An off-focus read / write table optical system

Abstract

This invention belongs to the field of optical imaging, specifically relating to an optical system for a defocused reading / writing station, comprising: a desktop; a distant image display mechanism, wherein a beam splitter is positioned above and opposite the desktop; a concave reflector is positioned at the rear of the desktop and opposite the beam splitter; after receiving light, the object on the desktop undergoes diffuse reflection, with some light incident on the beam splitter and reflected by the beam splitter to the concave reflector, and the light reflected by the concave reflector passes through the beam splitter in a transmitted form and exits towards the exit pupil, forming a final image with a focal depth greater than 2m; a defocus stimulation mechanism, positioned above and opposite the beam splitter, comprising a defocus light source and a defocus lens group; the defocus light source, after passing through the defocus lens group, is incident on the beam splitter, reflected by the beam splitter, and exits towards the exit pupil, forming a defocused image, the defocus range of which is -1D to +3D; the defocused image can provide defocus stimulation to the human eye.

Description

Technical Field

[0001] This invention belongs to the field of optical imaging, and more specifically relates to an optical system for a defocused reader / writer. Background Technology

[0002] The theory of myopia defocus has wide applications in myopia prevention and control among adolescents. Myopia defocus refers to the phenomenon where, when the eye views an object, the focal point of light does not fall on the retina but in front of it, resulting in blurred vision. Defocus control for myopia primarily involves a special design that ensures light from the central area of ​​the visual field focuses on the retina, guaranteeing clear central vision. Meanwhile, light from the peripheral areas focuses in front of the retina, creating myopia-induced defocus. This myopia-induced defocus helps inhibit excessive elongation of the eye axis, thereby slowing the progression of myopia. Adding a defocus design to a reading and writing system can further improve its usability.

[0003] For teenagers, studying at a desk takes up most of their day. The distance between the object being viewed and their eyes is limited. If the distance is too far, they will not be able to complete normal reading and writing. However, prolonged close-up viewing will put a lot of pressure on their eyes. In addition, because they cannot maintain a proper posture for a long time, they will spontaneously evolve to a more effortless posture, that is, their eyes will move closer to the table, which will further increase the pressure on their eyes on the original basis. Over a long period of time, this will cause a certain degree of myopia. Summary of the Invention

[0004] The present invention is proposed based on the above-mentioned needs of the prior art. The technical problem to be solved by the present invention is to provide an optical system for a defocused reading and writing station to reduce eye strain.

[0005] To address the above problems, the technical solution provided by this invention includes:

[0006] An optical system for a defocused reading / writing station is provided, comprising: a desktop for placing an object to be read or written on; and a remote image display mechanism including a beam splitter and a concave mirror, wherein the beam splitter is disposed above and opposite the desktop; the concave mirror is disposed at a rearward position on the desktop and opposite the beam splitter; a first optical path is formed in the remote image display mechanism, comprising: the object to be read or written on the desktop receiving light and undergoing diffuse reflection, with a portion of the light incident on the beam splitter and reflected by the lower surface of the beam splitter towards the concave mirror; the light reflected by the concave mirror is transmitted in a transmitted form. The light passes through the beam splitter and exits through the exit pupil, forming a final image with a focal depth greater than 2m. A defocus stimulation mechanism is positioned above and opposite the beam splitter. The defocus stimulation mechanism includes a defocus component, which comprises a defocus light source and a defocus lens group. The defocus stimulation mechanism and the beam splitter form a second optical path, wherein the defocus light source passes through the defocus lens group and is incident on the beam splitter. Under the reflection of the upper surface of the beam splitter, the light is emitted through the exit pupil, forming a defocus image. The defocus range of the defocus image is -1D to +3D. The defocus image generates a defocus stimulus.

[0007] Preferably, the defocus stimulation mechanism further includes a driving component, which includes a rotating shaft connected to a power source and rotating under the power output of the power source; a support disk, which is generally disc-shaped and fixedly connected to the rotating shaft at its center; and a track disposed on the support disk, one end of which is connected to the rotating shaft and extends from the rotating shaft to the outer periphery of the support disk. The shape of the track is adapted to the defocus component to allow the defocus component to slide on the track. When the rotating shaft rotates, the defocus component moves along the track towards or away from the center under the action of centripetal or centrifugal force, thereby changing the distance between the defocused image and the exit pupil center and adjusting the stimulation position of the defocused image in the viewer's eye.

