Patent Publication Number: US-2023142466-A1

Title: Grating structure and uv light

Description:
TECHNICAL FIELD 
     The present invention relates to the technical field of lighting equipment, particularly to a grating structure and UV light that applies the grating structure. 
     BACKGROUND 
     The upper-layer flat irradiation UV light refers to the light that is installed into the upper space above 2.1 m (this height refers to the distance between the ground or the floor) and can horizontally emit UV rays (wavelength: 200-400 nm) to sterilize and disinfect the upper space. During sterilization of the upper-layer flat irradiation UV light, people do not need to leave the sterilization occasion, and can freely move or work in the lower space below 2.1 m, facilitating sterilization and disinfection. 
     In prior art, the upper-layer flat irradiation UV light will be provided with a grating structure on the outside of the UV light source, this grating structure usually contains many baffles provided horizontally and at intervals, and baffles are usually of a slab structure (including: all the baffles are in the slab shape ( FIG.  1   ; or most baffles are in the slab shape, but there are a few of curve plates at the incoming light position ( FIG.  2   )), scattered UV rays from the UV light source can be emitted roughly in the horizontal direction after light interception via baffles ( FIG.  1    and  FIG.  2   ). To simplify expression, this grating structure is defined as the grating structure A, and all the “lights” below refer to “upper-layer flat irradiation UV light”, unless otherwise specified. 
     As the mounting height of the upper-layer flat irradiation UV light is higher, it is safer in use. In prior art, lights (including lights of the grating structure A) have a relatively large luminous angle and low precision, so UV rays emitted by such lights are likely to reach the lower space below 1.2 m. Especially strong UV rays of the large-power UV light above 20 W bring greater safety hazards to the lower space. Thus, in prior art, to guarantee the service safety, lights are usually installed above 2.5 m, they are not suitable for being installed at a height of 2.1 m-2.5 m, even though this mounting height enables UV light to indirectly sterilize the lower space better. However, when lights in the prior art are installed at a height of 2.1-2.5 m, UV rays of such lights are also very likely to access the lower space below 2.1 m, the safety performance is poor, and usually such lights can only reach the low safety level in  IEC  62471  Photobiology Safety of Light and Light System , i.e. risk group 1; it is hard to reach the safety level of exempt group. 
     Description: The luminous angle of the UV light in the present patent is a relative reference value which is different from the luminous angle of the white light source as defined. According to the standard of CIE, usually the luminous intensity of lighting fixtures is defined as 50% of the luminous intensity in the direction of the normal line, and the included angle between two lines is the luminous angle, i.e. half-intensity angle. The scheme of the present invention is the research on the safety of UV rays. Even though the UV ray radiation intensity in the lower space reaches 50% of that in the direction of the normal line, hazards may be brought to human body. So, the luminous angle in the present invention is the angle corresponding to safe radiation intensity. 
     SUMMARY 
     The main purpose of the present invention is to provide a grating structure applied to UV lights, aiming to make UV rays from UV lights be emitted horizontally after passing through the grating structure to lower the possibility of accessing the lower space and improve the service safety of UV lights. 
     To realize the above purpose, the grating structure in the present invention comprises at least two up-down baffles provided at intervals, the upper surface and the lower surface of each the baffle is provided with a light absorption layer, two adjacent baffles enclose to form a light outlet; 
     In the light emission direction of the light outlet, each the baffle comprises the incoming light section, the light filter section and the outgoing light section, and the incoming light section, the light filter section and the outgoing light section are respectively the first plate body, second plate body and third plate body connected in sequence, the upper surface and the lower surface of the light filter section are provided respectively with multiple upper convexes and multiple lower convexes, the height difference of the top of the upper convexes and the bottom of the lower convexes is greater than 1.5 mm. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily dawns to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG.  1    is a schematic diagram showing the cross section of the UV light in one embodiment of horizontal grating scheme A in the outgoing light direction; 
         FIG.  2    is a schematic diagram showing the cross section of the UV light in another embodiment of horizontal grating scheme A in the outgoing light direction; 
         FIG.  3    is a schematic diagram showing the cross section of the UV light in the outgoing light direction in stepwise grating scheme B; 
         FIG.  4    is a schematic diagram showing the cross section of baffles in  FIG.  3   ; 
         FIG.  5    is a schematic diagram showing the cross section of the UV light in the outgoing light direction in inclined angle scheme C; 
         FIG.  6    is a schematic diagram showing the cross section of the UV light in the outgoing light direction in waveform grating scheme D1; 
         FIG.  7    is a schematic diagram showing the cross section of the grating structure; 
         FIG.  8    is a schematic diagram showing the cross section of baffles in  FIG.  6   ; 
         FIG.  9    is a schematic diagram showing the cross section of baffles in the waveform grating scheme D2; 
         FIG.  10    is a schematic diagram showing the structure of the UV light in waveform grating scheme D2; 
         FIG.  11    is a schematic diagram showing the local structure of the UV light in  FIG.  10   ; 
         FIG.  12    is a schematic diagram showing the another local structure of the UV light in  FIG.  10   ; 
         FIG.  13    is a schematic diagram showing the explosion structure of local structure of the UV light in  FIG.  12   ; 
         FIG.  14    is a schematic diagram showing the cross section of baffles in the waveform grating scheme D3; 
         FIG.  15    is a schematic diagram showing the stacking structure of baffles in waveform grating scheme D1; 
         FIG.  16    is a schematic diagram showing the stacking structure of baffles in waveform grating scheme D2; 
         FIG.  17    is a schematic diagram showing the stacking structure of baffles in waveform grating scheme D3; 
         FIG.  18    is a schematic diagram showing the structure of baffles of the waveform grating scheme D1 in one embodiment; 
         FIG.  19    is a schematic diagram showing the structure of the UV light in waveform grating scheme D in another embodiment; 
         FIG.  20    is a schematic diagram showing the structure of light cap in  FIG.  19   ; 
         FIG.  21    is a schematic diagram showing dimensional data of the horizontal grating scheme A; 
         FIG.  22    is a schematic diagram showing dimensional data of stepwise grating scheme B; 
         FIG.  23    is a schematic diagram showing dimensional data of the waveform grating scheme D1; 
         FIG.  24    is a schematic diagram showing dimensional data of the waveform grating scheme D2; 
         FIG.  25    is a schematic diagram showing dimensional data of the waveform grating scheme D3. 
     
