Table lamp capable of adjusting light output angle

Abstract

The present invention relates to a desk lamp for adjusting light output angle, comprising a base, a lamp pole and a lamp holder; the lamp holder comprises a housing, a kit and an optical module, the optical module comprises an annular light strip, a light guide plate, a prism sheet, a reflective film and a diffusion film, the annular light strip is sleeved in the kit; wherein, along the axial direction of the kit, the light guide plate and the annular light strip are arranged flush, the reflective film is located on one side of the light guide plate, the diffusion film is located on the other side of the light guide plate, and the prism sheet is located between the light guide plate and the diffusion film, so that the light of the annular light strip is refracted through the prism sheet and diffused outward at the diffusion film. The desk lamp for adjusting light output angle of the present invention, since the light guide plate and the annular light strip are arranged flush, the reflective film is located on one side of the light guide plate, the diffusion film is located on the other side of the light guide plate, and the prism sheet is located between the light guide plate and the diffusion film, the light of the annular light strip is refracted through the prism sheet and diffused outward at the diffusion film, thereby avoiding the problem of uncontrollable light output angle caused by arranging the prism sheet at the outermost side.

Description

Technical Field

[0001] The invention relates to the technical field of optical lighting, and in particular to a desk lamp capable of adjusting a light output angle. Background Art

[0002] As a commonly used lighting furniture, table lamps are generally used on office desks or desks. Among them, LED optical modules can be used to provide light sources for LED table lamps. The quality of LED optical modules determines important parameters such as brightness and uniformity of LED table lamps, and to a large extent also determines the luminous efficiency of LED table lamps. Since there may be beds next to the desks, if users turn on the table lamps at night to catch up on homework or work, the large-angle light of the table lamps will shine on the bedding area, affecting the normal work and rest of others. However, if the light intensity of the table lamps is simply reduced, users will not be able to see the work content clearly, and are prone to drowsiness or visual fatigue.

[0003] Prior art, patent number CN 216280842 U is a study desk lamp, which includes a base, an adjustment rod and a lamp head assembly, wherein the lamp head assembly includes a focusing module and a floodlight module; the focusing module includes a spotlight housing, a spotlight source, a convex lens and an anti-glare ring portion, the spotlight housing is a cylindrical structure with at least one end open, the spotlight source and the convex lens are both fixedly arranged in the spotlight housing, and the light emitting center of the spotlight source and the transmission axis of the convex lens are arranged along the same straight line direction; the anti-glare ring portion is an annular structure and is sleeved on the outside of the convex lens, an anti-glare structure is arranged on the inner side of the anti-glare ring portion, and the anti-glare structure is located on the side of the convex lens away from the spotlight source; the floodlight module is an annular structure and is sleeved on the outside of the spotlight housing. Among them, the convex lens is fixed between the spotlight source and the annular structure of the anti-glare aperture ring, which can converge the light of the desk lamp. However, since the light convergence in this way is in a fixed relationship with the height of the desk lamp, and the illumination range is not adjustable, the light output angle when the user uses the desk lamp is not adjustable, and the user cannot adjust the light output angle according to actual needs. Therefore, how to control the light output angle to meet the user's requirements for the light output angle of the desk lamp is an urgent problem to be solved. Summary of the invention

[0004] The purpose of the present invention is to provide a desk lamp with adjustable light output angle, aiming to solve the problem of controlling the light output angle of the desk lamp to meet the user's demand for the light output intensity of the desk lamp.

