An optical system with imaging and ranging optical axes coupled

Abstract

This invention discloses an optical system for imaging and ranging optical axis coupling, comprising: a laser emitting module, a compound prism, a common lens group, a rear lens group, and a laser receiving module; wherein, the laser generated by the laser emitting module is guided by the compound prism to the common lens group, and the common lens group reflects the laser back to the compound prism to complete laser emission; the compound prism splits the laser beam, one beam is guided to the rear lens group for focusing and imaging, and the other beam is guided to the laser receiving module for ranging, thereby coupling the three optical axes of laser emission, laser reception, and imaging. This solves the problems of existing multi-functional camera products that integrate imaging functions with either laser emission or laser reception, resulting in numerous windows, large device size, and the need for complex focusing structures to achieve co-focusing of visible and infrared light in both bands.

Description

Technical Field

[0001] This application relates to the field of optical equipment technology, and in particular to an optical system that couples imaging and ranging optical axes. Background Technology

[0002] With the continuous development of optoelectronic technology, multi-functional camera products are playing an increasingly important role in practical applications. The continuous expansion of application scope has put forward higher requirements for the functionality and integration of multi-functional camera products. Miniaturized, highly integrated, lightweight and portable products have become the development trend.

[0003] Most existing multi-functional camera products integrate visible light imaging, near-infrared imaging, and laser ranging. However, due to structural differences in laser emitting and receiving components, these products often integrate imaging with either laser emission or laser reception, making it impossible to fully integrate imaging and laser ranging into a single optical path structure. This results in numerous windows and a larger device size. Furthermore, integrating near-infrared and visible light imaging often requires focusing structures or special surfaces to achieve dual-band parfocal focusing. The former has a complex structure and is significantly affected by ambient temperature, while the latter has high manufacturing and R&D costs. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention provides an optical system that couples imaging and ranging optical axes. This system can solve the problems of existing multi-functional camera products that integrate imaging functions with either laser emission or laser reception, resulting in numerous windows, large device size, and the need for complex focusing structures to achieve dual-band co-focusing of visible and infrared light.

[0005] Specifically, the present invention provides an optical system for coupling imaging and ranging optical axes, comprising: a laser emitting module, a compound prism, a common lens group, a rear lens group, and a laser receiving module; wherein, the laser generated by the laser emitting module is guided to the common lens group through the compound prism, and the common lens group reflects the laser back to the compound prism to complete laser emission; the compound prism splits the laser beam, one beam is guided to the rear lens group for focusing and imaging, and the other beam is guided to the laser receiving module for ranging, thereby coupling the three optical axes of laser emission, laser reception, and imaging.

[0006] In one embodiment of the present invention, the composite prism includes four right-angle prisms bonded together; wherein, the first right-angle prism and the second right-angle prism are the same size and bonded together along the inclined surface for beam splitting by wavelength; the right-angle face of the third right-angle prism is bonded to the right-angle face of the first right-angle prism, and the right-angle face of the fourth right-angle prism is bonded to the inclined surface of the third right-angle prism, for beam splitting by area.

[0007] In one embodiment of the present invention, the composite prism is disposed between the common lens group and the rear lens group, and one path of light from the laser emitted from the common lens group that passes through the first right-angle prism is modulated by the rear lens group to make visible light and infrared light co-focal and imaged.

[0008] In one embodiment of the present invention, another beam of light reflected by the first right-angle prism from the laser emitted by the shared lens group is split by the area of ​​the third right-angle prism for laser ranging.

[0009] In one embodiment of the present invention, the common lens group includes a common first cemented lens, a common third lens, and a common second cemented lens arranged sequentially. The common first cemented lens and the common second cemented lens are both formed by bonding a biconvex lens and a biconcave lens together, and the common third lens is a biconvex lens.

[0010] In one embodiment of the present invention, the laser emitting module includes: a laser source and a laser emitting lens, which are disposed relative to the inclined surface of the fourth right-angle prism; the laser receiving module includes: a laser receiving lens, a narrowband filter and an avalanche diode, which are disposed relative to the right-angle surface of the third right-angle prism.

[0011] In one embodiment of the present invention, the infrared light is near-infrared light in the wavelength range of 0.686nm to 0.840nm.

[0012] In one embodiment of the present invention, the common first cemented lens is made of H-K3 as a biconvex lens and H-ZLAF53 as a biconcave lens; the common third lens is made of H-K3 as a biconvex lens; and the common second cemented lens is made of H-K3 as a biconcave lens and H-LAK50A as a biconvex lens.

[0013] In one embodiment of the present invention, the rear lens group includes a first rear lens and a second rear lens, wherein the first rear lens is made of H-LAF3 and the second rear lens is made of H-ZF62.

