A fresnel lens and a luminaire comprising the same

Abstract

The application provides a Fresnel lens, which comprises a lens body, the lens body is oppositely provided with an entrance surface and an exit surface along a first direction, a plurality of convex teeth are adjacently arranged on the exit surface along a second direction which is perpendicular to the first direction, the convex teeth are formed by effective surfaces and ineffective surfaces, and the ineffective surfaces are arranged at an acute angle relative to the first direction; for the first convex tooth and the second convex tooth which are adjacent on the exit surface, the first convex tooth comprises a first effective surface and a first ineffective surface, the second convex tooth comprises a second effective surface and a second ineffective surface, the first ineffective surface and the second effective surface intersect to form a first valley point, and for a first light ray which is emitted from a light source and reaches the first valley point through the entrance surface, the first ineffective surface is arranged in the range of the included angle formed between the first light ray and the emergent light ray of the first light ray through the first valley point. The application makes the light ray passing through the lens body reach the effective surface as much as possible, thereby reducing stray light and enhancing light efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of lamps, in particular to a Fresnel lens and a lamp comprising the same. BACKGROUND

[0002] The Fresnel lens is evolved on the basis of the plano-convex lens (or aspheric lens), which is essentially to remove the part of the original lens that has no effect on the change of lens curvature, and only keep the part that can effectively refract.

[0003] If the ordinary Fresnel lens is directly applied in the light distribution of LED lighting, part of the light will enter the adjacent unit between the Fresnel micro-unit lenses, resulting in a larger angle of this part of light and more easily forming stray light. Figure 1 As shown in the figure, the surfaces that cannot effectively refract in the common Fresnel lens (i.e. ineffective surfaces) are parallel to the optical axis, and the light is affected by the edge of the ineffective surface and scattered at a large angle in the adjacent effective refractive surface, affecting the uniformity of the light.

[0004] Therefore, the skilled in the art is committed to developing a new type of Fresnel lens and related lamps to reduce stray light and make the light of the lamp more uniform. SUMMARY

[0005] In view of the above defects of the prior art, the technical problem to be solved by the present application is the stray light problem of the existing Fresnel lens.

[0006] To achieve the above-mentioned purpose, the present application provides a Fresnel lens, which comprises a lens body, the direction of the optical axis is the first direction, the lens body is relatively provided with an incident surface and an exit surface along the first direction, the light emitted from the light source passes through the incident surface and is refracted into the lens body, and then passes through the exit surface and is refracted to the outside, wherein, in the second direction perpendicular to the first direction, a plurality of convex teeth are arranged adjacent to each other on the exit surface, the convex teeth are formed by effective surfaces and ineffective surfaces, the effective surfaces are adapted to refract the light to the outside of the lens body, and the ineffective surfaces are arranged at an acute angle with the first direction.

[0007] For the first convex tooth and the second convex tooth adjacent to each other on the exit surface, the first convex tooth comprises a first effective surface and a first ineffective surface, the second convex tooth comprises a second effective surface and a second ineffective surface, and the first ineffective surface and the second effective surface intersect to form a first valley point.

[0008] For the first light (L1) emitted from the light source and reaching the first valley point through the incident surface, the first light (L1) forms a first included angle (α) with the first direction, the first ineffective surface forms a third included angle (θ) with the first direction, the emergent light (L1') of the first light (L1) through the first valley point forms a fourth included angle (γ) with the first direction, and the size of the third included angle (θ) is set between the first included angle (α) and the fourth included angle (γ).

[0009] Further, for the Fresnel lens as above, the following parameters are defined,

[0010] The second effective surface forms a second included angle (β) with the second direction,

[0011] The refractive index of the lens body is n, and n>1,

[0012] The first ineffective surface forms a third included angle (θ) with the first direction, and the third included angle (θ) satisfies the following relationship:

[0013] When α≥β,

[0014] α≤θ≤β+arcsin[nsin(α-β)]; or

[0015] When α<β,

[0016] β+arcsin[nsin(α-β)]≤θ≤α.

[0017] Optionally, the third included angle (θ) satisfies the following relationship:

[0018] θ=β+arcsin[nsin(α-β)].

