CN116203723A - Lens device and imaging apparatus - Google Patents

Abstract

The embodiment of the application provides a lens device and imaging equipment, wherein, the lens device includes: the Fresnel lens is provided with at least one Fresnel surface, and the Fresnel surface is provided with a plurality of annular bulges; the shading lens is arranged opposite to the Fresnel lens, a shading coating is arranged on one side surface of the shading lens, the shading coating comprises an annular shading belt which is arranged corresponding to at least one annular bulge, and the annular shading belt is used for shading incident light corresponding to the tooth tip part of the annular bulge. According to the technology of this application, can avoid light to get into annular bellied tooth point part, reduce fresnel lens and produce the probability of parasitic light, astigmatism, improve fresnel lens's printing opacity performance to be favorable to promoting imaging device's imaging.

Description

Lens device and imaging device

technical field

The present application relates to the field of optical technology, in particular to a lens device and an imaging device.

Background technique

As a "thinned version" of traditional lenses, Fresnel lenses are used in various optical imaging devices, such as camera lenses, VR (Virtual Reality, virtual reality technology) devices, and the like. However, the sawtooth structure of the Fresnel lens will produce serious stray light and astigmatism, especially in the application of VR equipment. Since the Fresnel lens is usually large in diameter, users are affected by stray light and astigmatism when viewing directly with the naked eye. impact, leading to poor user experience.

Contents of the invention

Embodiments of the present application provide a lens device and an imaging device to solve or alleviate one or more technical problems in the prior art.

As an aspect of the embodiment of the present application, the embodiment of the present application provides a lens device, including: a Fresnel lens having at least one Fresnel surface, and the Fresnel surface is provided with a plurality of annular protrusions; a light-shielding lens, Set opposite to the Fresnel lens, one side surface of the light-shielding lens is provided with a light-shielding coating, and the light-shielding coating includes an annular light-shielding band corresponding to at least one annular protrusion, and the annular light-shielding band is used to block the annular protrusion The tip of the tooth corresponds to the incident ray.

In one embodiment, the light-shielding lens is arranged on the light-incident side of the Fresnel lens.

In one embodiment, a plurality of annular protrusions are arranged concentrically, the number of annular light-shielding bands is the same as the number of annular protrusions, and the annular light-shielding bands are arranged in one-to-one correspondence with the annular protrusions.

In one embodiment, at least one of the width of the annular light-shielding band and the width of the tooth tip of the annular protrusion, the distance between the light-shielding lens and the tooth tip of the annular protrusion, and the incident angle of the incident light Factors are relevant.

In one embodiment, the formula for determining the width w of the annular shading belt is as follows:

w=w ₀ +2d*tanθ,

Among them, w ₀ is used to indicate the width of the tooth tip of the annular protrusion, d is used to indicate the distance between the light-shielding lens and the tooth tip of the annular protrusion, θ is used to indicate the incident angle of the incident light, and the incident angle is the angle between the incident direction of the incident light and the central axis of the shading lens.

In one embodiment, the light-shielding coating has an absorbance greater than or equal to 99%.

In one embodiment, the material of the light-shielding lens is glass or resin, and the light transmittance of the light-shielding lens is greater than or equal to 90%.

In one embodiment, the thickness of the light-shielding lens is 0.4 to 0.6 mm.

In one embodiment, the lens device further includes: a fixing part, the inner side of the fixing part defines a mounting cavity, the Fresnel lens and the light-shielding lens are arranged in the mounting cavity at intervals, and the mounting cavity is provided for fixing the Fresnel lens and /or the limit groove of the light-shielding lens.

In one embodiment, the fixing part has a plurality of fixing holes passing through its wall, and the fixing holes correspond to the installation positions of the Fresnel lens or the light-shielding lens, and the fixing holes are used for the fastener to pass through and make the The end of the fastener abuts against the peripheral wall of the Fresnel lens or the light-shielding lens.

As another aspect of the embodiments of the present application, the embodiments of the present application provide an imaging device, including the lens device in any one of the foregoing implementation manners of the present application.

