CN220820367U - Eyepiece optical system - Google Patents

Abstract

The application discloses an eyepiece optical system, which sequentially comprises the following components from an object side to an image side along an optical axis: a first lens having positive optical power; the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; a third lens having positive optical power, the object side surface of which is a convex surface; a fourth lens having positive optical power; a fifth lens having negative optical power; a sixth lens having positive optical power; half of the diagonal length h of the effective pixel region on the imaging surface of the eyepiece optical system and the total focal length f of the eyepiece optical system satisfy: h/f is more than or equal to 0.2 and less than or equal to 0.3.

Description

Eyepiece optical system

Technical Field

The present application relates to the field of optical elements, and more particularly to an eyepiece optical system.

Background

For military and foreign trade gun sighting telescope, especially for medium or heavy machinery, the sighting telescope has large impact force when shooting, and considering the condition that a shooter wears goggles or glasses, an eyepiece optical system is required to have a longer exit pupil distance to protect the safety of the shooter. On the other hand, in order to accommodate different human eyes, the visibility of the eyepiece needs to be adjustable, and therefore, the eyepiece needs to have a long optical back focus performance to satisfy the adjustment amount.

The eyepiece optical system in the prior art mainly has the following problems:

1. the exit pupil distance of the traditional ocular optical system is 20-25 mm, the rear end of the ocular is small in buffer space from an observer, and the observer is easy to be injured;

2. The current magnifying power of the gun sighting eyepiece is 10X or below.

Therefore, there is a need in the market for an eyepiece optical system that can achieve a long exit pupil, a large magnification, and a small volume.

Disclosure of utility model

The application provides an eyepiece optical system, which aims to solve the problems of short exit pupil distance, small magnification, large volume and the like of the eyepiece optical system in the prior art.

The present application provides an eyepiece optical system including, in order from an object side to an image side along an optical axis: a first lens having positive optical power, the image side surface of which is convex; the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; a third lens having positive optical power, the object side surface of which is a convex surface; a fourth lens element with positive refractive power having a convex object-side surface and a concave image-side surface; a fifth lens element with negative refractive power having a convex object-side surface and a concave image-side surface; and a sixth lens element with positive refractive power having a convex object-side surface and a concave image-side surface; half of the diagonal length h of the effective pixel region on the imaging surface of the eyepiece optical system and the total focal length f of the eyepiece optical system satisfy: h/f is more than or equal to 0.2 and less than or equal to 0.3.

In one embodiment, the focal length f1 of the first lens and the total focal length f of the eyepiece optical system satisfy: f1/f is more than or equal to 1.4 and less than or equal to 1.8.

In one embodiment, the focal length f2 of the second lens and the total focal length f of the eyepiece optical system satisfy: -2.6.ltoreq.f2/f.ltoreq.2.0.

In one embodiment, the focal length f3 of the third lens and the total focal length f of the eyepiece optical system satisfy: f3/f is more than or equal to 3.0 and less than or equal to 3.9.

In one embodiment, the focal length f4 of the fourth lens and the total focal length f of the eyepiece optical system satisfy: f4/f is more than or equal to 1.8 and less than or equal to 2.4.

In one embodiment, the focal length f5 of the fifth lens and the total focal length f of the eyepiece optical system satisfy: -1.6.ltoreq.f5/f.ltoreq.1.1.

In one embodiment, the focal length f6 of the sixth lens and the total focal length f of the eyepiece optical system satisfy: f6/f is more than or equal to 1.0 and less than or equal to 1.5.

In one embodiment, a distance TTL between the center of the object side surface of the first lens element and the imaging surface of the eyepiece optical system on the optical axis and a center distance BFL between the center of the image side surface of the sixth lens element and the imaging surface satisfy: BFL/TTL is more than or equal to 0.1 and less than or equal to 0.4.

In one embodiment, the distance TTL between the center of the object side surface of the first lens and the imaging surface of the eyepiece optical system on the optical axis and the total focal length f of the eyepiece optical system satisfy: TTL/f is less than or equal to 1.8 and less than or equal to 2.3.

In one embodiment, the combined focal length f12 of the first lens and the second lens and the total focal length f of the eyepiece optical system satisfy: f12/f is more than or equal to 5.2 and less than or equal to 6.6.

