Total internal reflection lens design method based on Bezier curve, total internal reflection lens and spotlight

Abstract

The present disclosure provides a total internal reflection lens design method based on Bezier curve, a total internal reflection lens and a spotlight. The above-mentioned total internal reflection lens design method based on Bezier curve can obtain a number of Bezier light incident refraction lines and a number of Bezier light exiting refraction lines of equal number by performing equal number division operation on the maximum light incident angle and the maximum light exiting angle, and then perform intersection reflection tangent processing on the Bezier light incident refraction lines and the Bezier light exiting refraction lines to obtain the reflection normal tangent angle at the incident and exiting intersection, and judge whether the light path formed by the current Bezier light incident refraction lines and the current Bezier light exiting refraction lines is close to the preset light path. After the light paths formed by each Bezier light incident refraction line and each Bezier light exiting refraction line corresponding to each other one by one are close to the preset light path, the actual reflection surface of the total internal reflection lens can be determined through each light reflection curve point, and the light projected by the total internal reflection lens can have less stray light through the actual reflection surface.

Description

Technical Field

[0001] The present disclosure relates to the technical field of lamp equipment, and in particular to a total internal reflection lens design method based on Bezier curves, a total internal reflection lens and a spotlight. Background Art

[0002] Total internal reflection refers to when light enters a medium with a high refractive index into a medium with a low refractive index, if the incident angle is greater than a certain critical angle, all the incident light will be reflected without entering the medium with a low refractive index. Based on the above optical phenomenon, people have designed various types of total internal reflection lenses such as CN116507954A, CN106952997A, and CN220287236U. However, combined with Figure 1a As shown, due to the structural design of the existing total internal reflection lens, when the incident light is refracted or reflected, a number of Fresnel reflection rays 10 will be formed, among which some Fresnel reflection rays 10 will form stray light in front of the total internal reflection lens side. The stray light will interfere with the main illumination light and cause problems such as uneven brightness and blurred image. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a total internal reflection lens design method based on Bezier curves, a total internal reflection lens and a spotlight that can design a lens with better light output effect and less stray light.

[0004] The purpose of this disclosure is achieved through the following technical solutions:

[0005] A total internal reflection lens design method based on Bezier curve, comprising:

[0006] S100: Obtaining a maximum light incident angle and a maximum light exit angle;

[0007] S200: performing an equal division operation on the maximum incident light angle and the maximum exit light angle to obtain a plurality of Bessel incident light refraction lines and a plurality of Bessel exit light refraction lines;

[0008] S300: performing intersection reflection tangent processing on the Bessel incident light refraction line and the Bessel outgoing light refraction line to obtain a reflection normal tangent angle at the incident and outgoing intersection point;

[0009] S400: Calculate the difference between the reflection normal tangent angle at the incident and outgoing intersection point and the preset reflection normal tangent angle to obtain a tangent angle difference;

[0010] S500: Calculating the difference between the tangent angle difference and a preset tangent angle difference to obtain a tangent angle difference deviation;

[0011] S600: If the tangent angle difference deviation is less than or equal to the preset tangent angle difference deviation, determine the intersection of the current Bessel light-incoming refraction line and the current Bessel light-outgoing refraction line as a light reflection curve point and return to S300;

[0012] S700: After a predetermined number of intersection reflection tangent line processing, a fitting operation is performed on each of the light reflection curve points to obtain a light reflection curve.

[0013] In some embodiments, the intersection reflection tangent processing of the Bessel incident light refraction line and the Bessel outgoing light refraction line to obtain the reflection normal tangent angle at the incident and outgoing intersection specifically includes: calculating the reflection normal tangent angle at the incident and outgoing intersection between any one of the Bessel incident light refraction lines and any one of the Bessel outgoing light refraction lines.

[0014] In some embodiments, the calculation of the reflection normal tangent angle at the incident and outgoing intersection point between any one of the Bessel incident light refraction lines and any one of the Bessel outgoing light refraction lines specifically includes the following steps:

[0015] Obtaining the angle between any one of the Bessel incident light refraction lines and any one of the Bessel outgoing light refraction lines, and determining it as an assumed light reflection angle;

[0016] Performing a halving operation on the assumed light reflection angle to obtain a reflection normal line between the current Bessel light-incoming refraction line and the current Bessel light-outgoing refraction line;

[0017] Obtain the perpendicular line of the reflection normal at the intersection point between the current Bessel incident light refraction line and the current Bessel outgoing light refraction line, and then calculate the tangent angle of the reflection normal at the incident and outgoing intersection point.

[0018] In some embodiments, the step of calculating the difference between the tangent angle difference and a preset tangent angle difference to obtain the tangent angle difference deviation may further include:

[0019] If the tangent angle difference deviation is greater than the preset tangent angle difference deviation, determining whether the reflection normal tangent angle at the incident-exit intersection is greater than the preset reflection normal tangent angle;

[0020] If the reflection normal tangent angle at the incident-outlet intersection is greater than the preset reflection normal tangent angle, the next Bessel incident light refraction line and the next Bessel exit light refraction line are selected; wherein the slope of the next Bessel incident light refraction line is less than the slope of the current Bessel incident light refraction line, and the next Bessel exit light refraction line is less than the slope of the current Bessel exit light refraction line;

[0021] Return to step S400.

[0022] In some embodiments, the determining whether the reflection normal tangent angle at the incident-outlet intersection point is greater than a preset reflection normal tangent angle further includes:

[0023] Determine whether the reflection normal tangent angle at the incident and outgoing intersection point is less than the preset reflection normal tangent angle;

[0024] If the reflection normal tangent angle at the incident-outlet intersection is less than the preset reflection normal tangent angle, the next Bessel incident light refraction line and the next Bessel outgoing light refraction line are selected; wherein the slope of the next Bessel incident light refraction line is greater than the slope of the current Bessel incident light refraction line, and the slope of the next Bessel outgoing light refraction line is greater than the slope of the current Bessel outgoing light refraction line;

[0025] Return to step S400.

[0026] In some embodiments, the maximum incident light angle and the maximum exit light angle are equally divided to obtain a plurality of Bessel incident light refraction lines and a plurality of Bessel exit light refraction lines, specifically comprising the following steps:

[0027] Divide the maximum incident light angle equally to obtain a first number of light rays emitted by the light source;

[0028] Calculate the incident angle of the Bezier incident light normal at the intersection point between each light source outgoing light and the incident Bezier surface;

[0029] Obtaining a first number of Bessel incident light refraction lines according to the incident angles of the Bessel incident light normal lines at the intersection points;

[0030] Dividing the maximum light output angle to obtain a first number of lens projected light rays;

[0031] Calculate the Bezier light normal exit angle at the intersection point between each lens projection light and the exit Bezier surface;

[0032] A first number of the Bessel light refraction lines are obtained according to the Bessel light normal line emission angles at each intersection.

[0033] In some embodiments, obtaining the maximum incident light angle specifically includes the following steps:

[0034] S110: Selecting a boundary incident light angle to obtain a boundary Bezier incident light refraction line;

[0035] S120: Calculating the angle between the boundary Bezier light-incoming refraction line and the preset boundary Bezier light-outgoing refraction line;

[0036] S130: Determine whether the angle is equal to a preset angle;

[0037] S140: If the angle value is equal to the preset angle value, the boundary incident light angle is determined as the maximum incident light angle.

[0038] In some embodiments, S130: determining whether the angle is equal to a preset angle, and then further comprising:

[0039] Determining whether the angle is greater than a preset angle;

[0040] If the angle is greater than the preset angle, the boundary incident angle is reduced and used as a new boundary incident angle and the process returns to step S120.

[0041] A total internal reflection lens comprises an incident Bezier surface, an exiting Bezier surface and a reflection surface formed by a light reflection curve obtained by using a total internal reflection lens design method based on Bezier curves as in any of the above embodiments.

[0042] A spotlight comprises a light source and a total internal reflection lens according to any one of the above embodiments, wherein the light emitted by the light source is directed toward an incident Bezier surface of the total internal reflection lens.

