Projection-angle-variable myopia prevention and control table lamp and control method

Abstract

The invention discloses a projection-angle-variable myopia prevention and control table lamp, which belongs to the technical field of lighting lamps and comprises an outer shell, a dimming lens, a driving motor and a first encoder. A reflection cavity is formed in the outer shell, and the two ends of the dimming lens are rotationally connected with the two side walls of the reflection cavity; the driving motor is fixed on the outer shell, the driving motor is provided with a power output shaft which is fixedly connected with one end of the dimming lens, the first encoder is fixedly connected with the outer shell, and the power output shaft of the driving motor is sleeved with the first encoder; a light emitting panel is arranged below the reflection cavity, the dimming lens is located at the edge position of one side of the reflection cavity, a light gathering part is arranged above the dimming lens, the light gathering part projects towards the other side of the reflection cavity, a perpendicular incidence part is arranged below the dimming lens, and the perpendicular incidence part projects towards the light emitting panel obliquely and downwards. Double light sources emit light, and the angle of the dimming lens is adjustable, so that the oblique angle of emitted light can be changed according to requirements, the adjustment angle is accurate and controllable, the light path is accurate, and the illumination effect is good.

Description

Technical Field

[0001] The present invention relates to the technical field of lighting fixtures, and in particular to a myopia prevention and control desk lamp with a variable projection angle and a control method. Background Art

[0002] Due to structural limitations, people usually need to tilt the lamp head upwards when reading so that the light can be directed to the area where they are reading or working. However, this greatly tilted lamp head will produce light that directly hits the human eye, causing severe glare. In addition, the light source of existing LED desk lamps has the characteristic of decreasing light intensity from the center to the surrounding area, and the illumination uniformity of the emitted light spot is low, resulting in uneven brightness distribution in the user's field of vision, which can easily cause visual fatigue, and long-term use may also affect vision. Chinese Patent Publication No. CN207555293U discloses a side-emitting desk lamp that will not produce shadows when writing, and will not cause glare, and the light is emitted obliquely.

[0003] However, the existing desk lamp has a fixed oblique angle, so that the distance from the desk lamp to the book is fixed. When the book is moved, the desk lamp also needs to be dragged, which is very inconvenient to move. Moreover, when there are many books on the desktop, there is not much space to move the desk lamp at will, which is very inconvenient to use. Summary of the invention

[0004] In view of the above problems, the present invention aims to solve the above problems. One purpose of the present invention is to provide a myopia prevention and control desk lamp with a variable projection angle to solve the above problems. The angle and distance of the tilted projection can be adjusted to make the use of the desk lamp more convenient. The desk lamp head does not need to be turned to a large angle so that no glare stimulation is generated during long-distance projection, thereby effectively protecting eyesight.

[0005] The solution adopted in this embodiment is: a myopia prevention and control desk lamp with variable projection angle, comprising an outer shell, a dimming lens, a driving motor and a first encoder; a reflecting cavity is arranged inside the outer shell, and both ends of the dimming lens are rotatably connected to the two side walls of the reflecting cavity; the driving motor is fixed on the outer shell, and the driving motor is provided with a power output shaft fixedly connected to one end of the dimming lens, the first encoder is fixedly connected to the outer shell, and the first encoder is sleeved on the power output shaft of the driving motor; the angle of the dimming lens is adjustable, so that the oblique angle of the light output can be changed according to needs.

[0006] A light emitting panel is arranged below the reflective cavity, the dimming lens is located at one edge of the reflective cavity, a light focusing portion is arranged above the dimming lens, the light focusing portion projects to the other side of the reflective cavity, and a direct-emitting portion is arranged below the dimming lens, the direct-emitting portion projects obliquely downward to the light emitting panel. The dual light sources emit light from two oblique angles, which makes the oblique side lighting effect better, and the effect is better when the oblique angle is adjusted.

[0007] A preferred technical solution is that a curved reflective surface is provided on the top of the reflective cavity, and the distance between the curved reflective surface and the light output panel gradually decreases in a direction gradually moving away from the dimming lens.