[0019] In another embodiment of the present application, the third included angle (θ) is equal to the first included angle (α) in size.

[0020] Further, along the direction away from the optical axis, the included angle of the effective surface of each protrusion of the light-out surface with the second direction gradually changes. Meanwhile further, along the direction away from the optical axis, the included angle of the ineffective surface of each protrusion of the light-out surface with the first direction gradually changes.

[0021] In an embodiment of the present application, along the direction away from the optical axis, the included angle of the effective surface of each protrusion of the light-out surface with the second direction gradually increases. Meanwhile further, along the direction away from the optical axis, the included angle of the ineffective surface of each protrusion of the light-out surface with the first direction gradually increases.

[0022] Preferably, each protrusion on the light-out surface is symmetrically arranged with respect to the optical axis.

[0023] Preferably, the light-in surface is a plane, and the light-in surface is arranged perpendicularly to the optical axis.

[0024] In addition, the present application also provides a lamp using the above Fresnel lens, comprising:

[0025] The Fresnel lens;

[0026] The light source is located on the optical axis, and is arranged on the side of the Fresnel lens close to the light-in surface.

[0027] Further, the lamp is long strip-shaped, the light source is linearly distributed along a third direction, the third direction is perpendicular to the first direction and the second direction, and the Fresnel lens is stretched along the third direction.

[0028] Technical effects:

[0029] The Fresnel lens of the present application avoids most of the light by setting the inclination angle of the invalid surface of the convex tooth, so that the light passing through the lens body reaches the effective surface as much as possible, thereby reducing stray light and enhancing light efficiency.

[0030] The concept, specific structure and technical effects of the present application will be further described below in combination with the drawings, so as to fully understand the purpose, features and effects of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a schematic diagram of the optical path of the Fresnel lens in the prior art.

[0032] Figure 2 is a schematic diagram of the structure of the Fresnel lens of the present application and a local enlarged view of H.

[0033] Figure 3 is a schematic diagram of the structure of the invalid surface in one embodiment of the Fresnel lens of the present application.

[0034] Figure 4 is a schematic diagram of the optical path relationship according to Figure 3 .

[0035] Figure 5 is a comparison diagram of the structure of the Fresnel lens according to Figure 3 and the structure of the prior art.

[0036] Figure 6 is a schematic diagram of the structure of the invalid surface in another embodiment of the Fresnel lens of the present application.

[0037] Figure 7 is a schematic diagram of the structure of the invalid surface in another embodiment of the Fresnel lens of the present application.

[0038] Figure 8 is a comparison diagram of the optical path of the Fresnel lens of the present application and the Fresnel lens of the prior art, wherein (a) is the Fresnel lens in the prior art, and (b) is the Fresnel lens of the present application.

[0039] Wherein:

[0040] 100 lens body, 1 light entrance surface, 2 light exit surface, 21 convex tooth, 211 effective surface, 212 ineffective surface, 22 first convex tooth, 221 first effective surface, 222 first ineffective surface, P first peak point, O first valley point, 23 second convex tooth, 231 second effective surface, 232 second ineffective surface, 3 light source, DO optical axis, D1 first direction, D2 second direction, D3 third direction, L1 first light, L2 second light, L3 third light, L4 fourth light, L1' first emergent light, L2' second emergent light, L3' third emergent light, a first included angle, b second included angle, g third included angle, y fourth included angle. DETAILED DESCRIPTION

[0041] As Figure 2 shown is a Fresnel lens provided by the present application, which comprises a lens body 100, Figure 2 shown is a longitudinal section of the lens body 100, which contains an optical axis DO of the lens body 100, a first direction D1 is defined as the direction in which the optical axis DO is located, the lens body 100 is relatively provided with a light entrance surface 1 and a light exit surface 2 along the first direction D1, and a light source 3 is relatively close to one side of the light entrance surface 1, light emitted from the light source 3 passes through the light entrance surface 1, refracts into the lens body 100, and then refracts to the outside through the light exit surface 2.