[0043] Compared with the prior art, the present invention has at least the following advantages:

[0044] The above-mentioned total internal reflection lens design method based on Bezier curve can obtain a number of Bezier light incident refraction lines and a number of Bezier light exiting refraction lines of equal number by performing equal number division operation on the maximum light incident angle and the maximum light exiting angle, and then perform intersection reflection tangent processing on the Bezier light incident refraction lines and the Bezier light exiting refraction lines to obtain the reflection normal tangent angle at the incident and exiting intersection, so that it is possible to determine whether the light path composed of the current Bezier light incident refraction lines and the current Bezier light exiting refraction lines is close to the preset light path by determining whether the reflection normal tangent angle at the incident and exiting intersection meets the requirements. After the light paths formed by each Bezier light incident refraction line and each Bezier light exiting refraction line corresponding to each other one by one are close to the preset light path, the actual reflection surface of the total internal reflection lens can be determined through each light reflection curve point. The actual reflection surface of the total internal reflection lens can make the light projected by the exiting Bezier surface of the total internal reflection lens achieve the distribution effect of light that will not be projected to the side and front of the total internal reflection lens, that is, reduce stray light, so that the brightness of the main light emitted by the total internal reflection lens is more uniform and the image blur is clearer. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1a This is a light output effect diagram of an existing total internal reflection lens;

[0047] Figure 1b This is a light emitting effect diagram when the peripheral light emitting surface of the existing total internal reflection lens is a flat surface;

[0048] Figure 2 This is a flow chart of a total internal reflection lens design method based on a Bezier curve according to an embodiment of the present disclosure;

[0049] Figure 3 A schematic diagram of a preset optical path of a total internal reflection lens according to another embodiment of the present disclosure;

[0050] Figure 4 for Figure 3 The light output effect diagram of the total internal reflection lens shown;

[0051] Figure 5 A flowchart of calculating the maximum light source angle according to another embodiment of the present disclosure;

[0052] Figure 6 A flowchart of setting the angle distribution of the outgoing light according to another embodiment of the present disclosure;

[0053] Figure 7 A flowchart for solving the initial reflection normal tangent angle of the reflection surface of the total internal reflection lens according to another embodiment of the present disclosure;

[0054] Figure 8 A flow chart of accurately calculating a complete optical path according to another embodiment of the present disclosure;

[0055] Fig. 9 A flowchart of solving a central light output curve according to another embodiment of the present disclosure;

[0056] Fig.10 A schematic diagram of a second-order Bezier curve used in an embodiment of the present disclosure;

[0057] Fig.11 For use Figure 2 The total internal reflection lens design method based on Bezier curve is shown in Figure 4 Program interface diagram of the light emitting effect of the total internal reflection lens.

[0058] Reference numerals:

[0059] 10. Fresnel reflection light; 20. Circumferential surface of incident light refraction; 30. Peripheral light emitting surface;

[0060] 210, incident Bezier surface; 220, reflection surface; 230, exiting Bezier surface;

[0061] 310. Light source;

[0062] 410. Center Bezier light-incoming surface; 420. Center light-emitting surface. DETAILED DESCRIPTION

[0063] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are given in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thoroughly and comprehensively understood.

[0064] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0065] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present disclosure. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0066] In order to better understand the technical solutions and beneficial effects of the present invention, the present invention is further described in detail below in conjunction with specific embodiments:

[0067] In order to facilitate the derivation of the light path projection effect according to the light refraction theorem, the incident light refraction surface 20 of the traditional total internal reflection lens is usually designed to be a flat surface. Figure 1aAs shown, since the light emitted by the light source 310 is distributed in a divergent shape, the light presents different incident angles on the incident refractive surface 20, so that part of the light will be reflected to the front side of the total internal reflection lens after passing through the total internal reflection lens to form Fresnel reflected light 10. The Fresnel reflected light 10 will form stray light to interfere with the main light, resulting in image blur and uneven brightness. At the same time, the peripheral light-emitting surface 30 of the total internal reflection lens is usually designed to be a flat surface. If the slope of the curve of the peripheral light-emitting surface 30 is too small, the center of the lens will be thicker, which will not only increase the production cost, but also be unfavorable for the design of the center light; please refer to Figure 1b If the slope of the curve of the peripheral light-emitting surface of the lens is too large, more Fresnel reflected light will be generated, thereby forming stray light. Therefore, in the total internal reflection lens disclosed in the present invention, the incident light refraction peripheral surface 20 is designed to be in the form of a curve of the incident Bezier surface 210, and the peripheral light-emitting surface 30 is designed to be in the form of a curve of the outgoing Bezier surface 230.

[0068] See also Figure 2 , a total internal reflection lens design method based on Bezier curve in one embodiment includes part or all of the following steps.

[0069] S100: Obtain a maximum light incident angle and a maximum light exit angle.

[0070] See also Figure 3 In this embodiment, the maximum incident angle k is the maximum angle formed between the light rays emitted by the light source 310 and projected onto the incident Bezier surface 210 of the total internal reflection lens, that is, the angle between the light ray with the lowest vertical position and the light ray with the highest vertical position among the multiple light rays projected by the light source 310 onto the incident Bezier surface 210 of the total internal reflection lens. The maximum light-emitting angle m is the maximum angle formed between the light rays projected by the exiting Bezier surface 230 of the total internal reflection lens when the preset light-emitting effect is met, that is, the maximum angle formed between the light ray closest to the light source 310 in the horizontal direction and the light ray farthest from the light source 310 in the horizontal direction among the multiple predetermined light rays projected by the exiting Bezier surface 230 of the total internal reflection lens. Among them, when the position of the light source 310 relative to the total internal reflection lens is determined and the preset light-emitting effect is determined, the maximum incident angle k and the maximum light-emitting angle m are both fixed values. The preset light-emitting effect is the distribution effect of light when the light projected by the exit Bezier surface 230 of the total internal reflection lens is not projected to the front side of the total internal reflection lens, that is, stray light is reduced under the preset light-emitting effect, so that the brightness of the main light emitted by the total internal reflection lens is more uniform and the image blur is clearer. In some embodiments, the preset light-emitting effect can reduce stray light by 50% to 60% compared with the traditional light-emitting effect.

[0071] S200: performing an equal division operation on the maximum incident light angle and the maximum exit light angle to obtain a plurality of Bessel incident light refraction lines and a plurality of Bessel exit light refraction lines.

[0072] See also Figure 3 In this embodiment, the maximum incident light angle k and the maximum light exiting angle m are divided into equal numbers, that is, the maximum incident light angle k and the maximum light exiting angle m are divided into the same number, that is, the maximum incident light angle k is divided into a number of incident light angles, and the maximum light exiting angle m is divided into a number of light exiting angles, and the number of the incident light angles is equal to the number of the light exiting angles. Among them, after the light source light at each incident light angle is refracted by the incident Bezier surface 210 of the total internal reflection lens, a number of Bezier incident light refraction lines q1 can be obtained, and the light projected from the exiting Bezier surface 230 at the light exiting angle before being refracted by the total internal reflection lens is the Bezier light exiting refraction line q2, so that each Bezier light exiting refraction line q2 can be calculated through each light exiting angle.

[0073] S300: performing intersection reflection tangent processing on the Bessel incident light refraction line and the Bessel outgoing light refraction line to obtain a reflection normal tangent angle at the incident and outgoing intersection.

[0074] See also Figure 3 In this embodiment, if the intersection of a Bessel incident light refraction line q1 and a Bessel exiting light refraction line q2 is located on the reflection surface 220 of the total internal reflection lens, then the angle between the Bessel incident light refraction line q1 and the Bessel exiting light refraction line q2 will be the light reflection angle of the total internal reflection lens. According to the light reflection theorem, the position of bisection of the light reflection angle of the total internal reflection lens is the normal line N2, and the perpendicular line to the normal line is the tangent line T2 of the reflection surface 220 of the total internal reflection lens. The tangent angle of the reflection normal at the intersection of the incident and the exiting point is the inclination angle of the tangent line of the reflection surface 220 of the total internal reflection lens.

[0075] S400: Calculate the difference between the tangent angle of the reflection normal at the intersection of the incident and the outgoing and the preset tangent angle of the reflection normal to obtain the tangent angle difference.

[0076] See also Figure 3In this embodiment, the preset reflection normal tangent angle is the reflection normal tangent angle at the last incident-outgoing intersection that meets the requirements, for example, the reflection normal tangent angle at the incident-outgoing intersection between the Bessel incident light refraction line corresponding to the boundary position of the maximum incident light angle and the Bessel outgoing light refraction line corresponding to the boundary position of the maximum outgoing light angle. When the reflection normal tangent angle at the incident-outgoing intersection meets the requirements, it indicates that the intersection between the current Bessel incident light refraction line q1 and the current Bessel outgoing light refraction line q2 is located on the reflection surface 220 of the total internal reflection lens, that is, the current Bessel incident light refraction line q1 and the current Bessel outgoing light refraction line q2 meet the light reflection theorem, that is, the current Bessel incident light refraction line q1 and the current Bessel outgoing light refraction line q2 can form a preset light path. When a Bessel incident light refraction line q1 and a Bessel outgoing light refraction line q2 meet the preset light path, the light emitted by the light source 310 passes through the preset light path and is projected from the total internal reflection lens as light that meets the preset light emitting effect.

[0077] S500: Calculate the difference between the tangent angle difference and the preset tangent angle difference to obtain the tangent angle difference deviation;

[0078] In this embodiment, the preset tangent angle difference is the difference between the tangent angle of the reflection normal at the previous incident-outgoing intersection that meets the requirements and the tangent angle of the reflection normal at the next incident-outgoing intersection that meets the requirements. By calculating the difference between the tangent angle difference and the preset tangent angle difference, the degree to which the tangent angle of the reflection normal at the current incident-outgoing intersection deviates from the tangent angle of the reflection normal at the next incident-outgoing intersection that meets the requirements can be detected.

[0079] S600: If the tangent angle difference deviation is less than or equal to the preset tangent angle difference deviation, the intersection of the current Bessel light-incoming refraction line and the current Bessel light-outgoing refraction line is determined as a light reflection curve point and the process returns to S300.