[0008] The specific optical lens structure is that the focusing part is in the shape of an arc protruding outward, the highest protrusion point of the focusing part is located above the central axis of the dimming lens, the light intensity of the focusing part gradually decreases from the highest protrusion point to both sides, and the light emitted by the focusing part is distributed on the entire top surface of the reflection cavity.

[0009] A preferred technical solution is that a light bar slot is provided on the back side of the dimming lens, an LED light bar is provided in the light bar slot, the LED light bar is fixed in the light bar slot, and an arc-shaped dimming surface is provided on the side of the light bar slot close to the light emitting surface, and the outgoing light of the LED light bar is respectively projected onto the focusing part and the direct-emitting part after being converged by the arc-shaped dimming surface.

[0010] A preferred technical solution is that a fixing part is provided on both side edges of the lower side of the outer shell, a fixing step is provided on the fixing part, the light output panel is fixed on the fixing step, the dimming lens is located above the fixing part on one side, and a gap of 3-15mm is provided between the fixing part and the dimming lens.

[0011] The specific structure of the outer shell installation is that a partition plate is provided at the end of the reflective cavity, the dimming lens is located on one side of the partition plate, the driving motor and the first encoder are located on the other side of the partition plate, the first encoder is fixed on the partition plate, the rotation angle of the dimming lens is 0-20°, and when the rotation angle of the dimming lens is 0°, the plane where the LED light strip is located is perpendicular to the plane where the light output panel is located.

[0012] Preferably, it also includes a desk lamp support rod, the end of which is provided with an adjustment shaft, the adjustment shaft is rotatably connected to the outer shell, and a damping is provided between the adjustment shaft and the outer shell, so that the outer shell can be fixedly positioned when it is selected to any angle; Furthermore, a second encoder is fixedly disposed in the outer shell, and the second encoder is sleeved on the adjusting shaft.

[0013] Preferably, it also includes a desk lamp base, in which a driving power supply and a control mainboard are arranged, and the control mainboard is electrically connected to the driving motor, the first encoder, the second encoder, and the LED light strip.

[0014] A method for controlling a myopia prevention and control desk lamp with a variable projection angle, comprising the following steps: Step S01: when the desk lamp is turned on, a driving motor drives a dimming lens to reset to a 0° position, and a first encoder count is reset to zero; Step S02: After the control main board receives the long-range tilt angle adjustment signal, it controls the driving motor to drive the dimming lens to rotate to a corresponding angle, and records the rotation angle through the first encoder; Step S03: The control mainboard adjusts the power output to the LED light strip according to the angle position of the dimming lens, and fine-tunes the output illumination of the desk lamp so that the projection area maintains a preset illumination value unchanged after the angle is changed.

[0015] Further, in step S02, the control main board performs calculations based on the angle signal of the second encoder. When the light-emitting surface of the outer shell is in a horizontal position, the angle is recorded as 0 degrees; when it is tilted toward the front, it is recorded as a positive angle. The coefficient a is used to calculate the angle and then control the rotation angle of the dimming lens; when it is tilted toward the rear, it is recorded as a negative angle. The coefficient b is used to calculate the angle and then control the rotation angle of the dimming lens.

[0016] Compared with the prior art, the myopia prevention and control desk lamp with variable projection angle of the present invention has the following technical effects: 1. The myopia prevention and control desk lamp with variable projection angle of the present application comprises an outer shell, a dimming lens, a driving motor and a first encoder; a reflecting cavity is arranged inside the outer shell, and two ends of the dimming lens are rotatably connected to two side walls of the reflecting cavity; the driving motor is fixed on the outer shell, and the driving motor is provided with a power output shaft fixedly connected to one end of the dimming lens, the first encoder is fixedly connected to the outer shell, and the first encoder is sleeved on the power output shaft of the driving motor; the dimming lens has an adjustable angle, so that the oblique angle of the light can be changed according to demand, and the adjustment angle is precisely controllable to ensure accurate light path and good lighting effect.

