the above focal length ratio, the optical module may have a span dimension TTL in the optical axis direction greater than and not more than three times the upper focal length limit ft of the optical module.
For example, 1.5 ≦ TTL/ft ≦ 3.
The span TTL is a distance between the incident mirror surface of the first lens group 10 facing away from the imaging target surface and the imaging target surface, and the upper limit of the focal length ft is a total focal length of the optical module when the second lens group 20 is located at a limit position close to the imaging target surface (in the telephoto mode shown in fig. 1 a).
In addition, in the case where the optical module further includes the filter 60, the fourth lens group 40 may be fixedly disposed between the third lens group 30 and the filter 60.
Referring to fig. 1a to fig. 1c in combination with fig. 2, the optical module in the above embodiment may further include a diaphragm 50.
The diaphragm 50 may be fixedly disposed between the third lens group 30 and the imaging target surface of the photosensitive element 70, for example, the distance between the diaphragm 50 and the imaging target surface of the photosensitive element 70 may be 36.19mm, and the maximum distance between the diaphragm 50 and the movable first lens group 10 may be 54.47mm. For the case where the optical module includes the fourth lens group 40 at the same time, the diaphragm 50 may be fixedly disposed between the third lens group 30 and the fourth lens group 40. Also, the diaphragm 50 may have a constant aperture (e.g., 13.85 mm). In addition, in the case where the optical module further includes the fourth lens group 40, the stop 50 may be fixedly disposed between the third lens group 30 and the fourth lens group 40.
Fig. 3 is a schematic diagram illustrating an optical path effect of the optical module in the wide-angle mode shown in fig. 1 a. Fig. 4 is a schematic diagram illustrating the optical path effect of the optical module in the tele mode shown in fig. 1 b. Fig. 5a to 5c are schematic diagrams illustrating optical path effects of the optical module in the intermediate mode shown in fig. 1 c. As can be seen from fig. 3, 4 and 5a to 5d, the optical module in the above embodiment can realize full-range clear focusing with a constant aperture size in the full range.
Referring back to fig. 1a to 1c, the above embodiment further provides a preferred lens allocation scheme for each lens group, which is as follows:
the first lens group 10 may include a first lens 11, a second lens 12, and a third lens 13 arranged in order at fixed relative intervals in a direction toward the imaging target surface, wherein the first lens 11 may be a meniscus spherical lens having a negative focal length, the second lens 12 may be a double-convex spherical lens, the third lens 13 may be a single-convex spherical lens having a positive focal length, and further preferably, the first lens 11 and the second lens 12 may be further cemented to form a first cemented lens;
the second lens group 20 may include a fourth lens 21, a fifth lens 22, and a sixth lens 23 arranged in this order at fixed relative pitches in a direction toward the imaging target surface, wherein the fourth lens 21 may be a biconcave aspheric lens having a negative focal length, the fifth lens 22 may be a biconcave spherical lens having a negative focal length, the sixth lens 23 may be a biconvex spherical lens having a positive focal length, and further preferably, the fifth lens 22 and the sixth lens 23 may be further formed by bonding as a second cemented lens;
the third lens group 30 may include a seventh lens 31 and an eighth lens 32 sequentially arranged at a fixed relative pitch in a direction toward the imaging target surface, wherein the seventh lens 31 may be a biconcave spherical lens having a negative focal length, and the eighth lens 32 may be a biconvex spherical lens having a positive focal length;
the fourth lens group 40 may include at least four of a ninth lens 41, a tenth lens 42, an eleventh lens 43, a twelfth lens 44, and a thirteenth lens 45 arranged in order at a fixed relative distance in a direction toward the imaging target surface, wherein the ninth lens 41 may be an aspheric lens having a positive focal length, the tenth lens 42 may be a biconcave spherical lens having a negative focal length, the eleventh lens 43 may be a biconvex spherical lens having a positive focal length, the twelfth lens 44 may be a meniscus spherical lens having a negative focal length, and the thirteenth lens 45 may be a meniscus spherical lens having a negative focal length.
The mirror radius Z of the lens described above may satisfy the following equation:
where, the parameter c is the curvature corresponding to the radius, y is the radial coordinate (the unit is the same as the unit of the lens length), k is the conic coefficient, and a2, a4, a6, a8, a10, a12, a14, and a16 represent the coefficients corresponding to the radial coordinates, respectively.
When the k coefficient is less than-1, the surface-shaped curve is a hyperbolic curve;
when the k coefficient is equal to-1, the surface-shaped curve is a parabola;
when the k coefficient is between-1 and 0, the surface-shaped curve is an ellipse;
when the k coefficient is equal to 0, the surface-shaped curve is circular;
when the k coefficient is larger than 0, the surface-shaped curve is oblate.
By the above parameters, the shape and size of the mirror surface (especially, the aspherical mirror surface) can be accurately set.
The preferred parameters of the mirror surface of each lens are listed in table 1 below, and in table 1, the light exit surface of the lens is regarded as the light entrance surface of the mirror gap located on the light exit side of the lens.