[0008] Preferably, a limiting mechanism is provided on the track. The limiting mechanism includes a baffle. During the movement of the defocusing component, the baffle prevents the defocusing component from continuing to move in the moving direction, so that it is relatively stationary and positioned at the limiting position.

[0009] Preferably, the limiting mechanism further includes a locking assembly, which includes two clamping arms disposed opposite each other on the left and right sides of the baffle, and the two clamping arms have elasticity in the direction of moving away from or towards each other; when the defocusing component moves to the locking assembly, it is locked into the middle area by the two clamping arms, and is simultaneously blocked by the baffle to be fixed at the limiting position, until it is subjected to an external force greater than the clamping force between the two clamping arms to disengage it.

[0010] Preferably, the limiting mechanism further includes a first magnet, which is disposed on the baffle. Correspondingly, the defocusing component is provided with a second magnet that cooperates with the first magnet. When the defocusing component approaches the first magnet, the first magnet and the second magnet attract each other, fixing the defocusing component at the baffle in the limiting position until it is subjected to an external force greater than the magnetic attraction force that causes it to leave the limiting position.

[0011] Preferably, the limiting mechanism further includes a spring, one end of which is connected to a preset position on the track and the other end is connected to the defocusing component. The baffle is disposed between the preset position and the defocusing component. Under the drive of the power source, the rotating shaft rotates continuously, causing the defocusing component to move to the baffle and abut against it to remain stationary.

[0012] Preferably, the defocus stimulation mechanism includes multiple defocus components and multiple tracks corresponding to the defocus components, and the defocus components are arranged in a ring around the rotating shaft.

[0013] Preferably, the track has an arc curving in a clockwise or counterclockwise direction. When the rotating shaft rotates in the same direction as the curvature of the track, the defocusing component moves away from the rotating shaft; when the rotating shaft rotates in the opposite direction to the curvature of the track, the defocusing component moves closer to the rotating shaft.

[0014] Preferably, multiple tracks bend in the same direction and with the same degree of bending.

[0015] Preferably, each track includes N defocusing components and has N+1 limiting positions, wherein the defocusing components move between two connected limiting positions.

[0016] Compared with existing technologies, this invention magnifies the reading and writing objects on the desktop and gives them a greater focal depth through a far-image display mechanism. This ensures that when a viewer looks at the object from the exit pupil position, regardless of the distance from the exit pupil, they will see an image at a greater distance from their eyes, and this image will be presented on the viewer's retina. This prevents visual fatigue caused by prolonged close-up viewing, reduces eye strain, and avoids myopia or prevents the progression of myopia. In addition, based on this image, a defocusing mechanism displays a defocused image. The defocused image can be imaged in front of the retina. Combined with the final image, it can create a myopia defocusing stimulus in the viewer's eyes, thereby inducing the viewer to want to see the defocused image clearly. This, to a certain extent, pulls the retina forward to inhibit axial elongation and achieves the goal of preventing myopia or preventing the progression of myopia. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a schematic diagram of the optical path structure of the defocused reader / writer optical system provided in an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the first optical path formed in an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the structure of the second optical path formed in an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the defocusing component in an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the defocusing component according to a feasible embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the defocusing component according to another feasible embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram of the defocusing component moving from the second position to the first position in an embodiment of the present invention;

[0025] Figure 8 This is a schematic diagram of the defocusing component moving from the first position to the second position in an embodiment of the present invention;

[0026] Figure 9 This is a schematic diagram of the optical path structure of another defocused reader / writer optical system in an embodiment of the present invention.