[0042] In a second direction D2 perpendicular to the first direction D1, a plurality of convex teeth 21 are arranged adjacent to each other on the light exit surface 2, the convex teeth 21 are formed by effective surfaces 211 and ineffective surfaces 212, the effective surface 211 is the part of the Fresnel lens that can effectively refract, and the effective surface 211 is adapted to refract light to the outside of the lens body 100, the ineffective surface 212 is transitionally connected between each effective surface 211, and the effective surface 211 and the ineffective surface 212 alternately constitute the light exit surface 2.

[0043] In the prior art, each ineffective surface 212 is usually parallel to the first direction D1. However, in the embodiment of the present application, the ineffective surface 212 forms an acute angle with the first direction D1.

[0044] For the adjacent first convex tooth 22 and second convex tooth 23 on the light exit surface 2, the first convex tooth 22 comprises a first effective surface 221 and a first ineffective surface 222, the second convex tooth 23 comprises a second effective surface 231 and a second ineffective surface 232, the first effective surface 221 and the first ineffective surface 222 intersect to form a first peak point P, and the first ineffective surface 222 and the second effective surface 231 intersect to form a first valley point O.

[0045] For the above structure, in the technical scheme of the present application, the first ineffective surface 222 forms an acute angle with the first direction D1, and is obliquely arranged within the included angle range between the first light L1 and the emergent light of the first light L1 passing through the first valley point O.

[0046] The design scheme of the present application is as follows Figure 3 For the first light L1 emitted from the light source 3 through the light entrance surface 1 to the first valley point O, the first light L1 forms a first included angle a with the first direction D1, the first ineffective surface 222 forms a third included angle θ with the first direction D1, and the first emitted light L1' of the first light L1 through the first valley point O forms a fourth included angle γ with the first direction D1. The third included angle θ is set between the first included angle a and the fourth included angle γ.

[0047] In this embodiment, the position of the first ineffective surface 222 depends on the angle of the first light through the first valley point O in the lens body 100 and the angle of the refracting surface when the first light is refracted at the first valley point O. The setting of the first ineffective surface 222 is described in combination with Figure 3 .

[0048] In one embodiment as shown in Figure 3 , the first light L1 becomes the first emitted light L1' after being refracted by the second effective surface 231 at the first valley point O. The first ineffective surface 222 is arranged to be coplanar with the first emitted light L1', that is, the third included angle θ of the first ineffective surface 222 with the first direction D1 is the same as the included angle of the first emitted light L1' with the first direction D1.

[0049] The implementation process of the first ineffective surface for reducing stray light is further described below.

[0050] In a Fresnel lens, for a given position of the light source 3, the light emitted by the light source 3 will sweep through an angle range, for example Figure 4 as shown. After being refracted through the light entrance surface 1, the first light L1, the second light L2 and the third light L3 adjacent to the first light L1 are arranged to reach the light exit surface 2. Among them, the first light L1 reaches the first valley point O; the second light L2 has an included angle with the first direction D1 smaller than the first included angle a of the first light L1 with the first direction D1, so the second light L2 is closer to the optical axis D0 than the first light L1, and reaches the second convex tooth 23 adjacent to the first valley point O; the third light L3 has an included angle with the first direction D1 larger than the first included angle a of the first light L1 with the first direction D1, so the third light L3 is farther from the optical axis D0 than the first light L1, and reaches the first convex tooth 22 adjacent to the first valley point O.

[0051] The third included angle θ of the first invalid surface 222 relative to the first direction D1 is the same as the included angle of the first emergent light L1' relative to the first direction D1, the first emergent light L1' passes out along the first invalid surface 222; the second light L2 is on the side of the first light L1 relative to the optical axis D0, after being refracted along the second effective surface 231, the second emergent light L2' formed is on the side of the first emergent light L1' relative to the optical axis D0, thus not passing through the first invalid surface 222; the third light L3 is on the side of the first light L1 away from the optical axis D0, if closer to the first light L1, it will reach the first invalid surface 222, the first invalid surface 222 mainly produces total reflection to the third light L3 reaching it, after total reflection, the light is refracted along the first effective surface 221 to pass out as the third emergent light L3', in this case, the emergent angle of the third emergent light L3' is adjusted by the first invalid surface 222 and the first effective surface 221, on the one hand, the light reaching the first invalid surface 222 is reduced, and on the other hand, the emergent angle of the third emergent light L3' is relieved, thereby reducing stray light.