In one embodiment, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -1.0.ltoreq.f1/f2.ltoreq.0.5.

In one embodiment, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: f3/f4 is more than or equal to 1.3 and less than or equal to 2.0.

In one embodiment, the center thickness ct1 of the first lens on the optical axis and the center thickness ct2 of the second lens on the optical axis satisfy: ct1/ct2 is more than or equal to 3.4 and less than or equal to 8.0.

In one embodiment, the center thickness ct4 of the fourth lens on the optical axis and the center thickness ct3 of the third lens on the optical axis satisfy: ct4/ct3 is less than or equal to 1.8 and less than or equal to 2.3.

In one embodiment, the center thickness ct6 of the sixth lens on the optical axis and the center thickness ct5 of the fifth lens on the optical axis satisfy: ct6/ct5 is less than or equal to 1.4 and less than or equal to 1.8.

In one embodiment, the eyepiece optics may have a magnification of up to 12.5.

In one embodiment, the exit pupil distance of the eyepiece optics is up to 55mm.

In one embodiment, the eyepiece optical system has an exit pupil diameter of 6mm or greater.

In one embodiment, the eyepiece optical system has a visibility range of: -5D- +3d.

In one embodiment, the first lens to the sixth lens are all glass lenses.

In one embodiment, the diagonal line length of the effective pixel area on the imaging surface of the eyepiece optical system is 10.4mm or more.

In another aspect, the application provides an electronic device. The electronic device comprises the eyepiece optical system provided by the application and an imaging element for converting an optical image formed by the eyepiece optical system into an electric signal.

The application adopts six lenses, and the eyepiece optical system has at least one beneficial effect of long exit pupil distance (55 mm), high magnification (12.5X magnification), large image surface (10.4 mm), miniaturization, back long focus and the like by optimizing the shape, focal power, reasonable setting of relevant parameters and the like of each lens.

Drawings

Other features, objects, and advantages of the present application will become more apparent from the following detailed description of the embodiments, taken in conjunction with the accompanying drawings. In the drawings:

fig. 1 is a schematic diagram showing the structure of an eyepiece optical system according to embodiment 1 of the present application;

fig. 2 is a schematic diagram showing the structure of an eyepiece optical system according to embodiment 2 of the present application;

Fig. 3 is a schematic diagram showing the structure of an eyepiece optical system according to embodiment 3 of the present application; and

Fig. 4 is a schematic diagram showing the structure of an eyepiece optical system according to embodiment 4 of the present application.

Detailed Description

In order that the application may be readily understood, a more complete description of the application will be rendered by reference to the appended drawings. It should be understood that the detailed description is merely illustrative of exemplary embodiments of the application and is not intended to limit the scope of the application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that in the present specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the feature. Accordingly, a first lens discussed below may also be referred to as a second lens or a third lens without departing from the teachings of the present application.

In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for convenience of explanation. In particular, the spherical or aspherical shape shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The figures are merely examples and are not drawn to scale.

Herein, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the convex position is not defined, then the lens surface is convex at least in the paraxial region; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is referred to as the object side of the lens, and the surface of each lens closest to the imaging side is referred to as the image side of the lens.

It will be further understood that the terms "comprises," "comprising," "includes," "including," "having," "containing," and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Furthermore, when a statement such as "at least one of the following" appears after a list of features that are listed, the entire listed feature is modified instead of modifying a separate element in the list. Furthermore, when describing embodiments of the application, use of "may" means "one or more embodiments of the application. Also, the term "exemplary" is intended to refer to an example or illustration.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.

The features, principles, and other aspects of the present application are described in detail below.

In an exemplary embodiment, the eyepiece optical system includes, for example, six lenses having optical power, i.e., a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The six lenses are arranged in order from the object side to the image side along the optical axis.

In an exemplary embodiment, the eyepiece optical system may further include a photosensitive element disposed on an image side of the sixth lens. Alternatively, the photosensitive element disposed on the image side of the sixth lens may be a photosensitive coupling element (CCD) or a complementary metal oxide semiconductor element (CMOS).

