Universal image transfer lens and optical device for prism compensation

Abstract

The invention relates to a universal image transfer lens which can be used for prism compensation, comprising a flat glass component, a first negative power lens group, a first positive power lens group, a second negative power lens group, a second positive power lens group and a third negative power lens group which are sequentially arranged on the optical path of a chip reflected light beam; the first negative power lens group is used for diverging the light beam so as to increase the diameter of the light beam; the first positive power lens group is used for converging the light beam, and the converged light beam has the smallest diameter in the second negative power lens group after being transmitted over a certain distance; the second negative power lens group is used for correcting the chromatic aberration of the light beam, and the second positive power lens group is used for converging the divergent light beam after correction; the third negative power lens group is used as a field lens to correct the field curvature again; the invention can be used for other display chips including LCOS, and can also be switched to an optical machine body with different prisms, and has low cost and good mass production performance.

Description

Technical Field

[0001] The present invention relates to the technical field, and more particularly to a universal image-relay lens and optical equipment that can be used for prism compensation. Background Art

[0002] In the projection system, when using DLP display technology or LCOS display technology, in order to output higher brightness, TIR / RTIR prism or polarization beam splitter prism (PBS) is required; the prism can be equivalent to a piece of flat glass of the same material in the imaging lens. If the projection lighting technology can be combined with the large number of industrial lenses currently on the market to build a system for scanning or detection, the mold opening cost and production cycle of customized lenses can be greatly reduced.

[0003] However, when general industrial lenses are designed, the back focus is set to air by default, and the prism material and thickness are not considered. Therefore, the industrial lens cannot directly match the projection lighting system. For example, patent CN202010723956.X has the following three shortcomings in its image-steering lens: first, it does not cover other display chips including LCOS; second, it cannot switch to an optical machine body with different prisms; third, there are many lenses, the tolerance is relatively tight, and the mass production performance is poor. The versatility of the steering lens is still limited, and a universal optical solution that can be used for prism compensation is needed. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a universal image relay lens that can be used for prism compensation in view of the above-mentioned defects of the prior art, and also provide an optical device using the image relay lens.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A universal image transfer lens for prism compensation is constructed, wherein the lens comprises a flat glass assembly, a first negative power lens group, a first positive power lens group, a second negative power lens group, a second positive power lens group and a third negative power lens group, which are sequentially arranged on the optical path of a chip reflected light beam; the flat glass assembly can adjust the material, thickness and front and rear air spacing; the first negative power lens group is used to diverge the light beam so as to increase the light beam diameter; the first positive power lens group is used to converge the light beam, and the converged light beam has the smallest diameter in the second negative power lens group after being transmitted over a certain distance; the second negative power lens group is used to correct the chromatic aberration of the light beam, and the second positive power lens group is used to converge the corrected divergent light beam; the third negative power lens group is used as a field lens to correct the field curvature again.

[0007] The universal image-transmitting lens for prism compensation of the present invention comprises the first negative optical power lens group which is a double concave negative lens, the optical power of which is controlled between -0.03 and 0.02, and the refractive index of which is between 1.5 and 1.7.

[0008] The universal image relay lens for prism compensation described in the present invention comprises: the first positive optical power lens group includes two first plano-convex lenses, and the convex sides of the two first plano-convex lenses are arranged opposite to each other; the optical power of the two first plano-convex lenses is between 0.02-0.03, and the refractive index is between 1.8-1.9.

[0009] The universal image relay lens for prism compensation described in the present invention, wherein the second negative optical focal length lens group includes a triplet lens consisting of two positive lenses and a negative lens between the two positive lenses; the overall optical focal length of the triplet lens is between -0.02 and 0.01.

[0010] The universal image-transmitting lens for prism compensation of the present invention has a refractive index of the negative lens between 1.8 and 1.9, a refractive index of the negative lens greater than that of the two positive lenses, and a relative dispersion coefficient of the negative lens between 0.01 and 0.02.

[0011] The universal image relay lens for prism compensation described in the present invention comprises a second plano-convex lens, a third plano-convex lens and a meniscus lens arranged in sequence; the second plano-convex lens is arranged opposite to the convex side of the third plano-convex lens, and the convex of the meniscus lens is arranged toward the third plano-convex lens; the focal power range of the second plano-convex lens is 0.01-0.02, the focal power range of the third plano-convex lens is 0.025-0.03, and the focal power range of the meniscus lens is 0.02-0.028; the refractive index range of the third plano-convex lens and the meniscus lens is both 1.8-1.85.

[0012] The universal image relay lens for prism compensation of the present invention, wherein the third negative optical power lens group comprises a plano-concave negative lens, the plano-concave negative lens has a refractive index of 1.6-1.7 and an optical power of -0.08-0.06.

