CN109027765B

CN109027765B - Light filling lens, light filling lamp and camera

Info

Publication number: CN109027765B
Application number: CN201710433784.0A
Authority: CN
Inventors: 唐海龙
Original assignee: Hangzhou Hikvision Digital Technology Co Ltd
Current assignee: Hangzhou Hikvision Digital Technology Co Ltd
Priority date: 2017-06-09
Filing date: 2017-06-09
Publication date: 2021-05-18
Anticipated expiration: 2037-06-09
Also published as: CN109027765A

Abstract

The invention provides a light supplementing lens, a light supplementing lamp and a camera. The light supplementing lens comprises an incident curved surface, a reflecting curved surface and an emergent smooth curved surface, wherein the incident curved surface comprises a free transmission curved surface and an inner side wall which is positioned around the free transmission curved surface and is adjacent to the free transmission curved surface, the reflecting curved surface comprises one or more free reflection curved surfaces, and each free reflection curved surface corresponds to one section of the inner side wall in the circumferential direction; the light supplementing lens is configured to form a light supplementing area of a target rectangle on a preset light supplementing plane when the matched light sources are in preset relative positions and used together. The invention has higher optical efficiency and energy utilization efficiency, and can realize light supplement in a larger angle range.

Description

Light filling lens, light filling lamp and camera

Technical Field

The invention relates to the technical field of video monitoring, in particular to a light supplementing lens, a light supplementing lamp and a camera.

Background

In video monitoring, in order to make up for insufficient illumination at night, an infrared light supplement lamp is usually additionally arranged on a monitoring camera, and light supplement is provided within the field of view of a lens of the camera, so that the brightness and the definition of the lens picture of the camera are improved, and people or objects are easy to recognize.

The photosensitive area of the image sensor for which the monitoring camera determines the shape of the lens frame is 16: 9 or 4: 3, if a rotationally symmetric light distribution scheme with a substantially circular cross section is adopted, the fill-in light angle is generally set to be slightly larger than the field angle of the diagonal of the lens in order to meet the requirement that the shot lens picture has no dark area and dark angle. Fig. 1 is a graph of a relationship between normalized light intensity and a light-emitting angle (an angle formed by a straight line between one point on a cross section of the fill light and one point on a cone of the fill light space and a center line of the cone) in rotationally symmetric light distribution. As can be seen in FIG. 1, the intensity at the diagonal field angle edge is typically 10-30% of the peak intensity, while the intensity at the horizontal (rectangular length direction) field angle edge is 30-40% of the peak intensity, and the intensity at the vertical (rectangular width direction) field angle edge is 50-60% of the peak intensity. However, in practical application, the ratio of the light intensity at the edge of the field of view is only 10% -30%, or the ratio of the light intensity at the edge of the field of view is within the same range, so that if rotational symmetric light distribution is adopted, energy waste can be caused, the light intensity at the edge of the vertical field of view is high, and defects such as close overexposure and white reflected light of a lens picture in the vertical direction are easily caused. Therefore, the rectangular light distribution technology appears, but the rectangular light distribution technology has defects.

One of them rectangle grading technique adds flute or micro-structure scheme for rotational symmetry total reflection, set up flute or micro-structure on the exit surface of lens promptly and reflect and the collimated light of mold core transmission carries out the rectangular distribution to the plane of reflection, great angle scope light filling can't be realized to this kind of grading technique, and along with the increase of light filling scope, lens transmissivity decay aggravates, and be subject to production technology in addition, the micro-structure size is little and the tolerance is little, be unfavorable for the product uniformity, seriously influence the performance stability of product.

The other rectangular light distribution technology is a scheme of combining and separating type free-form reflecting surfaces (reflecting cups) and lenses, and the light distribution technology is lack of flexibility and low in overall optical efficiency. And reflection of light cup and lens are the device of separation, for the accuracy of guaranteeing the separation device assembly, manufacturing cost can promote greatly, and the stability of product is relatively poor.

Disclosure of Invention

In view of this, the invention provides a light supplement lens, a light supplement lamp and a camera, so as to achieve higher optical efficiency while achieving rectangular light distribution.

Specifically, the method comprises the following technical scheme:

one aspect of the embodiments of the present invention provides a light supplementing lens, including an incident curved surface, a reflective curved surface, and an emergent smooth curved surface, where the incident curved surface includes a free transmission curved surface and an inner side wall located around and adjacent to the free transmission curved surface, the reflective curved surface includes one or more free reflection curved surfaces, and each free reflection curved surface corresponds to a section of the inner side wall in a circumferential direction;

the light supplementing lens is configured to form a light supplementing area of a target rectangle on a preset light supplementing plane when the matched light sources are in preset relative positions and used together, wherein the free transmission curved surface enables the light sources to sequentially pass through the free transmission curved surface and emergent light of the emergent smooth curved surface to form the light supplementing area which is overlapped with or positioned in the target rectangle on the preset light supplementing plane; each free-reflection curved surface enables emergent light of the light source, which enters the free-reflection curved surface through the inner side wall of the corresponding section, to be reflected by the free-reflection curved surface and then refracted by the emergent smooth curved surface, so that a light supplement area which is coincident with or positioned in the target rectangle is formed on the preset light supplement plane.

Optionally, the number of the one or more free-form reflective curved surfaces is four, and the inner side walls of the corresponding sections of the four free-form reflective curved surfaces are respectively located at the upper, lower, left and right sides of the free-form transmissive curved surface.