According to the technical solution of the present application, by setting a light-shielding lens with a light-shielding coating, and the light-shielding coating includes an annular light-shielding band corresponding to at least one annular protrusion, the annular light-shielding band can protect the tooth tip of the annular protrusion Partially forms a light-shielding effect, thereby preventing light from entering the tooth tip of the ring-shaped protrusion, thereby reducing the probability of stray light and astigmatism caused by the ring-shaped protrusion of the tooth tip of the Fresnel lens, and improving the Fresnel lens Excellent light transmission performance, which is beneficial to improve the imaging effect of the imaging device adopting the lens device of the embodiment of the present application.

The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present application will be readily apparent by reference to the drawings and the following detailed description.

Description of drawings

In the drawings, unless otherwise specified, the same reference numerals designate the same or similar parts or elements throughout the several drawings. The drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed according to the application, and should not be regarded as limiting the scope of the application.

FIG. 1 shows a schematic structural diagram of a lens device according to an embodiment of the present application.

Fig. 2 shows a schematic diagram of a light-shielding coating of a lens device according to an embodiment of the present application.

Fig. 3 shows a schematic diagram of determining the width of the annular light-shielding band of the lens device according to the embodiment of the present application.

Fig. 4 shows another schematic diagram of determining the width of the annular light-shielding band of the lens device according to the embodiment of the present application.

FIG. 5 shows a schematic diagram of a fixing part of a lens device according to an embodiment of the present application.

FIG. 6 shows another schematic diagram of the fixing part of the lens device according to the embodiment of the present application.

Explanation of reference signs

Lens device 1;

Fresnel lens 10; Fresnel surface 10a; annular protrusion 11; tooth tip portion 11a;

Light-shielding lens 20; Light-shielding coating 21; Ring-shaped light-shielding belt 22;

The fixing part 30 ; the limiting groove 31 ; the fixing hole 32 ; the fastener 33 .

Detailed ways

In the following, only some exemplary embodiments are briefly described. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present application. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature and not restrictive.

A lens device 1 according to an embodiment of the present application is described below with reference to FIGS. 1 to 6 .

FIG. 1 shows a schematic structural diagram of a lens device 1 according to an embodiment of the present application. As shown in FIG. 1 , the lens device 1 includes a Fresnel lens 10 and a light-shielding lens 20 .

Specifically, the Fresnel lens 10 has at least one Fresnel surface 10 a, and the Fresnel surface 10 a is provided with a plurality of annular protrusions 11 . The light-shielding lens 20 is arranged opposite to the Fresnel lens 10, and one side surface of the light-shielding lens 20 is provided with a light-shielding coating 21, and the light-shielding coating 21 includes an annular light-shielding belt 22 corresponding to at least one annular protrusion 11. The light-shielding strip 22 is used to shield the incident light corresponding to the tip portion 11 a of the annular protrusion 11 .

It can be understood that the Fresnel lens, also known as a threaded lens, is a thin sheet made of a light-transmitting material (such as polyolefin or glass) injected and pressed. Among the two opposite side surfaces of the Fresnel lens, at least one side surface is a Fresnel surface 10a. For example, one side surface of the Fresnel lens 10 may be a Fresnel surface 10a, and the other side surface may be a smooth convex, concave or flat surface. For another example, both side surfaces of the Fresnel lens 10 may be Fresnel surfaces 10a.

Exemplarily, the projected shape of the annular protrusion 11 on a plane perpendicular to the central axis of the Fresnel lens 10 may be a ring shape. A plurality of annular protrusions 11 are arranged concentrically, and the plurality of annular protrusions 11 are arranged at equal intervals, and the inner side of the innermost annular protrusion 11 defines a smooth convex surface, concave surface or plane. The cross-sectional shape of the annular protrusion 11 in a plane passing through the central axis of the Fresnel lens 10 can be sawtooth, and at least one of the inner surface and the outer surface of the annular protrusion 11 is opposite to the axial direction of the Fresnel lens 10. Tilt setting.

Next, take FIG. 3 as an example to explain the meaning of the inner surface and the outer surface of the annular protrusion 11 . As shown in FIG. 3 , the annular protrusion 11 has a first side surface 111 and a second side surface 112 opposite in the radial direction of the Fresnel lens 10 . Wherein, the first side surface 111 is disposed adjacent to the central axis L of the Fresnel lens 10 in the radial direction of the Fresnel lens 10, and the second side surface 112 is far away from the center of the Fresnel lens 10 in the radial direction of the Fresnel lens 10 The axis L is set. The inner surface of the annular protrusion 11 refers to the first side surface 111 of the annular protrusion 11 adjacent to the central axis L side of the Fresnel lens 10, and the outer surface of the annular protrusion 11 refers to the annular protrusion 11. The second side surface 112 of the lens 11 on the side away from the central axis L of the Fresnel lens 10 .