    
    
     The shape, dimension, proportion or position relationship of parts of the product in drawings may be real data of embodiments and they are under protection of the present invention. 
     DETAILED DESCRIPTION 
     To make the objective, technical solutions and advantages of the present invention clearer and be understood better, further detailed descriptions of embodiments of the present invention are made in combination with drawings. Understandably, the specific embodiments described are just used to explain but not limit the present invention. 
     The solving ideas of technical problems of the present invention and relevant product design solutions are as shown below: 
     I. Standard Analysis: 
     According to the IEC 62471 Photobiology Safety of Light and Light System, to make UVC UV sterilization light reach the safety level of risk group 1 (RG1), the radiation value of photochemical UV rays (ES) whose wavelength is 200-400 nm needs to be reduced to be lower than 0.003 W/m 2 ; to realize the safety level of exempt group (RG0), the radiation value of photochemical UV rays (ES) whose wavelength is 200-400 nm needs to be reduced to be lower than 0.001 W/m 2 . 
     II. Introduction to Characteristics of the Horizontal Grating Scheme A: 
     In scheme A ( FIG.  1    and  FIG.  2   ), the grating structure  1  contains multiple baffles  11  provided horizontally and at intervals (FIG.s only present 7 baffles  11 , all such baffles can be of a slab structure; or most baffles  11  are of a slab structure, but there is a few of curve plates at the incoming light section), and the clearance between adjacent baffles  11  constitutes the light outlet  13 . Each baffle  11  comprises the incoming light section  111 , light filter section  112  and outgoing light section  124  connected in sequence in the width direction, and the incoming light section  111 , light filter section  112  and outgoing light section  124  are basically on the same plane. The surface of the baffle  11  is provided with a light absorption layer that can absorb UV rays. When UV rays from the UV light source  2  on one side of multiple baffles  11  are emitted outside the light body via the light outlet  13 , partial UV rays at the incoming light section  111  will be intercepted, partial UV rays can be emitted via the light outlet  13  or after refraction on the surface of baffles  11 , partial UV rays emitted via the light outlet  13  are absorbed by the surface of baffles  11 , or can be refracted and absorbed after their intensity is weakened, so that UV rays can be emitted roughly in the horizontal direction via the grating subassembly. However, in scheme A, the grating structure  1  has a relatively large luminous angle and low precision, so UV rays emitted by such lights are likely to reach the lower space below 1.2 m. Especially strong UV rays of the large and medium-power UV light above 20 W bring greater safety hazards to the lower space. In other words, lights usually can only reach the low safety level in  IEC  62471  Photobiology Safety of Light and Light System , i.e. risk group 1; it is hard to reach the safety level of exempt group. 
     III. Introduction to Characteristics of the Stepwise Grating Scheme B: 
     Scheme B is another technical scheme that is the result of improvement of the scheme A, by keeping the width W and the clearance H of baffles  11  unchanged. In the scheme B ( FIG.  3    and  FIG.  4   ), the incoming light section  111  is bent downward, enabling it to better intercept upward or downward UV rays. Excessively downward or upward UV rays are inconsistent with the horizontal outgoing light direction, and it is hard to calibrate the emission direction of UV rays via baffles  11 , so UV rays cannot be emitted via the light outlet  13 . Thus, it is understood that interception of this part of UV rays at the incoming light section  111  is the first layer of filter of UV rays. In other embodiments, the incoming light section  111  can also be provided to be bent upward. Further, to improve the UV ray filter function of light filter section  112 , the light filter section  112  of baffles  11  on the upper side and the lower side can form stepwise patterns  113  that include multiple steps  114  provided in sequence in the outgoing light direction of the light outlet  13 , each step  114  comprises a long side  115  and a short side  116 , the short side  116  is provided by facing the incoming light section  111  (the height G of the short side  116  of this step  114  can be about 0.2-0.5 mm). Thus, when UV rays that have a great angle with the horizontal direction irradiate