[0005] In order to solve the above technical problems, a desk lamp with adjustable light output angle is provided, comprising a base, a lamp pole and a lamp head; one end of the lamp pole is hinged to the base; the lamp head comprises a shell, a kit and an optical module, the shell is hinged to the other end of the lamp pole, the kit is internally sleeved in the shell, the optical module is internally sleeved in the kit, the optical module comprises an annular light strip, a light guide plate, a prism sheet, a reflective film and a diffusion film, the annular light strip is internally sleeved in the kit; wherein, along the axial direction of the kit, the light guide plate and the annular light strip are arranged flush, the reflective film is located on one side of the light guide plate, the diffusion film is located on the other side of the light guide plate, and the prism sheet is slidably connected between the light guide plate and the diffusion film to change the distance between the prism sheet and the diffusion film, so that the light of the annular light strip is diffused outward at the diffusion film after adjusting the output angle through the prism sheet.

[0006] Furthermore, the prism sheet includes a first light emitting surface, the first light emitting surface is provided with a plurality of adjacent grooves, the grooves are formed with inclined enclosed side surfaces and a bottom surface connected to the side surfaces, the light is refracted at the side surfaces and enters the diffusion film, wherein the side surfaces are arc-shaped convex curved surfaces.

[0007] Furthermore, the starting angle between the side surface and the bottom surface is a, the radius of curvature of the side surface is R, and the distance between the prism sheet and the diffusion film is L, wherein 135°≤a≤175°,

[0008] Satisfies the relationship:

[0009] R = π*L / k*a;

[0010] Where k is a constant coefficient and π is equal to 180°.

[0011] Furthermore, the arc light strip includes a flexible strip body and lamp beads, a plurality of the lamp beads are arranged at intervals on one side of the flexible strip body, the flexible strip body is smoothly formed into an annular strip body, the side of the annular strip body away from the lamp beads is elastically deformed and abuts against the inner wall surface of the kit, and the cylindrical light incident surface of the light guide plate abuts against the lamp beads, so that the light of the plurality of annularly arranged lamp beads is radially incident on the light guide plate.

[0012] Furthermore, the light guide plate includes a second light emitting surface and a third light emitting surface arranged opposite to each other, the prism sheet also includes a first light incident surface arranged away from the first light emitting surface, the cylindrical light incident surface is located between the second light emitting surface and the third light emitting surface, the second light emitting surface faces the prism sheet, and the third light emitting surface faces the reflective film, wherein the reflective film reflects light to the third light emitting surface so that the light enters the prism sheet from the second light emitting surface.

[0013] Furthermore, the reflective film is attached to the third light emitting surface, and the radial distance of the reflective film is greater than the radial distance of the light guide plate.

[0014] Furthermore, the optical module also includes a flexible gasket, which abuts between the reflective film and the bottom plate of the kit along the axial direction of the kit; the outer shell includes a first shell and a second shell, the first shell and the second shell are detachably covered, and the first shell is formed with a light outlet, and when the first shell is covered with the second shell, the inner sleeve of the kit is connected to the second shell, and the diffusion film is located at the light outlet.

[0015] Furthermore, the first shell is provided with a light shielding ring, and the light outlet is located at the center of the light shielding ring.

[0016] Furthermore, the optical module also includes a liquid lens, which is arranged between the prism sheet and the diffusion film, wherein the liquid lens is used to adjust the light output angle of the prism sheet to change the light output angle of the light from the prism sheet to the diffusion film.

[0017] Furthermore, the liquid lens includes a cavity, a first electrode and a second electrode, the first electrode is connected to one end of the cavity, the second electrode is connected to the other end of the cavity, the cavity is filled with a first liquid and a second liquid, the first liquid and the second liquid form a liquid interface, and the curvature of the liquid interface is changed by controlling the voltage difference between the first electrode and the second electrode to change the deflection angle of the light entering the diffusion film.