Optionally, the abutment between adjacent free-form reflective curved surfaces is characterized by a rounded transition.

Optionally, each of the free-form reflective curved surfaces includes at least two sub-reflective curved surfaces, and each sub-reflective curved surface makes the emergent light emitted from the light source pass through the emergent smooth curved surface after being reflected by the sub-reflective curved surface, and a sub-light supplement region formed on the preset light supplement plane is overlapped with or located in the target rectangle.

Optionally, the fill-in lens is configured such that fill-in areas of the at least two free-form curved surfaces or sub-fill-in areas of the at least two sub-form curved surfaces at least partially coincide.

Optionally, each free-form reflecting curved surface is configured such that each preset area on the free-form reflecting curved surface projects the emergent light with the preset direction, projected to the area by the light source through the inner side wall of the corresponding segment, to the corresponding preset area of the target rectangle after being reflected by the emergent light and refracted by the emergent smooth curved surface; and/or the free transmission curved surface is configured to enable each preset area on the free transmission curved surface to project emergent light which is incident from the area and has a preset direction to a corresponding preset area of the target rectangle after being refracted by the light source and the emergent smooth curved surface.

Optionally, the fill lens is configured such that the ratio of the light intensity peak at the edge of the target rectangle is 10-30%.

Optionally, at least one free-reflection curved surface is configured to make the position of the corresponding peak light intensity of the light filling area deviate from the center of the target rectangle, and/or the free-transmission curved surface is configured to make the position of the corresponding peak light intensity deviate from the center of the target rectangle, so that the position of the peak light intensity of the target rectangle deviates from the center of the target rectangle.

Optionally, the fill lens is configured to make the peak light intensity of the target rectangle be located at a position offset from the center of the target rectangle in a vertically upward direction.

Optionally, the fill lens is configured such that the light intensity of the upper half of the target rectangle is greater than the light intensity of the lower half.

The embodiment of the invention provides a light supplement lamp, which comprises the light supplement lens and a matched light source, wherein the relative position of the matched light source and the light supplement lens is a preset position.

A further aspect of the embodiments of the present invention provides a camera including the fill-in light according to the second aspect.

The technical scheme provided by the embodiment of the invention has the beneficial effects that:

the light supplementing lens is characterized in that the refraction of the free transmission curved surface at the central position and the reflection of the free reflection curved surface arranged around the free transmission curved surface are utilized, emergent light rays from a matched light source are refracted by the emergent smooth curved surface and then projected to a target rectangle of a target plane, a corrugated structure or a microstructure is not required to be arranged on the emergent smooth curved surface, the light supplementing lens has high optical efficiency and energy utilization efficiency, light supplementation within a large angle range can be realized, meanwhile, the light intensity of each position of the target rectangle can meet preset requirements by arranging each free reflection curved surface, the flexibility is good, the optical device is simple in structure, the tolerance is large, and the stability is high.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a graph showing the relationship between the normalized light intensity and the light-emitting angle of the rotationally symmetric light distribution in the prior art;

fig. 2 is a schematic diagram illustrating a fill-in lens according to an embodiment of the invention, a fill-in lamp according to another embodiment of the invention, and optical paths of the fill-in lens and the fill-in lamp;

fig. 3 is a schematic diagram illustrating a light compensating lens according to an embodiment of the invention dividing light energy emitted from a light source;

FIG. 4 is a schematic diagram illustrating an appearance of a fill lens according to an embodiment of the invention when viewed from a light source side;

fig. 5 is a schematic diagram illustrating a mapping relationship between a free transmission curved surface a of a light supplementing lens and a light supplementing area a thereof according to an embodiment of the invention;

fig. 6 is a schematic diagram illustrating a mapping relationship between a free-form reflective curved surface B or C of a light filling lens and a light filling region B or C thereof according to an embodiment of the invention;

fig. 7 is a schematic diagram illustrating a mapping relationship between a free-form reflective curved surface D or E of a light filling lens and a light filling region D or E thereof according to an embodiment of the invention;

fig. 8 is a schematic diagram illustrating a mapping relationship between an exemplary reflective curved surface of a light filling lens and a light filling area thereof according to an embodiment of the invention;

fig. 9 is a schematic diagram illustrating a mapping relationship between an exemplary reflective curved surface including a plurality of sub-reflective curved surfaces and a light filling region of the exemplary reflective curved surface of the light filling lens according to an embodiment of the invention;

FIG. 10 is a schematic diagram illustrating a division of the light source emergent ray energy and the fill-in region according to an embodiment of the invention;

fig. 11 is a schematic diagram of a double-curved surface implementation of polarized light supplementary lighting in the prior art;

fig. 12 is a relationship curve between normalized light intensity and an emergent light included angle of emergent light corresponding to a free transmission curved surface a of a light filling lens for realizing polarized light, on a surface C0-180 and a surface C90-270 of a light filling spatial region according to an embodiment of the present invention;

fig. 13 is a relationship curve between normalized light intensity and an emergent light included angle of emergent light corresponding to a free-form reflection curved surface B or C of a light filling lens for realizing polarized light on a surface C0-180 and a surface C90-270 of a light filling spatial region according to an embodiment of the present invention;

fig. 14 is a relationship curve between normalized light intensity and an emergent light included angle of emergent light corresponding to a free-form reflection curved surface D or E of a light filling lens for realizing polarized light on a C0-180 plane and a C90-270 plane of a light filling spatial region according to an embodiment of the present invention;

fig. 15 is a graph showing a relationship between total light intensity and an angle of light emission on the C0-180 plane and the C90-270 plane of a fill-in space region of a fill-in lens for realizing polarized light according to an embodiment of the present invention.