[0080] See also Figure 3In this embodiment, the preset tangent angle difference deviation is a preset tolerance value of the reflected normal tangent angle at the next incident and exit intersection point that meets the requirements. The preset tangent angle difference deviation can be determined based on industry experience. If the tangent angle difference deviation is less than or equal to the preset tangent angle difference deviation, it indicates that the degree of deviation of the reflection normal tangent angle at the current incident-outlet intersection from the reflection normal tangent angle at the next incident-outlet intersection that meets the requirements is small, that is, the reflection normal tangent angle at the current incident-outlet intersection is close to the reflection normal tangent angle at the next incident-outlet intersection that meets the requirements, thereby indicating that the intersection between the current Bessel incident light refraction line q1 and the current Bessel exit light refraction line q2 is close to the reflection surface 220 of the total internal reflection lens, and further indicating that the light path formed by the current Bessel incident light refraction line q1 and the current Bessel exit light refraction line q2 is close to the preset light path, at this time, the intersection of the current Bessel incident light refraction line q1 and the current Bessel exit light refraction line q2 can be determined as a light reflection curve point, and the light reflection curve point is the point on the reflection surface 220 of the total internal reflection lens. In some embodiments, the preset tangent angle difference deviation is 0°, at which time the tangent angle difference deviation is equal to the preset tangent angle difference deviation, indicating that the tangent angle of the reflection normal at the current incident and output intersection is exactly the tangent angle of the reflection normal at the next incident and output intersection that meets the requirements, that is, the intersection between the current Bessel incident light refraction line q1 and the current Bessel exit light refraction line q2 is exactly located on the reflection surface 220 of the total internal reflection lens, that is, the light path formed by the current Bessel incident light refraction line q1 and the current Bessel exit light refraction line q2 is exactly the preset light path.

[0081] See also Figure 3 In this embodiment, after the current light reflection curve point is obtained, the next light reflection curve point can be obtained by returning to step S300, that is, repeating steps S300 to S600. After all Bessel incident light refraction lines q1 and all Bessel outgoing light refraction lines q2 are processed, a number of Bessel incident light refraction lines q1 and a number of Bessel outgoing light refraction lines q2 will intersect one by one, thereby obtaining a number of light reflection curve points. Among them, each light reflection curve point is close to the reflection surface 220 of the total internal reflection lens, and the light path formed by the one-to-one correspondence between the several Bessel incident light refraction lines q1 and the several Bessel outgoing light refraction lines q2 will project the light from the outgoing Bessel surface 230 of the total internal reflection lens close to the preset light emission effect, that is, the light projected from the outgoing Bessel surface 230 of the total internal reflection lens will achieve the distribution effect of the light when it is not projected to the front side of the total internal reflection lens.

[0082] S700: After a predetermined number of intersection reflection tangent line processing, a fitting operation is performed on each light reflection curve point to obtain a light reflection curve.

[0083] See also Figure 3For example, the maximum incident light angle and the maximum light output angle are divided into 500 parts. When 500 Bezier incident light refraction lines and 500 Bezier light output refraction lines are processed by intersection reflection tangent in sequence, 500 light reflection curve points can be obtained, and the predetermined number of times is obtained according to calculation. Since each light reflection curve point is close to the reflection surface 220 of the total internal reflection lens, by performing a fitting operation on each light reflection curve point, for example, connecting each light reflection curve point into a line, a light reflection curve can be obtained. The light reflection curve line is the cross-sectional line segment shape of the reflection surface 220 of the total internal reflection lens on the cross section, that is, the actual reflection surface 220 of the total internal reflection lens can be obtained through the light reflection curve, and the actual reflection surface 220 of the total internal reflection lens can make the light projected by the exit Bezier surface 230 of the total internal reflection lens achieve the distribution effect of not projecting light to the front side of the total internal reflection lens.

[0084] It can be understood that by performing an equal division operation on the maximum incident light angle and the maximum light exiting angle, a number of Bessel incident light refraction lines and a number of Bessel exiting light refraction lines of equal number can be obtained, and then the reflection normal tangent angle at the incident and output intersection point between any Bessel incident light refraction line and any Bessel exiting light refraction line is calculated, so that by determining whether the reflection normal tangent angle at the incident and output intersection point meets the requirements, it can be judged whether the light path composed of the current Bessel incident light refraction line and the current Bessel exiting light refraction line is close to the preset light path. After the light paths formed by the corresponding Bessel incident light refraction lines and the Bessel exiting light refraction lines are close to the preset light path, the actual reflection surface of the total internal reflection lens can be determined through each light reflection curve point. The actual reflection surface of the total internal reflection lens can make the light projected by the exiting Bessel surface of the total internal reflection lens achieve the distribution effect of light that will not be projected to the side and front of the total internal reflection lens, that is, reduce stray light, so that the brightness of the main light emitted by the total internal reflection lens is more uniform and the image blur is clearer.

[0085] In some of the embodiments, the Bessel incident light refraction line and the Bessel outgoing light refraction line are processed at the intersection point reflection tangent to obtain the reflection normal tangent angle at the incident and outgoing intersection point, specifically including: calculating the reflection normal tangent angle at the incident and outgoing intersection point between any Bessel incident light refraction line and any Bessel outgoing light refraction line.

[0086] In some embodiments, the calculation of the reflection normal tangent angle at the incident and outgoing intersection point between any one of the Bessel incident light refraction lines and any one of the Bessel outgoing light refraction lines specifically includes the following steps:

[0087] The angle between any one of the Bessel light-incoming refraction lines and any one of the Bessel light-outgoing refraction lines is obtained, and is determined as an assumed light reflection angle.

[0088] In this embodiment, by obtaining the angle between any Bessel incident light refraction line and any Bessel exiting light refraction line, assuming that the current Bessel incident light refraction line and the current Bessel exiting light refraction line can form a light path, then the angle between the current Bessel incident light refraction line and the current Bessel exiting light refraction line can be determined as the assumed light reflection angle, that is, assuming that the light reflection theorem is satisfied between the current Bessel incident light refraction line and the current Bessel exiting light refraction line.

[0089] The assumed light reflection angle is bisected to obtain a reflection normal between the current Bessel light-incoming refraction line and the current Bessel light-outgoing refraction line.

[0090] In this embodiment, since the current Bessel incident light refraction line and the current Bessel exit light refraction line satisfy the light reflection theorem, that is, the angle between the current Bessel incident light refraction line and the reflection normal is equal to the angle between the current Bessel exit light refraction line and the reflection normal, the bisector of the assumed light reflection angle can be obtained by bisecting the assumed light reflection angle, and the bisector of the assumed light reflection angle is the reflection normal.

[0091] Obtain the perpendicular line of the reflection normal at the intersection point between the current Bessel incident light refraction line and the current Bessel outgoing light refraction line, and then calculate the tangent angle of the reflection normal at the incident and outgoing intersection point.

[0092] In this embodiment, according to the light reflection theorem, the perpendicular line of the reflection normal at the intersection of the reflection normal and the reflection surface of the total internal reflection lens is the tangent of the reflection surface of the total internal reflection lens at that location. By calculating the slope of the tangent of the reflection surface of the total internal reflection lens at that location, the inclination angle of the tangent of the reflection surface of the total internal reflection lens at that location can be obtained, that is, the tangent angle of the reflection normal can be obtained.

[0093] It can be understood that by first assuming that the current Bessel incident light refraction line and the current Bessel exit light refraction line can form a light path, the assumed light reflection angle can be divided into two equal parts according to the light reflection theorem to obtain the normal between the current Bessel incident light refraction line and the current Bessel exit light refraction line, so that the angle of the tangent of the reflection surface of the total internal reflection lens at that point can be quickly obtained, that is, the reflection normal tangent angle can be obtained.

[0094] In some embodiments, after obtaining the difference between the tangent angle difference and the preset tangent angle difference to obtain the tangent angle difference deviation, the method further includes:

[0095] If the tangent angle difference deviation is greater than the preset tangent angle difference deviation, it is determined whether the reflection normal tangent angle at the incident and outgoing intersection point is greater than the preset reflection normal tangent angle.

[0096] In this embodiment, if the tangent angle difference deviation is greater than the preset tangent angle difference deviation, it indicates that the tangent angle of the reflection normal at the previous incident-outgoing intersection point deviates greatly from the tangent angle of the reflection normal at the next incident-outgoing intersection point that meets the requirements, that is, the tangent angle of the reflection normal at the current incident-outgoing intersection point is far away from the tangent angle of the reflection normal at the next incident-outgoing intersection point that meets the requirements, thereby indicating that the intersection between the current Bessel incident light refraction line and the current Bessel exit light refraction line is far away from the reflection surface of the total internal reflection lens, and further indicating that the light path formed by the current Bessel incident light refraction line and the current Bessel exit light refraction line is far away from the preset light path, and at this time, the light path formed by the current Bessel incident light refraction line and the current Bessel exit light refraction line cannot achieve the preset light emitting effect. Since the reflective surface of the total internal reflection lens is an outwardly convex surface, the reflection normal tangent angle at the intersection of the incident and the outgoing light will gradually increase as the intersection between the current Bessel incident light refraction line and the current Bessel outgoing light refraction line gradually moves away from the incident Bessel surface of the total internal reflection lens. By comparing the reflection normal tangent angle at the intersection of the incident and the outgoing light with the preset reflection normal tangent angle, it can reflect the deviation of the current Bessel incident light refraction line from the next Bessel incident light refraction line that meets the requirements and the deviation of the current Bessel outgoing light refraction line from the next Bessel outgoing light refraction line that meets the requirements.