[0018] Implementing the embodiments of the present invention will have the following beneficial effects:

[0019] 1. In the desk lamp with adjustable light output angle of this embodiment, since the prism sheet can be slidably connected between the light guide plate and the diffusion film, the user can change the distance between the prism sheet and the diffusion film, and then adjust the light output angle by moving the prism sheet and then diffuse outward at the diffusion film, thereby overcoming the problem in the prior art that it is difficult to meet the user's demand for light output intensity of the desk lamp by controlling the light output angle;

[0020] 2. In the table lamp with adjustable light output angle in this embodiment, since the first light output surface of the prism sheet is provided with a plurality of adjacent grooves, and the grooves are formed with inclined enclosed side surfaces and a bottom surface connected to the side surfaces, and the arc-shaped convex surface allows the light to be refracted from the side surfaces and enter the diffusion film, thereby avoiding the problem of uneven light output at the diffusion film;

[0021] 3. The desk lamp with adjustable light output angle in this embodiment is quite difficult to manufacture when the curvature radius R of the convex arc surface of the prism sheet is smaller. The starting angle between the side and the bottom is a, the curvature radius of the arc side is R, and the distance between the prism sheet and the diffusion film is L, R=π*L / k*a; thus, by increasing the distance L between the prism sheet and the diffusion film and increasing the curvature radius R of the arc side, the manufacturing difficulty of the prism sheet is reduced, so that the angle of refracted light of the prism sheet meets the use requirements, avoiding too small light output angle resulting in a limited lighting area that cannot meet the needs of users, and also avoiding too large light output angle resulting in a large lighting area that affects the normal work and rest of others;

[0022] 4. In the desk lamp with adjustable light output angle in this embodiment, since the liquid lens is arranged between the prism sheet and the diffusion film, the voltage difference between the first electrode and the second electrode is controlled, thereby changing the curvature of the liquid interface formed by the distribution of the first liquid and the second liquid, so that the light output angle of the light from the prism sheet to the diffusion film can be controlled and adjusted, so that the user can adjust the range of the lighting area according to actual needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is a structural schematic diagram of a desk lamp for adjusting light output angle according to Embodiment 1 of the present invention;

[0025] Figure 2 This is an exploded schematic diagram of the lamp holder according to the first embodiment of the present invention;

[0026] Figure 3 This is a schematic structural diagram of a prism sheet according to Embodiment 1 of the present invention;

[0027] Figure 4 It is a front view of the prism sheet according to the first embodiment of the present invention;

[0028] Figure 5 for Figure 4 Sectional view at AA in the middle;

[0029] Figure 6 for Figure 5 A partial enlarged view of point B in the middle;

[0030] Figure 7 A schematic diagram of the structure of an optical module described in part of an embodiment of the present invention;

[0031] Figure 8 This is a schematic diagram of the structure of the annular light strip according to the first embodiment of the present invention;

[0032] Fig. 9 It is a front view of the light guide plate according to the first embodiment of the present invention;

[0033] Fig.10 This is a schematic structural diagram of the first housing according to the first embodiment of the present invention;

[0034] Fig.11 This is an optical principle diagram of the liquid lens described in Example 2 of the present invention.

[0035] Among them: 100, desk lamp; 110, base; 120, lamp pole; 130, lamp holder; 131, shell; 1311, first shell; 13111, light outlet; 13112, light shielding ring; 1312, second shell; 132, kit; 133, optical module; 1331, annular light belt; 13311, flexible belt body; 13312, lamp beads; 1332, light guide plate; 13321, cylindrical light incident surface; 13322, second light exit surface; 13323, third light exit surface Optical surface; 1333, prism sheet; 13331, first light emitting surface; 13332, groove; 13301, side surface; 13302, bottom surface; 13333, first light incident surface; 1334, reflective film; 1335, diffusion film; 1336, flexible gasket; 1337, liquid lens; 13371, cavity; 13303, first liquid; 13304, second liquid; 13305, liquid interface; 13372, first electrode; 13373, second electrode. DETAILED DESCRIPTION

[0036] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention 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 understanding of the disclosure of the present invention more thorough and comprehensive.

[0037] 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.