Detailed Description

In order to make the technical solutions and advantages of the present invention clearer, the following will describe embodiments of the present invention in further detail with reference to the accompanying drawings.

In the present application, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. In the present application, the term "region" generally refers to an area on a plane or a curved surface when referring to the plane or the curved surface, and generally refers to an area on a three-dimensional space when referring to a space. In the application, the light supplementing space region is generally cone-shaped; the term "preset fill light plane" generally refers to a plane that is perpendicular to a central line (which may be roughly regarded as an optical axis of a corresponding lens) of a conical fill light space region of the fill light lens and on which the assumed fill light is finally projected; the term "light supplement area" can be regarded as a planar area of a conical light supplement space area intercepted by a preset light supplement plane; the term "target rectangle" does not refer to an absolute rectangle, which may have rounded corners; in the present application, the "forming a target rectangle" or "locating in the target rectangle" is generally relatively ideal, and in practice, due to machining or other factors, a part of light may be beyond the target rectangle, but a fill light region with the outline of the target rectangle as a whole can be obtained; the "vertical direction" mentioned in the present application generally refers to the width direction of the target rectangle, and the "horizontal direction" refers to the length direction (also generally horizontal in practice) of the rectangular fill-in light region, and assuming that projected onto the ground, the two long sides distributed in the vertical direction generally differ in length due to the high beam and the low beam, while the two short sides distributed in the horizontal direction do not differ in length due to the high beam and the low beam. The term "free-form surface" refers to an optical curved surface that cannot be represented by spherical or aspherical coefficients, it being understood that in this application, an optical curved surface that can be represented by spherical or aspherical coefficients may also be part of a free-form surface. The term "curved surface" may also refer to a plane or a curved surface comprising a planar area. The term "light energy" or "light energy" is generally expressed in terms of radiant flux, "radiant flux" refers to the total energy of light emitted by a luminary or received by an object or area in a unit time, while "light intensity" refers to the radiant flux emitted by a light source in a unit solid angle, "solid angle" is generally measured in terms of the area of a cone with its apex as the center of the sphere and a spherical surface of radius 1 truncated by a cone surface, and the measurement unit is referred to as "steradian". The term "lens picture" refers to a picture of a video frame or a photo taken by a camera through a lens, the shape of the picture is determined by an image sensing chip, at a preset supplementary lighting plane, the picture range taken by the lens picture is approximately the same as the target rectangle of the supplementary lighting lens of the corresponding supplementary lighting lamp, therefore, the optical axis of the lens is considered to pass through the center of the target rectangle, and under the condition of dark ambient light, the light and shade distribution condition of the lens picture greatly depends on the supplementary lighting distribution condition.

An embodiment of the invention provides a light supplement lens. Fig. 2 shows a longitudinal schematic cross section and a light emitting path diagram of the fill-in lens 1 and the light source 2, and as shown in fig. 2, the fill-in lens 1 includes an incident curved surface (including a and a' in fig. 2), a reflecting curved surface (including B and C in fig. 2), and an exit smooth curved surface F. In the present application, the incident curved surface means that the curved surface is closer to the light source than the emergent smooth curved surface and is firstly projected by the light of the light source, and the light is refracted into the lens from the air or vacuum; and the exit smooth curved surface means that the curved surface is far away from the light source relative to the incident curved surface, the light is refracted into the air from the lens, and the surface of the exit smooth curved surface is smooth and is not provided with a corrugated structure or a microstructure. As shown in fig. 2, the exit smooth curved surface F may be a plane, and in the following detailed description, the exit smooth curved surface is taken as an inclined plane (i.e. the normal of each point on the plane is inclined downwards relative to the optical axis) which is suitable for the case that the fill-in lamp composed of the fill-in lens 1 and the light source 2 irradiates downwards from a certain height.

As shown in fig. 2, the incident curved surface includes a free transmission curved surface a at the center and an inner sidewall a' located around the free transmission curved surface a and adjacent to the free transmission curved surface a. The light incident from the inner side wall A' is reflected by the reflection curved surface and then is emergent through the light emergent curved surface F, and the light incident from the transmission free curved surface A is directly emergent through the light emergent curved surface F.

The curved reflective surface includes two free-form curved reflective surfaces B, C, each of which corresponds to a section of the inner side wall a' in the circumferential direction. The correspondence here means that the incident light on the corresponding section of the inner sidewall a' is mostly projected to and reflected by the corresponding free-form reflective curved surface when under the predetermined light source condition. As shown in fig. 4, the curved reflective surface may include four free-form reflective surfaces B, C, D, E, the corresponding sections of their respective inner sidewalls a' are respectively located on the upper, lower, left and right four sides of the free-form transmissive curved surface a, i.e. their respective projections on the plane perpendicular to the optical axis are respectively located on the upper, lower, left and right four sides of the free-form transmissive curved surface a, and in other embodiments, other numbers of free-form reflective surfaces, such as a single free-form reflective surface, may be included. Fig. 3 shows a schematic diagram of the division of the light energy of the light source 2, and as can be seen from fig. 3, the light energy of the light source 2 is divided into a free transmission curve a and four free reflection curved surfaces B, C, D, E. Fig. 4 is an external view of the fill lens 1 viewed from the light source side, and it can be seen that the adjacent portions of the four free-form curved surfaces B, C, D, E are rounded and have no obvious gap. The smooth transition is beneficial to enabling the supplementary lighting to be uniform or stably changed, and the situation that the local part of the supplementary lighting area is too bright or too dark is prevented.