[0027] Figure label:

[0028] 1. Desktop; 2. Beam splitter; 3. Concave mirror; 4. Defocus assembly; 5. Defocus light source; 6. Defocus lens group; 7. First lens; 8. Second lens; 9. Final image; 11. Rotating axis; 12. Track; 13. Aperture stop; 14. Exit pupil; 15. LED light source; 16. First position; 17. Second position; 18. Carrier plate. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the term "connected" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0031] Throughout the text, the terms “top,” “bottom,” “above,” “below,” and “on top” refer to the relative positions of components of the device, such as the relative positions of the top and bottom substrates within the device. It is understood that the device is multifunctional and independent of its spatial orientation.

[0032] To facilitate understanding of the embodiments of the present invention, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. These embodiments do not constitute a limitation on the embodiments of the present invention.

[0033] This embodiment provides an optical system for a defocused reader / writer, such as... Figure 1 and Figure 9 As shown.

[0034] like Figure 1 As shown, the defocus reading and writing station optical system includes a desktop 1, a distant image display mechanism, and a defocus stimulation mechanism.

[0035] A desktop 1 is provided for placing reading and writing objects. Furthermore, the desktop 1 is provided with positioning marks. When using the defocus reading and writing station optical system, the reading and writing objects should coincide with the positioning marks to ensure that the final image of the reading and writing objects is located in the center of the field of view.

[0036] The remote image display mechanism includes a beam splitter 2 and a concave reflector 3.

[0037] Beam splitter 2 is positioned above and opposite the desktop 1. As an optical device, beam splitter 2 has the following functions: it can reflect a portion of the incident light rays and transmit the other portion of the incident light rays, and the relative ratio of the reflected light rays to the incident light rays is determined by its own beam splitting ratio.

[0038] like Figure 2 As shown, the relative positions of the desktop 1 and the beam splitter 2 are configured to ensure diffuse reflection of the object under external light source illumination. The diffusely reflected light enters from the lower side of the beam splitter 2. Under the beam splitting action of the beam splitter 2, part of the light is transmitted through the beam splitter 2 and exits from the upper side of the beam splitter 2; the other part of the light is reflected from the lower side of the beam splitter 2. The light emitted in the transmitted form no longer participates in the final image, while the light emitted in the reflected form continues to propagate and participates in the final image.

[0039] Furthermore, an LED light source 15 is provided below the beam splitter 2, which illuminates the desktop 1. The light emitted by the LED light source 15 is emitted towards the reading and writing object and diffusely reflected on the reading and writing object.

[0040] A concave reflector 3 is positioned opposite to the beam splitter 2, located at the rear of the tabletop 1. The concave reflector 3 has an inwardly concave surface that is recessed away from the beam splitter 2 to concentrate light for subsequent imaging.

[0041] The light reflected by the beam splitter 2 will be incident on the concave mirror 3, and after being reflected by the concave mirror 3, it will be incident on the lower side of the beam splitter 2. Part of the light will be reflected out from the lower side of the beam splitter 2, and the other part of the light will be transmitted out from the upper side of the beam splitter 2. The transmitted light will be emitted towards the exit pupil 14 and form the final image 9. The focal depth of the final image 9 is greater than 2m.

[0042] Under the influence of external light, the reading / writing object on the tabletop 1, the beam splitter 2, and the concave mirror 3 form the first optical path, and the first optical path presents the final image 9 at the exit pupil 14.

[0043] A defocusing stimulation mechanism is disposed above and opposite to the beam splitter 2. The defocusing stimulation mechanism includes a connected defocusing component 4 and a driving component.

[0044] like Figure 3 and Figure 4 As shown, the defocusing component 4 includes a defocusing light source 5 and a defocusing lens group 6.

[0045] The defocused light source 5 is positioned opposite to the beam splitter 2 and is oriented in the direction of the beam splitter 2.

[0046] The defocus lens group 6 includes at least one lens. The defocus lens group 6 is disposed between the defocus light source 5 and the beam splitter 2, and is positioned opposite to both the defocus light source 5 and the beam splitter 2. Further, the defocus lens group 6 includes a first lens 7 and a second lens 8. Light emitted from the defocus light source 5 is directed towards the defocus lens group 6, first passing through the first lens 7 to adjust its shape, then passing through the second lens 8 for further reshaping, and exiting from the aperture stop 13 of the defocus lens group. It continues to propagate forward, incident on the beam splitter 2, and, under the reflection of the beam splitter 2, exits towards the exit pupil 14.

