A reading and writing table device with peripheral defocus and unobstructed vision

Abstract

The present invention relates to a reading and writing table device with peripheral defocus and unobstructed vision, which includes a housing, a beam splitter, an eyepiece, and an object distance adjustment panel. The housing is a closed frame structure with an open front sidewall. The eyepiece is embedded on the rear sidewall of the housing. The eyepiece includes a concave mirror and a retroreflective lens tightly surrounding the periphery of the concave mirror. A beam splitter is inclinedly arranged in the housing between the open part of the housing and the eyepiece. The object distance adjustment panel is embedded on the lower sidewall of the housing, and the size of the object distance adjustment panel is adapted to the size of the retroreflective lens, so that the middle area of the picture seen by the human eye through the reading and writing table device is a virtual image, and the peripheral area is a real image, which can achieve the effect of preventing and controlling myopia. The included angle between the sidewall of the housing and the eyepiece satisfies a certain relational expression, so that the included angle between the sidewall of the housing and the eyepiece can be determined according to the exit angle of the marginal light rays, so as to achieve the viewing effect that the vision is not blocked by the housing, and improve the use experience and visual effect.

Description

Technical Field

[0001] The present invention relates to the technical field of reading and writing desks, and particularly to a reading and writing desk device with peripheral defocus and unobstructed vision. Background Art

[0002] Myopia has become a major public health problem affecting people's health. Long-term close viewing and working are one of the important "culprits" for the formation of myopia. The optical system of the reading and writing desk can image the desktop content at a long distance in the air, realizing the transformation from "near vision" to "distant vision", so as to achieve the purpose of myopia prevention and control.

[0003] A large number of studies have shown that peripheral defocus of the viewing content can make the imaging focus on the peripheral retina fall in front of the retina, forming myopic defocus and delaying the growth of the eye axis, thus playing a role in preventing myopia or delaying the development of myopia. However, some reading and writing desks do not have the defocus function, and thus the myopia prevention and control effect is poor.

[0004] Moreover, the side walls of the common reading and writing desk housing are arranged perpendicular to the eyepiece. The lens directly facing the eyes and directly seen by the human eyes in the reading and writing desk is the eyepiece, and the eyepiece in the reading and writing desk is a concave mirror. In this way, the marginal light rays emitted by the eyepiece will be blocked by the side walls of the housing, resulting in the peripheral part of the picture seen by the user being the side walls of the housing, and there is a problem of blocked viewing field of vision, seriously affecting the use experience and visual effect, as shown in the appendix. Figure 1 as shown.

[0005] Through the blue light propagation path shown in the appendix. Figure 1 It can be seen that when the right eye observes the left edge of the eyepiece, the light rays emitted from the left edge of the eyepiece are directed towards the side wall of the housing, and the light rays will be blocked by the side wall, thus resulting in the above problem of limited viewing field of vision. The reason is that on the basis of certain parameters of the eyepiece, the relationship between the eyepiece parameters and the shape and size of the housing is not considered. That is to say, the parameters of the eyepiece directly affect the shape and size of the housing. Only when the shape and size of the housing are adapted to the eyepiece can it be ensured that the side wall of the housing does not block the viewing field of vision. Summary of the Invention

[0006] In order to solve the problems of insufficient myopia prevention and control effect of some reading and writing desks and the easy blocking of the viewing field of vision by the housing of the reading and writing desk, the present invention provides a reading and writing desk device with peripheral defocus and unobstructed vision, optimizes the structure of the eyepiece to make the middle area of the picture seen by the human eye through the reading and writing desk device a virtual image and the peripheral area a real image, thereby achieving the effect of myopia prevention and control; at the same time, according to data such as the parameters of the eyepiece, calculations are carried out to ensure that the included angle between the side wall of the reading and writing desk housing and the eyepiece maintains a certain quantitative relationship, so as to ensure that the viewing field of vision is not blocked by the housing.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A reading and writing table device with peripheral defocus and unobstructed vision, comprising a housing, a beam splitter, an eyepiece and an object distance adjustment panel. The housing is a closed frame structure with an open front side wall, facilitating normal use of the reading and writing table by personnel. The eyepiece is embedded in the rear side wall of the housing. The eyepiece includes a concave mirror and a retroreflective lens tightly surrounding the periphery of the concave mirror.