It can be understood that, the light-shielding lens 20 and the Fresnel lens 10 are arranged oppositely, which means that the central axis of the light-shielding lens 20 is coaxially arranged with the central axis of the Fresnel lens 10 . For the Fresnel lens 10 provided with only one Fresnel surface 10a, the light-shielding lens 20 is located on the side of the Fresnel lens 10 adjacent to the Fresnel surface 10a. For the Fresnel lens 10 whose both side surfaces are Fresnel surfaces 10 a , the light-shielding lens 20 may be located on either side of the Fresnel lens 10 . The light-shielding coating 21 of the light-shielding lens 20 is made of light-shielding material, and the light-shielding coating 21 may include at least one ring-shaped light-shielding band 22 , and the ring-shaped light-shielding band 22 is arranged in one-to-one correspondence with the ring-shaped protrusions 11 .

In the embodiment of the present application, the number of annular light-shielding bands 22 may be the same as the number of annular protrusions 11 on the Fresnel surface 10a, or may be smaller than the number of annular protrusions 11 on the Fresnel surface 10a. In other words, the number of annular light-shielding bands 22 can be a plurality of one-to-one correspondence with all annular protrusions 11 on the Fresnel surface 10a, or can be partially annular with all annular protrusions 11 There are a plurality of protrusions 11 in one-to-one correspondence. In a specific example, when the number of annular light-shielding bands 22 is smaller than the number of annular protrusions 11 , the annular light-shielding bands 22 may be provided in one-to-one correspondence with some of the annular protrusions 11 adjacent to the central area.

Exemplarily, the light-shielding coating 21 can be provided on the side surface of the light-shielding lens 20 adjacent to the side surface of the Fresnel lens 10, and the shape of any annular light-shielding band 22 included in the light-shielding coating 21 can be the same as that of the corresponding annular The shape of the protrusion 11 is set accordingly. For example, for the ring-shaped protrusion 11 , the ring-shaped light-shielding strip 22 can be correspondingly set in the shape of a ring. The embodiment of the present application does not specifically limit the size of the ring-shaped light-shielding belt 22, such as the inner diameter or outer diameter, as long as the ring-shaped light-shielding belt 22 can block the incident light from the tooth tip portion 11a of the corresponding ring-shaped protrusion 11. Can.

In the embodiment of the present application, the tip portion 11a of the annular protrusion 11 refers to the portion of the end of the annular protrusion 11 away from the Fresnel surface 10a. The width of the annular light-shielding band 22 can be correspondingly set according to the width of the tip portion 11 a of the annular protrusion 11 , so as to block light from entering the tip portion 11 a of the annular protrusion 11 . Wherein, the width of the annular light-shielding belt 22 refers to the distance between the inner surface and the outer surface of the annular light-shielding belt 22, or refers to the distance between the annular light-shielding belt 22 on a plane perpendicular to the central axis of the light-shielding lens 20. One-half the difference between the outer and inner diameters of the projected torus.

According to the lens device 1 of the embodiment of the present application, a light-shielding lens 20 with a light-shielding coating 21 is provided, and the light-shielding coating 21 includes an annular light-shielding belt 22 corresponding to at least one annular protrusion 11, and the annular light-shielding belt 22 The light-shielding effect can be formed on the tooth tip portion 11a of the annular protrusion 11, thereby preventing light from entering the tooth tip portion 11a of the annular protrusion 11, thereby reducing the frequency of the Fresnel lens 10 caused by the tooth tip portion 11a of the annular protrusion 11. The probability of stray light and astigmatism generated by the part 11 a improves the light transmission performance of the Fresnel lens 10 , thereby improving the imaging effect of the imaging device using the lens device 1 of the embodiment of the present application.

In one embodiment, the light-shielding lens 20 is disposed on the light-incident side of the Fresnel lens 10 .