[0013] The universal image transfer lens for prism compensation described in the present invention comprises a flat glass component that is equivalent to an optical mechanical prism and an adjustable flat glass; the adjustable flat glass can adjust the material, thickness and front and rear air gaps according to different prism materials and thicknesses.

[0014] The universal image-relay lens for prism compensation of the present invention further comprises an industrial lens adapter flange, and the industrial lens adapter flange is used to fix industrial cameras with different interfaces.

[0015] An optical device, according to the above-mentioned universal image relay lens that can be used for prism compensation, wherein the optical device is provided with the universal image relay lens that can be used for prism compensation.

[0016] The beneficial effects of the present invention are as follows: the application of the image transfer lens solution of the present invention can not only be used universally with other display chips including LCOS, but also can be switched to optical machine bodies with different prisms, and the cost is low and has good mass production performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work:

[0018] Figure 1 It is a principle diagram of a universal image transfer lens that can be used for prism compensation in a preferred embodiment of the present invention;

[0019] Figure 2 Schematic diagram of the paths of the on-axis aperture edge light (solid line) and the main light (dashed line) of the edge field of view of the actual optical system of the universal image relay lens that can be used for prism compensation in a preferred embodiment of the present invention;

[0020] Figure 3 It is a schematic diagram of the complete on-axis field of view and edge field of view light beam of the actual system of the universal image relay lens that can be used for prism compensation in a preferred embodiment of the present invention;

[0021] Figure 4 It is a schematic diagram of the structure of a universal image relay lens that can be used for prism compensation in a preferred embodiment of the present invention;

[0022] Figure 5 It is a lens surface data table of a universal image relay lens that can be used for prism compensation in a preferred embodiment of the present invention;

[0023] Figure 6 The invention is a universal image transfer lens and a lens for prism compensation according to a preferred embodiment of the invention. Figure 5 The lens number view corresponding to the table in the figure;

[0024] Figure 7 This is an MTF curve diagram of the visible light band of a universal image relay lens that can be used for prism compensation in a preferred embodiment of the present invention;

[0025] Figure 8 It is a distortion curve of the visible light band of the universal image-relay lens that can be used for prism compensation in a preferred embodiment of the present invention;

[0026] Fig. 9 It is a vertical axis chromatic aberration curve of a universal image relay lens in the visible light band that can be used for prism compensation in a preferred embodiment of the present invention;

[0027] Fig.10 It is the defocus curve of the visible light band of the universal image relay lens which can be used for prism compensation in the preferred embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the following will be described clearly and completely in combination with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are partial embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0029] The universal image transfer lens that can be used for prism compensation in a preferred embodiment of the present invention is as follows: Figure 1 See also Figure 2-10 , including a flat glass component 1, a first negative focal power lens group 2, a first positive focal power lens group 3, a second negative focal power lens group 4, a second positive focal power lens group 5 and a third negative focal power lens group 6 which are sequentially arranged on the optical path of the chip reflected light beam; the flat glass component 1 can adjust the material, thickness and front and rear air gaps; the first negative focal power lens group 2 is used to diverge the light beam so that the light beam diameter is increased; the first positive focal power lens group 3 is used to converge the light beam, and the converged light beam has the smallest diameter in the second negative focal power lens group 4 after being transmitted over a certain distance; the second negative focal power lens group 4 is used to correct the chromatic aberration of the light beam, and the second positive focal power lens group 5 is used to converge the corrected divergent light beam; the third negative focal power lens group 6 is used as a field lens to correct the field curvature again; the application of the image transfer lens scheme applied by the present invention can not only be universally used for other display chips including LCOS, but also can be switched to optical machine bodies with different prisms, and the cost is low and has good mass production.

[0030] It should be noted that the principle description of this application is as follows Figure 1As shown in the figure: For a system with a large field of view and conjugated object and image, in order to obtain better image quality, various aberrations need to be corrected, among which chromatic aberration and field curvature are important aberrations; the correction of field curvature requires separation of positive and negative optical powers, and a high light height at the positive optical power and a low light height at the negative optical power; therefore, a "waist and belly" structure will appear in the light beam in the lens, with negative optical power at the "waist" where the light beam is tightened and positive optical power at the "belly" where the light beam is expanded; this light height distribution on the positive and negative optical powers effectively corrects the field curvature; the correction of chromatic aberration requires a cemented lens, and the overall optical power of the cemented lens is weak; therefore, the cemented lens is very suitable for being placed near the aperture of the system;

[0031] According to the above theory, the distribution of the focal length of the object-image conjugate system with a large field of view is a symmetrical distribution of "negative-positive-negative-positive-negative". Of course, since the object and image are not completely symmetrical (there is a prism on the object side but not on the image side), the specific lens profile or material is not completely symmetrical. The negative focal length at both ends of the system actually plays the role of a field lens, effectively correcting the field curvature and introducing fewer other aberrations. The curvature, thickness, material and air spacing of all lenses are used to correct other aberrations.