[0009] The beam splitter is inclined in the housing between the open part of the housing and the eyepiece, causing the light beam emitted from the middle area of the observed object to enter the human eye after being reflected by the beam splitter, reflected by the concave mirror and transmitted by the beam splitter, forming a virtual image.

[0010] The object distance adjustment panel is embedded in the lower side wall of the housing. The object distance adjustment panel is a square frame formed by several inclined single-layer square lenses. The size of the object distance adjustment panel is adapted to the size of the retroreflective lens, causing the light beam emitted from the peripheral area of the observed object to enter the human eye after being transmitted by the object distance adjustment panel, reflected by the beam splitter, reflected by the retroreflective lens and transmitted by the beam splitter, forming a real image.

[0011] The included angle between any left or right side wall of the housing and the eyepiece is a preset angle one; the light beam exit angle at the edge of the concave mirror is a preset angle two.

[0012] Further, the open position of the housing, the beam splitter and the eyepiece are arranged in a straight line from front to back in sequence, and the eyepiece is arranged vertically and perpendicular to the desktop.

[0013] Further, the retroreflective lens in the eyepiece is a square frame made of a glass bead structure or a spherical lens embedded with a diaphragm structure, facilitating the realization of retroreflection of light; the size of the concave mirror in the eyepiece is adapted to the size of the central hollow area of the object distance adjustment panel.

[0014] Further, the object distance adjustment panel is arranged horizontally, parallel to the desktop. The beam splitter is arranged above the object distance adjustment panel. The vertical height of the eyepiece is equal to the horizontal width of the object distance adjustment panel.

[0015] The longitudinal section of each single-layer square lens in the object distance adjustment panel is a right triangle. The thickness of the object distance adjustment panel decreases sequentially from the inner circle to the outer circle, and the cross-sectional area of the object distance adjustment panel decreases sequentially from top to bottom.

[0016] Further, the adjustment amount of the optical power of the object distance adjustment panel is expressed by the following formula:

[0017] ;

[0018] Wherein, D max is the maximum value of the optical power adjustment amount, D min is the minimum value of the optical power adjustment amount;

[0019] The maximum and minimum values of the optical power adjustment amount of the object distance adjustment panel are respectively expressed by the following formulas:

[0020] ;

[0021] ;

[0022] wherein, is the focal length of the single-layer square lens, is the vertical distance from the outer edge of the object distance adjustment panel to the tabletop, is the vertical distance from the inner edge of the object distance adjustment panel to the tabletop, is the vertical distance from the center of the beam splitter to the outer edge of the object distance adjustment panel, is the vertical distance from the center of the beam splitter to the inner edge of the object distance adjustment panel, is the horizontal distance from the human eye to the center of the beam splitter.

[0023] Furthermore, a light shield is provided on the upper plane of the object distance adjustment panel. The light shield is a sheet body in the shape of a square frame, and a plurality of hollow bull's-eye patterns are evenly distributed on the light shield. The bull's-eye pattern is one of a cross shape or a clover shape. The light shield improves the comfort and durability of human eye viewing.

[0024] Furthermore, the preset angle one is expressed by the following formula:

[0025] ;

[0026] wherein, is the exit angle of the marginal ray of the concave mirror, H is the width of the concave mirror, x is the inner and outer margin of the retroreflective lens;

[0027] The preset angle two is expressed by the following formula:

[0028] ;

[0029] wherein, W is the length of the concave mirror, is the standard binocular distance, is the distance from the human eye to the center of the concave mirror, is the radius of curvature of the concave mirror.