TABLE 1
In table 2 below, the limit values for the three variables in table 1 in the wide mode and tele mode are listed:
| wide angle end | Telephoto end | |
| D(5) | 0.60 | 26.37 |
| D(10) | 17.61 | 0.54 |
| D(14) | 3.11 | 0.8 |
TABLE 2
The following table 3 lists the coefficients a4, a6, a8, a10 (a 2, a12, a14, and a16 taken to be 0) for the aspheric light-entering surface:
TABLE 3
In addition, in another embodiment, an optical lens is provided, which includes the optical module according to the foregoing embodiments.
In another embodiment, there is also provided a camera including the light sensing element 70 and the optical lens according to the previous embodiment.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
1. An optical module, comprising:
the first lens group is movably arranged on the side of an imaging target surface of the photosensitive element and used for focusing the focus of an incident imaging light beam on the imaging target surface by adapting to the movement of a target object distance along the optical axis direction of the optical module, and the first lens group has a first lens group focal length which is a positive focal length;
a second lens group movably arranged between the first lens group and the imaging target surface and used for carrying out zoom adjustment on the imaging of the imaging light beam on the imaging target surface by adapting to the movement of expected multiplying power in the optical axis direction, wherein the second lens group has a second lens group focal length which is a negative focal length;
a third lens group movably arranged between the second lens group and the imaging target surface and used for dynamically compensating focusing deviation of the imaging light beam caused by focal length change in the zooming adjusting period through linkage with the second lens group in the optical axis direction, wherein the third lens group has a third lens group focal length which is a positive focal length; and
a fourth lens group fixedly arranged between the third lens group and the imaging target surface and used for forming convergence correction in a positive focal length direction on the imaging light beams projected by the first lens group, the second lens group and the third lens group in sequence, wherein the fourth lens group has a fourth lens group focal length which is a positive focal length;
wherein the linkage of the third lens group and the second lens group is: the second lens group and the third lens group move in the same direction in a way that the relative distance between the second lens group and the third lens group is variable, and the absolute value of the ratio of the stroke range of the second lens group to the focal length of the second lens group is larger than the ratio of the stroke range of the third lens group to the focal length of the third lens group;
wherein the absolute value of the ratio of the focal length of the first lens group to the focal length of the second lens group is greater than the ratio of the focal length of the first lens group to the focal length of the third lens group; and the ratio of the focal length of the first lens group to the focal length of the fourth lens group is larger than the ratio of the focal length of the first lens group to the focal length of the third lens group.
2. The optical module of claim 1,
in the process of switching between the wide-angle mode and the telephoto mode, the third lens group moves in the same direction as the second lens group, and the distance between the third lens group and the second lens group changes in a tendency of becoming larger first and smaller second in the full stroke of movement of the second lens group.
3. The optical module of claim 2,
the third lens group and the second lens group have a first distance therebetween in a wide-angle mode;
a second distance is provided between the third lens group and the second lens group in a tele mode;
the third lens group and the second lens group have a third distance therebetween in an intermediate mode, and the third distance is greater than each of the first distance and the second distance.
4. The optical module of claim 1,
the absolute value of the ratio of the stroke range of the second lens group to the focal length of the second lens group is less than or equal to a first distance ratio and greater than or equal to a second distance ratio;
the ratio of the travel range of the third lens group to the focal length of the third lens group is smaller than or equal to a third distance ratio, and is larger than or equal to a fourth distance ratio, and the third distance ratio is smaller than the second distance ratio.
5. The optical module of claim 1,
the absolute value of the ratio of the focal length of the first lens group to the focal length of the second lens group is less than or equal to a first focal length ratio and greater than or equal to a second focal length ratio;
the ratio of the focal length of the first lens group to the focal length of the third lens group is less than or equal to a third focal length ratio and greater than or equal to a fourth focal length ratio, and the third focal length ratio is less than the second focal length ratio; and the number of the first and second electrodes,
the ratio of the focal length of the first lens group to the focal length of the fourth lens group is less than or equal to a fifth focal length ratio and greater than or equal to a sixth focal length ratio, and the sixth focal length ratio is greater than the third focal length ratio.
6. The optical module of claim 1, further comprising:
a diaphragm fixedly disposed between the third lens group and the imaging target surface, and having a constant aperture diameter.
7. The optical module of claim 1 wherein a span dimension of the optical module in the optical axis direction is greater than an upper focal length limit of the optical module and no more than three times the upper focal length limit;
the span size is the distance between the light entrance mirror surface of the first lens group, which faces away from the imaging target surface, and the imaging target surface;
and the upper limit of the focal length is the total focal length of the optical module when the second lens group is located at the limit position close to the imaging target surface.