[0052] According to the above embodiment, the first invalid surface is defined by the following parameters:

[0053] As Figure 4 , the included angle of the first light L1 relative to the first direction D1 after passing into the lens body 100 is a first included angle α, the included angle of the second effective surface 231 relative to the second direction D2 is a second included angle β, the first invalid surface 222 extends from the first valley point O to the first effective surface 221 at a third included angle θ relative to the first direction D1, and the intersection point is the first peak point P;

[0054] In the lens body 100, the normal line of the second effective surface 231 is M1, the incident angle of the first light L1 relative to the normal line M1 is A1, according to geometric relationship, A1=α-β;

[0055] According to the Figure 4 , when α>β, the first light L1 is on the lower side of the normal line M1, that is, on the side close to the optical axis D0;

[0056] The refraction angle of the first light L1 after being refracted by the second effective surface 231 is B1, the refractive index of the lens body 100 is n, and for the lens external medium which is air, n>1, thus according to the refraction relationship:

[0057] n sinA1=sinB1; the size of the refraction angle B1 can be obtained accordingly;

[0058] The included angle of the first emergent light L1' after refraction relative to the first direction D1 is a fourth included angle γ, according to geometric relationship, γ=β+B1;

[0059]

[0060] ​Then according to calculation, the fourth included angle γ satisfies the following relationship:

[0061] γ = β + arcsin [n sin (α - β)];

[0062] Therefore, when the third included angle θ formed by the first invalid surface 222 relative to the first direction D1 is equal to the fourth included angle γ, the generation of stray light can be significantly reduced.

[0063] At this time, the third included angle θ is limited as follows:

[0064] θ = β + arcsin [n sin (α - β)];

[0065] In particular, when the first included angle α and the second included angle β are equal, the third included angle θ is set as θ = α = β.

[0066] As Figure 5 shown is a comparison between the structure of the Fresnel lens of the present application and the Fresnel lens of the prior art, to illustrate the effect of the structure of the Fresnel lens of the present application on reducing stray light.

[0067] As Figure 5 shown, the Fresnel lens of the prior art generally removes the part of the original lens that has no effect on the change of the curvature of the lens, and only retains the part that can effectively refract, so that each invalid surface is arranged in the direction parallel to the optical axis D0, i.e. the first direction D1, as shown in the OR section in Figure 5 , the triangle OPR is the part of the Fresnel lens of the prior art compared to the Fresnel lens of the present application. The first light ray L1 passes through the first valley point O and the first peak point P, the second light ray L2 is arranged to pass through the second valid surface 231 to reach the point R, and the fourth light ray L4 is parallel to the first light ray L1 and passes through the lens body 100 to reach the first peak point P. By comparison, it can be found that when the direction in which the first invalid surface 222 is inclined is equal to the direction of the first light ray L1 after passing through the first valley point O, the first invalid surface 222 only allows the light rays within the range between the first light ray L1 and the fourth light ray L4 to pass through the first invalid surface 222; compared with the Fresnel lens of the prior art, the stray light caused by the light rays passing through the OS section on the original invalid surface is reduced, and the included angle between the light rays and the invalid surface is also reduced, which has a moderating effect on the exit angle of the generated stray light.

[0068] As Figure 6 shown, another embodiment of the arrangement of the Fresnel lens of the present application is given.

[0069] With Figure 4The difference between the shown embodiment and the above embodiment is that the first ineffective surface 222 is inclined from the first valley point O, and the third angle θ formed by the first ineffective surface 222 relative to the first direction D1 is equal to the first angle α of the first light ray L1, i.e. θ = α. The first light ray L1 is refracted through the lens body 100 at the first effective surface 221 and exits.