[0038] 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 invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0039] Embodiment 1

[0040] Please refer to Figure 1-Figure 10The first embodiment of the present invention provides a desk lamp 100 for adjusting the light output angle, comprising a base 110, a lamp pole 120 and a lamp holder 130; one end of the lamp pole 120 is hinged to the base 110; the lamp holder 130 comprises a shell 131, a kit 132 and an optical module 133, the shell 131 is hinged to the other end of the lamp pole 120, the kit 132 is sleeved in the shell 131, the optical module 133 is sleeved in the kit 132, the optical module 133 comprises an annular light strip 1331, a light guide plate 1332, a prism sheet 1333, a reflective film 1334 and a diffusion film 1335, The annular light strip 1331 is inserted into the kit 132; wherein, along the axial direction of the kit 132, the light guide plate 1332 is flush with the annular light strip 1331, the reflective film 1334 is located on one side of the light guide plate 1332, the diffusion film 1335 is located on the other side of the light guide plate 1332, and the prism sheet 1333 is slidably connected between the light guide plate 1332 and the diffusion film 1335 to change the distance between the prism sheet 1333 and the diffusion film 1335, so that the light of the annular light strip 1331 is diffused outward at the diffusion film 1335 after the exit angle is adjusted through the prism sheet 1333.In specific applications, the desk lamp 100, as a common household lamp, is also increasingly tending towards a miniaturized design, especially the lamp head 130. Users prefer the desk lamp 100 with a thin and light design. However, the light-emitting elements of the desk lamp 100 with a thin and light design are generally arranged on the peripheral side to output the light source. In this case, a light guide plate 1332 is required to make the light output uniform in the center. However, the unavoidable defect of this solution is that the light brightness of the peripheral edge of the light guide plate 1332 close to the light source is higher, while the light in the center of the light guide plate 1332 becomes relatively dim, which makes the desk lamp 100 prone to glare, resulting in visual disturbances when the user uses it. One solution to the glare of the thin and light desk lamp 100 is to provide a prism sheet 1333 on the outermost side. The prism sheet 1333 refracts the light so that the light converges toward the center of the light output, thereby increasing the light intensity at the center of the light guide plate 1332 to prevent glare. Although this solution can make the thin and light desk lamp 100 converge light from the middle, the light output angle of the desk lamp 100 is difficult to control, and the deflection angle of the prism sheet 1333 further strengthens the light output at a large angle. In actual use, the following situation may occur: the user is late at night. When the desk lamp 100 is turned on at night, the large-angle light will irradiate the family members who are resting in bed, thereby affecting the normal rest of the family members. Therefore, it is very necessary to improve the solution of the thin desk lamp 100. Specifically, the kit 132 can be used for heat dissipation of the optical module 133, and along the axial direction of the kit 132, the light guide plate 1332 and the annular light strip 1331 are arranged flush, the reflective film 1334 is located on one side of the light guide plate 1332, and the diffusion film 1335 is located on the other side of the light guide plate 1332. The prism sheet 1333 is slidably connected between the light guide plate 1332 and the diffusion film 1335 to change the prism sheet 1333. The distance between the prism sheet 1333 and the diffusion film 1335 is such that the light of the annular light strip 1331 is diffused outward at the diffusion film 1335 after adjusting the exit angle through the prism sheet 1333. In this way, it is possible to avoid the light on the prism sheet 1333 from being deflected at a large angle and illuminating the light. After the light of the annular light strip 1331 is refracted through the prism sheet 1333, the light deflected at a large angle will be absorbed by the diffusion film 1335. Changing the distance between the prism sheet 1333 and the diffusion film 1335 allows the operator to flexibly control the filtering and removal of light with a large deflection angle, thereby greatly reducing the possibility of large-angle light deflection of the desk lamp 100.

