CN211653295U

CN211653295U - Reflective telescopic imaging system

Info

Publication number: CN211653295U
Application number: CN202020459429.8U
Authority: CN
Inventors: 曾晨欣; 季轶群
Original assignee: Suzhou University
Current assignee: Suzhou University
Priority date: 2020-04-01
Filing date: 2020-04-01
Publication date: 2020-10-09
Anticipated expiration: 2030-04-01

Abstract

The utility model discloses a reflective telescope imaging system. Incident light on the object side penetrates through the front surface of the first piece of one-way perspective glass and is emitted to the convex reflector from the rear surface, the light is reflected back to the rear surface of the first piece of one-way perspective glass, is reflected by the rear surface, is emitted to the front surface of the second piece of one-way perspective glass at an angle of 45 degrees, is emitted to the concave reflector from the rear surface, is converged and imaged and is reflected back to the rear surface of the second piece of one-way perspective glass, and is reflected and imaged on the CMOS image sensor through the rear surface. The two pieces of one-way perspective glass act as a turning optical axis, and because the two pieces of one-way perspective glass have the characteristics of reflecting and transmitting light at the same time, the defects that the light of the traditional coaxial reflecting telescope is shielded at the position close to the optical axis and the imaging quality is reduced are overcome. The utility model provides an optical system colour difference is less, all has good formation of image effect to each wave band.

Description

Reflective telescopic imaging system

Technical Field

The utility model relates to a follow-on reflective telescope imaging system.

Background

The reflective imaging structure has been widely applied to the technical field of telescopic imaging systems, and has the advantages of wide working wavelength band, small chromatic aberration and the like. However, in the case of the coaxial reflective imaging system, if the optical axis is not folded by using the reflector, the optical sensor device blocks the optical path, so that a part of the scenery in the central field of view cannot be imaged at all, and the imaging effect is reduced (see the document: Niuhuang. research and application of the panoramic annular staring imaging optical system [ D ]. Zhejiang university, 2010.). Although the off-axis reflective imaging system can solve the problem of light path shielding, the assembly is difficult due to the complex spatial structure of the off-axis reflective imaging system, the imaging effect is damaged by the random vibration of the off-axis reflective imaging system, and the manufacturing cost of the off-axis reflective imaging system is high (see the literature: luchao, sun anxin, che yin, wang jia ann.

Disclosure of Invention

The utility model discloses not enough to present reflective image system that looks far exists uses one-way perspective glass, provides a simple structure, and the no light shelters from, has better imaging definition's improved generation reflective image system that looks far.

The utility model provides a reflection type telescopic imaging system, which is a coaxial optical system and comprises two pieces of one-way perspective glass, a convex reflector, a concave reflector and a CMOS image sensor; the included angles between the two pieces of half mirror and the optical axis are both 45 degrees, and the curvature radiuses of the convex reflector and the concave reflector are opposite numbers; incident light on the object side penetrates through the front surface of the first piece of one-way perspective glass and is emitted to the convex reflector from the rear surface, the convex reflector reflects the light back to the rear surface of the first piece of one-way perspective glass, the light is emitted to the front surface of the second piece of one-way perspective glass at an angle of 45 degrees after being reflected by the rear surface, the light is emitted to the concave reflector from the rear surface, the light is converged and imaged by the concave reflector and is reflected back to the rear surface of the second piece of one-way perspective glass, and the light is reflected and imaged on the CMOS image sensor through the rear surface.

The utility model provides a reflective telescopic imaging system, the field of view range is-2 to 2 degrees; the f-number of the system is 5.

Compared with the prior art, the beneficial effects of the utility model are that: by reasonably arranging the half-mirror and turning the optical axis, the subsequent reflecting mirror and the CMOS photosensitive element do not shield the optical path any more, so that the optical imaging capability of the system is improved; the curvatures of the two reflecting mirrors are opposite, the negative field curvature generated by the convex reflecting mirror balances the positive field curvature generated by the concave reflecting mirror to a large extent, and partial spherical aberration is effectively balanced.

Drawings

Fig. 1 is a schematic structural diagram of a reflective telescopic imaging system according to an embodiment of the present invention;

fig. 2 is a schematic structural view of a half mirror provided in an embodiment of the present invention;

fig. 3 is a schematic light path diagram of a reflective telescopic imaging system according to an embodiment of the present invention;

fig. 4 is a Modulation Transfer Function (MTF) diagram of a reflective telescopic imaging system according to an embodiment of the present invention;

fig. 5 is an optical path difference optical fan diagram (OPD) of the reflective telescopic imaging system according to an embodiment of the present invention.