In an exemplary embodiment, the object side of the first lens may be provided with a stop for limiting the light beam to further improve the imaging quality of the eyepiece optical system. The diaphragm is favorable for converging light rays entering the ocular optical system, reducing the caliber of the front end of the ocular optical system and reducing the assemblage sensitivity of the system. In the embodiment of the present application, the diaphragm may be disposed in the vicinity of the object side of the first lens. It should be noted, however, that the locations of the diaphragms disclosed herein are merely examples and not limiting; in alternative embodiments, the diaphragm may be arranged in other positions as desired.

In an exemplary embodiment, the first lens and the second lens constitute a cemented lens, an image side of the first lens cemented with an object side of the second lens. The first lens and the second lens are arranged as a cemented lens, which is favorable for correcting chromatic aberration and realizing better tolerance sensitivity.

In an exemplary embodiment, the first lens has positive optical power, and its image side is convex. The first lens has positive focal power, the lens shape is gentle, the angle of incident light can be compressed to realize smooth transition of the light, the divergent light smoothly enters the rear, further the light trend is smoothly transited, and the caliber of the rear-end lens is reduced; the image side surface of the first lens is a convex surface, which is favorable for reducing the angle of incident light rays and the overall size of the lens.

In an exemplary embodiment, the second lens has a negative power, the object-side surface of which is concave, and the image-side surface of which is convex, which is advantageous in smoothing out high-angle rays collected at the first lens while helping to reduce aberrations of the eyepiece optical system.

In an exemplary embodiment, the third lens has positive optical power, with the object-side surface being convex and the image-side surface being concave or planar. The third lens is positioned at the highest position of the system light, adopts a convex-flat or convex-concave shape, is favorable for reducing the caliber of the lens, reduces the light with a large angle, reduces the incident angle of the light of the rear group lens, and is more favorable for correcting the aberration of the rear group.

In an exemplary embodiment, the fourth lens element has positive optical power, and the object-side surface thereof is convex and the image-side surface thereof is concave. The fourth lens has positive focal power and gentle lens shape, adopts convex-concave shape, is favorable for reducing the angle of light rays with large angles, reduces the incident angle of light rays of the rear group lens, and is more favorable for correcting aberration of the rear group.

In an exemplary embodiment, the fifth lens element has negative optical power, and the object-side surface thereof is convex and the image-side surface thereof is concave. The fifth lens adopts a convex-concave shape, bears the main negative focal power of the ocular optical system, is favorable for compensating spherical aberration introduced by the front lens, can further correct aberration generated by the front lens group, ensures that large-angle light rays enter the system as much as possible, and is more favorable for improving illuminance.