[0041] In a possible embodiment, the prism sheet 1333 includes a first light emitting surface 13331, the first light emitting surface 13331 is provided with a plurality of adjacent grooves 13332, the grooves 13332 are formed with an inclined enclosed side surface 13301 and a bottom surface 13302 connected to the side surface 13301, and light is refracted at the side surface 13301 and enters the diffusion film 1335, wherein the side surface 13301 is a convex curved surface with an arc shape. In a specific application, in order to make the refracted light of the prism sheet 1333 produce continuous and soft changes, the first light-emitting surface 13331 of the prism sheet 1333 is provided with a plurality of adjacent grooves 13332, and the grooves 13332 are formed with an inclined enclosed side surface 13301 and a bottom surface 13302 connected to the side surface 13301. The light is refracted at the side surface 13301 and enters the diffusion film 1335, wherein the side surface 13301 is an arc-shaped convex surface. Since the convex arc surface is smooth and continuous, the light refracted through the convex surface also has linear continuity, so that the light from the desk lamp 100 with adjusted light-emitting angle is more uniform and soft, thereby reducing the energy of the light intensity deflected at a large angle and reducing the impact on the surrounding environment.

[0042] In a possible implementation, let the starting angle between the side surface 13301 and the bottom surface 13302 be a, the radius of curvature of the side surface 13301 be R, the distance between the prism sheet 1333 and the diffusion film 1335 be L, wherein 135°≤a≤175°, and satisfy the relationship: R=π*L / k*a; wherein k is a constant coefficient, and π is equal to 180°. In a specific application, the value range of a is between 135° and 180°. Since the light output angle of the prism sheet 1333 needs to be controlled within a suitable lighting area, the relationship needs to be satisfied: R = π*L / k*a, that is, L is inversely proportional to the values ​​of a and R, respectively. It can be understood that when the L value is larger, it means that the coverage area of ​​the desk lamp 100 that adjusts the light output angle from the light output point (light source) to the lighting area will tend to be larger. At this time, it is necessary to suppress the lighting range of the desk lamp 100 that adjusts the light output angle. Therefore, the angles a and R between the side surface 13301 and the bottom surface 13302 should be as small as possible. A small a value means a small light output angle, and a small R value means that the curvature of the side surface 13301 is large, which can deflect the large-angle light output light toward the center. When the L value is smaller, it means that the coverage area of ​​the desk lamp 100 with adjustable light output angle that diffuses outward from the light output point (light source) to the illuminated area will tend to be smaller. At this time, it is necessary to improve the illumination range of the desk lamp 100 with adjustable light output angle. Therefore, the angles a and R between the side surface 13301 and the bottom surface 13302 should be as large as possible. A large a value means a large light output angle, and a large R value means a small curvature of the side surface 13301 can reduce the suppression of large-angle light output, thereby improving the illumination range of the desk lamp 100 with adjustable light output angle. If you want the R value to be as large as possible (so that the curvature of the side surface 13301 is reduced) to reduce the difficulty of producing the prism sheet 1333, it is preferred that the desk lamp with adjustable light output angle used by the user has a large L value and a small a value.

[0043] In a possible embodiment, the arc light strip includes a flexible strip body 13311 and lamp beads 13312, and a plurality of lamp beads 13312 are arranged at intervals on one side of the flexible strip body 13311. The flexible strip body 13311 smoothly forms an annular strip body, and the side of the annular strip body away from the lamp beads 13312 is elastically deformed and abuts against the inner wall surface of the kit 132, and the cylindrical light incident surface 13321 of the light guide plate 1332 abuts against the lamp beads 13312, so that the light from the plurality of annularly arranged lamp beads 13312 is radially incident on the light guide plate 1332. In specific applications, in order to make the arc-shaped light strip abut against the kit 132 to prevent accidental falling off, multiple lamp beads 13312 are arranged at intervals on one side of the flexible belt body 13311, and the flexible belt body 13311 is smoothly formed into an annular belt body. The side of the annular belt body away from the lamp beads 13312 is elastically deformed and abuts against the inner wall surface of the kit 132, and the cylindrical light incident surface 13321 of the light guide plate 1332 abuts against the lamp beads 13312, so that the light of the multiple annularly arranged lamp beads 13312 is radially incident on the light guide plate 1332. In this way, the annular belt body abuts against the inner wall surface of the kit 132 under the restoring deformation force of the annular belt body, wherein the multiple lamp beads 13312 are arranged at intervals on one side of the flexible belt body 13311. When the flexible belt body 13311 is annular, the multiple lamp beads 13312 surround into a ring toward the light guide plate 1332, so that the cylindrical light incident surface 13321 of the light guide plate 1332 receives light more evenly.