In the figure, 1, a convex reflector; 2. a first sheet of half mirror; 3. a concave reflector; 4. a second piece of one-way perspective glass; a CMOS image sensor.

Detailed Description

The technical solution of the present invention will be further explained with reference to the accompanying drawings and examples.

Example 1

Referring to fig. 1, a schematic structural diagram of a reflective telescopic imaging system according to this embodiment is shown; the improved reflection type telescopic imaging structure comprises a first piece of one-way perspective glass 2, a convex reflector 1, a second piece of one-way perspective glass 4, a concave reflector 3 and a CMOS image sensor 5 which are sequentially arranged from an object space.

Referring to fig. 2, it is a schematic diagram of a structure of a half mirror of an optical element, which is a glass having a large reflectance to light, and is divided into a transmission surface and a reflection surface, wherein the transmission surface has a good transmittance, and the reflection surface has a good reflectance.

As can be seen from fig. 1, the specific structure of the reflective telescopic imaging system provided in this embodiment is as follows: the light-transmitting side of the first piece of unidirectional perspective glass 2 faces the light incidence direction, the light-transmitting side of the second piece of unidirectional perspective glass 4 faces the first piece of unidirectional perspective glass 2, and the included angles between the two pieces of unidirectional perspective glass and the optical axis are both 45 degrees. Incident light passes through the front surface of the first piece of unidirectional perspective glass 2, is emitted to the convex reflector 1 from the back surface of the first piece of unidirectional perspective glass, and becomes a virtual image through the convex reflector 1, and actual light is reflected by the back surface (reflecting surface) of the first piece of unidirectional perspective glass 2, then passes through the second piece of unidirectional perspective glass 4, is reflected by the concave mirror 3, and then is reflected by the back surface (reflecting surface) of the second piece of unidirectional perspective glass, and becomes an actual image on the CMOS image sensor 5.

Referring to fig. 3, for the optical path schematic diagram of the reflective telescopic imaging system provided by the present invention, light enters the system with the maximum 2-degree half field angle parallel light, and finally forms an image on the CMOS.

Specific parameters of each optical element in the reflective telescopic imaging system provided by the embodiment are shown in table 1, wherein "element" is a corresponding number of a mirror or a half mirror in the system; "radius" is the spherical radius of the corresponding surface; "pitch" is the axial distance from the surface of the element to the surface of the next element in the list, and "element property" is the corresponding property of the element.

TABLE 1

Component	Radius of curvature (mm)	Spacing (mm)	Properties of the elements
				1	-100	2	Convex reflector
2	Infinite number of elements	100	One-way perspective glass
				3	100	40	Concave reflector
4	Infinite number of elements	17.717	One-way perspective glass
				5	Infinite number of elements		CMOS image sensor

Referring to fig. 4, a Modulation Transfer Function (MTF) diagram of the reflective telescopic imaging system provided for the present embodiment; as can be seen from FIG. 4, the transfer function mode values are greater than 0.5 for all fields of view below the cutoff frequency of 126 line pairs/mm.

Referring to fig. 5, an optical path difference optical fan diagram (OPD) of the reflective telescopic imaging system provided in this embodiment; as can be seen from FIG. 5, the optical system has small chromatic aberration and good imaging effect on each waveband.

The utility model discloses a two one-way perspective glass structures, its effect is the refraction optical axis, owing to have the characteristics of simultaneous reflection, transmitted light, has solved the light of traditional coaxial reflection formula telescope and is being sheltered from near optical axis department, reduces the not enough of image quality. The utility model provides an optical system colour difference is less, all has good formation of image effect to each wave band.

Claims

1. A reflective telescopic imaging system, characterized by: the coaxial optical system comprises two pieces of one-way perspective glass, a convex reflector, a concave reflector and a CMOS image sensor; the included angles between the two pieces of half mirror and the optical axis are both 45 degrees, and the curvature radiuses of the convex reflector and the concave reflector are opposite numbers; incident light on the object side penetrates through the front surface of the first piece of one-way perspective glass (2) and is emitted to the convex reflector (1) from the rear surface, the convex reflector (1) reflects the light back to the rear surface of the first piece of one-way perspective glass (2), the light is reflected by the rear surface, then is emitted to the front surface of the second piece of one-way perspective glass (4) at an angle of 45 degrees, is emitted to the concave reflector (3) from the rear surface, is converged and imaged by the concave reflector (3), is reflected back to the rear surface of the second piece of one-way perspective glass (4), and is reflected and imaged on the CMOS image sensor (5) through the rear surface.

2. A reflective telescopic imaging system according to claim 1, wherein: the field of view of the system ranges from-2 degrees to 2 degrees.

3. A reflective telescopic imaging system according to claim 1, wherein: the f-number of the system is 5.