It can be understood that, for a Fresnel lens 10 with only one Fresnel surface 10a, the light incident side of the Fresnel lens 10 refers to one of the adjacent Fresnel surfaces 10a of the Fresnel lens 10. side, that is, the light-shielding lens 20 may be disposed on a side of the Fresnel lens 10 adjacent to the Fresnel surface 10a. For the Fresnel lens 10 provided with two Fresnel surfaces 10a, the light incident side of the Fresnel lens 10 can be any side in the axially opposite sides of the Fresnel lens 10, namely The light-shielding lens 20 may be provided on any one of opposite sides in the axial direction of the Fresnel lens 10 .

In one embodiment, as shown in Figure 2, a plurality of annular protrusions 11 are arranged concentrically, the number of annular light-shielding bands 22 is the same as the number of annular protrusions 11, and the annular light-shielding bands 22 and the annular protrusions From 11 to one-to-one corresponding setting.

Exemplarily, the shape of the ring-shaped protrusions 11 is a ring shape, and the diameters of different ring-shaped protrusions 11 are not equal, so that a plurality of ring-shaped protrusions 11 arranged concentrically are nested with each other. The annular light-shielding band 22 is a plurality of one-to-one correspondence with a plurality of annular protrusions 11, and the shape of the annular light-shielding band 22 is the same as or similar to that of the annular protrusion 11, for example, the shape of the annular light-shielding band 22 It can also be set as a circular ring. The width and diameter of the annular light-shielding belt 22 can be set correspondingly according to the width and diameter of the annular protrusion 11 , which is not specifically limited here.

Wherein, the position of the ring-shaped light-shielding belt 22 and the position of the corresponding ring-shaped protrusion 11 can be arranged facing each other, and can also be arranged in a staggered manner. Specifically, it can be specified according to the incident angle of the incident light corresponding to the tip portion 11a of the ring-shaped protrusion 11. set up. For example, when the incident angle of the incident light is 0 degrees, that is, the incident direction of the incident light is the same as the axial direction of the Fresnel lens 10, then the position of the annular light-shielding band 22 can be directly opposite to the position of the annular protrusion 11 set up.

In one embodiment, the width of the annular light-shielding belt 22 is related to the width of the tooth tip portion of the annular protrusion 11, the distance between the light-shielding lens 20 and the tooth tip portion 11a of the annular protrusion 11, and the incidence of the incident light. At least one factor in the angle is relevant.

In the embodiment of the present application, the width of the annular light-shielding belt 22 refers to the distance between the inner surface and the outer surface of the annular light-shielding belt 22, wherein the inner surface refers to the distance between the adjacent light-shielding lens 20 of the annular light-shielding belt 22 The surface on one side of the central axis and the outer surface refer to the surface of the ring-shaped light-shielding belt 22 on the side away from the central axis of the light-shielding lens 20 . The distance between the light-shielding lens 20 and the tip portion 11a of the annular protrusion 11 refers to the distance between the surface of the light-shielding lens 20 on the side adjacent to the Fresnel lens 10 and the Fresnel surface 10a. The incident angle of the incident light refers to the angle between the incident direction of the incident light and the central axis of the Fresnel lens 10 .

It can be understood that the width of the annular light-shielding band 22 is positively correlated with the width of the tooth tip portion of the annular protrusion 11, that is, the larger the width of the tooth tip portion of the annular protrusion 11, the correspondingly the width of the annular light-shielding band 22 The width is also larger. The width of the annular light-shielding band 22 is positively related to the distance between the light-shielding lens 20 and the tip portion 11a of the annular protrusion 11, that is, the larger the distance between the light-shielding lens 20 and the Fresnel surface 10a, the correspondingly the annular The width of the shading strip 22 is also larger. The width of the annular light-shielding belt 22 is positively correlated with the incident angle of the incident light, that is, the larger the incident angle of the incident light is, the larger the width of the annular light-shielding belt 22 is correspondingly. It should be noted that any one or any of the width of the tooth tip portion of the aforementioned annular protrusion 11, the distance between the light-shielding lens 20 and the tooth tip portion 11a of the annular protrusion 11, and the incident angle of the incident light When the two factors are invariant, the width of the annular light-shielding belt 22 can be determined according to the remaining factors. For example, under the condition that the distance between the light-shielding lens 20 and the tooth tip portion 11a of the annular protrusion 11 and the incident angle of the incident light are invariant, then the tooth tip portion of the annular protrusion 11 can The width of 11a determines the width of the annular light-shielding belt 22 accordingly.