[0030] Furthermore, the beam splitter is arranged at a 45° inclination;

[0031] The upper side length of the beam splitter is expressed by the following formula:

[0032] ;

[0033] The side length of the spectroscope is expressed by the following formula:

[0034] ;

[0035] The height of the spectroscope is expressed by the following formula:

[0036] .

[0037] By the above technical solutions, the beneficial effects of the present invention are as follows:

[0038] In the present invention, the eyepiece structure is optimized to arrange retroreflective lenses around the concave mirror. The concave mirror and the retroreflective lenses form the eyepiece. Then, the light beam emitted by the object to be observed is reflected by the spectroscope and reaches the concave mirror, and then is reflected by the concave mirror and transmitted through the spectroscope into the human eye. The reverse extension line of the light beam converges in front of the human eye to form a virtual image; the light beam emitted by the peripheral area of the object to be observed reaches the spectroscope through the object distance adjustment panel, and then is reflected by the spectroscope to the retroreflective lens. The retroreflected light beam is transmitted and converged by the spectroscope behind the human eye to form a real image. That is, the middle area of the picture seen by the human eye through the reading and writing table device is a virtual image, and the peripheral area is a real image, thereby achieving the effect of preventing and controlling myopia.

[0039] The present invention proposes a relational expression for the angle between the side wall of the housing and the eyepiece. According to a series of parameters of the eyepiece and through the calculation of the corresponding relational expression, the angle between the side wall of the housing and the eyepiece can be obtained. According to this angle, the shape and size of the housing can be judged to ensure that the side wall of the manufactured housing does not block the outgoing light rays at the edge of the concave mirror, thereby achieving the viewing effect that the field of view is not blocked by the housing and improving the use experience and visual effect. At the same time, on the basis of determining the angle between the side wall of the housing and the eyepiece, a calculation relational expression for the size of the spectroscope is also given, so as to ensure that the manufactured spectroscope is adapted to the housing and ensure the good use of the entire reading and writing table. Description of the Drawings

[0040] Figure 1 It is a schematic diagram of the state where the side wall of the reading and writing table housing blocks the outgoing light rays at the edge of the eyepiece. In the figure, point A represents the right eye of the human body, and point B represents the curvature center of the eyepiece.

[0041] Figure 2 It is an overall schematic diagram of a reading and writing table device with peripheral defocus and unobstructed field of view according to the present invention. In the figure, point A represents the position of the magnified virtual image formed by the object to be observed passing through the reading and writing table, point B represents the position of the projected real image formed by the object to be observed passing through the reading and writing table, the C rectangular area represents the imaging area of the concave mirror on the desktop, and the D square area represents the imaging area of the retroreflective lens on the desktop.

[0042] Figure 3This is the optical path diagram of a reading and writing table device with peripheral defocus and unobstructed vision according to the present invention. In the figure, point A represents the lens, point B represents the retina, rectangular area C represents the imaging area of the concave mirror on the tabletop, square area D represents the imaging area of the retroreflective lens on the tabletop, and point E represents the position of the magnified virtual image formed by the object to be observed passing through the reading and writing table.

[0043] Figure 4 This is a schematic diagram of the arrangement state of each optical component of a reading and writing table device with peripheral defocus and unobstructed vision according to the present invention. In the figure, A represents the human eye.

[0044] Figure 5 This is the optical path diagram when the light beam of a reading and writing table device with peripheral defocus and unobstructed vision passes through the retroreflective lens. Diagram a shows the optical path when the light beam passes through the retroreflective lens with a glass bead structure, and diagram b shows the optical path when the light beam passes through the retroreflective lens with a ball lens embedded diaphragm structure. In the figure, point A represents the light spot formed after the light beam passes through the retroreflective lens.

[0045] Figure 6 This is the top view of the object distance adjustment panel of a reading and writing table device with peripheral defocus and unobstructed vision according to the present invention.