[0047] A second optical path is formed by a defocusing light source 5, a defocusing lens group 6, and a beam splitter 2, presenting a defocused image at the exit pupil 14. The defocus range of the defocused image is -1D to +3D. The first and second optical paths are coupled at the beam splitter 2, so that the final image 9 and the defocused image are imaged at the exit pupil 14, thereby creating a myopia defocus stimulus in the eye.

[0048] The defocused image and the final image 9 form a myopic defocus in the eye, that is, the final image 9 can fall on the retina of the human eye, while the defocused image falls in front of the retina of the human eye, resulting in blurred vision of the defocused image. This prompts the generation of a force that drives the retina forward without affecting vision, which helps to inhibit excessive growth of the axial length of the eye, thereby achieving the purpose of delaying the increase of myopia.

[0049] Regarding the setting of the defocus component 4, in one feasible implementation, such as Figure 5 As shown, the defocus lens group 6 includes two lenses, and the optical system parameters of the optical surfaces participating in the second optical path are shown in Table 1.

[0050] Table 1 Optical system parameters of the second optical path

[0051] Serial Number face shape radius of curvature thickness Refractive index Abbe number property 16e spherical unlimited 4450 / / refraction 16d Spherical aperture (aperture) unlimited 0 / / refraction 16c1 aspherical -6.70179 -4.97121 1.492 57.5 refraction 16c2 aspherical -18.5169 -4.05361 / / refraction 16b1 aspherical -4.7259 -4.72789 1.534 55 refraction 16b2 aspherical -14.5018 -1.24729 / / refraction 16a1 spherical unlimited -0.7 1.52 64.3 refraction 16a2 spherical unlimited 0 / / refraction

[0052] Wherein, 16e represents the defocused image, 16d represents the aperture stop 13; 16c1 represents one surface of the second lens 8 in the defocused lens group 6, 16c2 represents the other surface of the second lens 8 in the defocused lens group 6, 16b1 represents one surface of the first lens 7 in the defocused lens group 6, 16b2 represents the other surface of the first lens 7 in the defocused lens group 6, 16a1 represents the glass cover plate covering the front of the defocused light source 5; and 16a2 represents the light-emitting surface of the defocused light source 5.

[0053] Among the surfaces mentioned above, the surfaces that constitute the aspherical surface satisfy the following equation: c is the reciprocal of the radius of curvature, r is the radial distance from a point on the surface, and k is the quadratic surface constant. Ai These are the coefficients of higher-order terms.

[0054] Table 2 Aspheric coefficients of Example 1

[0055] item 16c1 16c2 16b1 16b2 1 / c -6.701790E+00 -1.851688E+01 -4.725895E+00 -1.450179E+01 k 0 0 0 0 <![CDATA[A2]]> 1.295408E-04 1.421255E-04 7.929467E-04 -4.857112E-03 <![CDATA[A3]]> 1.262603E-05 9.113125E-06 -4.742140E-06 2.394573E-04 <![CDATA[A4]]> -3.445730E-07 3.407134E-07 4.516460E-06 6.641867E-05 <![CDATA[A5]]> 1.257579E-08 -5.838170E-09 1.301421E-07 -3.749989E-06

[0056] The exit pupil 14 of the optical system formed by the second optical path has a diameter of 10 mm, a focal length of 9.3 mm, and a diagonal field of view of 20°.

[0057] In another feasible implementation, such as Figure 6 As shown, the defocus lens group 6 includes three lenses, and the optical system parameters of the optical surfaces participating in the second optical path are shown in Table 3.