Optionally, the formula for determining the width w of the annular shading belt 22 is as follows:

w=w ₀ +2d*tanθ,

Among them, w ₀ is used to represent the width of the tooth tip portion 11a of the annular protrusion 11, d is used to represent the distance between the light-shielding lens 20 and the tooth tip portion 11a of the annular protrusion 11, and θ is used to represent the distance of the incident light The incident angle, the incident angle is the angle between the incident direction of the incident light and the central axis of the light-shielding lens 20 .

In one example, as shown in FIG. 3 , when the incident direction of the incident light is parallel to the axial direction of the light shielding lens 20, that is, the incident angle of the incident light is 0 degrees, the annular light shielding belt 22 is aligned with the light shielding lens 20 The ring-shaped protrusion 11 is arranged in a direction parallel to the central axis of the ring-shaped protrusion 11, and the width w of the annular light-shielding band 22 may be the same as the width _w0 of the tooth tip portion 11a of the ring-shaped protrusion 11.

In another example, as shown in FIG. 4 , when the incident direction of the incident light is not parallel to the axial direction of the light-shielding lens 20, that is, the incident angle of the incident light is greater than 0 degrees or less than 90 degrees, the ring-shaped light-shielding belt 22 is arranged opposite to the ring-shaped protrusion 11 in a direction parallel to the central axis of the light-shielding lens 20, and the width w of the ring-shaped light-shielding band 22 can be equal to or equal to the width w of the tooth tip portion 11a of the ring-shaped protrusion ₁₁ . Add 2d ₀ *tanθ to the base.

According to the relationship between the width w of the annular light-shielding strip 22 and the aforementioned multiple factors, in a specific example, the width w of the annular light-shielding strip 22 may be 10 to 100 microns. Preferably, the width w of the ring-shaped light-shielding belt 22 may be specifically 70 microns.

In one embodiment, the light-shielding coating 21 has an absorbance greater than or equal to 99%.

Exemplarily, the material used for the light-shielding coating 21 may be any material, as long as it has light-shielding performance and meets the requirements for shielding incident light. For example, the material of the light-shielding coating 21 can specifically be ink, carbon nanotube black body, acrylic resin, etc., as long as the light absorption rate can reach more than 99%. Not specifically limited.

In one embodiment, the light-shielding coating 21 is processed and shaped by a photolithography process.

Exemplarily, the material of the light-shielding coating 21 can be acrylic resin with light-shielding performance, thus, the light-shielding coating 21 is processed on the light-shielding lens 20 through a photolithography process, on the one hand, the processing efficiency of the light-shielding coating 21 is improved, and on the other hand On the one hand, the processing accuracy of the plurality of ring-shaped light-shielding bands 22 in the light-shielding coating 21 can be ensured.

In one embodiment, the material of the light-shielding lens 20 is glass or resin, and the light transmittance of the light-shielding lens 20 is greater than or equal to 90%.

It can be understood that, in the embodiment of the present application, the light-shielding coating 21 on the light-shielding lens 20 is only used to shield the tooth tips of at least some of the ring-shaped protrusions 11 on the Fresnel surface 10a. For the incident light corresponding to the part 11a, for the rest of the Fresnel surface 10a except the tooth tip part 11a of the aforementioned at least part of the annular protrusion 11, the light-shielding lens 20 does not block the incident light corresponding to the remaining part, that is, it can Make sure that the light enters the rest of the Fresnel facet 10a.

Exemplarily, the refractive index of the light-shielding lens 20 is 1.5 to 1.6. Therefore, by setting the refractive index of the light-shielding lens 20 higher, it is beneficial to reduce the thickness of the light-shielding lens 20 , thereby reducing the weight of the lens device 1 and meeting the lightweight requirement of the lens device 1 .

Optionally, the thickness of the light-shielding lens 20 is 0.4 to 0.6 mm. Preferably, the thickness of the light-shielding lens 20 may be 0.5mm.

In one embodiment, the lens device 1 further includes a fixing part 30, the inside of the fixing part 30 defines an installation cavity, the Fresnel lens 10 and the light-shielding lens 20 are arranged in the installation cavity at intervals, and the installation cavity is provided for fixing the Fresnel lens. The limit groove 31 of the Niel lens 10 and/or the light-shielding lens 20 .