In an exemplary embodiment, the sixth lens element has positive optical power, with the object-side surface being convex and the image-side surface being concave. The sixth lens is convex-concave and has gentle lens shape, which is beneficial to reducing the caliber of the sixth lens, so that the light can be effectively and stably converged at last, and the light can stably reach the imaging surface; meanwhile, more light rays can be collected to enter the image plane so as to increase luminous flux, and higher imaging quality is realized.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: h/f is more than or equal to 0.2 and less than or equal to 0.3, wherein h is half of the diagonal length of an effective pixel area on an imaging surface of the ocular optical system, and f is the total focal length of the ocular optical system. Satisfies h/f which is more than or equal to 0.2 and less than or equal to 0.3, and is favorable for realizing larger magnification.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: and f1/f is more than or equal to 1.4 and less than or equal to 1.8, wherein f1 is the focal length of the first lens, and f is the total focal length of the ocular optical system. Satisfies 1.4.ltoreq.f1/f.ltoreq.1.8, helps making incident light refraction angle change comparatively mild, avoids refraction change too strong and produces too much aberration, helps more light to get into rear mirror optical system simultaneously, and then increases illuminance.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: -2.6.ltoreq.f2/f.ltoreq.2.0, wherein f2 is the focal length of the second lens and f is the total focal length of the eyepiece optics. Satisfying-2.6 is less than or equal to f2/f is less than or equal to-2.0, which is helpful for stabilizing the light trend and reducing the aberration of the ocular optical system.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: and f3/f is more than or equal to 3.0 and less than or equal to 3.9, wherein f3 is the focal length of the third lens, and f is the total focal length of the ocular optical system. Satisfies f3/f 3.9, is beneficial to reducing the aperture of the lens and reducing the sensitivity of the ocular optical system.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: f4/f is more than or equal to 1.8 and less than or equal to 2.4, wherein f4 is the focal length of the fourth lens, and f is the total focal length of the ocular optical system. Satisfies f4/f less than or equal to 1.8 and less than or equal to 2.4, is favorable for making imaging light more gentle and is favorable for improving image quality.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: -1.6.ltoreq.f5/f.ltoreq.1.1, where f5 is the focal length of the fifth lens and f is the total focal length of the eyepiece optics. Satisfies f5/f less than or equal to-1.6 and less than or equal to 1.1, is favorable for compensating the spherical aberration introduced by the front lens, and can further correct the aberration generated by the front lens group.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: f6/f is more than or equal to 1.0 and less than or equal to 1.5, wherein f6 is the focal length of the sixth lens, and f is the total focal length of the ocular optical system. Satisfies f6/f less than or equal to 1.0 and less than or equal to 1.5, is favorable for enabling light to stably enter an image plane, centralizes a defocusing curve, and is favorable for improving resolution.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: and BFL is equal to or less than 0.1 and equal to or less than 0.4, wherein TTL is the distance between the center of the object side surface of the first lens and the imaging surface of the ocular optical system on the optical axis, and BFL is the center distance between the center of the image side surface of the sixth lens and the imaging surface. The ratio of the back focal length to the total length of the eyepiece optical system is controlled to ensure that BFL/TTL is less than or equal to 0.1 and less than or equal to 0.4, and the eyepiece optical system can be suitable for most optical products.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: 1.8.ltoreq.TTL/f.ltoreq.2.3, wherein TTL is the distance between the center of the object side surface of the first lens and the imaging surface of the ocular optical system on the optical axis, and f is the total focal length of the ocular optical system. The total length of the eyepiece optical system and the ratio of the focal length are controlled to ensure that TTL/f is less than or equal to 1.8 and less than or equal to 2.3, and the system can realize the characteristic of small volume.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: and f12/f is more than or equal to 5.2 and less than or equal to 6.6, wherein f12 is the combined focal length of the first lens and the second lens, and f is the total focal length of the ocular optical system. The first lens and the second lens are glued pieces, the f12/f is more than or equal to 5.2 and less than or equal to 6.6, the focal length of the glued pieces is reasonably distributed, the offset of the eyepiece optical system for imaging at high and low temperatures is controlled, and the thermal compensation of the eyepiece optical system at high and low temperatures is good.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: -1.0.ltoreq.f1/f2.ltoreq.0.5, wherein f1 is the focal length of the first lens and f2 is the focal length of the second lens. Satisfies-1.0-1/f 2-0.5, and is beneficial to smooth transition of light and image quality improvement.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: 1.3.ltoreq.f3/f4.ltoreq.2.0, where f3 is the focal length of the third lens and f4 is the focal length of the fourth lens. Satisfies f3/f4 less than or equal to 1.3 and less than or equal to 2.0, is favorable for smooth transition of light and is favorable for improving image quality.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: 3.4.ltoreq.ct1/ct2.ltoreq.8.0, wherein ct1 is the central thickness of the first lens on the optical axis, and ct2 is the central thickness of the second lens on the optical axis. Satisfies that ct1/ct2 is less than or equal to 3.4 and less than or equal to 8.0, is favorable for maintaining better resolution of the eyepiece optical system at high and low temperatures, and ensures that the eyepiece optical system has better temperature performance.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: 1.8.ltoreq.ct4/ct3.ltoreq.2.3, wherein, the central thickness of the ct4 fourth lens on the optical axis, and ct3 is the central thickness of the third lens on the optical axis. Satisfies 1.8-2.3 of ct4/ct3, is helpful for smooth transition of light and reduces sensitivity of eyepiece optical system.

In an exemplary embodiment, the eyepiece optical system according to the present application may satisfy: 1.4.ltoreq.ct6/ct5.ltoreq.1.8, wherein ct6 is the center thickness of the sixth lens on the optical axis, and ct5 is the center thickness of the fifth lens on the optical axis. Satisfies 1.4-1.8 of ct6/ct5, is favorable for enabling light to stably enter an image plane, centralizes a defocusing curve and is favorable for improving resolution.