As shown in fig. 2, the fill lens 1 is configured to be used with a mating light source 2 at a preset relative position. The matched light source is a light source which is preset to be matched with the light supplementing lens 1 for use or has a light emitting characteristic meeting the matching requirement of the light supplementing lens 1, or the light supplementing lens 1 is designed to be matched with the light source for use. In the present application, the light compensating lens 1 generally plays a role in the case where it is used in cooperation with a light source. The preset relative position means that the relative position of the matched light source and the light supplementing lens is unchanged and is preset. The light path of the light emitted from the light source 2 passing through each portion of the fill-in lens 1 will be described with reference to fig. 5 to 8.

When the fill-in lens 1 is used with the matching light source 2 at the preset relative position, a target rectangular fill-in area is formed on the preset fill-in plane, that is, the fill-in area formed on the preset fill-in plane is a rectangle, which matches with the shape of the lens of the camera. Note that the predetermined fill light plane is an assumed plane, and may be considered as any plane perpendicular to a center line of the cone-shaped fill light space region of the fill light lens.

As shown in fig. 5, the free-form transmission curved surface a forms the light supplement region of the target rectangle a on the preset light supplement plane by the light source 2 passing through it and the emergent light from the emergent smooth curved surface F in sequence, that is, the corresponding light supplement region of the free-form transmission curved surface a. In the present application, a light supplement region of a curved surface is generally referred to as a light supplement region formed when light from other sources is not considered and only light from the source is used for light supplement. The target rectangle a is a planar area of the conical supplementary lighting spatial area of the free transmission curved surface a, which is intercepted by a preset supplementary lighting plane. It should be understood that, in other embodiments, the fill-in light area formed by the free-form transmission curved surface a on the preset fill-in light plane may be only a part of the target rectangle a.

Meanwhile, each free-reflection curved surface enables emergent light of the light source 2, which enters the free-reflection curved surface through the corresponding section of the inner side wall A', to be reflected by the free-reflection curved surface and then refracted by the emergent smooth curved surface F, so that a light supplement area which is overlapped with the target rectangle a or is positioned in the target rectangle a is formed on the preset light supplement plane. The light filling area of each free-reflection curved surface is a planar area of a conical light filling spatial area corresponding to the free-reflection curved surface, which is intercepted by a preset light filling plane, and may coincide with the target rectangle a or be a part of the target rectangle a.

As shown in fig. 6, for the free-form reflective curved surface B or C, the emergent light of the light source 2, which is incident to the free-form reflective curved surface through the corresponding section of the inner sidewall a', is reflected by the free-form reflective curved surface B or C and then refracted by the emergent smooth curved surface F, so as to form a corresponding light supplement area B or C on the preset light supplement plane, where the light supplement area B or C may be overlapped with the target rectangle a or cover a part of the target rectangle a.

As shown in fig. 7, for the free-form reflective curved surface D or E, the emergent light of the light source 2, which is incident to the free-form reflective curved surface through the corresponding section of the inner sidewall a', is reflected by the free-form reflective curved surface D or E and then refracted by the emergent smooth curved surface F, so as to form a corresponding light supplement area D or E on the preset light supplement plane, where the light supplement area D or E may be overlapped with the target rectangle a or cover a part of the target rectangle a.

Fig. 8 is a longitudinal cross-sectional view showing a mapping relationship between a reflective curved surface and a corresponding fill-in light region. As shown in fig. 8, after the light emitted from the light source 2 is reflected by the reflection curved surface and refracted by the light-emitting curved surface, a light supplement area is formed on the preset light supplement plane. The curved reflective surface in fig. 8 may be any one or part of any one of the free-form curved reflective surfaces B, C, D and E.

When the fill-in lens 1 of the present embodiment is used with the light source 2, the emitted light is emitted from the light source 2 and then generally forms a fill-in area of the target rectangle a on the preset fill-in plane, wherein a part of the emitted light enters the fill-in lens 1 through the free transmission plane a, and is refracted by the exit smooth curved surface F to form a fill-in area coinciding with or being a part of the target rectangle a on the preset fill-in plane, and another part of the emitted light is projected onto the corresponding free reflection curved surface through the corresponding section of the inner side wall a' of the incident curved surface, reflected and refracted by the exit smooth curved surface F to form a fill-in area coinciding with or being a part of the target rectangle a on the preset fill-in plane, thereby increasing the light intensity in the target rectangle a and the cone-shaped fill-in area with rectangular cross section, and facilitating the camera with a corresponding rectangle to record more clearly, And the video for image recognition is more favorable.