[0032] Figure 4 Reference numeral 80 is the effective surface of the chip, 81 is the chip protection glass, and 82 is the imaging surface;

[0033] Figure 7 The MTF curve in the figure represents the comprehensive resolving power of the optical system. The horizontal axis represents the spatial frequency, and the unit is cycles / mm. The vertical axis represents the value of the modulation transfer function (MTF). The MTF value is used to evaluate the imaging quality of the lens, and the value range is 0 to 1. The higher and straighter the MTF curve is, the better the imaging quality of the lens is, the stronger the ability to restore the real image is, the better the degree of overlap of the curves of each field of view is, and the better the consistency of the image quality is.

[0034] from Figure 7 It can be seen that when the spatial frequency of the visible light band is 93 1p / mm, the MTF of the whole field of view is greater than 0.55, and the image quality consistency of each field of view is very high;

[0035] Figure 8 The distortion curve describes the deviation between the actual image plane and the ideal image plane, and is usually expressed as a percentage. The distortion is controlled within 0.1%, which can meet the needs of most lenses on the market.

[0036] Fig. 9This is the vertical axis chromatic aberration curve. The vertical axis chromatic aberration describes the difference in the height direction of the main light of different light waves at each field of view. The smaller the difference, the smaller the chromatic aberration of the system and the better the imaging quality. According to 93lp / mm, the pixel size is 5.4um. Now the vertical axis chromatic aberration is controlled within 2.5um, with excellent performance.

[0037] Fig.10 The defocus curve describes the distribution of MTF of each field of view near the image plane and can be used to determine the depth of field. The greater the defocus, the better the depth of field and the better the tolerance to lens tolerance. According to the industry standard of MTF ≥ 0.3, the current depth of field can reach 0.028mm;

[0038] Preferably, the first negative optical power lens group 2 is a double concave negative lens, the optical power is controlled between -0.03 and 0.02, and the refractive index is between 1.5 and 1.7; it can quickly increase the beam aperture within a short distance.

[0039] Preferably, the first positive optical focal length lens group 3 includes two first plano-convex lenses 30, and the convex sides of the two first plano-convex lenses are arranged opposite to each other; the optical focal length of the two first plano-convex lenses 30 is between 0.02-0.03, and the refractive index is between 1.8-1.9; the strong positive optical focal length is shared by the two first plano-convex lenses 30 to reduce high-order aberrations; in order to avoid high-order aberrations caused by excessive light angles, the optical focal length is controlled between 0.02 and 0.03, and the refractive index is between 1.8 and 1.9. The use of high refractive index materials is beneficial to improving the light deflection ability of the lens.

[0040] Preferably, the second negative optical power lens group 4 includes a triplet lens consisting of two positive lenses 40 and a negative lens 41 between the two positive lenses; the overall optical power of the triplet lens is between -0.02 and 0.01; the refractive index of the negative lens is between 1.8 and 1.9, and the refractive index of the negative lens is greater than that of the two positive lenses, satisfying the chromatic aberration correction principle; the relative dispersion coefficient of the negative lens is between 0.01 and 0.02, which can effectively correct the secondary spectrum;

[0041] Here, chromatic aberration correction can also be achieved by using a combination of double-cemented lenses and single lenses.

[0042] Preferably, the second positive power lens group 5 comprises a second plano-convex lens 50, a third plano-convex lens 51 and a meniscus lens 52 which are arranged in sequence; the second plano-convex lens is arranged opposite to the convex side of the third plano-convex lens, and the convex of the meniscus lens is arranged toward the third plano-convex lens; the focal power range of the second plano-convex lens is 0.01-0.02, the focal power range of the third plano-convex lens is 0.025-0.03, and the focal power range of the meniscus lens is 0.02-0.028; the refractive index range of the third plano-convex lens and the meniscus lens is both 1.8-1.85; in order to share the strong positive power, three positive lenses are used here to share the burden, so as to reduce high-order aberrations;

[0043] The second positive power lens group 5 has one more positive lens than the first positive power lens group 3 because it is closer to the imaging surface 82 and needs a stronger light deflection capability;

[0044] Among them, the third plano-convex lens and the meniscus lens are lenses that bear the main optical power, and the second plano-convex lens uses a low-refractive-index and low-dispersion material to reduce chromatic aberration.