Exemplarily, the fixing part 30 may be configured as a cylindrical structure, and the fixing part 30 may adopt a hollow structure to define an installation cavity inside it. Both ends of the fixing portion 30 in the axial direction are open, so that the installation cavity communicates with the external space.

More specifically, the inner wall surface of the fixing part 30 may be provided with a limiting groove 31 corresponding to the Fresnel lens 10 and/or the light-shielding lens 20, and the width of the limiting groove 31 is corresponding to the Fresnel lens 10 and the light-shielding lens 20. And/or the thickness of the light-shielding lens 20 is correspondingly set, for locking the Fresnel lens 10 and/or the light-shielding lens 20 in the corresponding limiting groove 31 . Thus, the positioning of the Fresnel lens 10 and/or the light-shielding lens 20 in the installation cavity is realized.

In an example, the limiting groove 31 may be one corresponding to the Fresnel lens 10 or the light-shielding lens 20 . For example, in the example shown in FIG. 1, there can be one limiting groove 31 and it is set corresponding to the Fresnel lens 10, wherein the width of the limiting groove 31 corresponds to the thickness of the edge of the Fresnel lens 10, so that Two opposite inner surfaces of the limiting groove 31 are respectively in surface contact with two opposite side surfaces of the Fresnel lens 10 .

In another example, there may be two limiting grooves 31 corresponding to the Fresnel lens 10 and the light-shielding lens 20 respectively, and the widths of the two limiting grooves 31 are the same as the thickness of the Fresnel lens 10 and the light-shielding lens 20 respectively. The thicknesses are set correspondingly, so as to avoid the relative positions of the Fresnel lens 10 and the light-shielding lens 20 in the axial direction from shifting.

Optionally, in one embodiment, the fixing part 30 has a plurality of fixing holes 32 penetrating through its wall, and the plurality of fixing holes 32 correspond to the installation positions of the Fresnel lens 10 or the light-shielding lens 20, and the fixing holes 32 It is used for passing the fastener 33 and making the end of the fastener 33 abut against the peripheral wall of the Fresnel lens 10 or the light-shielding lens 20 .

Exemplarily, a limiting groove 31 corresponding to the Fresnel lens 10 is provided in the installation cavity of the fixing part 30 for limiting the axial position and the radial position of the Fresnel lens 10 . The plurality of fixing holes 32 are distributed at equal intervals along the circumferential direction of the fixing portion 30 and correspond to the axial positions of the light-shielding lens 20 . Specifically, the fixing hole 32 can be configured as a screw hole, and the diameter of the fixing hole 32 can be 1 mm. Specifically, the fastener 33 may be a screw adapted to the screw hole, so that the screw can pass through the screw hole from the outside of the fixing part 30 and form a threaded connection. Wherein, the ends of the plurality of screws corresponding to the plurality of fixing holes 32 are adapted to abut against the peripheral wall of the light-shielding lens 20 to position the light-shielding lens 20 .

It can be understood that by adjusting the lengths of different screws protruding into the installation cavity, the radial position of the light-shielding lens 20 can be adjusted while the light-shielding lens 20 is positioned axially, so that the position of the light-shielding lens 20 can be adjusted The light-shielding coating 21 is aligned with at least part of the corresponding ring-shaped protrusions 11 on the Fresnel lens 10 to ensure that the light-shielding coating 21 can accurately align at least part of the corresponding ring-shaped protrusions 11 The incident light is blocked.

In other examples of the present application, a limiting groove 31 corresponding to the light-shielding lens 20 is provided in the installation cavity of the fixing part 30 for limiting the axial position and the radial position of the light-shielding lens 20 . A plurality of fixing holes 32 are distributed at equal intervals along the circumferential direction of the fixing part 30 and correspond to axial positions of the Fresnel lens 10 . Thus, the radial position of the Fresnel lens 10 can be adjusted by adjusting the lengths of different screws extending into the installation cavity. The incident light of at least part of the corresponding ring-shaped protrusion 11 is blocked

In addition, the number of fixing holes 32 is not specifically limited in this embodiment of the present application. For example, as shown in FIG. 5 , the number of fixing holes 32 may be three, distributed at equal intervals in the circumferential direction of the fixing part 30 . For another example, as shown in FIG. 6 , the number of fixing holes 32 may be four, which are distributed at equal intervals in the circumferential direction of the fixing portion 30 .