onto the short side  116  of step  114 , the short side  116  of the step  114  can reflect such UV rays to realize filter of non-horizontal UV rays by the light filter section  112 . Also, the surface of the light filter section  112  is provided with stepwise patterns  113 , and the area of the surface of baffles  11  can be increased to improve the UV ray absorption capacity of the surface of baffles  11 . Further, the long side  115  can be provided upward in an inclined way by facing the incoming light section  111 , so that it can collaborate with the short side  116  and receive partial UV rays reflected by the short side  116  and reflect again such UV rays. After several times of reflection, such UV rays are absorbed by the light absorption layer on the baffles  11  gradually. And, the short side  116  can be a straight vertical side or curve side, or the bottom of the short side  116  can be a straight side, while its top and the long side  115  on adjacent steps  114  are provided in the arc transition form. 
     Additionally, like scheme A, the UV light source  2  in scheme B is 30 W, the grating structure  1  comprises 7 baffles  11 , the width W of baffles  11  is 57 mm, and the clearance of baffles  11  is 8.6 mm. During testing of the UV light  100 , the mounting height of its bottom (regarded as the bottom of grating structure  1 ) is 2.3 m from the ground. In such a case, the UV ray radiation intensity scope on the horizontal plane at the height of 2.1 m in testing is: 0.001-0.003 W/m 2 , and the UV light  100  belongs to the risk group 1. 
     IV. Introduction to characteristics of the inclined angle scheme C: 
     Scheme C as the further improvement of scheme B is shown in  FIG.  5   . On the basis of the grating structure  1  in scheme B, the grating structure  1  is inclined to make the incoming light section  111  of baffles  11  inclined upward by facing the outgoing light section  124 , that is, there is an included angle (defined as a) between baffles  11  and the horizontal plane to from the grating structure  1  in scheme C. During the test, the radiation intensity of UV rays at the height of 2.1 m is tested once for increase of each 1° of the included angle from 0°. According to the test data, when the included angle (i.e. the “angle of inclination”) reaches above 10°, the radiation intensity of UV rays at the height of 2.1 m will reduce to 0.001 W/m 2  and reach the safety level of exempt group. Thus, by providing the grating structure  1  to be inclined upward in scheme C, the UV light  100  can reach the safety level of exempt group, but when the angle of inclination of grating structure  1  reaches 10°, the effective radiation distance of 30 W UV light source  2  can reach 5 m, and the difference of inclination height of UV rays will be more than 0.868 m (=5 m)*sin 10°. The best sterilization scheme of the patented product aims to realize more UV rays within the height difference of 0.4 m at the height of 2.1-2.5 m without access to the lower space. For UV rays whose effective radiation distance can reach 5 m, if inclination of UV rays needs to be within the height difference of 0.4 m, the corresponding ideal angle of inclination should be smaller than 4.59° [=arcsin (0.4 m/5 m)]. In such a case, the safety angle of inclination 10° of scheme C is far greater than 4.59°. So, the angle of inclination of the grating structure  1  of the scheme C is too big, UV rays is further from the lower space, and cannot realize indirect sterilization of the lower space very well. Nevertheless, the indirect sterilization effect of the scheme C in the lower space is still better than that of the scheme A and scheme B, because scheme C can not only guarantee that the radiation intensity of UV rays in the lower space is lower than 0.001 W/m 2  as required in the standard and can also guarantee that many UV rays access the space at the height of 2.1-2.5 m. 
     V. Introduction to Characteristics of the Waveform Grating Scheme D: 
     Scheme D is the further improvement of scheme A, scheme B and scheme C. 
     Specifically speaking, in scheme D ( FIG.  6   ), it is defined as that the UV light  100  possesses an up-down direction, the grating structure  1  comprises at least two baffles  11  provided at intervals in the up-down direction, the upper surface and the lower surface of each baffle  11  are provided with a light absorption layer, and two adjacent baffles  11  enclose each other to form a light outlet  13 ; In the outgoing light direction of light outlet  13 , each baffle  11  comprises the incoming light section  111 , light filter section  112  and outgoing light section  124 , and the incoming light section  111 , light filter section  112  and outgoing light section  124  respectively connect to the first plate body  125 , the second plate body  126  and the third plate body  127  in sequence, the upper surface and the lower surface of the light filter section  112  are respectively provided with multiple upper convexes  117  and multiple lower convexes  118 , and the height difference of the top of the upper convexes  117  and the bottom of the lower convexes  118  is greater than 1.5 mm. 