[0046] Figure 7 This is the top view of the light blocking plate of a reading and writing table device with peripheral defocus and unobstructed vision according to the present invention. Diagrams a and b in the figure show two different types of light blocking plates.

[0047] Figure 8 This is the calculation schematic diagram of the light exit angle of the edge light of the concave mirror of a reading and writing table device with peripheral defocus and unobstructed vision according to the present invention. φ Point B represents the center of curvature of the concave mirror.

[0048] Figure 9 This is a reading and writing table device with peripheral defocus and unobstructed vision according to the present invention. Top view of the housing at [specific time].

[0049] Figure 10 This is a reading and writing table device with peripheral defocus and unobstructed vision according to the present invention. Top view of the housing at [specific time].

[0050] In the attached drawings, the reference numerals are: 1 housing, 2 beam splitter, 3 eyepiece, 31 concave mirror, 32 retroreflective lens, 4 object distance adjustment panel, 5 light blocking plate, 6 object to be observed. Detailed Description of the Invention

[0051] The following describes in detail the specific embodiments of the present invention with reference to the accompanying drawings:

[0052] As Figures 2 to 10As shown in the figure, a reading and writing table device with peripheral defocus and unobstructed vision includes a housing 1, a beam splitter 2, an eyepiece 3, and an object distance adjustment panel 4. The housing 1 is a closed frame structure with an open front sidewall. The open front sidewall of the housing 1 does not block the line of sight, facilitating the normal viewing and use of the reading and writing table. The beam splitter 2, the eyepiece 3, and the object distance adjustment panel 4 are all centrally arranged on the housing 1 and supported by the housing 1. At the same time, the open position of the housing 1 does not hinder the propagation of light.

[0053] The eyepiece 3 is embedded in the rear sidewall of the housing 1, and the eyepiece 3 corresponds to the open position of the housing 1. The eyepiece 3 is arranged vertically and perpendicular to the tabletop. The eyepiece 3 includes a concave mirror 31 and a retroreflective lens 32 closely surrounding the periphery of the concave mirror 31. The length of the concave mirror 31 is 260 mm, the width is 220 mm, and the radius of curvature is 1200 mm, forming a tabletop field of view with a length of 400 mm and a width of 300 mm.

[0054] The retroreflective lens 32 is an optical element that can reflect incident light back in the original path towards the light source direction. The retroreflective lens 32 is a square box made of a glass bead structure or a spherical lens with an embedded aperture stop structure. The width of the retroreflective lens 32 is 50 mm, that is, the inner and outer margins of the retroreflective lens 32 are 50 mm. The peripheral field of view formed by the retroreflective lens 32 is 60 mm wide, and the peripheral field of view closely surrounds the viewing field of the concave mirror 31. The incident angle of light is equal in value and opposite in sign to the exit angle after passing through the retroreflective lens 32.

[0055] If the retroreflective lens 32 adopts a glass bead structure, then the retroreflective lens 32 is composed of densely arranged tiny glass beads with a diameter of 0.1 mm and a refractive index of 2. The rear surface of the glass beads is coated with a reflective film to achieve light reflection. If the retroreflective lens 32 adopts a spherical lens with an embedded aperture stop structure, the spherical lens with an embedded aperture stop means that an aperture stop is set at the center inside the spherical lens. The clear aperture of the aperture stop is one-tenth of the diameter of the spherical lens. The diameter of the spherical lens is 0.05 mm and the refractive index is 2. The rear surface of the spherical lens is coated with a reflective film.

[0056] The beam splitter 2 is inclined inside the housing 1 between the open position of the housing 1 and the eyepiece 3. The beam splitter 2 is arranged at a 45° inclination. The open position of the housing 1, the beam splitter 2, and the eyepiece 3 are arranged in a straight line in sequence from front to back. In this way, the light beam emitted from the middle area of the observed object 6 enters the human eye after being reflected by the beam splitter 2, reflected by the concave mirror 31, and transmitted by the beam splitter 2, forming a virtual image.