In an exemplary embodiment, the eyepiece optical system of the present application has an exit pupil diameter of 6mm or more.

In an exemplary embodiment, the eyepiece optical system of the present application may have a magnification of up to 12.5.

In an exemplary embodiment, the maximum exit pupil distance of the eyepiece optical system of the application can reach 55mm, when the eyepiece optical system is applied to shooting eyepieces, the impact force is large in shooting, and the long exit pupil distance can protect the safety of a shooter.

In an exemplary embodiment, the eyepiece optical system can realize-5D- +3D vision adjustment, so that the eyepiece optical system has better adaptability and adapts to different human eye requirements.

In an exemplary embodiment, the eyepiece optical system has the characteristic of a large image surface, the maximum image surface can reach 10.4mm, the large image surface can be matched with more sensors, the application prospect is wide, and the market competitiveness is improved.

In an exemplary embodiment, the eyepiece optical system can realize no virtual focus in the high-low temperature process, and can realize that the temperature range from minus 40 ℃ to 85 ℃ keeps good image quality through the use and matching of different materials. The eyepiece optical system made of glass can inhibit the shift of optical back focus along with the change of temperature so as to improve the stability of the system. Illustratively, the first lens to the sixth lens in the eyepiece optical system of the present application may be made of glass to achieve a plastic-free lens. Of course, in some embodiments, the first lens to the sixth lens in the eyepiece optical system may be made of plastic, or made of plastic and glass in combination, which is not particularly limited in the present application.

In an exemplary embodiment, the eyepiece optical system of the present application may further include a filter and/or a cover glass disposed between the sixth lens and the imaging surface as needed to filter light rays having different wavelengths and prevent an image Fang Yuanjian (e.g., a chip) of the eyepiece optical system from being damaged.

In an exemplary embodiment, the first to sixth lenses may be spherical lenses or aspherical lenses. The application is not particularly limited to the specific number of spherical lenses and aspherical lenses, and can increase the number of aspherical lenses even if all lenses use aspherical lenses when focusing on the imaging quality. The aspherical lens is characterized in that: the curvature varies continuously from the center to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center to the periphery of the lens, an aspherical lens has a better radius of curvature characteristic, and has advantages of improving distortion aberration and improving astigmatic aberration. After the aspheric lens is adopted, aberration generated during imaging can be eliminated as much as possible, and therefore imaging quality of the lens is improved. Optionally, at least one of an object side surface and an image side surface of each of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens is an aspherical mirror surface. Optionally, the object side surface and the image side surface of each of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are spherical mirror surfaces.

According to the eyepiece optical system of the embodiment of the application, through reasonable arrangement of the shapes, the focal powers and the related parameters of each lens, under the condition of using only six lenses, the eyepiece optical system has at least one beneficial effect of small volume, no plastic lenses, long service life and the like, and the distance of an exit pupil of 55mm, the aperture of an exit pupil of 6mm, the magnification of 12.5X and the range of-5D to +3D visibility are realized.

However, those skilled in the art will appreciate that the various results and advantages described in this specification can be obtained by changing the number of lenses making up a lens barrel without departing from the technical solution claimed in the present application. For example, although six lenses are described as an example in the embodiment, the eyepiece optical system is not limited to including six lenses. The eyepiece optics may also include other numbers of lenses if desired. Specific examples of eyepiece optical systems applicable to the above-described embodiments are further described below with reference to the drawings.

Example 1

An eyepiece optical system according to embodiment 1 of the present application is described below with reference to fig. 1. Fig. 1 shows a schematic configuration diagram of an eyepiece optical system according to embodiment 1 of the present application.

As shown in fig. 1, the eyepiece optical system includes, in order from an object side to an image side along an optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6.

The first lens element L1 has positive refractive power, wherein an object-side surface S1 thereof is convex, and an image-side surface S2 thereof is convex.

The second lens element L2 has negative refractive power, wherein an object-side surface S2 thereof is concave, and an image-side surface S3 thereof is convex.

The third lens element L3 has positive refractive power, wherein an object-side surface S4 thereof is convex, and an image-side surface S5 thereof is planar.