The following describes a lens device 1 according to an embodiment of the present application with reference to a specific example in FIG. 1 . As shown in FIG. 1 , the lens device 1 includes a Fresnel lens 10 , a light-shielding lens 20 , and a fixing unit 30 . Wherein, one side surface of the Fresnel lens 10 is a Fresnel surface 10a, and the other side surface is an aspherical surface. The light-shielding lens 20 is made of glass with a refractive index of 1.5 to 1.55 and a thickness of 0.5 mm. The diameter of the light-shielding lens 20 is not smaller than the diameter of the Fresnel lens 10 . A side surface of the light-shielding lens 20 adjacent to the Fresnel lens 10 is coated with a light-shielding coating 21 . The light-shielding coating 21 may include a plurality of annular light-shielding strips 22 arranged concentrically, and the number of the annular light-shielding strips 22 does not exceed the number of the annular protrusions 11 on the Fresnel surface 10a. The light-shielding coating 21 is provided in one-to-one correspondence with at least some of the annular protrusions 11 of all the annular protrusions 11 on the Fresnel surface 10a. Wherein, the width of the annular masking strip is 70um, and the material of the light-shielding coating 21 is acrylic resin, and the absorption rate of visible light can reach 99.99%. The light-shielding coating 21 may be formed on the side surface of the light-shielding lens 20 through a photolithography process. The fixing part 30 is configured as a cylindrical structure, and the inner peripheral wall of the fixing part 30 is provided with a limiting groove 31 for limiting the Fresnel lens 10 . The wall of the fixing part 30 is provided with 4 screw holes (i.e. fixing holes 32) distributed at equal intervals, which are used for passing screws (i.e. fasteners 33) and forming threaded connections, and the ends of the screws are suitable for It is in contact with the outer peripheral wall of the light-shielding lens 20 . Wherein, the diameter of the screw hole may be 1mm.

The following describes the installation method of the lens device 1 according to the embodiment of the present application by using a specific example. When assembling the lens device 1 , the Fresnel lens 10 can be first installed and fixed on the side of the fixing part 30 without the screw hole, wherein the Fresnel surface 10 a is disposed adjacent to the side with the screw hole. The light-shielding lens 20 is then fitted into the side of the fixing portion 30 having the screw hole, wherein the side surface having the light-shielding coating 21 is disposed adjacent to the Fresnel surface 10a. Afterwards, the fixing part 30 is observed under a microscope, wherein the Fresnel surface 10a is placed upward. During the observation process, judge whether the ring-shaped light-shielding band 22 in the light-shielding coating 21 on the light-shielding lens 20 corresponds exactly to the tooth tip portion 11a of the ring-shaped protrusion 11 of the Fresnel surface 10a, if not exactly corresponding, then place The screws are screwed into the screw holes one by one, so that the end of the screw contacts the light-shielding lens 20, thereby pushing the light-shielding lens 20 to move toward the direction where the light-shielding coating 21 is exactly corresponding to the tooth tip portion 11a of the ring-shaped protrusion 11, until it is in each direction. , the light-shielding pattern corresponds exactly to the tip portion 11a of the annular protrusion 11, and finally tightens all the screws.

It can be understood that if the light-shielding coating 21 on the light-shielding lens 20 corresponds to the tooth tip portion 11a of the annular protrusion 11 at the beginning, then the screws are screwed into the screw holes in sequence, and the light-shielding coating is ensured during the screw-in process. The layer 21 is kept in exact correspondence with the tooth tips of the Fresnel face 10a, and finally all the screws are tightened. After all the screws are tightened, the light-shielding lens 20 can be fixed in other ways, and then all the screws can be removed. Alternatively, no other operations are performed, and the light-shielding lens 20 is fixed by screws.

As another aspect of the embodiments of the present application, the embodiments of the present application provide an imaging device, including the lens device 1 in any one of the above-mentioned implementation manners of the present application.

In the embodiment of the present application, the imaging device may be a camera or a VR device, etc., which is not specifically limited in the embodiment of the present application.

According to the imaging device of the embodiment of the present application, by adopting the lens device 1 of the above-mentioned embodiment of the present application, the probability of stray light and astigmatism generated by the Fresnel lens 10 due to the tooth tip portion 11a of the ring-shaped protrusion 11 is reduced, and the performance of the Fresnel lens 10 is improved. The light transmission performance of the Neel lens 10 is beneficial to improve the imaging effect of the imaging device of the lens device 1 .