[0045] Preferably, the third negative optical power lens group 6 includes a plano-concave negative lens with a refractive index of 1.6-1.7 and an optical power of -0.08-0.06; it acts as a field lens to reduce field curvature and ensure image telecentricity, and its output light beam is projected onto the imaging surface 82 to form a clear light spot.

[0046] It can be understood that each of the above lens groups can be constructed with different numbers of lenses according to actual conditions. For a system with more complex requirements, the minimum unit of the alternating arrangement of positive and negative optical power groups can also increase the number of repetitions. For example, the optical power distribution of the lens can be "negative-positive-negative-positive-negative-positive-negative";

[0047] Preferably, the flat glass assembly 1 includes an optical-mechanical prism equivalent flat glass 10 and an adjustable flat glass 11; the adjustable flat glass can adjust the material, thickness and front and rear air gaps according to different prism materials and thicknesses.

[0048] Preferably, the universal image transfer lens that can be used for prism compensation also includes an industrial lens adapter flange 7, which is used to fix industrial cameras with different interfaces and ensure corresponding back focus. It can be customized and machined according to the standard interface or non-standard interface actually required by the customer; the industrial lens adapter flange can be a separate component or a series of structural parts.

[0049] Plano-convex lenses or plano-concave lenses are used many times throughout the lens. The main purpose is to reduce errors in the processing and assembly process and improve mass production.

[0050] An optical device, according to the above-mentioned universal image relay lens that can be used for prism compensation, wherein the optical device is provided with a universal image relay lens that can be used for prism compensation; the optical device can be a photographing device, a video recording device, etc.

[0051] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A universal image relay lens that can be used for prism compensation, characterized in that: The invention comprises a flat glass component, a first negative power lens group, a first positive power lens group, a second negative power lens group, a second positive power lens group and a third negative power lens group which are sequentially arranged on the optical path of the chip reflected light beam; the flat glass component can adjust the material, thickness and front and back air gaps; the first negative power lens group is used to diverge the light beam so as to increase the light beam diameter; the first positive power lens group is used to converge the light beam, and the converged light beam has the smallest diameter in the second negative power lens group after being transmitted over a certain distance; the second negative power lens group The lens group is used to correct the chromatic aberration of the light beam, and the second positive focal power lens group is used to converge the divergent light beam after correction; the third negative focal power lens group is used as a field lens to correct the field curvature again; the first negative focal power lens group is a double concave negative lens, the focal power is controlled between -0.03 and 0.02, and the refractive index is between 1.5 and 1.7; the first positive focal power lens group includes two first plano-convex lenses, and the convex sides of the two first plano-convex lenses are arranged opposite to each other; the focal power of the two first plano-convex lenses is between 0.02 and 0.03, and the refractive index is between 1.8 and 1.9; the second negative power lens group includes a triplet lens consisting of two positive lenses and a negative lens between the two positive lenses; the overall focal power of the triplet lens is between -0.02 and 0.01; the second positive power lens group includes a second plano-convex lens, a third plano-convex lens and a meniscus lens arranged in sequence; the second plano-convex lens is arranged opposite to the convex side of the third plano-convex lens, and the convex side of the meniscus lens is arranged toward the third plano-convex lens; the focal power range of the second plano-convex lens is 0.01-0.02, and the third plano-convex lens The focal power range is 0.025-0.03, and the focal power range of the meniscus lens is 0.02-0.028; the refractive index ranges of the third plano-convex lens and the meniscus lens are both in the range of 1.8-1.85; the third negative focal power lens group includes a plano-concave negative lens, the refractive index of the plano-concave negative lens is 1.6-1.7, and the focal power is -0.08-0.06; the flat glass assembly includes an optical mechanical prism equivalent flat glass and an adjustable flat glass; the adjustable flat glass can adjust the corresponding material, thickness and front and rear air gap according to different prism materials and thicknesses.

2. The universal image relay lens for prism compensation according to claim 1, characterized in that: The refractive index of the negative lens is between 1.8 and 1.9, and the refractive index of the negative lens is greater than that of the two positive lenses; the relative dispersion coefficient of the negative lens is between 0.01 and 0.

02.

3. The universal image relay lens for prism compensation according to claim 1, characterized in that: The universal image transfer lens that can be used for prism compensation also includes an industrial lens adapter flange, and the industrial lens adapter flange is used to fix industrial cameras with different interfaces.

4. An optical device, according to any one of claims 1 to 3, wherein the universal image relay lens for prism compensation is characterized in that: The optical device is provided with the universal image relay lens which can be used for prism compensation.

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