The fourth lens element L4 has positive refractive power, wherein an object-side surface S6 thereof is convex, and an image-side surface S7 thereof is concave.

The fifth lens element L5 has a negative refractive power, wherein an object-side surface S8 thereof is convex, and an image-side surface S9 thereof is concave.

The sixth lens element L6 has positive refractive power, wherein an object-side surface S10 thereof is convex and an image-side surface S11 thereof is concave.

The first lens L1 and the second lens L2 may be cemented to constitute a cemented lens.

The eyepiece optical system may further include a stop STO, which may be disposed on the object side of the first lens L1 to improve imaging quality.

Optionally, the eyepiece optical system may further include a filter CG having an object side surface S12 and an image side surface S13 and/or a cover glass (not shown) having an object side surface and an image side surface. The filter CG and/or the cover glass may be used for correcting color deviations, and the filter CG and/or the cover glass may also be used for protecting the image sensing chip IMA located at the imaging plane. Light from the object sequentially passes through the respective surfaces S1 to S13 and is finally imaged on the imaging plane.

Table 1 shows the radius of curvature, thickness/distance, refractive index, and abbe number of each lens of the eyepiece optical system of example 1, wherein the units of the radius of curvature, thickness/distance are millimeters (mm).

TABLE 1

Example 2

An eyepiece optical system according to embodiment 2 of the present application is described below with reference to fig. 2. In this embodiment and the following embodiments, descriptions of portions similar to embodiment 1 will be omitted for brevity. Fig. 2 shows a schematic configuration diagram of an eyepiece optical system according to embodiment 2 of the present application.

As shown in fig. 2, the eyepiece optical system includes, in order from an object side to an image side along an optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6.

The first lens element L1 has positive refractive power, wherein an object-side surface S1 thereof is convex, and an image-side surface S2 thereof is convex.

The second lens element L2 has negative refractive power, wherein an object-side surface S2 thereof is concave, and an image-side surface S3 thereof is convex.

The third lens element L3 has positive refractive power, wherein an object-side surface S4 thereof is convex, and an image-side surface S5 thereof is concave.

The fourth lens element L4 has positive refractive power, wherein an object-side surface S6 thereof is convex, and an image-side surface S7 thereof is concave.

The fifth lens element L5 has a negative refractive power, wherein an object-side surface S8 thereof is convex, and an image-side surface S9 thereof is concave.

The sixth lens element L6 has positive refractive power, wherein an object-side surface S10 thereof is convex and an image-side surface S11 thereof is concave.

The first lens L1 and the second lens L2 may be cemented to constitute a cemented lens.

The eyepiece optical system may further include a stop STO, which may be disposed on the object side of the first lens L1 to improve imaging quality.

Optionally, the eyepiece optical system may further include a filter CG having an object side surface S12 and an image side surface S13 and/or a cover glass (not shown) having an object side surface and an image side surface. The filter CG and/or the cover glass may be used for correcting color deviations, and the filter CG and/or the cover glass may also be used for protecting the image sensing chip IMA located at the imaging plane. Light from the object sequentially passes through the respective surfaces S1 to S13 and is finally imaged on the imaging plane.

Table 2 shows the radius of curvature, thickness/distance, refractive index, and abbe number of each lens of the eyepiece optical system of example 2, wherein the units of the radius of curvature, thickness/distance are millimeters (mm).

TABLE 2

Example 3

An eyepiece optical system according to embodiment 3 of the present application is described below with reference to fig. 3. Fig. 3 shows a schematic configuration diagram of an eyepiece optical system according to embodiment 3 of the present application.

As shown in fig. 3, the eyepiece optical system includes, in order from an object side to an image side along an optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6.

The first lens element L1 has positive refractive power, wherein an object-side surface S1 thereof is convex, and an image-side surface S2 thereof is convex.

The second lens element L2 has negative refractive power, wherein an object-side surface S2 thereof is concave, and an image-side surface S3 thereof is convex.

The third lens element L3 has positive refractive power, wherein an object-side surface S4 thereof is convex, and an image-side surface S5 thereof is concave.

The fourth lens element L4 has positive refractive power, wherein an object-side surface S6 thereof is convex, and an image-side surface S7 thereof is concave.