[0058] Table 3 Optical System Parameters for Example 2

[0059] Serial Number face shape radius of curvature thickness Refractive index Abbe number property 26f spherical unlimited 4450 / / refraction 26e2 aspherical 46.2738 6.5 1.492 57.5 refraction 26e1 aspherical -52.0038 12.1988 / / refraction 26d Spherical aperture (aperture) unlimited 16 / / refraction 26c2 aspherical -41.77804 5 1.492 57.5 refraction 26c1 aspherical -13.08723 0.1 / / refraction 26b2 aspherical 8.77795 4.5 1.534 55 refraction 26b1 aspherical 9.06869 5.00124 / / refraction 26a2 spherical unlimited 0.7 1.52 64.3 refraction 26a1 spherical unlimited 0 / / refraction

[0060] Wherein, 26f represents the defocused image, 26e2 represents one surface of the third lens in the defocused lens group 6, 26e1 represents the other surface of the third lens in the defocused lens group 6, 26d represents the aperture stop 13; 26c2 represents one surface of the second lens 8 in the defocused lens group 6, 26c1 represents the other surface of the second lens 8 in the defocused lens group 6, 26b2 represents one surface of the first lens 7 in the defocused lens group 6, 26b1 represents the other surface of the first lens 7 in the defocused lens group 6, 26a2 represents the glass cover plate covering the front of the defocused light source 5; 26a1 represents the light-emitting surface of the defocused light source 5.

[0061] Among the surfaces mentioned above, the surfaces that constitute the aspherical surface satisfy the following equation: c is the reciprocal of the radius of curvature, r is the radial distance from a point on the surface, and k is the quadratic surface constant. A i These are the coefficients of higher-order terms.

[0062] Table 4 Aspherical coefficients of Example 2

[0063] item 26e2 26e1 26c2 26c1 26b2 26b1 1 / c -4.627382E+01 5.200380E+01 4.177804E+01 1.308723E+01 -8.777955E+00 -9.068685E+00 k 0 0 0 0 0 0 <![CDATA[A2]]> 1.259333E-05 3.281149E-06 -1.872733E-04 -2.646706E-04 1.490019E-04 6.329899E-04 <![CDATA[A3]]> 1.817472E-08 1.301549E-08 2.794595E-07 -2.849863E-07 5.461631E-06 8.662680E-06 <![CDATA[A4]]> 1.060790E-11 -3.146053E-11 -2.003372E-09 4.564503E-09 -1.144121E-07 -4.094577E-08 <![CDATA[A5]]> -1.521476E-13 -5.587548E-14 -3.519621E-11 -9.405466E-11 2.112100E-09 4.339048E-11

[0064] The exit pupil 14 of the optical system formed by the second optical path has a diameter of 30mm, a focal length of 26.8mm, and a diagonal field of view of 16°.

[0065] Driver components, such as Figures 7-9As shown, the assembly includes a rotating shaft 11, a track 12, and a support disk 18. The rotating shaft is connected to a power source and rotates under the power output of the power source. The support disk 18 is generally disc-shaped and its center is fixedly connected to the rotating shaft. The track is disposed on the support disk 18, with one end connected to the rotating shaft and extending from the rotating shaft to the outer periphery of the support disk 18. The track 12 has curvature and internal space for movement, allowing the defocusing assembly 4 to slide on the track. When the rotating shaft 11 rotates, it drives the track 12 to rotate around the rotating shaft 11, causing the defocusing assembly 4 to move along the track 12. Specifically, when the rotation direction of the rotating shaft 11 is consistent with the curvature direction of the track 12, the defocusing assembly 4 moves closer to the rotating shaft 11; when the rotation direction of the rotating shaft 11 is opposite to the curvature direction of the track 12, the defocusing assembly 4 moves away from the rotating shaft 11.

[0066] By adjusting the position of the defocus component, the distance between the defocused image and the center of the exit pupil is adjusted, thereby changing the stimulation position of the defocused image in the viewer's eye to provide defocus stimulation at different positions. This can affect the axial length of the eye to a certain extent, effectively preventing myopia and inhibiting the progression of myopia.

[0067] The track 12 has limiting positions, including a first position 16 and a second position 17. A limiting mechanism associated with the defocusing component 4 is provided at the first position 16 and the second position 17. When the defocusing component 4 moves to the first position 16 or the second position 17, under the action of the limiting mechanism, the defocusing component 4 can be relatively stationary and fixed at the first position 16 or the second position 17 until it is subjected to external force again.