[0017] 2. A light emitting panel is arranged below the reflecting cavity, the dimming lens is located at one edge of the reflecting cavity, a light focusing portion is arranged above the dimming lens, the light focusing portion projects to the other side of the reflecting cavity, and a direct-emitting portion is arranged below the dimming lens, the direct-emitting portion projects obliquely downward to the light emitting panel. The dual light sources emit light from two oblique angles, which makes the oblique side lighting effect better, and the effect is better when the oblique angle is adjusted.

[0018] 3. A control method for a myopia prevention and control desk lamp with a variable projection angle, comprising the following steps: Step S01: When the desk lamp is turned on, the driving motor drives the dimming lens to reset to the 0° position, and the first encoder counts to zero; Step S02: After the control main board receives the long-range tilt angle adjustment signal, the driving motor is controlled to drive the dimming lens to rotate to the corresponding angle, and the rotation angle is recorded by the first encoder; Step S03: The control main board adjusts the power output to the LED light bar according to the angle position of the dimming lens, and fine-tunes the output illumination of the desk lamp, so that the projection area maintains the preset illumination value unchanged after the angle changes. The illumination of the corresponding area will decrease during long-range projection, and the first encoder is used to accurately record the long-range projection angle and calculate the illumination compensation value, so that the illumination remains constant when the long-range projection angle changes.

[0019] 4. In step S02, the control mainboard calculates according to the angle signal of the second encoder. When the light-emitting surface of the outer shell is in a horizontal position, the angle is recorded as 0 degrees. When it is tilted to the front side, it is recorded as a positive angle. The coefficient a is used to calculate the angle to control the rotation angle of the dimming lens. When it is tilted to the rear side, it is recorded as a negative angle. The coefficient b is used to calculate the angle to control the rotation angle of the dimming lens. The long-distance angle is controlled by rotating the lamp head. After combining the small-angle physical rotation angle of the lamp head, the internal light emission angle is adjusted to adjust the oblique light emission angle in combination, so that the glare value and illumination value light optical parameters are better while ensuring an excellent long-distance angle.

[0020] Other characteristic features and advantages of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are incorporated into the specification and constitute a part of the specification, illustrate embodiments of the present invention and are used together with the description to explain the principles of the present invention. In these drawings, similar reference numerals are used to represent similar elements. The drawings described below are some embodiments of the present invention, but not all embodiments. For those of ordinary skill in the art, other drawings can be obtained from these drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the overall structure of a myopia prevention and control desk lamp with a variable projection angle provided in a specific embodiment of the present invention; Figure 2 It is a structural schematic diagram of a dimming lens provided in a specific embodiment of the present invention being located in a reflective cavity; Figure 3 is a schematic diagram of the installation position structure of the drive motor provided in a specific embodiment of the present invention; In the figure: 1. Desk lamp base; 2. Desk lamp support pole; 3. Outer shell; 4. Dimming lens; 5. LED light strip; 6. Light output panel; 7. Driving motor; 8. First encoder; 9. Second encoder; 31. Reflection cavity; 32. Arc-shaped reflection surface; 33. Fixing part; 34. Fixing step; 35. Partition plate; 41. Focusing part; 42. Direct-emitting part; 43. Light strip slot. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other arbitrarily without conflict.

[0024] The following describes in detail the myopia prevention and control desk lamp with variable projection angle and the control method in conjunction with the accompanying drawings and embodiments. Example