[0097] If the tangent angle of the reflection normal at the intersection of the incident and the outgoing light is greater than the preset tangent angle of the reflection normal, the next Bessel incident light refraction line and the next Bessel outgoing light refraction line are selected; wherein the slope of the next Bessel incident light refraction line is less than the slope of the current Bessel incident light refraction line, and the slope of the next Bessel outgoing light refraction line is less than the slope of the current Bessel outgoing light refraction line.

[0098] In this embodiment, if the tangent angle of the reflection normal at the intersection of the incident and the outgoing light is greater than the preset tangent angle of the reflection normal, it indicates that the intersection between the current Bessel incident light refraction line and the current Bessel outgoing light refraction line is on the side of the total internal reflection lens where the focus of the next Bessel incident light refraction line that meets the requirements and the next Bessel outgoing light refraction line that meets the requirements is far away from the incident Bessel surface of the total internal reflection lens. At this time, the next Bessel incident light refraction line is selected and the slope of the next Bessel incident light refraction line is made smaller than the slope of the current Bessel incident light refraction line, so that the next selected Bessel incident light refraction line is closer to the next Bessel incident light refraction line that meets the requirements. Similarly, the next Bessel exit light refraction line is selected and the slope of the next Bessel exit light refraction line is made smaller than the slope of the current Bessel exit light refraction line, so that the next selected Bessel exit light refraction line is closer to the next Bessel exit light refraction line that meets the requirements. In other words, the intersection of the next selected Bessel exit light refraction line and the next selected Bessel exit light refraction line is closer to the intersection between the next Bessel incident light refraction line that meets the requirements and the next Bessel exit light refraction line that meets the requirements.

[0099] Return to step S400.

[0100] In this embodiment, since the intersection of the selected next Bessel light-emitting refraction line and the selected next Bessel light-emitting refraction line is closer to the intersection between the next Bessel light-entering refraction line that meets the requirements and the next Bessel light-emitting refraction line that meets the requirements, by returning to step S400, that is, repeating steps S400 to S600, the reflection normal tangent angle at the incident-outgoing intersection between the selected next Bessel light-emitting refraction line and the selected next Bessel light-entering refraction line can be obtained. Since the intersection of the selected next Bessel light-emitting refraction line and the selected next Bessel light-emitting refraction line is closer to the intersection of the next Bessel light-entering refraction line that meets the requirements, the reflection normal tangent angle at the incident-outgoing intersection between the selected next Bessel light-emitting refraction line and the selected next Bessel light-entering refraction line can be obtained. The intersection between the refraction line and the next Bessel light-emitting refraction line that meets the requirements can make the reflection normal tangent angle at the incident-outgoing intersection point between the next selected Bessel light-emitting refraction line and the next selected Bessel light-incoming refraction line closer to the reflection normal tangent angle at the next incident-outgoing intersection point that meets the requirements, so that the tangent angle difference deviation between the reflection normal tangent angle at the incident-outgoing intersection point and the preset reflection normal tangent angle is closer to the preset tangent angle difference deviation, which makes the next selected Bessel light-emitting refraction line and the next selected Bessel light-emitting refraction line closer to the preset light path, so that the light reflection curve point can be obtained more quickly.

[0101] In some embodiments, the determining whether the reflection normal tangent angle at the incident-outlet intersection point is greater than a preset reflection normal tangent angle further includes:

[0102] Determine whether the reflection normal tangent angle at the incident and outgoing intersection point is less than the preset reflection normal tangent angle.

[0103] In this embodiment, by comparing the size of the reflection normal tangent angle at the intersection of the incident and the outgoing with the preset reflection normal tangent angle, it can reflect the deviation of the current Bessel incident light refraction line from the next Bessel incident light refraction line that meets the requirements and the deviation of the current Bessel outgoing light refraction line from the next Bessel outgoing light refraction line that meets the requirements.

[0104] If the tangent angle of the reflection normal at the intersection of the incident and the outgoing light is less than the preset tangent angle of the reflection normal, the next Bessel incident light refraction line and the next Bessel outgoing light refraction line are selected; wherein the slope of the next Bessel incident light refraction line is greater than the slope of the current Bessel incident light refraction line, and the slope of the next Bessel outgoing light refraction line is greater than the slope of the current Bessel outgoing light refraction line.

[0105] In this embodiment, if the tangent angle of the reflection normal at the intersection of the incident and the outgoing light is less than the preset tangent angle of the reflection normal, it indicates that the intersection between the current Bessel incident light refraction line and the current Bessel outgoing light refraction line is close to one side of the incident Bessel surface of the total internal reflection lens at the focal point of the next Bessel incident light refraction line that meets the requirements and the next Bessel outgoing light refraction line that meets the requirements. At this time, the next Bessel incident light refraction line is selected and the slope of the next Bessel incident light refraction line is made smaller than the slope of the current Bessel incident light refraction line, so that the next selected Bessel incident light refraction line is closer to the next Bessel incident light refraction line that meets the requirements. Similarly, the next Bessel exit light refraction line is selected and the slope of the next Bessel exit light refraction line is made smaller than the slope of the current Bessel exit light refraction line, so that the next selected Bessel exit light refraction line is closer to the next Bessel exit light refraction line that meets the requirements. In other words, the intersection of the next selected Bessel exit light refraction line and the next selected Bessel exit light refraction line is closer to the intersection between the next Bessel incident light refraction line that meets the requirements and the next Bessel exit light refraction line that meets the requirements.

[0106] Return to step S400.

[0107] In this embodiment, since the intersection of the selected next Bessel light-emitting refraction line and the selected next Bessel light-emitting refraction line is closer to the intersection between the next Bessel light-entering refraction line that meets the requirements and the next Bessel light-emitting refraction line that meets the requirements, by returning to step S400, that is, repeating steps S400 to S600, the reflection normal tangent angle at the incident-outgoing intersection between the selected next Bessel light-emitting refraction line and the selected next Bessel light-entering refraction line can be obtained. Since the intersection of the selected next Bessel light-emitting refraction line and the selected next Bessel light-emitting refraction line is closer to the intersection of the next Bessel light-entering refraction line that meets the requirements, the reflection normal tangent angle at the incident-outgoing intersection between the selected next Bessel light-emitting refraction line and the selected next Bessel light-entering refraction line can be obtained. The intersection between the refraction line and the next Bessel light-emitting refraction line that meets the requirements can make the reflection normal tangent angle at the incident-outgoing intersection point between the next selected Bessel light-emitting refraction line and the next selected Bessel light-incoming refraction line closer to the reflection normal tangent angle at the next incident-outgoing intersection point that meets the requirements, so that the tangent angle difference deviation between the reflection normal tangent angle at the incident-outgoing intersection point and the preset reflection normal tangent angle is closer to the preset tangent angle difference deviation, which makes the next selected Bessel light-emitting refraction line and the next selected Bessel light-emitting refraction line closer to the preset light path, so that the light reflection curve point can be obtained more quickly.

[0108] In some embodiments, the step S200 of performing an equal division operation on the maximum incident light angle and the maximum exit light angle to obtain a plurality of Bessel incident light refraction lines and a plurality of Bessel exit light refraction lines specifically includes the following steps:

[0109] The maximum incident light angle is equally divided to obtain a first number of light rays emitted by the light source.

[0110] Calculate the incident angle of the Bezier incident light normal at the intersection point between each light source outgoing light and the incident Bezier surface;

[0111] Based on the light refraction theorem, a first number of Bessel incident light refraction lines are obtained according to the incident angles of the Bessel incident light normal lines at the intersection points.

[0112] In this embodiment, since the maximum incident angle of the light projected by the light source to the incident Bezier surface of the total internal reflection lens after the total internal reflection lens is installed is a fixed value, the maximum incident angle can be equally divided to obtain a first number of light source output light rays on the incident Bezier surface of the total internal reflection lens, and the first number of light source output light rays are light source output light rays uniformly distributed on the incident Bezier surface of the total internal reflection lens. In addition, since the output light rays of each light source will be refracted when passing through the incident Bezier surface of the total internal reflection lens, that is, according to the principle of light refraction, the incident angle of the Bezier incident light normal at the intersection point is equal to the exit angle of the Bezier incident light normal at the intersection point, so each Bezier incident light refraction line can be obtained.

[0113] Dividing the maximum light output angle to obtain a first number of lens projected light rays;

[0114] Calculate the Bezier light normal exit angle at the intersection point between each lens projection light and the exit Bezier surface;

[0115] Based on the light refraction theorem, a first number of the Bessel light-emitting refraction lines are obtained according to the Bessel light-emitting normal line emission angles at each of the intersection points.

[0116] It can be understood that since the preset light-emitting effect is fixed, that is, among the predetermined light rays projected by the outgoing Bezier surface of the total internal reflection lens, the maximum light-emitting angle formed between the light ray closest to the light source in the lateral direction and the light ray farthest from the light source in the lateral direction is fixed, the first number of lens-projected light rays can be obtained on the incident Bezier surface of the total internal reflection lens by dividing the maximum incident light angle. The first number of lens-projected light rays are the light rays projected by the outgoing Bezier surface of the total internal reflection lens that can achieve the preset light-emitting effect. Furthermore, since the first number of lens-projected light rays are obtained through the outgoing Bezier surface of the total internal reflection lens, that is, according to the principle of light refraction, the outgoing angle of the Bezier light-emitting normal at the intersection is equal to the incident angle of the Bezier light-emitting normal at the intersection, each Bezier light-emitting refraction line can be obtained in this way. Among them, the number of the first number of lens-projected light rays is equal to the number of the first number of Bezier light-emitting refraction lines.