[0014] As can be seen from the above, the embodiments of the present invention can have one or more of the following beneficial effects:

[0015] (1) By using a shared lens group, a compound prism and a rear lens group, the three optical axes of laser emission, laser reception and visible light / near infrared imaging are combined into one, which effectively solves the problem that existing multi-functional camera products integrate the camera function with either laser emission or laser reception, resulting in more windows and a larger device size;

[0016] (2) Without using special materials, aspherical surfaces, diffraction surfaces, or focusing structures, it achieves parfocal imaging of visible light and near-infrared light through the cooperation of a shared lens group and a rear lens group, and has good imaging quality in temperatures ranging from -40℃ to +70℃. It can be used in high-temperature and cold environments and has strong environmental adaptability. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A schematic diagram of the structure of an optical system for coupling imaging and ranging optical axes provided in an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of the modulation transfer function of visible light under low-temperature conditions provided in an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of the modulation transfer function of visible light under normal temperature and high temperature environments provided in an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of the modulation transfer function of near-infrared light under low-temperature conditions provided in an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the modulation transfer function of near-infrared light under normal temperature and high temperature environments provided in the embodiments of the present invention.

[0023] Explanation of reference numerals in the attached figures

[0024] 1 is a shared first cemented lens, 2 is a shared third lens, 3 is a shared second cemented lens, 4 is a first right-angle prism, 5 is a second right-angle prism, 6 is a rear first lens, 7 is a rear second lens, 8 is a third right-angle prism, 9 is a fourth right-angle prism, 10 is a laser emitting lens, 11 is a laser receiving lens, and 12 is a narrowband filter. Detailed Implementation

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described with reference to the accompanying drawings and embodiments.

[0026] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments, and should all fall within the protection scope of the present invention.

[0027] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are applicable in distinguishing similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or applicable to such processes, methods, products, or apparatus.

[0028] It should also be noted that the division of multiple embodiments in this invention is only for the convenience of description and should not constitute a special limitation. Features in various embodiments can be combined and referenced in each other without contradiction.

[0029] like Figure 1 As shown, the first embodiment of the present invention proposes an optical system for coupling imaging and ranging optical axes, which includes, for example, a laser emitting module, a compound prism, a common lens group, a rear lens group and a laser receiving module.

[0030] The laser emitted by the laser emitting module is guided to the common lens group by the composite prism, and the common lens group reflects the laser back to the composite prism to complete the laser emission. The composite prism splits the laser emitted through the common lens group, with one beam guided to the rear lens group for focusing and imaging, and the other beam guided to the laser receiving module for ranging, thus coupling the three optical axes of laser emission, laser reception, and imaging.

[0031] In one implementation, such as Figure 1 As shown, the composite prism includes, for example, four right-angle prisms bonded together; wherein, the first right-angle prism 5 and the second right-angle prism 4 are the same size and bonded together along the inclined surface, the inclined surface is coated with a 45° beam-splitting film for beam splitting by wavelength; the right-angle surface of the third right-angle prism 8 is bonded to the right-angle surface of the first right-angle prism 5, and the right-angle surface of the fourth right-angle prism 9 is bonded to the inclined surface of the third right-angle prism 8, the inclined surface is not coated, and beam splitting is performed by area.

[0032] Furthermore, the composite prism is, for example, positioned between the common lens group and the rear lens group. One beam of laser light emitted from the common lens group, passing through the first right-angle prism 5, is modulated by the rear lens group to achieve parfocal imaging of visible and infrared light. Another beam of laser light emitted from the common lens group, reflected by the first right-angle prism 5, is then split by the area of ​​the third right-angle prism 8 for laser ranging.

[0033] Furthermore, the laser emitting module includes, for example, a laser source and a laser emitting lens 10, which are arranged on the inclined surface relative to the fourth right-angle prism 9; the laser receiving module includes a laser receiving lens 11, a narrow-band filter 12, and an avalanche diode, which are arranged on the right-angle surface relative to the third right-angle prism 8.

[0034] The specific principle of this optical system is as follows:

[0035] The emitted laser passes through the laser emitting lens 10, then through the fourth right-angle prism 9 and the third right-angle prism 8 to the inclined surface of the first right-angle prism 5. It then passes through a common lens group to complete laser emission. Simultaneously, visible light, near-infrared light, and the received laser return from the common lens group to the composite prism. After passing through the first right-angle prism 5, one of the light rays passes through the rear lens group and is received by the CMOS, completing the parfocal imaging of visible and near-infrared light. The other light ray is area-splittered by the third right-angle prism 8, passes through the laser receiving lens 11, and after the visible and near-infrared light are filtered out by the narrow-band filter 12, it is responded to by the avalanche diode, completing laser reception.

[0036] In this way, by using a shared lens group, a compound prism, and a rear lens group, the three optical axes of laser emission, laser reception, and visible / near-infrared imaging are combined into one, avoiding the need to integrate the camera function with either laser emission or laser reception. This effectively reduces the number of windows and the size of the device.