[0025] like Figure 1-3As shown, the present invention provides a myopia prevention and control desk lamp with variable projection angle, including an outer shell 3, a dimming lens 4, a driving motor 7 and a first encoder 8; a reflecting cavity 31 is arranged inside the outer shell 3, and the two ends of the dimming lens 4 are rotatably connected to the two side walls of the reflecting cavity 31; the driving motor 7 is fixed on the outer shell 3, and the driving motor 7 is provided with a power output shaft fixedly connected to one end of the dimming lens 4, the first encoder 8 is fixedly connected to the outer shell 3, and the first encoder 8 is sleeved on the power output shaft of the driving motor 7; the dimming lens 4 is adjustable in angle, so that the oblique angle of the light can be changed according to demand. The light emitted by the LED lamp beads converges and changes the path under the action of the dimming lens 4, and most of the light is projected to the top surface of the reflecting cavity 31 so that the emitted light is uniform, and the light uniformity is ensured under the joint action of the dimming lens 4 and the reflecting cavity 31. The angle of the dimming lens 4 is controlled by the driving motor 7, and the driving motor 7 adopts a small high-precision stepping motor to accurately control the rotation angle, and is matched with the first encoder 8 to detect the rotation angle, detect whether the rotation angle of the driving motor 7 is accurate, and record the angle after rotation. High-precision automatic dimming control is adopted to make the light output effect better after dimming. A light output panel 6 is arranged below the reflection cavity 31, and the dimming lens 4 is located at one side edge of the reflection cavity 31. A focusing portion 41 is arranged above the dimming lens 4, and the focusing portion 41 projects to the other side of the reflection cavity 31. A direct-emitting portion 42 is arranged below the dimming lens 4, and the direct-emitting portion 42 projects obliquely downward to the light output panel 6. Dual light sources emit light, which is superimposed at two oblique angles, so that the oblique side lighting effect is better, and the effect is better when the oblique angle is adjusted. The light output panel 6 is made of transparent acrylic material, which will not further disperse the incoming light, and maintain the existing angle of refraction, so that the light output effect can maintain the oblique projection. Different from the existing oblique side light desk lamp, the dimming lens 4 uses a double light output area to control the lighting effect. After adjusting the light output angle of the lamp bead, the existing oblique desk lamp also needs to reflect in the reflection cavity 31 before outputting. The curvature of the reflection cavity 31 determines that the angle of the output light will not change much. In this embodiment, the dimming lens 4 is provided with a direct portion 42 so that the light is directly projected through the light output panel 6. When the angle of the dimming lens 4 changes, this part of the output light will follow the change of the output angle. This part of the light will not be affected by the curvature of the curved surface of the reflection cavity 31, and the angle can be changed accurately and in a large range. At the same time, the light output angle of the focusing portion 41 will also change accordingly. After the light is emitted by the focusing portion 41, it will also change the angle slightly after being reflected by the reflection cavity 31. The superposition of the two parts of the light output causes the inclination angle of the output light to change significantly.

[0026] The curved surface structure of the reflection cavity 31 is that a curved reflection surface 32 is provided on the top of the reflection cavity 31, and the distance between the curved reflection surface 32 and the light output panel 6 gradually decreases as it gradually moves away from the dimming lens 4. The curvature of the curved surface can be calculated by a person skilled in the art through relevant parameters, and the curvature of each position of the curved surface can be simulated and designed using optical software after the projection angle range is determined. The distance between the top surface of the reflection cavity 31 and the light output panel 6 gradually decreases, so that the reflected light can be emitted at an inclined angle to achieve oblique side emission.

[0027] The specific structure of the optical lens is that the focusing portion 41 is in the shape of an arc protruding outward, and the rotation axis of the dimming lens 4 is located at the center of the focusing portion 41, so that the angle during rotation is the rotation angle of the light-emitting point of the light converged by the focusing portion 41. The highest protruding point of the focusing portion 41 is located above the central axis of the dimming lens 4, and the light intensity of the focusing portion 41 gradually decreases from the highest protruding point to the two sides, and the light emitted by the focusing portion 41 is distributed on the entire top surface of the reflecting cavity 31. When the optical lens is not rotated, the focusing portion 41 converges most of the light to the side close to the top of the reflecting cavity 31. The focusing portion 41 is in the shape of an arc protruding outward, so that the light is dispersed to the top of the reflecting cavity 31 at a certain angle when it is emitted, but most of the light will be relatively converged into a straight line. This part of the light is reflected according to the preset curvature, so that the main light emitting area is inclined to emit at an angle. Preferably, the arc surface at the top of the reflective cavity 31 is provided with multiple sections with different curvatures. When the dimming lens 4 rotates, the light emitted by the focusing portion 41 is projected onto sections with different curvatures, so that the projection angle can be changed to a large extent.