     For different grating schemes ( FIG.  7   ), provided that the width of the baffle  11  is W, the thickness of the baffle  11  is D, and the clearance of adjacent baffles  11  is H, light outlet  13  possesses a critical angle β, when the included angle between the edge of UV rays and the horizontal angle is greater than β, UV rays cannot directly pass through the light outlet  13 , and the trigonometric function of the critical angle is tan β=(H−D)/W. 
     In this scheme D, the incoming light section  111  of the grating structure  1  restrict UV rays whose included angle with the horizontal angle is greater than the critical angle β to be emitted into the light outlet  13  to intercept partial UV rays that are hard to pass through the light outlet  13  in advance. 
     Further, UV rays whose included angle with the horizontal plane is smaller than the critical angle β are restricted by upper convexes  117  and lower convexes  118  at the light filter section  112 , after entering the light filter section  112 , and then UV rays in the horizontal direction and UV rays approaching the horizontal direction can pass through the light outlet  13  smoothly; while other UV rays whose included angle with the horizontal plane is big will be gradually absorbed or attenuated between upper convexes  117  or lower convexes  118 , and then will be emitted via the outgoing light section  124 . As a result, it can be realized that the luminous angle of the grating structure  1  can be reduced without increasing the width of the baffle  11  or narrowing the clearance of the baffle  11 . With the same testing condition of the scheme A, scheme B and scheme C, it is found that even the baffle  11  in scheme D is provided horizontally, when the UV light  100  is provided at a height of 2.1-2.5 m (this height refers to the distance from the ground or the floor), the radiation intensity of UV rays in the lower space can reach the safety level of exempt group; this also enables the UV light  100  to emit more UV rays into the space of 2.1-2.5 m, which will improve the direct sterilization capacity in the low-height area in the upper space, make air in the upper space exchange with the air in the lower space better and improve its indirect sterilization capacity in the lower space. 
     Further, the scheme D in one embodiment is defined as scheme D1. In scheme D1 ( FIG.  6    and  FIG.  8   ), the second plate body  126  is provided in a curve shape to form multiple upper convexes  117  and multiple lower convexes  118 , at least partial upper convexes  117  and lower convexes  118  connect in sequence to form a continuous waveform structure, adjacent upper convexes  117  and lower convexes  118  of the continuous waveform structure are connected by the first section  119 . 
     In this embodiment, the curve second plate body  126  directly forms the upper convexes  117  and the lower convexes  118 , enabling the upper convexes  117  and the lower convexes  118  to be processed easily, without adding an additional structure on the second plate body  126 . Wherein, the second plate body  126  is in the curve shape. It can be bent on the plane or on a curve surface. However, the waveform structure can be continuous ( FIG.  8   ); or it can be incontinuous ( FIG.  9   ). In addition, as shown in  FIG.  8   , the upper surface and the lower surface of multiple first sections  119  can be plane; or the upper surface and the lower surface of the first section  119  can be curve; or, the upper surface and the lower surface of partial first sections  119  are plane, and the upper surface and the lower surface of other first sections  119  are curve. Wherein, the clearance L between adjacent upper convexes  117  or adjacent lower convexes  118  can be 12 mm. 
     In another embodiment of the scheme D, it is defined as scheme D2. In scheme D2 ( FIG.  9   ), when the second plate body  126  is provided in a curve shape to form multiple upper convexes  117  and multiple lower convexes  118 , and at least partial upper convexes  117  and lower convexes  118  connect in sequence to form a continuous waveform structure; the light filter section  112  comprises two continuous waveform structures connected via the second section  122 , the second section  122  is a horizontal plate body structure, while both ends of the second section  122  can respectively connect two adjacent first sections  119 . 