[0070] According to the above setting, for the first light ray L1 and the second light ray L2 and the third light ray L3 adjacent to the first light ray L1: the third light ray L3 is farther from the optical axis D0 than the first light ray L1, and the angle between the third light ray L3 and the first direction D1 is greater than the first angle α of the first light ray L1 and the first direction D1, so the first light ray L1 and the third light ray L3 are both refracted through the lens body 100 in a straight line to the first effective surface 221 and exit; the second light ray L2 is closer to the optical axis D0 than the first light ray L1, and the angle between the second light ray L2 and the first direction D1 is smaller than the first angle α of the first light ray L1 and the first direction D1, so the second light ray L2 reaches the second convex tooth 23 adjacent to the first valley point O and is refracted at the second effective surface 231 and exits, and when the second light ray L2 is close to the first light ray L1, it is refracted through the first ineffective surface 222 after being refracted through the first convex tooth 22 and exits.

[0071] Therefore, according to the above setting, because of the inclined setting of the first ineffective surface 222, the light rays near the first valley point O form a smaller angle with the first ineffective surface 222, and the range of light rays passing through the first ineffective surface 222 is greatly reduced, thereby reducing the generation of stray light.

[0072] Further, in combination with the embodiments of Figure 4 and Figure 6 , the third angle θ formed by the first ineffective surface 222 relative to the first direction D1 is set between the fourth angle γ of the first exiting light ray and the first angle α of the first light ray L1 and the first direction D1, i.e.

[0073] α≤θ≤β+arcsin[nsin(α-β)];

[0074] Based on the above setting, if the third angle θ formed by the first ineffective surface 222 relative to the first direction D1 is set too large, more light rays in the lens body 100 will be totally reflected at the first ineffective surface 222, and if the third angle θ is set too small, more light rays will pass through the first ineffective surface 222 after passing through the second effective surface 231 and be totally reflected in the lens body, which will all cause an increase in stray light.

[0075] According to the above setting of the Fresnel lens, for the light rays emitted from the light source, by setting each ineffective surface relative to the first direction D1 to be inclined, the range of light rays received by each ineffective surface is reduced, which can significantly reduce the influence of stray light.

[0076] For example Figure 7Figure 2 shows another embodiment of the Fresnel lens of the present application. As shown in Figure 2, the Fresnel lens comprises a lens body 100, a first direction D1 and an optical axis DO. The lens body 100 comprises a first valley point O, a first convex tooth 22 and a second convex tooth 23. The first convex tooth 22 is adjacent to the first valley point O, and the second convex tooth 23 is adjacent to the first valley point O. The first convex tooth 22 comprises a first effective surface 221 and a first ineffective surface 222. The first effective surface 221 is formed by a first angle α relative to the first direction D1. The second convex tooth 23 comprises a second effective surface 231 and a second ineffective surface 232. The second effective surface 231 is formed by a second angle β relative to the first direction D1. The first angle α is smaller than the second angle β. Figure 4 The embodiment shown in Figure 2 differs from the embodiment shown in Figure 1 in the shape of the convex tooth. In the embodiment shown in Figure 2, the first angle α is smaller than the second angle β, and the first ineffective surface 222 is set accordingly.

[0077] The first light ray LI in the lens body 100 has an incident angle A1 = β - α relative to the normal M1. The refracted first emergent light ray LI' has a refracted angle B1. The first emergent light ray LI' has a fourth angle γ = β - B1 relative to the first direction D1. Similarly, the second light ray L2 has a fifth angle δ = B1 - A1 relative to the first direction D1, and the third light ray L3 has a sixth angle φ = A1 - B1 relative to the first direction D1.

[0078] γ = β + arcsin [n sin (α - β)].

[0079] The first light ray LI, the second light ray L2 and the third light ray L3 are adjacent to each other. The first light ray LI is refracted as the first emergent light ray LI' after reaching the first valley point O. The second light ray L2 has an angle smaller than the first angle α relative to the first direction D1, and thus is closer to the optical axis DO than the first light ray LI. The second light ray L2 reaches the second convex tooth 23 adjacent to the first valley point O, and exits after being refracted by the second effective surface 231. The second emergent light ray L2' is closer to the optical axis DO. The third light ray L3 has an angle larger than the first angle α relative to the first direction D1, and thus is further from the optical axis DO than the first light ray LI. The third light ray L3 reaches the first convex tooth 22 adjacent to the first valley point O, and exits after being refracted by the first effective surface 221.