[0028] In order to ensure the stability of the light source, a light bar slot 43 is provided on the back of the dimming lens 4, and an LED light bar 5 is provided in the light bar slot 43. The LED light bar 5 is fixed in the light bar slot 43, and an arc dimming surface is provided on the side of the light bar slot 43 close to the light emitting surface. The light emitted by the LED light bar 5 is respectively projected to the focusing part 41 and the direct-emitting part 42 after being converged by the arc dimming surface. The LED light bar 5 is connected as a whole, so that when the dimming lens 4 rotates, the light source itself will not change, but the relative angle relationship between the dimming lens 4 and the reflection cavity 31 will change. At the same time, the light bar slot 43 can ensure the accurate installation of the LED light bar 5, and due to the setting of the arc dimming surface, the light of multiple LED lamp beads can evenly enter the dimming lens 4, making the light output more uniform.

[0029] The installation position of the dimming lens 4 is that a fixing part 33 is provided on both side edges of the lower side of the outer shell 3, and a fixing step 34 is provided on the fixing part 33. The light emitting panel 6 is fixed on the fixing step 34. The dimming lens 4 is located above the fixing part 33 on one side. A gap of 3-15mm is provided between the fixing part 33 and the dimming lens 4, and the preferred distance is 6mm, to ensure that there is no obstruction during rotation. At the same time, the distance between the direct-emitting part 42 and the light emitting panel 6 is controlled so that the light emitted directly is not too dazzling and a relatively high uniformity can be ensured. After the dimming lens 4 is installed, there is a little gap around it so that it will not be blocked by the outer shell 3 when rotating. The light emitting panel 6 is installed on the fixing step 34, which is easy to install and ensures a larger light emitting surface.

[0030] The specific structure of the installation of the outer shell 3 is that a partition plate 35 is provided at the end of the reflection cavity 31, the dimming lens 4 is located on one side of the partition plate, the driving motor 7 and the first encoder 8 are located on the other side of the partition plate 35, the first encoder 8 is fixed on the partition plate 35, the rotation angle of the dimming lens 4 is 0-20°, and when the rotation angle of the dimming lens 4 is 0°, the plane where the LED light bar 5 is located is perpendicular to the plane where the light output panel 6 is located. The partition plate 35 divides the outer shell 3 into a reflection cavity 31 and a cavity for installing other parts. The dimming lens 4 is located in the reflection cavity 31 to ensure an excellent light environment. Considering that the dimming lens 4 does not need to rotate frequently, wear-resistant bushings can be used at both ends of the dimming lens 4 to ensure smooth rotation, or small bearings can be selected to reduce friction.

[0031] The structure of the desk lamp also includes a desk lamp support rod 2, and an adjustment shaft is provided at the end of the desk lamp support rod 2. The adjustment shaft is rotatably connected to the outer shell 3, and damping is provided between the adjustment shaft and the outer shell 3, so that the outer shell 3 can be fixed in position when it is selected to any angle; further, a second encoder 9 is fixedly provided in the outer shell 3, and the second encoder 9 is sleeved on the adjustment shaft. The damping can be a rubber ring, so that the desk lamp head is subject to resistance when rotating, and the angle is fixed after rotation due to the existence of resistance. The second encoder 9 is used to record the angle of rotation of the lamp head.

[0032] Furthermore, it also includes a desk lamp base 1, in which a driving power supply and a control mainboard are provided, and the control mainboard is electrically connected to the driving motor 7, the first encoder 8, the second encoder 9, and the LED light strip 5. The driving power supply and the control mainboard are weighted in the desk lamp base 1. The driving power supply is provided with a battery, which can realize direct supply of mains electricity or portable mobile power supply. The control mainboard processes the signals of the first encoder 8 and the second encoder 9, and then controls the rotation of the driving motor 7 and controls the output power of the LED light strip 5. Example

[0033] The control method of this embodiment makes the change of the projection angle of the desk lamp more precise, so that the lighting environment remains good after the angle is adjusted.