[0117] Generally, when the specifications of the total internal reflection lens are different, the relative position relationship of the light source with respect to the incident Bezier surface will change. For example, when the distance between the light source and the incident Bezier surface is reduced, the maximum incident light angle will increase. If the maximum incident light angle and the maximum light output angle are still divided equally according to a predetermined number, there will be large intervals between the points of the obtained light reflection curve, which will easily cause a large error in the fitted light reflection curve.

[0118] In order to make the light reflection curve obtained by fitting each light reflection curve point more accurate, in one embodiment, if the tangent angle difference deviation is less than or equal to the preset tangent angle difference deviation, the intersection of the current Bessel light input refraction line and the current Bessel light output refraction line is determined as the light reflection curve point, and then further includes:

[0119] Obtaining the distance between the light reflection curve point and the light source to obtain the detection distance;

[0120] Calculating the difference between the detection spacing and the preset spacing to obtain a spacing tolerance value;

[0121] Determine whether the spacing tolerance value is greater than the preset tolerance value;

[0122] If the spacing tolerance value is greater than the preset tolerance value, determining whether the detection spacing is less than the preset spacing;

[0123] If the detection interval is smaller than the preset interval, increasing the number of divisions when performing an equal division operation on the maximum incident light angle and the maximum exit light angle;

[0124] Return to step S200.

[0125] It can be understood that the preset spacing is the spacing between the light source and the reflective surface of the total internal reflection lens when the maximum incident angle of the light source does not change. The detection spacing is obtained by obtaining the spacing between the light reflection curve point and the light source. The detection spacing can reflect the distance between the light source and the reflective surface of the total internal reflection lens. The spacing tolerance value is obtained by obtaining the difference between the detection spacing and the preset spacing. The spacing tolerance value can reflect the degree of deviation between the detection spacing and the preset spacing. If the spacing tolerance value is greater than the preset tolerance value, it indicates that the degree of deviation between the detection spacing and the preset spacing is too large, and if the detection spacing is less than the preset spacing, it indicates that the distance between the light source and the incident Bezier surface is reduced by a large margin, that is, the light source is too close to the reflective surface of the total internal reflection lens, resulting in an increase in the maximum incident angle, which will increase the interval between the obtained light reflection curve points. By increasing the number of divisions when performing equal division operations on the maximum incident angle and the maximum light output angle, the interval between the obtained light reflection curve points can be reduced, and finally the light reflection curve obtained by fitting each light reflection curve point is more accurate. In some embodiments, the preset tolerance value is 0, and of course those skilled in the art can make other choices based on experience.

[0126] In some embodiments, after determining whether the detection interval is less than a preset interval, the method further includes:

[0127] If the detection interval is greater than or equal to the preset interval, the number of divisions in the current equal division operation on the maximum incident light angle and the maximum light output angle remains unchanged;

[0128] Return to step S300.

[0129] It can be understood that if the detection interval is greater than or equal to the preset interval, it means that the distance between the light source and the incident Bezier surface increases or remains unchanged, that is, the maximum incident light angle decreases or remains unchanged. At this time, the maximum incident light angle is equally divided according to the number of divisions when the maximum incident light angle and the maximum light output angle are currently divided equally. This will make the obtained light reflection curve points closer or unchanged, and ultimately stabilize the accuracy of the light reflection curve obtained by fitting each light reflection curve point.

[0130] In some embodiments, after determining whether the spacing tolerance value is less than the preset tolerance value, the method further includes:

[0131] If the spacing tolerance value is less than or equal to the preset tolerance value, the number of divisions in the current equal division operation on the maximum incident light angle and the maximum light output angle remains unchanged;

[0132] Return to step S300.

[0133] It can be understood that if the spacing tolerance value is less than or equal to the preset tolerance value, it means that the distance between the light source and the incident Bezier surface changes little, that is, the intervals between the light reflection curve points do not change much, that is, the accuracy of the light reflection curve obtained by fitting the light reflection curve points changes little.

[0134] Generally, in the process of fitting each light reflection curve point, the line shape of the entire light reflection curve may be deformed due to the deviation of some light reflection curve points.

[0135] In order to reduce the linear deformation of the light reflection curve, in one embodiment, returning to step S300, the method further includes:

[0136] S610: Obtaining a sorting direction between the light reflection curve points according to a tangent angle of a reflection normal at an incident and outgoing intersection of the light reflection curve points;

[0137] S620: sequentially calculating the distance between any two adjacent light reflection curve points according to the sorting direction to obtain a curve point distance difference;

[0138] S630: Calculate the difference between the curve point distance difference and the preset curve point distance difference to obtain each distance difference deviation value;

[0139] S640: Determine whether each of the distance difference deviation values ​​is greater than a preset distance difference deviation value;

[0140] S650: If the distance difference deviation value is greater than the preset distance difference deviation value, obtaining the distances between the two current light reflection curve points and the next light reflection curve point to obtain a first distance and a second distance;

[0141] S660: Determine whether the first spacing is greater than the second spacing;

[0142] S670: If the first spacing is greater than the second spacing, reduce the first spacing and increase the second spacing;

[0143] S680: If the first spacing is smaller than the second spacing, increase the first spacing and decrease the second spacing;

[0144] S690: Return to step S630.

[0145] It can be understood that, since the reflective surface of the total internal reflection lens is an outwardly convex curved surface, the tangent angle of the reflection normal at the incident and outgoing intersection of each of the light reflection curve points changes in a trend, for example, in an increasing or decreasing manner, so that the sorting direction between the light reflection curve points can be obtained through the change trend. The preset curve point distance difference is the average distance between adjacent light reflection curve points when the light reflection curve is deformed. By obtaining the difference between the curve point distance difference and the preset curve point distance difference and comparing the distance difference deviation value with the preset distance difference deviation value, the deviation degree of the current distance between the two light reflection curve points from the average distance can be obtained. The distance difference deviation value is greater than the preset distance difference deviation value. The value indicates that the distance between the two light reflection curve points deviates greatly from the average distance. By calculating the distance between the current two light reflection curve points and the next light reflection curve point, the distance between the current two light reflection curve points and the next light reflection curve point can be obtained. When the first distance is greater than or less than the second distance, it indicates that the distance between the next light reflection curve point and one light reflection curve point is too large, while the distance between the next light reflection curve point and the other light reflection curve point is too small. By reducing the larger distance and increasing the smaller distance, the distance between the two light reflection curve points can be reduced to be close to the average distance, thereby effectively avoiding the linear deformation of the entire light reflection curve.

[0146] In one embodiment, the present disclosure further provides a total internal reflection lens design method based on Bezier curve, comprising the following steps:

[0147] Calculate the maximum light source angle; set the outgoing light angle distribution of the outgoing Bezier surface; solve the light reflection curve.

[0148] See also Figure 5In this embodiment, the step of calculating the maximum light source angle includes: first, setting the initial angle of the light source angle, usually setting the initial angle of the light source angle to 0°; then starting from 0°, increasing the light source angle by 0.05° until it reaches 90°; converting each incremented light source angle into a straight line parameter to represent the direction and position of the source light; using the converted straight line parameters, calculating the intersection of the source light and the incident Bezier surface to obtain the coordinates of the intersection; calculating the normal angle of the source light on the incident Bezier surface according to the coordinates of the intersection and the shape of the incident Bezier surface; using the light source angle and the normal angle, calculating the angle of the incident light of the light source entering the incident Bezier surface using the light refraction theorem. The angle of the light after the incident Bezier surface is obtained; the angle of the light after the incident Bezier surface is combined with the coordinates of the intersection point to create a new straight line parameter to represent the refraction path of the light source light in the total internal reflection lens; the intersection point between the light and the reflection surface of the assumed total internal reflection lens is calculated using the new straight line parameter; it is determined whether the horizontal coordinate X of the intersection point is greater than the maximum inner circle radius of the total internal reflection lens; if X is not equal to the maximum inner circle radius of the total internal reflection lens, the light is invalid, and the method returns to the incremental light source angle, and continues to increment the next light source angle for calculation; if X is equal to the maximum inner circle radius of the total internal reflection lens, the light source angle at this time is the maximum effective angle on the reflection surface, thereby obtaining the maximum light source angle, that is, the maximum incident angle.

[0149] See also Figure 6 In this embodiment, the step of setting the angle distribution of the outgoing light includes: initializing parameters, setting the number of horizontal coordinates X of the curve function that divides the outgoing Bezier surface equally to 500 according to the maximum light source light angle, obtaining 500 target X values, initializing the initial value of the Bezier root value t of the curve function of the outgoing Bezier surface to 0, setting the initial value of the incremental step to 0.1, the minimum value to 0.00001, and setting the tolerance range of the target X value;

[0150] Iterative calculation of Y value includes the following steps:

[0151] a. Initialize t to t0 = 0 (for the first X value) or inherit t determined by the previous calculation point n value (for subsequent X values).