[0044] In one possible embodiment, the light guide plate 1332 includes a second light emitting surface 13322 and a third light emitting surface 13323 which are arranged opposite to each other, and the prism sheet 1333 also includes a first light incident surface 13333 which is arranged away from the first light emitting surface 13331, and the cylindrical light incident surface 13321 is located between the second light emitting surface 13322 and the third light emitting surface 13323, the second light emitting surface 13322 faces the prism sheet 1333, and the third light emitting surface 13323 faces the reflective film 1334, wherein the reflective film 1334 reflects light to the third light emitting surface 13323 so that the light is emitted from the second light emitting surface 13322 into the prism sheet 1333. In specific applications, in order to reduce the energy consumption of the desk lamp 100 for adjusting the light output angle and improve the utilization rate of the light source, the light guide plate 1332 is provided with a second light output surface 13322 and a third light output surface 13323 back to back, the prism sheet 1333 is provided with a first light incident surface 13333 away from the first light output surface 13331, the cylindrical light incident surface 13321 is located between the second light output surface 13322 and the third light output surface 13323, the second light output surface 13322 faces the prism sheet 1333, and the third light output surface 13323 faces the reflective film 1334, wherein the reflective film 1334 reflects the light to the third light output surface 13323, so that the light of the light guide plate 1332 is all emitted from the second light output surface 13322 into the prism sheet 1333.

[0045] In a possible implementation, the reflective film 1334 is attached to the third light emitting surface 13323, and the radial distance of the reflective film 1334 is greater than the radial distance of the light guide plate 1332. In a specific application, in order to avoid light leakage from the optical module 133 (there is light on the opposite side of the light emitting), the optical module is attached to the third light emitting surface 13323, and the radial distance of the reflective film 1334 is greater than the radial distance of the light guide plate 1332. In this way, the light leakage problem between the third light emitting surface 13323 and the reflective film 1334 of the light guide plate 1332 can be avoided.

[0046] In a possible embodiment, the optical module 133 also includes a flexible gasket 1336, and along the axial direction of the kit 132, the flexible gasket 1336 abuts between the reflective film 1334 and the bottom plate of the kit 132; the outer shell 131 includes a first shell 1311 and a second shell 1312, and the first shell 1311 and the second shell 1312 are detachably covered, and the first shell 1311 is formed with a light outlet 13111. When the first shell 1311 is covered on the second shell 1312, the inner sleeve of the kit 132 is connected to the second shell 1312, and the diffusion film 1335 is located at the light outlet 13111. In a specific application, since the optical module 133 also includes a flexible gasket 1336, along the axial direction of the kit 132, the flexible gasket 1336 abuts between the reflective film 1334 and the bottom plate of the kit 132, thus preventing the desk lamp 100 for adjusting the light output angle from damaging the internal optical module 133 when it falls; since the outer shell 131 includes a first shell 1311 and a second shell 1312, the first shell 1311 and the second shell 1312 are detachably covered, and the first shell 1311 is formed with a light outlet 13111, when the first shell 1311 is covered on the second shell 1312, the inner sleeve of the kit 132 is connected to the second shell 1312, and the diffusion film 1335 is located at the light outlet 13111, thereby realizing the assembly of the lamp head 130.