[0068] Furthermore, the limiting mechanism can be a specific physical structure.

[0069] For example, the limiting mechanism includes a baffle and a locking assembly. The baffle prevents the defocusing assembly from moving further in the moving direction during its movement, keeping it relatively stationary at the limiting position. The locking assembly includes two clamping arms, which are disposed opposite each other on the left and right sides of the baffle and have elasticity in the direction of moving away from or towards each other. When the defocusing assembly moves to the locking assembly, it is locked into the middle area by the two clamping arms and simultaneously blocked by the baffle to fix it at the limiting position until it is subjected to an external force greater than the clamping force between the two clamping arms to disengage it.

[0070] For example, the limiting structure includes a baffle and a first magnet. During the movement of the defocusing component, the baffle prevents the defocusing component from continuing to move in the moving direction, so that it is relatively stationary at the limiting position. The first magnet is disposed on the baffle. Correspondingly, the defocusing component is provided with a second magnet that cooperates with the first magnet. When the defocusing component approaches the first magnet, the first magnet and the second magnet attract each other, fixing the defocusing component at the baffle at the limiting position until it is subjected to an external force greater than the magnetic attraction force that causes it to leave the limiting position.

[0071] For example, the limiting mechanism further includes a baffle and a spring. One end of the spring is connected to a preset position on the track, and the other end is connected to the defocusing component. The baffle is positioned between the preset position and the defocusing component. Driven by a power source, the rotating shaft rotates continuously, causing the defocusing component to move to the baffle and abut against it to remain stationary. In this configuration, the rotating shaft needs to rotate continuously to ensure that the resulting defocused image is circular.

[0072] In one feasible implementation of this embodiment, the first position 16 is closer to the rotating shaft 11, the second position 17 is farther away from the rotating shaft 11, and the track 12 is bent in a counterclockwise direction. When the rotating shaft 11 rotates counterclockwise, as... Figure 7 As shown, the defocusing component 4 moves along the track 12 towards the rotating shaft 11 based on inertia until it is fixed at the first position 16. At this point, the defocused image formed is relatively close to the center of the exit pupil 14. Figure 8 As shown, to increase the distance between the defocused image and the center of the exit pupil 14, rotate the shaft 11 clockwise with a force greater than the force that fixes the defocusing component 4 in the first position 16. Due to inertia, the defocusing component 4 moves outward along the track 12 until it reaches the second position 17. At this point, the defocused image is closer to the center of the exit pupil 14. Similarly, to decrease the distance between the defocused image and the center of the exit pupil 14, rotate the shaft 11 counterclockwise with a force greater than the force that fixes the defocusing component 4 in the second position 17.

[0073] By setting a limiting position to fix the defocus component, stable imaging of the defocused image in the eye is ensured. At the same time, by selecting a relatively suitable defocus position, the stimulation position of the defocused image on the eye can be adjusted in a personalized manner according to the actual situation of the viewer's eyes.

[0074] Furthermore, there are multiple defocusing components 4 arranged in a ring around each other. Correspondingly, the driving component includes multiple tracks 12. The center of the defocusing component 4 overlaps with the rotating shaft 11 and also with the center of the positioning mark. The multiple tracks 12 are curved in the same direction. When the rotating shaft 11 rotates, the defocusing components 4 on the multiple tracks 12 have the same direction of movement, so that the defocusing components 4 can simultaneously reach the first position 16 or the second position 17, maintaining the uniform distribution of the defocusing components 4.

[0075] Furthermore, the same track 12 includes multiple defocusing components 4, corresponding to multiple limiting positions. If each track 12 includes N defocusing components 4, each track 12 has N+1 limiting positions, and the defocusing component 4 moves between two connected limiting positions. For example, when the same track 12 includes two defocusing components 4, the track 12 has a first position 16, a second position 17, and a third position. One defocusing component 4 moves between the first position 16 and the second position 17, while the other defocusing component 4 moves between the second position 17 and the third position. When the rotating shaft 11 is rotated and stabilized, the two defocusing components 4 are respectively located at the first position 16 and the second position 17 or the second position 17 and the third position.