[0152] b. Use the current t value and step size t s Calculate the X value of the curve function of the outgoing Bezier surface;

[0153] c. Compare the calculated X value of the curve function of the outgoing Bezier surface with the target X value:

[0154] If the calculated X value is less than the target X value and does not meet the tolerance range, t n Increase the step value t s, and recalculate the X value of the curve function of the outgoing Bezier surface.

[0155] If the calculated X value is greater than the target X value and does not meet the tolerance range, the initial value of t0 is set to the previous t n -t s , reduce the step size t s t s / 10, and recalculate the X value of the curve function of the outgoing Bezier surface.

[0156] If the calculated X value meets the tolerance range, the current t is determined n value.

[0157] d. Use a certain t n Value Calculates the X value of the curve function that exits the Bezier surface.

[0158] e. Use the calculated Y value as the target light angle parameter.

[0159] In this embodiment, the steps of solving the light reflection curve include: obtaining the initial reflection normal tangent angle of the reflection surface; accurately calculating the complete light path; and fitting to obtain the light reflection curve.

[0160] See also Figure 7 , wherein obtaining the initial reflection normal tangent angle of the reflection surface of the total internal reflection lens specifically comprises the following steps:

[0161] According to the preset light source angle, the initial light source light is obtained;

[0162] Find the intersection point of the initial light source ray and the incident Bezier surface curve;

[0163] Obtain the normal angle at the intersection of the initial light source light and the incident Bezier surface curve, and obtain the light after entering the incident Bezier surface, which is the initial Bezier incident light refraction line;

[0164] According to the preset outgoing light angle, the initial outgoing light is obtained;

[0165] Find the intersection point of the initial outgoing ray and the curve of the outgoing Bezier surface;

[0166] Obtain the normal angle at the intersection of the initial outgoing light ray and the curve of the outgoing Bezier surface, and obtain the light ray before it is emitted to the outgoing Bezier surface, which is the initial Bezier outgoing light refraction line;

[0167] The reflection normal tangent angle at the initial incident-outgoing intersection point between the initial Bessel incident light refraction line and the initial Bessel outgoing light refraction line is calculated to obtain the initial reflection normal tangent angle R0 of the reflection surface.

[0168] See also Figure 8, wherein the accurate calculation of the complete optical path specifically includes the following steps:

[0169] Initialization parameters, the initial value of the initial increment step is R s (10>R s >0.00001); set the size of the tangent angle deviation, that is, set the tolerance range.

[0170] Iterative calculation of the outgoing light angle includes the following steps:

[0171] Initialize the preset reflection normal tangent angle to R n R0 (for the first preset reflection normal tangent angle) or the reflection normal tangent angle R inherited from the last incident and outgoing intersection that meets the requirements n-1 (For subsequent preset reflection normal tangent angle);

[0172] Using the current R n Value and step size R s Calculate the angle of the emitted light;

[0173] Compare whether the outgoing light angle is consistent with the target outgoing light angle; wherein the target outgoing light angle is obtained by converting the target light angle.

[0174] If the outgoing light angle is less than the target outgoing light angle and does not meet the tolerance range, then R n Increase the step value R s , and recalculate the angle of the emitted light;

[0175] If the outgoing light angle is greater than the target outgoing light angle and does not meet the tolerance range, the initial value of R0 is set to the previous R n -R s , reduce the step size R s For R s / 10 and recalculate the outgoing light angle.

[0176] If the outgoing light angle meets the tolerance range, the current R n value, at this time the light source light and the outgoing light form a complete light path.

[0177] Using the current R n The value is used to calculate the reflection normal tangent angle of the outgoing light angle.

[0178] The fitting process to obtain the light reflection curve specifically includes the following steps:

[0179] Obtain each reflection normal tangent angle that meets the requirements, obtain the reflection curve point corresponding to each reflection normal tangent angle light, perform a fitting operation on each of the light reflection curve points, and obtain a light reflection curve.

[0180] The light source light and the outgoing light form a complete light path, which specifically includes the following steps:

[0181] According to the light angle of the light source, the light source light is obtained;

[0182] Find the intersection point of the light source ray and the incident Bezier surface curve;

[0183] Calculate the normal angle at the intersection of the light source and the incident Bezier surface curve, and obtain the light after entering the incident Bezier surface, which is the Bezier incident light refraction line;

[0184] According to the light reflection theorem, the angle of the Bessel incident light refraction line after being reflected by the total internal reflection lens is calculated, thereby obtaining the Bessel outgoing light refraction line;

[0185] Find the intersection of the Bezier incident light refraction line and the exiting Bezier surface curve;

[0186] The normal angle at the intersection of the Bezier incident light refraction line and the curve of the outgoing Bezier surface is calculated to obtain the light reflected by the outgoing Bezier surface, which is the outgoing light.

[0187] Please also refer to Fig.10 and Fig.11 Furthermore, the curve of the incident Bezier surface, the curve of the exiting Bezier surface and the curve of the central Bezier incident light surface are all Bezier curves, such as second-order Bezier curves.

[0188] The second-order Bezier curve satisfies the following equation:

[0189] P0"=(1-t) 2 P0+2t(1-t)P1+t 2 P2, where t∈[0,1];

[0190] Among them, P0 (X0, Y0), P1 (X1, Y1), and P2 (X2, Y2) are all Bezier control points; specifically, the Bezier control points of the curve of the incident Bezier surface are P0 (17.5, 15.5), P1 (22.75, 21.7), and P2 (30, 28); the Bezier control points of the curve of the exit Bezier surface are P0 (17.57, 0), P1 (14.24, 5.77), and P2 (13.5, 12.82).

[0191] At the same time, since the light propagates in a straight line, that is, the central incoming light, the central outgoing light, the central Bessel incoming light refraction line, the Bessel incoming light refraction line, and the Bessel outgoing light refraction line all satisfy the following straight line equation:

[0192] Y=kX+b

[0193] Therefore, the coordinates of the intersection of the Bezier curve and the straight line of the light can be obtained according to the following set of equations:

[0194] Y=(1-t) 2 X0+2t(1-t)X1+t 2 X2;

[0195] Y = kX + b;

[0196] After the following conversion:

[0197] V0=X0*k-Y0;

[0198] V1=X1*k-Y1;

[0199] V2=X2*k-Y2;

[0200] M0=V0-2*V1+V2;

[0201] M1 = 2*(V1-V0);

[0202] M2=V0+b;

[0203] t=(-M1+V0) / (2*M0);

[0204] Substitute the root value t into the Bessel equation to obtain the intersection coordinates (X, Y);

[0205] X=(1-t) 2 X0+2t(1-t)X1+t 2 X2;

[0206] Y=(1-t) 2 Y0+2t(1-t)Y1+t 2 Y2;

[0207] Derivative the above equations respectively, and substitute the intersection point t value determined in the previous calculation equation into it to calculate the tangent slope;

[0208] X'=2*((1-t)*(X1-X0)+t*(X2-X1));

[0209] Y'=2*((1-t)*(Y1-Y0)+t*(Y2-Y1));

[0210] k = Y' / X' is the tangent slope value;

[0211] rad=arctan(k) converts the slope into radians through inverse trigonometric functions

[0212] Finally, the radian value is converted into an angle, that is, the tangent angle between the straight line and the Bezier curve is obtained.

[0213] The angle of the light after incident is obtained through the refraction theorem n1*sinθ1=n2*sinθ2, where θ1 is the angle between the incident light and the normal, n1 is the refractive index of the incident light, θ2 is the angle between the outgoing light and the normal, and n2 is the refractive index of the outgoing light.

[0214] θ1=θ N –θ V’ ; where θ N is the angle of the normal line of the inclined plane, θ V’ is the light angle;

[0215] rad=arcsin(Sin(θ1) / n2) to get the radian value after emission;

[0216] Convert radians to angle θ v And adding the normal angle can get the angle after the light enters the Bezier curve.

[0217] In some embodiments, obtaining the maximum incident light angle specifically includes the following steps:

[0218] S110: Selecting a boundary incident light angle to obtain a boundary Bezier incident light refraction line;

[0219] S120: Calculating the angle between the boundary Bezier light-incoming refraction line and the preset boundary Bezier light-outgoing refraction line;

[0220] S130: Determine whether the angle is equal to a preset angle;

[0221] S140: If the angle value is equal to the preset angle value, the boundary incident light angle is determined as the maximum incident light angle.

[0222] Understandable, see Figure 4 , since the relative position relationship between the total internal reflection lens and the light source is fixed after installation, that is, the distribution range of the light emitted by the light source is fixed, the boundary incident light angle is the angle of any light within the distribution range of the light emitted by the light source. Since the light emitted by the light source will first pass through the incident Bezier surface of the total internal reflection lens, the boundary Bezier incident light refraction line can be obtained according to the light refraction theorem. The boundary Bezier incident light refraction line is the light projected at the angle of the currently selected light within the distribution range of the light emitted by the light source. Because the preset light emission effect is fixed, the preset boundary Bezier light emission refraction line is the Bezier light emission refraction line at the boundary of the preset light emission effect, and the preset angle is the angle between the Bezier light emission refraction line at the maximum incident light angle of the incident Bezier surface and the Bezier light emission refraction line at the boundary of the preset light emission effect. If the angle h is equal to the preset angle, it means that the light projected at the angle of the currently selected light is just at the maximum incident light angle of the incident Bezier surface, that is, the current boundary incident light angle is the maximum incident light angle.