In summary, the present embodiment provides a light supplement lens, which projects the emergent light from the matched light source onto the target plane to form a target rectangle by using the refraction of the free transmission curved surface, the reflection of the free reflection curved surface and the refraction of the emergent smooth curved surface at the central position, and a corrugated structure or a microstructure does not need to be arranged on the emergent smooth curved surface; because the light rays have smaller incident angles when being refracted by the free transmission curved surface and the emergent smooth curved surface, the Fresnel loss is greatly reduced; the light path is distributed in a horizontal divergent mode, the emergent angle is small, and the formation of total reflection on the transmission surface is inhibited, so that the optical efficiency and the energy utilization efficiency are high, and the lens efficiency can reach more than 90%; the defect that total reflection is easy to generate caused by a corrugated structure or a microstructure is avoided, and light supplement in a large angle range can be realized; meanwhile, the light intensity of each area in the target rectangle can meet the preset requirement by arranging each free reflection curved surface, the flexibility is good, the optical device is simple in structure, the tolerance is large, and the stability is high.

In this embodiment, each free-form curved surface may be a single free-form curved surface, or may be a combined free-form curved surface, that is, includes at least two sub-reflective curved surfaces, and each sub-reflective curved surface makes the emergent light emitted from the light source 2, which is reflected by the sub-reflective curved surface and then passes through the emergent smooth curved surface F, coincide with the target rectangle a or be located within the target rectangle a in the light supplement region formed on the preset light supplement plane. Fig. 9 is a cross-sectional view illustrating a mapping relationship between an exemplary reflective curved surface including a plurality of sub-reflective curved surfaces and corresponding fill light regions. As shown in fig. 9, after the light emitted from the light source 2 is reflected by the sub-reflecting curved surfaces and refracted by the light-emitting curved surface F, a corresponding light supplement area is formed on the preset light supplement plane. Therefore, one free-form emission curved surface can be divided into N sections of free-form curved surfaces, so that the reflection point of the free-form emission curved surface and each light supplementing point on the target plane form many-to-one mapping, for example, in the case of four free-form emission curved surfaces, theoretically, there may be one light supplementing point on the light supplementing area corresponding to 4 × N reflection points and 1 transmission point. Because a plurality of reflection points map a light supplementing point, even if one reflection point has an error, the light supplementing effect is not influenced, thereby effectively improving the product tolerance and reducing the production cost.

In the present embodiment, each position of the target rectangle a is generally projected by light from at least one free-form reflection curved surface in addition to the light projection through the free-form transmission curved surface a. The fill lens 1 may be configured such that fill areas of the at least two free-form curved surfaces or sub-fill areas of the at least two sub-reflective curved surfaces at least partially coincide, i.e. emergent light from the at least two free-form curved surfaces or the at least two sub-reflective curved surfaces is projected at each position of the coincidence. The overlapping portion may be the entire region of the target rectangle a or a partial region thereof. Because emergent light from at least two free reflection curved surfaces or at least two sub-reflection curved surfaces is projected at each position of the superposition position, even if a part of a certain reflection curved surface is mechanically intercepted (namely, light is blocked by an obstacle) due to an assembly mode, the light intensity of the part of the reflection curved surface is not obviously reduced and a dark shadow area appears because the corresponding light supplement area still has the projected light of other reflection curved surfaces. That is to say, to one place in target light filling region, there are many places to contribute the light filling on the free reflection curved surface of light filling lens 1, and when there is some machinery light interception in the light filling lamp that contains light filling lens 1, the light filling region can not produce unexpected weak light region yet, and when light filling lamp assembly tolerance was relatively poor, the light filling effect of light filling lamp can not produce regionally bad.

In the present embodiment, each free-form reflective curved surface or its sub-reflective curved surfaces may be configured such that: each preset area on the curved surface projects the emergent light with the preset direction, which is projected to the area by the light source 2, to the corresponding preset area of the target rectangle a after being reflected and refracted by the emergent smooth curved surface F. The preset area and the corresponding preset area can refer to a small area or even a point. Meanwhile, the free transmission curved surface a may also be configured such that: and each preset area on the light source 2 projects emergent light which is incident from the area and has a preset direction to a corresponding preset area of the target rectangle a after the emergent light is refracted by the refraction and the refraction of the emergent smooth curved surface. This means that any area on the free-form reflective curved surface or the free-form transmissive curved surface can meet the predetermined optical requirements. In practice, the free-form reflective curved surfaces and the free-form transmissive curved surfaces can be designed and realized as follows:

energy such as emergent light projected from a light source to a free transmission curved surface or a certain free reflection curved surface is distributed into M parts. For accuracy, M needs to be large enough, which can be understood as the number of rays dispensed, each ray having equal radiant flux and each having a solid angle. It is apparent that the region where the intensity of the outgoing light is large distributes more light than the region where the intensity of the outgoing light is small. Then, the corresponding preset supplementary lighting area (it should be understood that the supplementary lighting spatial area corresponding to each free-form reflection curved surface is cone-shaped, and the light intensity is based on a solid angle, so that the light intensity distribution of each cross section perpendicular to the optical axis is the same, so that the light intensity distribution of the spatial area can be replaced by the light intensity distribution of the two-dimensional planar preset supplementary lighting area) is correspondingly divided into M sub-areas based on the light intensity distribution, and the light rays of each sub-area also have equal energy. The light intensity distribution setting of the preset fill-in light region may be a light intensity distribution setting that satisfies a specific function distribution, a light intensity distribution setting that is shaped based on a specific function, or a light intensity distribution setting that does not satisfy any conventional function (a light intensity distribution setting given by a designer according to a requirement). On the basis, by using the SNELL law, under the condition that a light source, a preset light supplement area, a side wall and an emergent smooth curved surface are fixed, a mapping relation is created according to the light energy corresponding relation between a free reflection curved surface or a free transmission curved surface and the preset corresponding light supplement area, and the free reflection curved surface and the free transmission curved surface which meet requirements are obtained through iterative solution. Fig. 10 exemplarily shows a mapping relationship between a predetermined region on the reflection curved surface and a corresponding sub-region on the predetermined light compensation surface T, light source emergent light in a unit solid angle with positive included angles θ i and φ n with respect to the x-axis and the Z-axis respectively enters a corresponding free curved surface on the light compensation lens, and after reflection and refraction, enters a region between two rectangles with vertex coordinates (Xn, Yn, Z0) and (Xn +1, Yn +1, Z0) on the light compensation surface T, where Z0 is a distance between the predetermined target surface and the light source.