[0034] A control method for a myopia prevention and control desk lamp with a variable projection angle comprises the following steps: Step S01: when the desk lamp is turned on, a driving motor 7 drives a dimming lens 4 to reset to a 0° position, and a first encoder 8 counts to zero; a limit structure is provided on an outer shell 3 or the dimming lens 4 as a reference for each reset, and the desk lamp can be set to reset when it is powered off and then powered on again. Resetting helps to eliminate errors caused by multiple angle adjustments, ensure the accuracy of each angle adjustment, and make the light output effect more accurately match the current angle.

[0035] Step S02: After the control main board receives the long-range tilt angle adjustment signal, it controls the drive motor 7 to drive the dimming lens 4 to rotate to the corresponding angle, and records the rotation angle through the first encoder 8; the drive motor 7 can achieve a smaller angle of rotation, and the first encoder 8 uses a relatively high precision to ensure that the optical path is accurate after each angle adjustment.

[0036] Step S03: The control mainboard adjusts the power output to the LED light strip 5 according to the angular position of the dimming lens 4, and fine-tunes the output illumination of the desk lamp so that the projection area maintains the preset illumination value after the angle changes. When the oblique angle increases, the projection distance of the main illumination area increases, and the original output light intensity cannot guarantee the unchanged illumination. The preset calculation formula performs different degrees of light intensity compensation at different angles, so that the illumination remains unchanged after the angle changes, effectively protecting students' eyesight. The desk lamp is set with multiple levels of illumination adjustment, and the light intensity of 3000k-5000k can be selected according to needs. The projection angle can be set with 5 adjustment buttons or stepless adjustment touch area.

[0037] Furthermore, in step S02, the control mainboard performs calculations based on the angle signal of the second encoder 9. When the light-emitting surface of the outer shell 3 is in a horizontal position, the angle is recorded as 0 degrees. When it is tilted to the front side, it is recorded as a positive angle. The coefficient a is used to calculate the angle and then control the rotation angle of the dimming lens 4. When it is tilted to the rear side, it is recorded as a negative angle. The coefficient b is used to calculate the angle and then control the rotation angle of the dimming lens 4. The height of the desk lamp is relatively low, and strong glare will not be generated when the desk lamp head is rotated at a small angle. The rotation angle of the desk lamp head can be superimposed on the light emission angle, so that the projection angle is larger and the projection area is farther. Preferably, the desk lamp head is set with an adjustment range of plus or minus 5°. Slightly rotating the desk lamp head can synchronously control the rotation of the drive motor 7 to achieve a linkage adjustment angle.

[0038] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, the elements defined by the sentence "include..." do not exclude the existence of other identical elements in the article or device including the elements.

[0039] The above embodiments are only used to illustrate the technical solution of the present invention and are not intended to limit the present invention. The present invention is described in detail with reference to the preferred embodiments. It should be understood by those skilled in the art that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, and should be included in the scope of the claims of the present invention.

Claims

1. A myopia prevention and control desk lamp with variable projection angle, characterized by: It includes an outer shell, a dimming lens, a driving motor and a first encoder; a reflecting cavity is arranged inside the outer shell, and two ends of the dimming lens are rotatably connected to two side walls of the reflecting cavity; The driving motor is fixed on the outer shell, the driving motor is provided with a power output shaft fixedly connected to one end of the dimming lens, the first encoder is fixedly connected to the outer shell, and the first encoder is sleeved on the power output shaft of the driving motor; A light emitting panel is arranged below the reflecting cavity, the dimming lens is located at one side edge of the reflecting cavity, a focusing portion is arranged above the dimming lens, the focusing portion projects toward the other side of the reflecting cavity, and a direct-emitting portion is arranged below the dimming lens, the direct-emitting portion projects obliquely downward toward the light emitting panel.