It should be noted that other configurations of the imaging device in the above embodiments can be adopted from various technical solutions known to those skilled in the art now and in the future, and will not be described in detail here.

In the description of this specification, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial" , "radial", "circumferential" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the application and simplifying the description, rather than indicating or implying the referred device or Elements must have certain orientations, be constructed and operate in certain orientations, and thus should not be construed as limiting the application.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of these features. In the description of the present application, "plurality" means two or more, unless otherwise specifically defined.

In this application, terms such as "installation", "connection", "connection" and "fixation" should be interpreted in a broad sense, for example, it can be a fixed connection or a detachable connection, unless otherwise clearly specified and limited. , or integrated; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection or an indirect connection through an intermediary, it can be the internal communication of two components or the interaction relationship between two components . Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

In this application, unless otherwise expressly specified and limited, a first feature being "on" or "under" a second feature may include direct contact between the first and second features, and may also include the first and second features Not in direct contact but through another characteristic contact between them. Moreover, "above", "above" and "above" the first feature on the second feature include that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. "Below", "beneath" and "under" the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

The above disclosure provides many different implementations or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and arrangements of specific examples are described above. Of course, they are examples only and are not intended to limit the application. Furthermore, the present application may repeat reference numerals and/or reference letters in various instances, such repetition is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and/or arrangements discussed.

The above is only a specific embodiment of the application, but the scope of protection of the application is not limited thereto. Any person familiar with the technical field can easily think of its various changes or modifications within the technical scope disclosed in the application. Replacement, these should be covered within the protection scope of this application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims (11)

1. A lens apparatus, comprising:

the Fresnel lens is provided with at least one Fresnel surface, and the Fresnel surface is provided with a plurality of annular bulges;

the shading lens is arranged opposite to the Fresnel lens, a shading coating is arranged on one side surface of the shading lens, the shading coating comprises an annular shading belt which is arranged corresponding to at least one annular bulge, and the annular shading belt is used for shading incident light rays corresponding to tooth tip parts of the annular bulge.

2. The lens apparatus of claim 1, wherein the light blocking lens is provided on an incident side of the fresnel lens.

3. The lens apparatus according to claim 1, wherein the plurality of annular protrusions are concentrically arranged, the number of the annular light shielding strips is the same as the number of the annular protrusions, and the annular light shielding strips are arranged in one-to-one correspondence with the annular protrusions.

4. The lens apparatus according to claim 1, wherein a width of the annular light shielding tape is related to at least one of a width of the annular convex tooth tip portion, a distance between the light shielding lens and the annular convex tooth tip portion, and an incident angle of the incident light ray.

5. The lens apparatus of claim 4 wherein the formula for determining the width w of the annular shade band is as follows:

w＝w ₀ +2d*tanθ，

wherein w is ₀ And d is used for representing the distance between the shading lens and the tooth tip part of the annular bulge, and theta is used for representing the incident angle of the incident light, wherein the incident angle is an included angle between the incident direction of the incident light and the central axis of the shading lens.

6. The lens device of claim 1, wherein the light-blocking coating has an absorbance of greater than or equal to 99%.

7. The lens device according to claim 1, wherein the light-shielding lens is made of glass or resin, and the light transmittance of the light-shielding lens is 90% or more.

8. The lens apparatus according to claim 1, wherein the light shielding lens has a thickness of 0.4 to 0.6mm.

9. The lens apparatus according to any one of claims 1 to 8, further comprising:

the fixing part is characterized in that an installation cavity is defined on the inner side of the fixing part, the Fresnel lens and the shading lens are arranged in the installation cavity at intervals, and the installation cavity is provided with a limiting groove for fixing the Fresnel lens and/or the shading lens.

10. The lens apparatus according to claim 9, wherein the fixing portion has a plurality of fixing holes penetrating through a wall thereof, the plurality of fixing holes corresponding to mounting positions of the fresnel lens or the shade lens, the fixing holes being for passing a fastener and abutting an end of the fastener against the peripheral wall of the fresnel lens or the shade lens.

11. An image forming apparatus comprising the lens device according to any one of claims 1 to 10.

Images