In the present embodiment, the fill lens 1 is preferably configured such that the ratio of the light intensity peak at the edge of the target rectangle a (i.e. the ratio of the light intensity at this point to the maximum light intensity in the region) is 10-30%. This is actually achieved by designing the free-form reflective curved surface so that less light rays are projected to the edge in the vertical direction after being reflected by the free-form reflective curved surface. In the prior art, the peak ratio of the light intensity at the edge in the vertical direction can reach 50% -60%, and the over-brightness and over-exposure phenomenon is easy to occur, and after the peak ratio is reduced to 10% -30%, the over-brightness and over-exposure phenomenon can be effectively reduced, and meanwhile, energy waste caused by unreasonable light intensity distribution is avoided. The specific value of the ratio of the light intensity peak to the edge can be determined according to the actual requirement.

Under some monitoring environments, the peak light intensity of a region needing light supplement is staggered with the optical axis of the lens to form an included angle without superposition (called as polarized light), so that the illumination uniformity of the lens on the far and near ground in a picture is better realized, and the object identification capability is improved. The polarization can be achieved by the following two means in the present embodiment.

The first means is: the at least one free-form reflecting curved surface is configured such that a position at which a corresponding peak light intensity of a corresponding fill light region formed by light reflected therefrom is located deviates from the center of the target rectangle a, i.e., the optical axis of the lens. Note that the corresponding peak intensity of the corresponding fill light region does not take into account other sources of light. In practice, the corresponding light supplement area may be overlapped with the target rectangle a, but the position of the corresponding peak light intensity is deviated from the center of the target rectangle a by setting the shape of the free reflection curved surface, for example, more light rays are reflected by the corresponding reflection area where the preset peak light intensity is located, or more reflection areas reflect light rays to the position where the preset peak light intensity is located; the corresponding light supplement area can only occupy a part of the target rectangle a, the centers of the light supplement area and the target rectangle a are not coincident, even the corresponding light supplement area does not include the center of the target rectangle a, and therefore the position of the corresponding peak light intensity is deviated from the center of the target rectangle a. By selecting the number of the free-reflection curved surfaces, setting the shape of the free-reflection curved surfaces and selecting the position and the light intensity distribution of the light supplement area corresponding to the free-reflection curved surfaces, the position of the peak light intensity of the target rectangle a can be deviated from the center of the target rectangle a and is positioned at a preset position. It should be understood that, for a free-form curved surface including a plurality of sub-curved reflective surfaces, the configuration may be such that all the sub-curved reflective surfaces included therein are configured identically, or only a part of the sub-curved reflective surfaces are configured.

The second means is: the free-form transmission curved surface a is configured such that it forms a position where the corresponding peak light intensity is located off the center of the target rectangle a, i.e., the optical axis of the lens. Note that the corresponding peak intensity formed by the free perspective projection surface a does not take into account other sources of light. In practice, the shape of the free-form reflection curved surface may be set so that the position of the corresponding peak light intensity is deviated from the center of the target rectangle a, for example, the area of the corresponding transmission region where the corresponding peak light intensity is located is made larger or the transmitted light is made stronger. This makes it possible to make the peak light intensity of the target rectangle a at a predetermined position offset from the center of the target rectangle a.

The above two means may be adopted separately or in combination.

The conventional way of implementing rectangular polarization is implemented by a transmissive hyperboloid as shown in fig. 11. As can be seen from fig. 11, the light emitted from the light source 2 'laterally passes through the first transmissive curved surface 11' of the light supplement lens 1 ', and then has a lower light emitting point, and exits through the second transmissive curved surface 12' at a large angle, which is easily limited by the assembly structure of the light supplement lamp, so that the light emitted at the large angle is mechanically shielded and cannot exit to the area needing light supplement.

In the embodiment, the free-reflection curved surface is adopted, and the light emitted from the side of the light source 2 is reflected by the free-reflection curved surface and then emitted from the emergent smooth curved surface F, so that the light emitting height of the light emitted from the emergent smooth curved surface F is improved, mechanical light interception is effectively avoided, and the assembly compatibility is better. The embodiment can realize required polarized light while meeting the rectangular light distribution, thereby providing better light compensation effect.