2. The myopia prevention and control desk lamp with variable projection angle as claimed in claim 1, characterized in that: The top of the reflection cavity is provided with an arc-shaped reflection surface, and the distance between the arc-shaped reflection surface and the light output panel gradually decreases in a direction gradually away from the dimming lens.

3. The myopia prevention and control desk lamp with variable projection angle as claimed in claim 2, characterized in that: The focusing portion is in the shape of an arc protruding outward, the highest protrusion point of the focusing portion is located above the central axis of the dimming lens, the light intensity of the focusing portion gradually decreases from the highest protrusion point to both sides, and the light emitted by the focusing portion is distributed on the entire top surface of the reflection cavity.

4. The myopia prevention and control desk lamp with variable projection angle as claimed in claim 1, characterized in that: A light bar slot is provided on the back side of the dimming lens, an LED light bar is provided in the light bar slot, the LED light bar is fixed in the light bar slot, an arc-shaped dimming surface is provided on the side of the light bar slot close to the light emitting surface, and the light emitted by the LED light bar is respectively projected onto the focusing part and the direct-emitting part after being converged by the arc-shaped dimming surface.

5. The myopia prevention and control desk lamp with variable projection angle as claimed in claim 1, characterized in that: The outer shell is provided with fixing parts on both side edges of the lower side, and fixing steps are provided on the fixing parts. The light output panel is fixed on the fixing steps. The dimming lens is located above the fixing part on one side, and a gap of 3-15mm is provided between the fixing part and the dimming lens.

6. The myopia prevention and control desk lamp with variable projection angle as claimed in claim 4, characterized in that: A partition plate is provided at the end of the reflective cavity, the dimming lens is located on one side of the partition plate, the driving motor and the first encoder are located on the other side of the partition plate, the first encoder is fixed on the partition plate, the rotation angle of the dimming lens is 0-20°, and when the rotation angle of the dimming lens is 0°, the plane where the LED light strip is located is perpendicular to the plane where the light output panel is located.

7. The myopia prevention and control desk lamp with variable projection angle as claimed in claim 4, characterized in that: It also includes a desk lamp support rod, the end of which is provided with an adjustment shaft, the adjustment shaft is rotatably connected to the outer shell, and a damping is provided between the adjustment shaft and the outer shell, so that the outer shell can be fixedly positioned when it is selected to any angle; A second encoder is also fixedly disposed in the outer shell, and the second encoder is sleeved on the adjusting shaft.

8. The myopia prevention and control desk lamp with variable projection angle as claimed in claim 7, characterized in that: It also includes a desk lamp base, in which a driving power supply and a control mainboard are arranged, and the control mainboard is electrically connected to the driving motor, the first encoder, the second encoder, and the LED light strip.

9. A method for controlling the myopia prevention and control desk lamp with variable projection angle as claimed in claim 8, characterized in that: The method comprises the following steps: Step S01: when the desk lamp is turned on, the driving motor drives the dimming lens to reset to the 0° position, and the count of the first encoder returns to zero; Step S02: After the control main board receives the long-range tilt angle adjustment signal, it controls the driving motor to drive the dimming lens to rotate to a corresponding angle, and records the rotation angle through the first encoder; Step S03: The control mainboard adjusts the power output to the LED light strip according to the angle position of the dimming lens, and fine-tunes the output illumination of the desk lamp so that the projection area maintains a preset illumination value unchanged after the angle is changed.

10. The method for controlling the myopia prevention and control desk lamp with variable projection angle according to claim 9, characterized in that: In step S02, the control main board performs calculations based on the angle signal of the second encoder. When the light-emitting surface of the outer shell is in a horizontal position, the angle is recorded as 0 degrees. When it is tilted toward the front, it is recorded as a positive angle. The coefficient a is used to calculate the angle and then control the rotation angle of the dimming lens. When it is tilted toward the rear, it is recorded as a negative angle. The coefficient b is used to calculate the angle and then control the rotation angle of the dimming lens.

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