[0047] In a possible implementation, the first shell 1311 is provided with a light shielding ring 13112, and the light outlet 13111 is located in the center of the light shielding ring 13112. In a specific application, since there is a small amount of large-angle light from the diffusion film 1335 to the light outlet 13111, a light shielding ring 13112 is provided on the first shell 1311, and the light outlet 13111 is located in the center of the light shielding ring 13112, so that a small amount of excess large-angle light can be further shielded.

[0048] Embodiment 2

[0049] Compared with the first embodiment, this embodiment adds a liquid lens 1337, specifically:

[0050] Please refer to Figure 1 and Fig.11, Embodiment 2 of the present invention further provides a desk lamp 100 for adjusting the light emission angle, wherein the optical module 133 further includes a liquid lens 1337, and the liquid lens 1337 is disposed between the prism sheet 1333 and the diffusion film 1335, wherein the liquid lens 1337 is used to adjust the light emission angle of the prism sheet 1333, so as to change the light emission angle of the light from the prism sheet 1333 to the diffusion film 1335. In specific applications, the light emission angle of the light is controlled by adjusting the internal structure of the optical module 133 in the prior art, but the light angle after control in this way has a fixed value, so that the irradiation range is a fixed value, and therefore, it is not convenient to adjust the irradiation range of the desk lamp 100 with the light emission angle. Therefore, by adding the liquid lens 1337 between the prism sheet 1333 and the diffusion film 1335, the liquid lens 1337 can change the light emission angle of the prism sheet 1333, so that the light emission angle of the light can be controlled, thereby facilitating the user to adjust the illumination range of the desk lamp 100 with the light emission angle.

[0051] In one possible embodiment, the liquid lens 1337 includes a cavity 13371, a first electrode 13372 and a second electrode 13373, the first electrode 13372 is connected to one end of the cavity 13371, the second electrode 13373 is connected to the other end of the cavity 13371, the cavity 13371 is filled with a first liquid 13303 and a second liquid 13304, the first liquid 13303 and the second liquid 13304 form a liquid interface 13305, and the curvature of the liquid interface 13305 is changed by controlling the voltage difference between the first electrode 13372 and the second electrode 13373 to change the deflection angle of the light entering the diffusion film 1335. In a specific application, changing the voltage difference between the first electrode 13372 and the second electrode 13373 can change the curvature of the liquid interface 13305, thereby adjusting the angle of light irradiated from the prism sheet 1333 to the diffusion film 1335, wherein the effect of the liquid interface 13305 being a concave lens or a convex lens can be achieved. When the liquid lens 1337 is a concave lens, the light is deflected outward along the center line, thereby increasing the illumination range; when the liquid lens 1337 is a convex lens, the light is deflected inward along the center line, thereby shrinking the illumination range. It is worth noting that, due to a conductive solution and a non-conductive oil, and the two have different refractive indices and the same density. Since the fluids do not mix, they form a smooth and curved interface like a lens. We change the way the two liquid surfaces interact with each other by applying voltage to the conductive solution, thereby changing the curvature radius of the interface. The first liquid 13303 is set as a conductive solution, and the second liquid 13304 is set as non-conductive oil. A liquid interface 13305 is formed under the voltage difference between the first electrode 13372 and the second electrode 13373. By changing the polarity of the first electrode 13372 and the second electrode 13373, such as when the first electrode 13372 is the anode and the second electrode 13373 is the cathode, the liquid lens 1337 is defined as a convex lens; such as when the first electrode 13372 is the cathode and the second electrode 13373 is the anode, the liquid lens 1337 is defined as a concave lens. By controlling the continuous voltage difference between the first electrode 13372 and the second electrode 13373, the change in the curvature of the liquid interface 13305 can be controlled, thereby controlling the change in the lighting range of the desk lamp 100 that adjusts the light output angle.