In this embodiment, the fill-in lens 1 may be further specifically configured such that the light intensity of the upper half of the target rectangle a is greater than that of the lower half, that is, the light intensity of the point located in the upper half is greater than that of the point located in the lower half, among the two points symmetrical about the horizontal center line of the target rectangle a. This is because the vertically lower edge (i.e. the long side relatively far from the ground) of the target rectangle a is closer to the ground than the vertically lower edge (i.e. the long side relatively close to the ground), therefore, in the lens frame, of the two points symmetrical about the horizontal center line, the light rays represented by the points located on the upper half portion reach a longer distance than the light rays represented by the points located on the lower half portion, that is, the depth range of the upper half part is larger than that of the lower half part, if the supplementary lighting distribution is not adjusted, the light intensity of the upper half part and the lower half part of the target rectangle a will be equal, therefore, the illumination of the far object surface appearing in the upper half (e.g., near the upper edge) of the lens frame is insufficient, and the illumination of the near object surface appearing in the lower half (e.g., near the lower edge) is too high, so that the upper edge is too dark and the lower edge is too bright and overexposed in the lens frame. In the embodiment, the free-reflection curved surface is designed, so that the total light intensity of the light rays projected to the upper half part after being reflected by the free-reflection curved surface is higher than that of the light rays of the lower half part, and the phenomena of over-dark of the upper edge and over-bright and over-exposure of the lower edge in the vertical direction in a lens picture are avoided. This can also be achieved, for example, by polarization.

One solution of realizing polarization by the fill lens 1 when the four free-form reflecting curved surfaces B, C, D and E are included as shown in fig. 4 will be described below with reference to fig. 12 to 15. It should be understood that the C0-180 plane mentioned in the description of the drawings refers to a horizontal plane of the center line of the overfill space region, and the C90-270 plane refers to a vertical plane of the center line of the overfill space region, so that the intersection of the C0-180 plane and the target rectangle a is the horizontal bisector of the overcenter of the target rectangle a, and the intersection of the C90-270 plane and the target rectangle a is the vertical bisector of the overcenter of the target rectangle a. Since the light intensity is relative to the unit solid angle, the light intensity distribution on the horizontal bisector and the vertical bisector of the target rectangle a represents the light intensity distribution on the C0-180 plane and the C90-270 plane, respectively. Based on this, for the sake of clarity and simplicity, the C0-180 and C90-270 planes are directly represented below by horizontal and vertical bisectors, respectively. In fig. 12 to 15, the solid line represents a relationship curve between the normalized light intensity and the light-emitting angle on the horizontal bisector of the corresponding light compensation region, and the dotted line represents a relationship curve between the normalized light intensity and the light-emitting angle on the vertical bisector of the corresponding light compensation region. The light-emitting included angle refers to an included angle formed by a straight line passing through a point on a horizontal bisector or a vertical bisector and a cone vertex of the light-supplementing space region and a cone central line (namely an optical axis), is an included angle formed by the assumed light rays when the light rays are emitted from the cone vertex and the optical axis, and does not refer to an included angle formed by actual light rays.

Fig. 12 shows a solid line as a relation curve between the normalized light intensity and the light-emitting included angle of the emergent ray corresponding to the free transmission curved surface a on the horizontal bisector of the target rectangle a, and a dotted line as a relation curve between the normalized light intensity and the light-emitting included angle of the emergent ray corresponding to the free transmission curved surface a on the vertical bisector of the target rectangle a. It can be seen that, in the horizontal direction, the corresponding peak light intensity is located at the center of the target rectangle a (the light-emitting included angle is zero, i.e. on the lens optical axis), and in the vertical direction, the corresponding peak light intensity is located at an included angle of about 20 degrees with the lens optical axis, which can be achieved by setting the shape of the free transmission curved surface a, for example, by making more light rays to the corresponding peak light intensity.

For the free-reflection curved surfaces B or C located at both sides of the free-transmission curved surface a in the vertical direction, the solid line in fig. 13 is a relationship curve between the normalized light intensity and the light-emitting included angle of the emergent light corresponding to the free-reflection curved surface B or C on the horizontal bisector of the target rectangle a, and the dotted line is a relationship curve between the normalized light intensity and the light-emitting included angle of the emergent light corresponding to the free-reflection curved surface B or C on the vertical bisector of the target rectangle a. It can be seen that, in the horizontal direction, the corresponding peak light intensity is located on the optical axis of the lens where the light-emitting included angle is zero, and in the vertical direction, the corresponding peak light intensity forms an included angle of about 20 degrees with the optical axis of the lens. And in the vertical direction, the light-emitting included angle range of light is narrow, which is actually realized by making the corresponding light supplement area formed by the free reflection curved surface B or C be a narrow and long strip-shaped area. Fig. 2 shows an optical path diagram for implementing a narrow and long strip-shaped light supplement region, and as can be seen from fig. 2, the emergent light reflected from the free-form curved surface B or C becomes near-parallel light or a narrow light beam, which can be implemented by adjusting the corresponding light supplement region and light intensity distribution of the curved surface B or C.

For the free-reflection curved surfaces D or E located at both sides of the free-transmission curved surface a in the horizontal direction, the solid line in fig. 14 is a relationship curve between the normalized light intensity and the light-emitting included angle of the emergent light corresponding to the free-reflection curved surface D or E on the horizontal bisector of the target rectangle a, and the dotted line is a relationship curve between the normalized light intensity and the light-emitting included angle of the emergent light corresponding to the free-reflection curved surface D or E on the vertical bisector of the target rectangle a. It can be seen that, in the horizontal direction, the corresponding peak light intensity is located on the lens optical axis where the light-emitting included angle is zero, and in the vertical direction, the corresponding peak light intensity and the lens optical axis form an included angle of about 20 degrees, which can be realized by adjusting the corresponding light supplement area and light intensity distribution of the reflective curved surface D or E.