[0223] In some embodiments, S130: determining whether the angle is equal to a preset angle, and then further comprising:

[0224] Determining whether the angle is greater than the preset angle;

[0225] If the angle value is greater than the preset angle value, the boundary incident light angle is reduced and used as a new boundary incident light angle and the process returns to step S120.

[0226] It can be understood that the angle amount is greater than the preset angle amount, indicating that the light projected by the angle of the currently selected light deviates from the maximum incident angle of the incident Bezier surface. In this embodiment, due to the design of the total internal reflection lens structure, the angle between the preset boundary Bezier light-emitting refraction line and the boundary Bezier light-incident refraction line at the minimum boundary incident angle is an acute angle, wherein the minimum boundary incident angle is 0°. As the boundary incident angle increases, the angle of the angle amount will increase, and the angle amount is greater than the preset angle amount, indicating that the boundary incident angle where the light projected by the angle of the currently selected light is greater than the boundary incident angle of the boundary Bezier light-incident refraction line at the maximum light-emitting angle, by reducing the boundary incident angle where the light projected by the angle of the previously selected light is located and returning it to step S120, that is, repeating steps S120 to S140, thereby further reducing the difference between the boundary incident angle where the light projected by the angle of the currently selected light is located and the boundary incident angle of the boundary Bezier light-incident refraction line at the maximum light-emitting angle, so as to more quickly determine the size of the maximum incident angle.

[0227] In some embodiments, S130: determining whether the angle is equal to a preset angle, and then further comprising:

[0228] Determining whether the angle is less than the preset angle;

[0229] If it is determined that the angle value is less than the preset angle value, the boundary incident light angle is increased and used as a new boundary incident light angle and the process returns to step S120.

[0230] It can be understood that if the angle amount is less than the preset angle amount, it means that the boundary incident angle of the light projected by the currently selected light angle is less than the boundary incident angle of the boundary Bezier incident refraction line at the maximum light output angle. By reducing the boundary incident angle of the light projected by the previously selected light angle and returning it to step S120, that is, repeating steps S120 to S140, the difference between the boundary incident angle of the light projected by the currently selected light angle and the boundary incident angle of the boundary Bezier incident refraction line at the maximum light output angle is further reduced, so as to more quickly determine the size of the maximum incident angle.

[0231] In one embodiment, the step S140: if the angle value is equal to the preset angle value, determining the boundary incident angle as the maximum incident angle, and then further comprising:

[0232] SI: According to the maximum incident light angle, the maximum central incident light angle and the maximum central light output angle are obtained;

[0233] SII: performing an equal division operation on the maximum central incident light angle and the maximum central light output angle to obtain a plurality of central Bezier incident light refraction lines and a plurality of central light output lines;

[0234] SIII: Calculate the center outgoing refraction normal angle at the intersection between any one of the center Bezier incident light refraction lines and any one of the center outgoing light lines;

[0235] SIV: Calculate the difference between the center outgoing refraction normal angle at the intersection and the center outgoing refraction normal angle at the preset intersection to obtain the center refraction normal angle difference;

[0236] SV: Determine whether the central refraction normal angle difference is less than or equal to a preset central refraction normal angle difference;

[0237] SVI: If the central refraction normal angle difference is equal to the preset central refraction normal angle difference, the intersection point between the central Bezier incident light refraction line at the current intersection point and the current central outgoing light line is determined as the central outgoing light surface point;

[0238] SVII: Return to step SIII;

[0239] SVIII: Perform a fitting operation on each of the central light output curve points to obtain a central light output curve.

[0240] See also Figure 3 In this embodiment, since the maximum incident light angle k has been obtained and the light source light output angle is a fixed value, the maximum angle formed by the light rays projected by the light source 310 onto the central Bessel incident light curved surface 410 of the total internal reflection lens can be obtained, which is the maximum central incident light angle z. By dividing the maximum central incident light angle z and the maximum central light output angle into a number of equal central incident light rays a1 and a number of central output light rays a2, the light rays after the central incident light ray a1 is incident on the central Bessel incident light curved surface 410 of the total internal reflection lens can be obtained according to the light refraction theorem, that is, the central Bessel incident light refraction line a3 can be obtained. When the central Bessel incident light refraction line a3 and the central outgoing light a2 can form a preset light path, the central Bessel incident light refraction line a3 and the central outgoing light a2 will satisfy the light refraction theorem, so the normal N5 on the central light output curve at the intersection of the central Bessel incident light refraction line a3 and the central outgoing light a2 can be obtained, and the central outgoing refraction normal angle at the intersection can be obtained by obtaining the slope of the normal N5.

[0241] The center outgoing refraction normal angle at the preset intersection is the center outgoing refraction normal angle at the previous intersection that meets the requirements, for example, the center outgoing refraction normal angle at the intersection between the center Bessel incident light refraction line corresponding to the boundary position of the maximum center incident light angle z and the center outgoing light line corresponding to the boundary position of the maximum center outgoing light angle. The center refraction normal angle difference can be obtained by obtaining the difference between the center outgoing refraction normal angle at the intersection and the center outgoing refraction normal angle at the preset intersection. The center refraction normal angle difference can reflect the deviation of the intersection between the current center Bessel incident light refraction line a3 and the current center outgoing light line a2 and the intersection between the previous center Bessel incident light refraction line and the center outgoing light line that meet the requirements. The preset center refraction normal angle difference is the difference between the center outgoing refraction normal angle at the intersection between the next center Bessel incident light refraction line and the center outgoing light line that meet the requirements when the preset optical path is reached and the center outgoing refraction normal angle at the intersection between the previous center Bessel incident light refraction line and the center outgoing light line that meet the requirements. If the central refraction normal angle difference is equal to the preset central refraction normal angle difference, the optical path composed of the current central Bessel incident light refraction line a3 and the current central outgoing light a2 on the surface reaches the preset optical path. At this time, the intersection between the central Bessel incident light refraction line a3 and the current central outgoing light a2 at the current intersection is just located on the central outgoing light curve. The intersection between the central Bessel incident light refraction line a3 and the current central outgoing light a2 at the current intersection is determined as the central outgoing light surface point 420. Then, steps SIII to SVI are repeated to determine all the central outgoing light surfaces 420 points. The central outgoing light curve can be obtained by fitting each of the central outgoing light curve points. The central outgoing light surface 420 of the total internal reflection lens obtained by the central outgoing light curve can achieve the preset light-emitting effect.

[0242] See also Fig. 9 In some embodiments, solving the central light output curve includes the following steps: converting the central incident light emitted by the light source into a straight line equation, calculating the intersection of the straight line equation and the central Bessel light incident surface, calculating the normal angle of the central incident light on the central Bessel light incident surface, calculating the light after incident on the central Bessel light incident surface of the total internal reflection lens through the light source angle and the normal angle as the central Bessel light incident refraction line, converting the central Bessel light incident refraction line into a straight line equation to obtain the angle of the central Bessel light incident refraction line, obtaining the central outgoing refraction normal angle at the intersection according to the central Bessel light incident refraction line and the central outgoing light, and referring to the central outgoing refraction normal angle at the previous intersection that meets the requirements. If the difference between the central outgoing refraction normal angle at the current intersection and the central outgoing refraction normal angle at the previous intersection that meets the requirements meets the requirements, then the intersection between the current central Bessel light incident refraction line and the current central outgoing light is determined as the central light output surface point, and the central light output curve points are fitted to obtain the central light output curve.

[0243] The maximum central incident angle is the angle from the center of the light source to the edge of the central Bessel incident surface. The calculation process is:

[0244] Through trigonometric functions, we can obtain rad=arctan2((X, Y)–(0, Y2)), where (X, Y) is the coordinate of the intersection between the central Bessel incident light refraction line and the central outgoing light line at the maximum central incident light angle, and Y2 is the distance of the light source relative to the central Bessel incident light surface;

[0245] Convert radians to degrees to get θ;

[0246] By establishing an equation through the refraction theorem n1*sinθ1=n2*sinθ2, we can obtain the normal angle.

[0247] Calculation process of the angle distribution of the central light:

[0248] The process is similar to the step of setting the angle distribution of the outgoing light, and the Y value of the curve equation of the central Bezier incident light surface is used as the target central light angle parameter, and the number of central light angle parameters is 500. It should be noted that because the central light in the middle is vertically emitted, the target central light angle of the central light in the middle is 0°.

[0249] The formula for calculating the surface tangent angle through the normal angle is as follows:

[0250] sin(θ V’ -θ n )=n*sin(θ V -θ n ), where n is the normal angle, θ V’ is the incident angle, θ V is the exit angle;

[0251] tan(θ n )=(n*sin(θ V )-sin(θ V’ )) / (n*cos(θ V )-cos(θ V’ ))Simplify the calculation process;

[0252] Central Bessel incident light surface tangent angle = θ n +90°; the tangent line of the central Bessel incident light surface is perpendicular to the normal line on the central light output curve at the intersection of the central Bessel incident light refraction line and the central light output line. The normal angle on the central light output curve at the intersection of the central Bessel incident light refraction line and the central light output line needs to be added by 90° to obtain the tangent angle of the central Bessel incident light surface.