     In this embodiment, the second section  122  is of a horizontal plate body structure, its shape is relatively regular to form a mounting surface, facilitating installation via the relatively regular second section  122 . Specifically speaking, in the UV light  100  comprising the grating structure  1  in the scheme D2 ( FIG.  10   - FIG.  13   ), the UV light  100  also comprises multiple connecting cylinders  3  whose ends are connected, the central columns  4  and nut  5 ; one end of one of multiple connecting cylinders  3  is against the lower surface of the lowest baffle  11 , opposite two ends of other connecting cylinders  3  are against the part between two adjacent baffles, and the position of multiple baffles  11  corresponding to the connecting cylinders  3  is provided with mounting holes  123 ; the central columns  4  pass through multiple connecting cylinders  3  and mounting holes  123 , the lateral peripheral surface of the lower end of the central columns  4  is provided with a convex mounting part  41  against the lower surface of the lowest connecting cylinder  3 ; threads of the nut  5  connect to the upper end of the central columns  4  and are against the upper surface of the top baffle  11 , the nut  5  collaborates with the central columns  4  to clamp and fix multiple baffles  11  and multiple connecting cylinders  3 . In such a case, multiple baffles  11  can be connected with at least two central columns  4  to improve the connection stability of multiple baffles  11  in the scheme D2. Further, to improve the stability of installation of the grating structure  1  to the UV light  100  in scheme D2, the UV light  100  also comprises a housing  6  and crews  7 ; the inner bottom wall of the housing  6  connects to two bending plates  61  that are opposite and provided at intervals and enclose with the inner bottom wall of the housing  6  to form the chute  63 ; the grating structure  1  is provided inside the housing  6 , the convex mounting part  41  on the lower end of the central column  4  is installed inside the chute via two bending plates  61 , the upper surface of the convex mounting part  41  is against the top wall of the chute  63 ; screws  7  pass through the top wall of the housing  6  and insert into the top pend of central column  4  and connect to the central column  4  through threads to make the grating structure  1  fix into the housing  6 . In such a case, the lower end of the central column  4  slides from one end of two bending plates  61  into the chute  63  to make the convex mounting part  41  of the central column  4  against the top wall of the chute  63  to locate the convex mounting part  41 . In the meanwhile, the grating structure  1  can be mounted and fixed quickly by connecting the screws  7  on the top wall of the housing  6  to the upper end of the central column  4 . Wherein, the convex mounting part  41  can be a convex ring forming an integrated structure with the central column  4 , or can be a gasket fixed onto the central column  4  via screws, and both bending plates  61  can be of a L-shaped structure. The nut  5  and the screw  7  can be other fastening or locating structures. 
     Further, the scheme D in one embodiment is defined as scheme D3. In the scheme D3 ( FIG.  14   ), the second plate body  126  is provided in the slab shape, the light filter section  112  comprises multiple convex rib groups  120 , partial convex rib groups  120  are provided on the upper surface of the second plate body  126  to form multiple upper convexes  117 , partial convex rib groups  120  are provided on the lower surface of the second plate body  126  to form multiple lower convexes  118 . 
     In this embodiment, the second plate body  126  is roughly of a slab structure which is relatively simple and easy to process. Wherein, one convex rib group  120  forms an upper convex  117  or lower convex and comprises one convex rib  121 . Of course, there can be multiple convex ribs  121  and the height of multiple convex ribs  121  can be different (for example, the middle multiple convex ribs  121  can be high, and those on both ends are low). 
     Further, some common characteristics in scheme D1, scheme D2 and scheme D3 can be provided as follows: 