[0076] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An optical system for a defocused reader / writer, characterized in that, include: A desktop, used to place reading and writing materials; A remote image display mechanism includes a beam splitter and a concave reflector, wherein the beam splitter is disposed above the table and opposite to the table; The concave reflector is positioned at the rear of the tabletop and is opposite to the beam splitter. The first optical path is formed in the far-image display mechanism, including: the reading and writing object on the table receives light and undergoes diffuse reflection, part of the light is incident on the beam splitter, and is reflected by the lower surface of the beam splitter and emitted to the concave mirror. The light reflected by the concave mirror passes through the beam splitter in the form of transmission and is emitted to the exit pupil, forming a final image with a focal plane depth greater than 2m. A defocusing stimulation mechanism is disposed above and opposite the beam splitter. The defocusing stimulation mechanism includes multiple defocusing components, multiple tracks and drive components corresponding to the defocusing components, and the defocusing components include a defocusing light source and a defocusing lens group. The driving assembly includes: a rotating shaft connected to a power source and rotating under the power output of the power source; the defocusing components are arranged in a ring around the rotating shaft; a support disk, generally disc-shaped, with its center fixedly connected to the rotating shaft; and a track disposed on the support disk, one end of which is connected to the rotating shaft and extends from the rotating shaft to the outer periphery of the support disk. The shape of the track is adapted to the defocusing components to allow the defocusing components to slide on the track. When the rotating shaft rotates, the defocusing components move along the track towards or away from the center under the action of centripetal or centrifugal force, thereby changing the distance between the defocused image and the exit pupil center. The distance adjusts the stimulation position of the defocused image in the viewer's eye; the track has an arc curving in a clockwise or counterclockwise direction, multiple tracks curving in the same direction and with the same degree of curvature, when the rotating shaft rotates in the same direction as the track curvature, the defocusing component moves away from the rotating shaft; when the rotating shaft rotates in the opposite direction to the track curvature, the defocusing component moves closer to the rotating shaft; a limiting mechanism is provided on the track, the limiting mechanism including a baffle, the baffle prevents the defocusing component from continuing to move in the moving direction during the movement of the defocusing component, so that it is relatively stationary at the limiting position; The defocus stimulation mechanism and the beam splitter form a second optical path, including: the defocus light source passes through the defocus lens group and is incident on the beam splitter; under the reflection of the upper surface of the beam splitter, it is emitted towards the exit pupil to form a defocus image; the defocus range of the defocus image is -1D to +3D; the final image and the defocus image form a defocus stimulation.

2. The defocused reader / writer optical system according to claim 1, characterized in that, The limiting mechanism also includes a locking assembly, which includes two clamping arms. The two clamping arms are arranged opposite each other on the left and right sides of the baffle, and the two clamping arms have elasticity in the direction of moving away from or towards each other. When the defocusing component moves to the locking assembly, it is locked into the middle area by the two clamping arms, and is blocked by the baffle to be fixed at the limiting position until it is subjected to an external force greater than the clamping force between the two clamping arms to release it.

3. The defocused reader / writer optical system according to claim 1, characterized in that, The limiting mechanism also includes a first magnet, which is disposed on the baffle. Correspondingly, the defocusing component is provided with a second magnet that cooperates with the first magnet. When the defocusing component approaches the first magnet, the first magnet and the second magnet attract each other, fixing the defocusing component at the baffle in the limiting position until it is subjected to an external force greater than the magnetic attraction force that causes it to leave the limiting position.

4. The defocused reader / writer optical system according to claim 1, characterized in that, The limiting mechanism also includes a spring, one end of which is connected to a preset position on the track and the other end is connected to the defocusing component. The baffle is set between the preset position and the defocusing component. Driven by the power source, the rotating shaft rotates continuously, causing the defocusing component to move to the baffle and abut against it to remain stationary.

5. The defocused reader / writer optical system according to claim 1, characterized in that, Each track includes N defocusing components, and each track has N+1 limiting positions, wherein the defocusing components move between two adjacent limiting positions.

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