[0253] See also Figure 3A total internal reflection lens, the total internal reflection lens having an incident Bezier surface 210, an exiting Bezier surface 230, and a reflection surface 220 formed by a light reflection curve obtained by a total internal reflection lens design method based on a Bezier curve as in any of the above embodiments. It can be understood that the light reflection curve-shaped reflection surface 220 obtained by the total internal reflection lens design method based on a Bezier curve of the present disclosure enables the reflection surface 220 of the formed total internal reflection lens to reflect the Bezier incident light refraction line formed by the light source 310 through the incident Bezier surface 210 along a predetermined light path to form a Bezier light exit refraction line, and the light projected by the Bezier light exit refraction line after being refracted by the exiting Bezier surface 230 is close to the preset light exit effect, that is, the light projected by the exiting Bezier surface 230 of the total internal reflection lens achieves the distribution effect of light that will not be projected to the front side of the total internal reflection lens, that is, stray light is reduced, so that the brightness of the main light emitted by the total internal reflection lens is more uniform and the image blur is clearer.

[0254] See also Figure 4 and Figure 5 A spotlight, comprising the total internal reflection lens described in any of the above embodiments, wherein the light emitted by the light source 310 is directed toward the incident Bezier surface 210 of the total internal reflection lens. It can be understood that since the light emitted by the light source 310 is directed toward the incident Bezier surface 210 of the total internal reflection lens, the light emitted by the light source 310 is sequentially projected through the incident Bezier surface 210, the reflection surface 220 and the exit Bezier surface 230 to achieve a preset light output effect, which can reduce stray light, so that the brightness of the main light emitted by the total internal reflection lens is more uniform and the blurred image is clearer.

[0255] Compared with the prior art, the present invention has at least the following advantages:

[0256] The above-mentioned total internal reflection lens design method based on Bezier curve can obtain a number of Bezier light incident refraction lines and a number of Bezier light exiting refraction lines of equal number by performing equal number division operation on the maximum light incident angle and the maximum light exiting angle, and then perform intersection reflection tangent processing on the Bezier light incident refraction lines and the Bezier light exiting refraction lines to obtain the reflection normal tangent angle at the incident and exiting intersection, so that it is possible to determine whether the light path composed of the current Bezier light incident refraction lines and the current Bezier light exiting refraction lines is close to the preset light path by determining whether the reflection normal tangent angle at the incident and exiting intersection meets the requirements. After the light paths formed by each Bezier light incident refraction line and each Bezier light exiting refraction line corresponding to each other one by one are close to the preset light path, the actual reflection surface of the total internal reflection lens can be determined through each light reflection curve point. The actual reflection surface of the total internal reflection lens can make the light projected by the exiting Bezier surface of the total internal reflection lens achieve the distribution effect of light that will not be projected to the side and front of the total internal reflection lens, that is, reduce stray light, so that the brightness of the main light emitted by the total internal reflection lens is more uniform and the image blur is clearer.

[0257] The above-mentioned embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the patent of the present disclosure shall be subject to the attached claims.

Claims

1. A total internal reflection lens design method based on Bezier curve, characterized in that: include: S100: Obtaining a maximum light incident angle and a maximum light exit angle; S200: performing an equal division operation on the maximum incident light angle and the maximum exit light angle to obtain a plurality of Bessel incident light refraction lines and a plurality of Bessel exit light refraction lines; S300: performing intersection reflection tangent processing on the Bessel incident light refraction line and the Bessel outgoing light refraction line to obtain a reflection normal tangent angle at the incident and outgoing intersection point; S400: Calculate the difference between the reflection normal tangent angle at the incident and outgoing intersection point and the preset reflection normal tangent angle to obtain a tangent angle difference; S500: Calculating the difference between the tangent angle difference and a preset tangent angle difference to obtain a tangent angle difference deviation; S600: If the tangent angle difference deviation is less than or equal to the preset tangent angle difference deviation, determine the intersection of the current Bessel light-incoming refraction line and the current Bessel light-outgoing refraction line as a light reflection curve point and return to S300; S700: After a predetermined number of intersection reflection tangent line processing, a fitting operation is performed on each of the light reflection curve points to obtain a light reflection curve.

2. The total internal reflection lens design method based on Bezier curve according to claim 1, characterized in that: The processing of the intersection reflection tangent of the Bessel incident light refraction line and the Bessel outgoing light refraction line to obtain the reflection normal tangent angle at the incident and outgoing intersection specifically includes: calculating the reflection normal tangent angle at the incident and outgoing intersection between any one of the Bessel incident light refraction lines and any one of the Bessel outgoing light refraction lines.

3. The total internal reflection lens design method based on Bezier curve according to claim 2, characterized in that: The step of calculating the reflection normal tangent angle at the incident and outgoing intersection point between any one of the Bessel incident light refraction lines and any one of the Bessel outgoing light refraction lines specifically comprises the following steps: Obtaining the angle between any one of the Bessel incident light refraction lines and any one of the Bessel outgoing light refraction lines, and determining it as an assumed light reflection angle; Performing a halving operation on the assumed light reflection angle to obtain a reflection normal line between the current Bessel light-incoming refraction line and the current Bessel light-outgoing refraction line; Obtain the perpendicular line of the reflection normal at the intersection point between the current Bessel incident light refraction line and the current Bessel outgoing light refraction line, and then calculate the tangent angle of the reflection normal at the incident and outgoing intersection point.

4. The total internal reflection lens design method based on Bezier curve according to claim 1, characterized in that: The step of calculating the difference between the tangent angle difference and the preset tangent angle difference to obtain the tangent angle difference deviation may further include: If the tangent angle difference deviation is greater than the preset tangent angle difference deviation, determining whether the reflection normal tangent angle at the incident-exit intersection is greater than the preset reflection normal tangent angle; If the reflection normal tangent angle at the incident-outlet intersection is greater than the preset reflection normal tangent angle, the next Bessel incident light refraction line and the next Bessel exit light refraction line are selected; wherein the slope of the next Bessel incident light refraction line is less than the slope of the current Bessel incident light refraction line, and the next Bessel exit light refraction line is less than the slope of the current Bessel exit light refraction line; Return to step S400.

5. The total internal reflection lens design method based on Bezier curve according to claim 4, characterized in that: The step of determining whether the reflection normal tangent angle at the incident and outgoing intersection point is greater than a preset reflection normal tangent angle further includes: Determine whether the reflection normal tangent angle at the incident and outgoing intersection point is less than the preset reflection normal tangent angle; If the reflection normal tangent angle at the incident-outlet intersection is less than the preset reflection normal tangent angle, the next Bessel incident light refraction line and the next Bessel outgoing light refraction line are selected; wherein the slope of the next Bessel incident light refraction line is greater than the slope of the current Bessel incident light refraction line, and the slope of the next Bessel outgoing light refraction line is greater than the slope of the current Bessel outgoing light refraction line; Return to step S400.

6. The total internal reflection lens design method based on Bezier curve according to claim 1, characterized in that: The step of performing an equal division operation on the maximum incident light angle and the maximum exit light angle to obtain a plurality of Bessel incident light refraction lines and a plurality of Bessel exit light refraction lines specifically comprises the following steps: Divide the maximum incident light angle equally to obtain a first number of light rays emitted by the light source; Calculate the incident angle of the Bezier incident light normal at the intersection point between each light source outgoing light and the incident Bezier surface; Obtaining a first number of Bessel incident light refraction lines according to the incident angles of the Bessel incident light normal lines at the intersection points; Dividing the maximum light output angle to obtain a first number of lens projected light rays; Calculate the Bezier light normal exit angle at the intersection point between each lens projection light and the exit Bezier surface; A first number of the Bessel light refraction lines are obtained according to the Bessel light normal line emission angles at each intersection.

7. The total internal reflection lens design method based on Bezier curve according to claim 1, characterized in that: The obtaining of the maximum incident light angle specifically comprises the following steps: S110: Selecting a boundary incident light angle to obtain a boundary Bezier incident light refraction line; S120: Calculating the angle between the boundary Bezier light-incoming refraction line and the preset boundary Bezier light-outgoing refraction line; S130: Determine whether the angle is equal to a preset angle; S140: If the angle value is equal to the preset angle value, the boundary incident light angle is determined as the maximum incident light angle.

8. The total internal reflection lens design method based on Bezier curve according to claim 7, characterized in that: S130: Determine whether the angle is equal to a preset angle, and then include: Determining whether the angle is greater than a preset angle; If the angle is greater than the preset angle, the boundary incident angle is reduced and used as a new boundary incident angle and the process returns to step S120.

9. A total internal reflection lens, characterized in that: The total internal reflection lens comprises an incident Bezier surface, an exiting Bezier surface, and a reflection surface formed by a light reflection curve obtained by using the total internal reflection lens design method based on Bezier curves according to any one of claims 1 to 8.

10. A spotlight, characterized in that: It comprises a light source and the total internal reflection lens as claimed in claim 9, wherein the light emitted by the light source is directed toward the incident Bezier surface of the total internal reflection lens.

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