The solid line in fig. 15 is a curve relating the total light intensity of each point on the horizontal bisector of the target rectangle a to the light-emitting angle of the superimposed emergent light, and the dotted line is a curve relating the total light intensity of each point on the vertical bisector of the target rectangle a to the light-emitting angle of the superimposed emergent light, where the total peak light intensity in the vertical direction is 1. It can be seen that, in the horizontal direction, the total peak light intensity is located on the optical axis of the lens, and in the vertical direction, the total peak light intensity is located at an included angle of about 20 degrees with the optical axis of the lens, that is, the peak light intensity of the target rectangle a is located at a position deviated from the center of the target rectangle a in the vertical direction. The light supplement lens is far away from the light supplement lens, so that the light supplement is more, the vertical illumination and uniformity of the ground are improved, the vertical illumination of the surface of the illuminated object is improved, and the success rate of image recognition is increased. It should be understood that although the angles between the vertical peak light intensity and the optical axis of the lens are all about 20 degrees, in some other embodiments, the angles may be other degrees, and the angles of different lens surfaces may be different; meanwhile, an included angle can be formed between the position of the peak light intensity in the horizontal direction and the optical axis according to requirements.

Another embodiment of the present invention provides a light supplement lamp, including the light supplement lens and a matching light source of the previous embodiment, where a relative position of the matching light source and the light supplement lens is a preset position. Fig. 2 also shows the structure of the fill-in light, which includes a fill-in lens 1 and a matched light source 2. The light source 2 may be an LED lamp or other type of light fixture. In an implementation scene, the light filling lamp can be infrared light filling lamp, and light source 2 sends the infrared light promptly, is convenient for realize the control of making a video recording night. According to the needs of assembly and use, the fill light can also include other accessories, and the description is omitted here.

Another embodiment of the present invention provides a camera, which includes the fill-in light of the previous embodiment. The camera may be used to monitor camera shooting, but is not limited thereto, and may be used for other suitable purposes.

The above description is only for facilitating the understanding of the technical solutions of the present invention by those skilled in the art, and is not intended to limit the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A light supplementing lens is characterized by comprising an incident curved surface, a reflection curved surface and an emergent smooth curved surface, wherein the incident curved surface comprises a free transmission curved surface and an inner side wall which is positioned around the free transmission curved surface and is adjacent to the free transmission curved surface, the reflection curved surface comprises one or more free reflection curved surfaces, each free reflection curved surface corresponds to one section of the inner side wall in the circumferential direction, so that light rays incident from the inner side wall are respectively reflected by the free reflection curved surfaces corresponding to the inner side wall in the circumferential direction and then are emergent through the emergent smooth curved surface, and the light rays incident from the free transmission curved surface are directly emergent through the emergent smooth curved surface;

2. A fill-in lens according to claim 1, wherein the one or more than one free-form reflective curved surfaces are four, and inner sidewalls of corresponding sections of the four free-form reflective curved surfaces are respectively located at upper, lower, left and right sides of the free-form transmissive curved surface.

3. A fill-in lens as claimed in claim 1, wherein the adjacent free-form reflective curved surfaces are rounded at their junctions.

4. A light supplementing lens according to claim 1, wherein each free-form reflecting curved surface includes at least two sub-reflecting curved surfaces, and each sub-reflecting curved surface makes an emergent light emitted from the light source and reflected by the light source to pass through the emergent smooth curved surface, and a sub-light supplementing region formed on the preset light supplementing plane coincides with or is located within the target rectangle.

5. A fill-in lens as claimed in claim 4, wherein the fill-in lens is configured such that at least two fill-in areas of the free-form curved surfaces or at least two sub-fill-in areas of the sub-form curved surfaces at least partially coincide.

6. The fill-in lens of claim 1, wherein each free-form reflective curved surface is configured such that each preset region on the free-form reflective curved surface projects the outgoing light with a preset direction, projected to the region from the light source through the corresponding section inner sidewall, onto the corresponding preset region of the target rectangle after being reflected by the outgoing light and refracted by the outgoing smooth curved surface; and/or the free transmission curved surface is configured to enable each preset area on the free transmission curved surface to project emergent light which is incident from the area and has a preset direction to a corresponding preset area of the target rectangle after being refracted by the light source and the emergent smooth curved surface.

7. A fill-in lens as claimed in claim 1, wherein the fill-in lens is configured such that the ratio of the peak intensity to the edge of the target rectangle is 10-30%.

8. A fill-in lens according to any one of claims 1 to 7, wherein at least one free-form reflecting curved surface is configured such that the corresponding peak light intensity of the fill-in region is located off the center of the target rectangle, and/or the free-form transmitting curved surface is configured such that the corresponding peak light intensity formed by the free-form transmitting curved surface is located off the center of the target rectangle, such that the peak light intensity of the target rectangle is located off the center of the target rectangle.

9. A fill-in lens as claimed in claim 8, wherein the fill-in lens is configured such that the peak intensity of the target rectangle is located vertically off-center from the center of the target rectangle.

10. A fill-in lens as claimed in any one of claims 1 to 7, wherein the fill-in lens is configured such that the light intensity of the upper half of the target rectangle is greater than the light intensity of the lower half.

11. A light supplement lamp, comprising the light supplement lens and the mating light source of any one of claims 1 to 10, wherein the relative position of the mating light source and the light supplement lens is a preset position.

12. A camera comprising the fill light of claim 11.