[0080] Therefore, the first ineffective surface 222 is inclined from the first valley point O, and is set between the first emergent light ray LI' and the third light ray L3 which passes through the lens body 100 in a straight line. As a result, the light rays do not pass through the first ineffective surface 222, and the generation of stray light is greatly reduced.

[0081] Therefore, as a preferred embodiment, the third angle θ formed by the first ineffective surface 222 relative to the first direction D1 is set between the fourth angle γ of the first emergent light ray LI' and the first angle α of the first light ray LI relative to the first direction D1, i.e.

[0082] β + arcsin [n sin (α - β)] ≤ θ ≤ α.

[0083] Therefore, for any adjacent first convex tooth 22 and second convex tooth 23 in the Fresnel lens provided by the present application, the first ineffective surface 222 of the first convex tooth 22 is set according to the first angle α and the second angle β as described above, and the third angle θ formed by the first ineffective surface 222 relative to the first direction D1 is set between α and β + arcsin [n sin (α - β)].

[0084] In another optional embodiment of the present application, the third included angle θ is set according to the following relationship: θ = β + arcsin [n sin (α - β)].

[0085] In another optional embodiment of the present application, the third included angle θ is equal to the first included angle α, that is, for each tooth 21 distributed along the second direction D2, the third included angle θ of the ineffective surface 212 of each tooth 21 with respect to the first direction D1 is gradually set according to the angle at which the light ray reaches the valley point of the tooth 21.

[0086] Further, along the direction away from the optical axis D0, the included angle of the effective surface of each tooth 21 of the light exit surface 2 with respect to the second direction D2 is gradually increased; accordingly, along the direction away from the optical axis D0, the included angle of the ineffective surface 212 of each tooth 21 of the light exit surface 2 with respect to the first direction D1 is gradually increased. Such setting can make the light rays from the light source 3 on the optical axis D0 be distributed on the light exit surface 2 as much as possible, while reducing the light rays passing through the ineffective surface 212.

[0087] In another embodiment of the present application, the Fresnel lens has a symmetrical structure, and each tooth 21 on the light exit surface 2 is symmetrically arranged with respect to the optical axis D0. Preferably, the light entrance surface 1 is a plane, and the light entrance surface 1 is arranged perpendicular to the optical axis D0.

[0088] Figure 8 A comparison diagram of the light path of the Fresnel lens of the present application and the Fresnel lens of the prior art is given, in which Figure 8 (a) is the Fresnel lens of the prior art, Figure 8 (b) is the Fresnel lens of the present application, and it can be seen from the comparison that the Fresnel lens of the present application can reduce stray light refracted to the upper and lower sides of the lens.

[0089] Based on the structural characteristics of the above Fresnel lens, the present application further provides a lamp using the above Fresnel lens, comprising:

[0090] The Fresnel lens comprises a lens body 100, the lens body 100 is relatively arranged with a light entrance surface 1 and a light exit surface 2 along a first direction D1, and a light source 3 is located on an optical axis D0 and arranged on the side of the Fresnel lens close to the light entrance surface 1.

[0091] The light rays emitted from the light source 3 are refracted into the lens body 100 through the light entrance surface 1 and then refracted to the outside through the light exit surface 2, and a plurality of teeth 21 are arranged adjacent to each other along a second direction D2 on the light exit surface 2, and the teeth 21 are formed by an effective surface 211 and an ineffective surface 212; the ineffective surface 212 of each tooth 21 forms an included angle with the first direction D1, and the included angle is set according to the included angle of the adjacent effective surface 211 with respect to the second direction D2 and the included angle of the light ray passing through the adjacent valley point with respect to the first direction D1.