The fifth lens element L5 has a negative refractive power, wherein an object-side surface S8 thereof is convex, and an image-side surface S9 thereof is concave.

The sixth lens element L6 has positive refractive power, wherein an object-side surface S10 thereof is convex and an image-side surface S11 thereof is concave.

The first lens L1 and the second lens L2 may be cemented to constitute a cemented lens.

The eyepiece optical system may further include a stop STO, which may be disposed on the object side of the first lens L1 to improve imaging quality.

Optionally, the eyepiece optical system may further include a filter CG having an object side surface S12 and an image side surface S13 and/or a cover glass (not shown) having an object side surface and an image side surface. The filter CG and/or the cover glass may be used for correcting color deviations, and the filter CG and/or the cover glass may also be used for protecting the image sensing chip IMA located at the imaging plane. Light from the object sequentially passes through the respective surfaces S1 to S13 and is finally imaged on the imaging plane.

Table 3 shows the radius of curvature, thickness/distance, refractive index, and abbe number of each lens of the eyepiece optical system of example 3, wherein the units of the radius of curvature, thickness/distance are millimeters (mm).

TABLE 3 Table 3

Example 4

An eyepiece optical system according to embodiment 4 of the present application is described below with reference to fig. 4. Fig. 4 shows a schematic configuration diagram of an eyepiece optical system according to embodiment 4 of the present application.

As shown in fig. 4, the eyepiece optical system includes, in order from an object side to an image side along an optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6.

The first lens element L1 has positive refractive power, wherein an object-side surface S1 thereof is planar, and an image-side surface S2 thereof is convex.

The second lens element L2 has negative refractive power, wherein an object-side surface S2 thereof is concave, and an image-side surface S3 thereof is convex.

The third lens element L3 has positive refractive power, wherein an object-side surface S4 thereof is convex, and an image-side surface S5 thereof is concave.

The fourth lens element L4 has positive refractive power, wherein an object-side surface S6 thereof is convex, and an image-side surface S7 thereof is concave.

The fifth lens element L5 has a negative refractive power, wherein an object-side surface S8 thereof is convex, and an image-side surface S9 thereof is concave.

The sixth lens element L6 has positive refractive power, wherein an object-side surface S10 thereof is convex and an image-side surface S11 thereof is concave.

The first lens L1 and the second lens L2 may be cemented to constitute a cemented lens.

The eyepiece optical system may further include a stop STO, which may be disposed on the object side of the first lens L1 to improve imaging quality.

Optionally, the eyepiece optical system may further include a filter CG having an object side surface S12 and an image side surface S13 and/or a cover glass (not shown) having an object side surface and an image side surface. The filter CG and/or the cover glass may be used for correcting color deviations, and the filter CG and/or the cover glass may also be used for protecting the image sensing chip IMA located at the imaging plane. Light from the object sequentially passes through the respective surfaces S1 to S13 and is finally imaged on the imaging plane.

Table 4 shows the radius of curvature, thickness/distance, refractive index, and abbe number of each lens of the eyepiece optical system of example 4, wherein the units of the radius of curvature, thickness/distance are millimeters (mm).

TABLE 4 Table 4

In summary, examples 1 to 4 each satisfy the relationships shown in table 5 below. In table 5, units of f, f1, f2, f3, f4, f5, BFL, TTL, h, f, ct1, ct2, ct3, ct4, ct5, and ct6 are millimeters (mm).

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TABLE 5

The present application also provides an electronic apparatus that may include the eyepiece optical system according to the above-described embodiment of the present application and an imaging element for converting an optical image formed by the eyepiece optical system into an electrical signal. The electronic device may be a stand-alone electronic device such as a detection range camera or may be an imaging module integrated with such a detection range device. The electronic device may also be a stand-alone imaging device, such as an onboard camera, or an imaging module integrated on, for example, a driving assistance system.

The above description is only illustrative of the preferred embodiments of the present application and of the principles of the technology employed. It will be appreciated by persons skilled in the art that the scope of the application referred to in the present application is not limited to the specific combinations of the technical features described above, but also covers other technical features formed by any combination of the technical features described above or their equivalents without departing from the inventive concept. Such as the above-mentioned features and the technical features disclosed in the present application (but not limited to) having similar functions are replaced with each other.