     As shown in  FIG.  15   - FIG.  17   , in one embodiment, the upper surface of the baffle  11  constitutes the upper outline, the lower surface of the baffle  11  constitutes the lower outline, when multiple baffles  11  are stacked, the upper outline can be against the lower outline. 
     When multiple baffles  11  are stacked, their load bearing can be more even, reducing the possibility that the surface of baffles  11  is scratched, better protecting the light absorption layer on the surface of the baffle  11 . At the same time, such setting can reduce the stacking volume and facilitate transportation and storage. In addition, the lamination of the upper outline and the lower outline can prevent baffles  11  sliding down during stacking, which will improve the placement stability. 
     As shown in  FIG.  15   , in one embodiment, the upper surface and the lower surface of baffles  11  are provided with multiple convex patterns  128  or concave patterns vertical to the outgoing light direction. Different from the upper convexes  117  and the lower convexes  118 , convex patterns  128  or concave patterns are designed to increase the surface area of baffles  11  to improve the UV ray absorption capacity of baffles  11 . The diameter or width of the convex patterns  128  or concave patterns is usually smaller than 0.5 mm; while the height difference of the upper convexes  117  and the lower convexes  118  is usually greater than 1.5 mm, and the clearance of adjacent upper convexes  117  or adjacent lower convexes  118  is usually greater than 5 mm. Wherein, the first section  119  of the baffle  11  can be provided with convex patterns  128  or concave patterns. Further, when the baffle  11  is provided with the first section  119 , the convex patterns  128  or concave patterns can be provided on the upper surface and the lower surface of each first section  119 . When the second plate body  126  of the baffle  11  is provided with multiple convex rib groups  120 , the convex patterns  128  or concave patterns can be provided on the upper surface and the lower surface of the area of the second plate body  126  that is not provided with convex rib groups  120 . 
     In one embodiment, the baffle  11  is made of aluminum alloy that is easy to form and process; the surface of baffle  11  is processed with black anodic oxidation, and the light absorption layer is formed through oxidation treatment of the baffle  11 . 
     Such design can improve the UV ray absorption efficiency of baffle  11 , and then improve the UV ray filter effect. 
     In one embodiment ( FIG.  15   ), the incoming light section  111  is bent upward or downward. 
     Since upward or downward outgoing UV rays whose included angle with the horizontal angle is greater than the critical angle β is inconsistent with the horizontal outgoing light, their emission direction is hard to be calibrated via the baffle  11 . Such UV rays can be reflected well via upward bent incoming light section  111 , so that upward or downward UV rays at the incoming light section  111  can be intercepted well. Similarly, the incoming light section  111  can be bent downward too. 
     In one embodiment, the outgoing light section  124  is provided in the form of horizontal extension. 
     In such a case, the horizontal setting of the outgoing light section  124  can better guide the outgoing light direction of the grating structure  1  to form the basically horizontal UV rays. 
     In one embodiment ( FIG.  18   ), the baffle  11  is provided in a strip shape, and the light emission direction of the light outlet  13  is the width direction of the baffle  11 . In such a case, the shape of the baffle  11  is relatively simple, which can improve the convenience of processing. Of course, the present invention is not limited to this. In other embodiments ( FIG.  19    and  FIG.  20   ), the baffle  11  is provided in a circle, and the incoming light section  111  of the baffle  11  is on the inner side of the baffle  11 . In such a case, the baffle  11  can be a circle, square or other circular structures. The UV light source  2  is provided on the inner side of the circular structure. In addition, the baffles  11  can be provided oppositely in the up-down direction (in other words, the connecting line of outgoing light section  124  of multiple baffles  11  is a vertical line), or can be slightly staggered (in other words, the connecting line of outgoing light section  124  of multiple baffles  11  is an inclined line that forms an included angle with the up-down direction). 
     VI. As shown in  FIG.  21   - FIG.  25   , the data about the grating structure  1  of scheme A, scheme B, scheme C and scheme D are as shown in the following table: 
     