[0092] As an embodiment of the lamp using the Fresnel lens according to the present application, the lamp is long strip-shaped, the light sources are linearly distributed along the third direction D3 which is perpendicular to the first direction D1 and the second direction D2, and the Fresnel lens is stretched along the third direction D3. According to the lamp, in any cross section of the Fresnel lens which is perpendicular to the third direction D3, the light emitting surface 2 of the lens is arranged to enable the light rays from the light source 3 on the optical axis DO to be distributed on the light emitting surface 2 as much as possible, while reducing the light rays passing through the invalid surface 212, so that a better use effect is achieved.

[0093] The preferred embodiments of the present application are described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations without departing from the concept of the present application. Therefore, any technical solution obtained by logical analysis, reasoning or limited experiments based on the prior art according to the concept of the present application should be within the protection scope defined by the claims.

Claims

1. A Fresnel lens comprising a lens body (100), a first direction (D1) being a direction in which an optical axis (D0) of the lens body (100) is located, the lens body (100) being relatively provided with an entrance surface (1) and an exit surface (2) along the first direction (D1), characterized in that, In a second direction (D2) perpendicular to the first direction (D1), the light-out surface (2) is sequentially provided with a plurality of convex teeth (21) in adjacency, the convex teeth (21) are formed by an effective surface (211) and an ineffective surface (212), wherein the ineffective surface (212) is arranged at an acute angle relative to the first direction (D1); For the first convex tooth (22) and the second convex tooth (23) adjacent to each other on the light-out surface (2), the first convex tooth (22) comprises a first effective surface (221) and a first ineffective surface (222), the second convex tooth (23) comprises a second effective surface (231) and a second ineffective surface (232), and the first ineffective surface (222) and the second effective surface (231) intersect to form a first valley point (O); For a first light ray (L1) emitted from a light source (3) and reaching the first valley point (O) through the light-in surface (1), the first light ray (L1) forms a first included angle α relative to the first direction (D1), the first ineffective surface (222) forms a third included angle θ relative to the first direction (D1), and an emergent light ray (L1') of the first light ray (L1) through the first valley point (O) forms a fourth included angle γ relative to the first direction (D1), and the third included angle θ is set to be between the first included angle α and the fourth included angle γ; Along a direction away from the optical axis (D0), the included angle of the ineffective surface (212) of each convex tooth (21) of the light-out surface (2) relative to the first direction (D1) gradually increases in sequence.

2. The Fresnel lens of claim 1, wherein Definitions: The second effective surface (231) forms a second included angle β relative to the second direction (D2), The refractive index of the lens body (100) is n, and n>1, The third included angle θ satisfies the following relationship: When α≥β, α≤θ≤β+arcsin[nsin(α-β)]; or When α<β, β+arcsin[nsin(α-β)]≤θ≤α.

3. The Fresnel lens of claim 2, wherein, The third included angle θ satisfies the following relationship: θ=β+arcsin[nsin(α-β)].

4. The Fresnel lens of claim 2, wherein The third included angle θ is equal in size to the first included angle α.

5. The Fresnel lens of claim 1, wherein, Along a direction away from the optical axis (D0), the included angle of the effective surface (211) of each convex tooth (21) of the light-out surface (2) relative to the second direction (D2) gradually changes in sequence.

6. The Fresnel lens of claim 5, wherein, Along a direction away from the optical axis (D0), the included angle of the effective surface (211) of each convex tooth (21) of the light-out surface (2) relative to the second direction (D2) gradually increases in sequence.

7. The Fresnel lens of claim 1, wherein Each convex tooth (21) on the light-out surface (2) is symmetrically arranged relative to the optical axis (D0).

8. The Fresnel lens of claim 1, wherein, The light-in surface (1) is a plane, and the light-in surface (1) is arranged perpendicular to the optical axis (D0).

9. A luminaire characterized by, Comprising: The Fresnel lens according to any one of claims 1-8; The light source (3) is located on the optical axis (D0) and is arranged on the side of the Fresnel lens close to the light-in surface (1).

10. The luminaire of claim 9, wherein, The lamp is long strip-shaped, the light source (3) is linearly distributed along a third direction (D3), the third direction (D3) is perpendicular to the first direction (D1) and the second direction (D2), and the Fresnel lens is stretched along the third direction (D3).

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