Claims (15)

1. An eyepiece optical system, characterized in that the eyepiece optical system sequentially comprises, from an object side to an image side along an optical axis:

a first lens having positive optical power, the image side surface of which is convex;

the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface;

A third lens having positive optical power, the object side surface of which is a convex surface;

A fourth lens element with positive refractive power having a convex object-side surface and a concave image-side surface;

a fifth lens element with negative refractive power having a convex object-side surface and a concave image-side surface; and

A sixth lens element with positive refractive power having a convex object-side surface and a concave image-side surface;

Half h of the diagonal length of the effective pixel area on the imaging surface of the eyepiece optical system and the total focal length f of the eyepiece optical system satisfy: h/f is more than or equal to 0.2 and less than or equal to 0.3.

2. The eyepiece optical system of claim 1 wherein a focal length f1 of the first lens and a total focal length f of the eyepiece optical system satisfy: f1/f is more than or equal to 1.4 and less than or equal to 1.8.

3. The eyepiece optical system of claim 1 wherein a focal length f2 of the second lens and a total focal length f of the eyepiece optical system satisfy: -2.6.ltoreq.f2/f.ltoreq.2.0.

4. The eyepiece optical system of claim 1 wherein a focal length f3 of the third lens and a total focal length f of the eyepiece optical system satisfy: f3/f is more than or equal to 3.0 and less than or equal to 3.9.

5. The eyepiece optical system of claim 1 wherein a focal length f4 of the fourth lens and a total focal length f of the eyepiece optical system satisfy: f4/f is more than or equal to 1.8 and less than or equal to 2.4.

6. The eyepiece optical system of claim 1 wherein a focal length f5 of the fifth lens and a total focal length f of the eyepiece optical system satisfy: -1.6.ltoreq.f5/f.ltoreq.1.1.

7. The eyepiece optical system of claim 1 wherein a focal length f6 of the sixth lens and a total focal length f of the eyepiece optical system satisfy: f6/f is more than or equal to 1.0 and less than or equal to 1.5.

8. The eyepiece optical system of any one of claims 1-7 wherein a distance TTL on the optical axis from a center of an object side surface of the first lens to an imaging surface of the eyepiece optical system and a center of an image side surface of the sixth lens to a center of the imaging surface BFL satisfies: BFL/TTL is more than or equal to 0.1 and less than or equal to 0.4.

9. The eyepiece optical system of any one of claims 1-7 wherein a distance TTL on the optical axis from a center of an object side surface of the first lens to an imaging surface of the eyepiece optical system and a total focal length f of the eyepiece optical system satisfy: TTL/f is less than or equal to 1.8 and less than or equal to 2.3.

10. The eyepiece optical system of any one of claims 1-7 wherein a combined focal length f12 of the first lens and the second lens and a total focal length f of the eyepiece optical system satisfy: f12/f is more than or equal to 5.2 and less than or equal to 6.6.

11. The eyepiece optical system of any one of claims 1-7 wherein a focal length f1 of the first lens and a focal length f2 of the second lens satisfy: -1.0.ltoreq.f1/f2.ltoreq.0.5.

12. The eyepiece optical system of any one of claims 1-7 wherein a focal length f3 of the third lens and a focal length f4 of the fourth lens satisfy: f3/f4 is more than or equal to 1.3 and less than or equal to 2.0.

13. The eyepiece optical system of any one of claims 1-7 wherein a center thickness ct1 of the first lens on the optical axis and a center thickness ct2 of the second lens on the optical axis satisfy: ct1/ct2 is more than or equal to 3.4 and less than or equal to 8.0.

14. The eyepiece optical system of any one of claims 1-7 wherein a center thickness ct4 of the fourth lens on the optical axis and a center thickness ct3 of the third lens on the optical axis satisfy: ct4/ct3 is less than or equal to 1.8 and less than or equal to 2.3.

15. The eyepiece optical system of any one of claims 1-7 wherein a center thickness ct6 of the sixth lens on the optical axis and a center thickness ct5 of the fifth lens on the optical axis satisfy: ct6/ct5 is less than or equal to 1.4 and less than or equal to 1.8.