[0052] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A desk lamp with adjustable light output angle, characterized in that: include: Base; A lamp pole, one end of which is hinged to the base; A lamp holder, the lamp holder comprising a shell, a kit and an optical module, the shell being hinged to the other end of the lamp pole, the kit being sleeved in the shell, the optical module being sleeved in the kit, the optical module comprising an annular light strip, a light guide plate, a prism sheet, a reflective film and a diffusion film, the annular light strip being sleeved in the kit; The prism sheet includes a first light emitting surface, the first light emitting surface is provided with a plurality of adjacent grooves, the grooves are formed with inclined enclosed side surfaces and a bottom surface connected to the side surfaces, the light is refracted at the side surfaces and enters the diffusion film, wherein the side surfaces are arc-shaped convex curved surfaces, the starting angle between the side surfaces and the bottom surface is a, the radius of curvature of the side surfaces is R, the distance between the prism sheet and the diffusion film is L, wherein 135°≤a≤175°, and the relationship is satisfied: R=π*L / k*a; wherein k is a constant coefficient, and π is equal to 180°; Among them, along the axial direction of the kit, the light guide plate and the annular light strip are arranged flush, the reflective film is located on one side of the light guide plate, and the diffusion film is located on the other side of the light guide plate. The prism sheet is slidably connected between the light guide plate and the diffusion film to change the distance between the prism sheet and the diffusion film, so that the light of the annular light strip is diffused outward at the diffusion film after adjusting the exit angle through the prism sheet.

2. The table lamp with adjustable light output angle according to claim 1, characterized in that: The annular light strip includes a flexible strip body and lamp beads, wherein a plurality of the lamp beads are arranged at intervals on one side of the flexible strip body, and the flexible strip body is smooth to form an annular strip body, and the side of the annular strip body away from the lamp beads is elastically deformed to abut against the inner wall surface of the kit, and a cylindrical light incident surface is formed on one side of the light guide plate, and the cylindrical light incident surface abuts against the lamp beads so that light from the plurality of annularly arranged lamp beads can be radially incident on the light guide plate.

3. The table lamp with adjustable light output angle according to claim 2, characterized in that: The light guide plate includes a second light emitting surface and a third light emitting surface arranged opposite to each other, and the prism sheet also includes a first light incident surface arranged away from the first light emitting surface, the cylindrical light incident surface is located between the second light emitting surface and the third light emitting surface, the second light emitting surface faces the prism sheet, and the third light emitting surface faces the reflective film, wherein the reflective film reflects light to the third light emitting surface, so that the light enters the prism sheet from the second light emitting surface.

4. The table lamp with adjustable light output angle according to claim 3, characterized in that: The reflective film is attached to the third light emitting surface, and the radial distance of the reflective film is greater than the radial distance of the light guide plate.

5. The table lamp with adjustable light output angle according to claim 1, characterized in that: The optical module also includes a flexible gasket, which abuts between the reflective film and the bottom plate of the kit along the axial direction of the kit; the outer shell includes a first shell and a second shell, the first shell and the second shell are detachably covered, and the first shell is formed with a light outlet. When the first shell is covered with the second shell, the inner sleeve of the kit is connected to the second shell, and the diffusion film is located at the light outlet.

6. The table lamp with adjustable light output angle according to claim 5, characterized in that: The first shell is provided with a light shielding ring, and the light outlet is located at the center of the light shielding ring.

7. The table lamp with adjustable light output angle according to claim 1, characterized in that: The optical module further includes a liquid lens, which is disposed between the prism sheet and the diffusion film, wherein the liquid lens is used to adjust the light emission angle of the prism sheet to change the light emission angle of the light from the prism sheet to the diffusion film.

8. The table lamp with adjustable light output angle according to claim 7, characterized in that: The liquid lens includes a cavity, a first electrode and a second electrode, wherein the first electrode is connected to one end of the cavity, and the second electrode is connected to the other end of the cavity. The cavity is filled with a first liquid and a second liquid, and the first liquid and the second liquid form a liquid interface. By controlling the voltage difference between the first electrode and the second electrode, the curvature of the liquid interface is changed to change the deflection angle of the light entering the diffusion film.

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