8. An optical module, comprising:
the first lens group is movably arranged on the side of the imaging target surface of the photosensitive element and used for focusing the focus of the incident imaging light beam on the imaging target surface by adapting the movement of the target object distance along the optical axis direction of the optical module;
a second lens group movably arranged between the first lens group and the imaging target surface and used for carrying out zoom adjustment on the imaging of the imaging light beam on the imaging target surface by adapting to the movement of expected magnification in the optical axis direction;
a third lens group movably arranged between the second lens group and the imaging target surface and used for dynamically compensating the focusing deviation of the imaging light beam caused by the focal length change in the zooming adjusting period through linkage with the second lens group in the optical axis direction;
a fourth lens group fixedly arranged between the third lens group and the imaging target surface;
wherein the linkage between the third lens group and the second lens group is: the second lens group and the third lens group move in the same direction with a variable relative distance therebetween; the fourth lens group is configured to form convergence correction in a positive focal length direction on the imaging light beams projected through the first lens group, the second lens group, and the third lens group in this order, and:
the first lens group comprises a first lens, a second lens and a third lens which are sequentially arranged at fixed relative intervals in the direction facing the imaging target surface, wherein the first lens is a meniscus spherical lens with a negative focal length, the second lens is a double-convex spherical lens, and the third lens is a single-convex spherical lens with a positive focal length;
the second lens group comprises a fourth lens, a fifth lens and a sixth lens which are sequentially arranged in a direction facing the imaging target surface at fixed relative intervals, wherein the fourth lens is a biconcave aspheric lens with a negative focal length, the fifth lens is a biconcave spherical lens with a negative focal length, and the sixth lens is a biconvex spherical lens with a positive focal length;
the third lens group comprises a seventh lens and an eighth lens which are sequentially arranged in a direction facing the imaging target surface at a fixed relative distance, wherein the seventh lens is a biconcave spherical lens with a negative focal length, and the eighth lens is a biconvex spherical lens with a positive focal length;
the fourth lens group comprises at least four of a ninth lens, a tenth lens, an eleventh lens, a twelfth lens and a thirteenth lens which are sequentially arranged in a direction facing the imaging target surface at fixed relative intervals, wherein the ninth lens is an aspheric lens with a positive focal length, the tenth lens is a biconcave spherical lens with a negative focal length, the eleventh lens is a biconvex spherical lens with a positive focal length, the twelfth lens is a meniscus spherical lens with a negative focal length, and the thirteenth lens is a meniscus spherical lens with a negative focal length.
9. The optical module of claim 8,
the first lens and the second lens are further formed into a first cemented lens by bonding; and/or the presence of a gas in the gas,
the fifth lens and the sixth lens are further cemented into a second cemented lens.
10. An optical lens comprising an optical module according to any one of claims 1 to 9.
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| CN202010156658.7A CN113448071B (en) | 2020-03-09 | 2020-03-09 | Optical module |
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| EP0320021A2 (en) * | 1987-12-11 | 1989-06-14 | EASTMAN KODAK COMPANY (a New Jersey corporation) | Zoom lens |
| US5995296A (en) * | 1997-07-25 | 1999-11-30 | Canon Kabushiki Kaisha | Zoom lens |
| US6282032B1 (en) * | 1998-10-14 | 2001-08-28 | Canon Kabushiki Kaisha | Zoom lens |
| CN101369049A (en) * | 2007-08-15 | 2009-02-18 | 索尼株式会社 | Zoom lens and image forming apparatus |
| CN102253474A (en) * | 2011-01-17 | 2011-11-23 | 深圳市保千里电子有限公司 | Low-cost miniaturized multiple optical zoom lens |
| CN102789044A (en) * | 2012-08-08 | 2012-11-21 | 中国科学院长春光学精密机械与物理研究所 | Aspherical focal length-variable photoetching objective lens system |
| CN107229113A (en) * | 2016-03-25 | 2017-10-03 | 富士胶片株式会社 | Zoom lens and camera device |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014211468A (en) * | 2013-04-17 | 2014-11-13 | ソニー株式会社 | Zoom lens and imaging apparatus |
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2020
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| EP0320021A2 (en) * | 1987-12-11 | 1989-06-14 | EASTMAN KODAK COMPANY (a New Jersey corporation) | Zoom lens |
| US5995296A (en) * | 1997-07-25 | 1999-11-30 | Canon Kabushiki Kaisha | Zoom lens |
| US6282032B1 (en) * | 1998-10-14 | 2001-08-28 | Canon Kabushiki Kaisha | Zoom lens |
| CN101369049A (en) * | 2007-08-15 | 2009-02-18 | 索尼株式会社 | Zoom lens and image forming apparatus |
| CN102253474A (en) * | 2011-01-17 | 2011-11-23 | 深圳市保千里电子有限公司 | Low-cost miniaturized multiple optical zoom lens |
| CN102789044A (en) * | 2012-08-08 | 2012-11-21 | 中国科学院长春光学精密机械与物理研究所 | Aspherical focal length-variable photoetching objective lens system |
| CN107229113A (en) * | 2016-03-25 | 2017-10-03 | 富士胶片株式会社 | Zoom lens and camera device |
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| CN113448071A (en) | 2021-09-28 |
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