       
         
           
               
               
            
               
                   
                   
               
               
                   
                 The length of the 
               
               
                   
                 long side of the 
               
               
                   
                 step/horizontal 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Effective 
                   
                 Length E of the 
                 distance F between 
               
            
           
           
               
               
               
               
               
               
            
               
                 Grating 
                 Width W of 
                 thickness D 
                 Clearance 
                 outgoing light 
                 the upper convex 
               
               
                 scheme 
                 baffle 
                 of baffle 
                 H of baffles 
                 section 
                 and the lower convex 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Scheme A 
                 W1 
                 57 
                 D1 
                 3.17 
                 H1 
                 8.6 
                 E1 
                 3 
                 F1 
                 / 
               
               
                 Scheme B 
                 W2 
                 57 
                 D2 
                 3.63 
                 H2 
                 8.6 
                 E2 
                 3 
                 F2 
                   5.72 
               
               
                 Scheme C 
                 / 
                 / 
                 / 
                 / 
                 / 
                 / 
                 / 
                 / 
                 / 
                 / 
               
               
                 Scheme D1 
                 W3 
                 57 
                 D3 
                 2.66 
                 H3 
                 8.6 
                 E3 
                 3.13 
                 F3 
                 6 
               
               
                 Scheme D2 
                 W4 
                 57 
                 D4 
                 2.43 
                 H4 
                 8.6 
                 E4 
                 3.6 
                 F4 
                 6 
               
               
                 Scheme D3 
                 W5 
                 57 
                 D5 
                 2.68 
                 H5 
                 8.6 
                 E5 
                 3.13 
                 F5 
                 6 
               
               
                   
               
               
                 Notes: 
               
               
                 (1) Unit: mm; 
               
               
                 (2) The clearance of baffles is the distance between center 
               
               
                 points of baffles (FIG. 21-FIG. 25); 
               
               
                 (3) D2 and D3 are the extension of the embodiment of scheme D1; 
               
               
                 (4) Data of the scheme B are the same as that of the scheme C; 
               
            
           
         
       
     
     According to the data in the above table, the width of baffles in scheme A, scheme B, scheme C and scheme D remains the same, the clearance H of two adjacent baffles  11  remains the same too, and the effective thickness D of baffles in scheme D is also smaller than that in scheme A, scheme B and scheme C. It is shown that main technical characteristics of decreasing the luminous angle of the grating structure  1  lies in that the second plate body  126  of the baffle  11  is provided with the upper convexes  117  and the lower convexes  118 , instead of increasing the width of the baffle  11  and the height of the baffle  11  or shortening the clearance between adjacent baffles  11 . When decreasing the thickness of baffles  11  but not increasing the width of baffles  11 , the luminous angle is decreased. In scheme A, to decrease the luminous angle, the width of baffles  11  can be expanded to 100 mm, while the width of baffles  11  in scheme D is only 57 mm, significantly decreasing the volume of the grating structure  1  and the UV light  100 . 
     As shown in  FIG.  6   , the present invention also provides a UV light  100  comprising the grating structure  1  whose specific structure is as shown in the above embodiment. Since the UV light  100  adopts all the technical schemes of all the above-mentioned embodiments, at least the UV light  100  possesses all the beneficial effects brought by the above-mentioned embodiments, such beneficial effects are not described in details here. The UV light  100  can comprise the UV light source  2  provided on one side of the incoming light section  111  of the baffle  11  of the grating structure  1 . Further, the UV ray module can also comprise a reflective housing  8  provided on one side of the UV ray module deviating from the grating structure  1  to adjust the luminous angle of UV rays to make UV rays be emitted by facing the grating structure  1 . 
     The above description only presents the preferred embodiments of the present invention, and it is not for this reason that the patent scope of the invention is limited. Any equivalent structural transformation made by using the description of the invention and the drawings, or direct/indirect application in other related technical fields under the inventive concept of the invention, is included in the patent protection scope of the invention.