[0037] Furthermore, the shared lens group includes a shared first cemented lens 1, a shared third lens 2, and a shared second cemented lens 3 arranged sequentially. The shared first cemented lens 1 and the shared second cemented lens 3 are both formed by bonding a biconvex lens and a biconcave lens, and the shared third lens 2 is a biconvex lens. Specifically, the shared first cemented lens 1 is, for example, a biconvex lens made of H-K3 and a biconcave lens made of H-ZLAF53; the shared third lens 2 is a biconvex lens made of H-K3; and the shared second cemented lens 3 is a biconcave lens made of H-K3 and a biconvex lens made of H-LAK50A. Furthermore, the rear lens group includes, for example, a rear first lens 6 and a rear second lens 7, where the rear first lens 6 is made of H-LAF3 and the rear second lens 7 is made of H-ZF62.

[0038] The specific parameters of the optical system are shown in the table below:

[0039]

[0040] Combination Figures 2 to 5 As shown, the combination of the aforementioned shared lens group and the rear lens group enables non-focusing imaging of visible light and near-infrared light with the same aperture, i.e., parfocal imaging of visible light and near-infrared light, and has good imaging quality under the full temperature range of -40℃ to +70℃.

[0041] In summary, the optical system proposed in this invention, which couples imaging and ranging optical axes, achieves the integration of three optical axes—laser emission, laser reception, and visible / near-infrared imaging—through the cooperation of a shared lens group, a compound prism, and a rear lens group. This effectively solves the problem of existing multi-functional camera products integrating imaging functions with either laser emission or laser reception, resulting in numerous windows and a large device size. It does not use special materials, aspherical surfaces, diffractive surfaces, or focusing structures. Through the cooperation of the shared lens group and the rear lens group, it achieves parfocal imaging of visible and near-infrared light, and maintains good imaging quality at temperatures ranging from -40℃ to +70℃, making it suitable for both high-temperature and low-temperature environments and exhibiting strong environmental adaptability.

[0042] The foregoing description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of embodiments of this disclosure upon considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described herein. The specification and embodiments are to be considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

[0043] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0044] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An optical system for coupling imaging and ranging optical axes, characterized in that, include: The system includes a laser emitting module, a compound prism, a shared lens group, a rear lens group, and a laser receiving module; among which, The laser generated by the laser emitting module is guided to the common lens group through the composite prism, and the common lens group reflects the laser back to the composite prism to complete the laser emission. The composite prism splits the laser beam, with one beam being guided to the rear lens group for focusing and imaging, and the other beam being guided to the laser receiving module for ranging, thus coupling the three optical axes of laser emission, laser reception, and imaging. The composite prism includes four right-angle prisms bonded together; the first and second right-angle prisms are the same size and bonded together along their inclined surfaces for beam splitting by wavelength; the right-angle face of the third right-angle prism is bonded to the right-angle face of the first right-angle prism, and the right-angle face of the fourth right-angle prism is bonded to the inclined surface of the third right-angle prism, utilizing area division for beam splitting.

2. The optical system for coupling imaging and ranging optical axes according to claim 1, characterized in that, The composite prism is disposed between the common lens group and the rear lens group. One path of light from the laser emitted from the common lens group, which passes through the first right-angle prism, is modulated by the rear lens group to make the visible light and infrared light co-focal and imaged.

3. The optical system for coupling imaging and ranging optical axes according to claim 2, characterized in that, The laser emitted from the shared lens group is used for laser ranging after the other light reflected by the first right-angle prism is split by the area of ​​the third right-angle prism.

4. The optical system for coupling imaging and ranging optical axes according to claim 1, characterized in that, The shared lens group includes a shared first cemented lens, a shared third lens, and a shared second cemented lens arranged in sequence. The shared first cemented lens and the shared second cemented lens are both made by bonding a biconvex lens and a biconcave lens together, and the shared third lens is a biconvex lens.

5. The optical system for coupling imaging and ranging optical axes according to claim 1, characterized in that, The laser emitting module includes a laser source and a laser emitting lens, which are arranged relative to the inclined surface of the fourth right-angle prism; the laser receiving module includes a laser receiving lens, a narrow-band filter, and an avalanche diode, which are arranged relative to the right-angle surface of the third right-angle prism.

6. The optical system for coupling imaging and ranging optical axes according to claim 2, characterized in that, The infrared light is near-infrared light in the wavelength range of 0.686nm to 0.840nm.

7. The optical system for coupling imaging and ranging optical axes according to claim 4, characterized in that, The shared first cemented lens is a biconvex lens made of H-K3 and a biconcave lens made of H-ZLAF53; the shared third lens is a biconvex lens made of H-K3; the shared second cemented lens is a biconcave lens made of H-K3 and a biconvex lens made of H-LAK50A.

8. The optical system for coupling imaging and ranging optical axes according to claim 1, characterized in that, The rear lens group includes a first rear lens and a second rear lens, wherein the first rear lens is made of H-LAF3 and the second rear lens is made of H-ZF62.

Images