[0057] The object distance adjustment panel 4 is embedded in the lower side wall of the housing 1. The object distance adjustment panel 4 is horizontally arranged and parallel to the desktop. The beam splitter 2 is arranged above the object distance adjustment panel 4. The object distance adjustment panel 4 is a square box formed by several inclined single-layer square lenses. Thus, the central area of the object distance adjustment panel 4 is hollow, and the size of the concave mirror 31 is adapted to the size of the central hollow area of the object distance adjustment panel 4. The lower side wall of the housing 1 does not block the central hollow area of the object distance adjustment panel 4.

[0058] The "inclined" in the inclined single-layer square lens means that the longitudinal section of each single-layer square lens is a right triangle. One right-angled surface of the single-layer square lens is the upper plane of the object distance adjustment panel 4, and the other right-angled surface is the inner ring surface of the object distance adjustment panel 4. In this way, the thickness of the object distance adjustment panel 4 in the object distance adjustment panel 4 decreases sequentially from the inner circle to the outer circle, and the cross-sectional area of the object distance adjustment panel 4 decreases sequentially from top to bottom. The side length of the single-layer square lens is 93.5, the focal length is 385, and the included angle with the desktop normal is 60°.

[0059] The size of the object distance adjustment panel 4 is adapted to the size of the retroreflective lens 32. In this way, the light beam emitted from the peripheral area of the observed object 6 enters the human eye after passing through the object distance adjustment panel 4, being reflected by the beam splitter 2, reflected by the retroreflective lens 32, and transmitted by the beam splitter 2, forming a real image. That is, the light beam passing through the single-layer square lens just reaches the retroreflective lens 32, increasing the object distance and achieving a farther imaging distance, so as to form a myopic defocus imaging in the peripheral area of the retina behind the human eye.

[0060] The adjustment amount of the optical power of the object distance adjustment panel 4 is expressed by the following formula:

[0061]

[0062] Where, D max is the maximum value of the optical power adjustment amount, D min is the minimum value of the optical power adjustment amount.

[0063] The maximum and minimum values of the optical power adjustment amount of the object distance adjustment panel 4 are expressed by the following formulas respectively:

[0064]

[0065]

[0066] Where, is the focal length of the single-layer square lens, is the vertical distance from the outer edge of the object distance adjustment panel 4 to the desktop, where is 346mm; is the vertical distance from the inner edge of the object distance adjustment panel 4 to the desktop. Here is 300 mm; is the vertical distance from the center of the beam splitter 2 to the outer edge of the object distance adjustment panel 4. Here is 160 mm; is the vertical distance from the center of the beam splitter 2 to the inner edge of the object distance adjustment panel 4. Here is 206 mm; is the horizontal distance from the human eye to the center of the beam splitter 2. Here is 245 mm.

[0067] Substituting the above data into the formula, it can be calculated that the optical power adjustment amount of the object distance adjustment panel 4 is 900 mm to 3000 mm, that is, the light beam emitted by the observed object 6 passes through the object distance adjustment panel 4 and the retroreflective lens 32 and converges at a position 900 mm to 3000 mm behind the human eye, forming myopic defocus. The convergence and divergence of light can be controlled by changing the viewing distance of the human eye or changing the height of the reading and writing table, so as to achieve clear imaging of the reading and writing table.

[0068] In the present invention, the beam splitter 2, the eyepiece 3 and the object distance adjustment panel 4 are connected and fixed together by the housing 1, and through the cooperation of the beam splitter 2, the eyepiece 3 and the object distance adjustment panel 4, it can be realized that: the light beam emitted from the middle area of the observed object 6 is reflected by the beam splitter 2 and reaches the concave mirror 31, and then after being reflected by the concave mirror 31, it passes through the beam splitter 2 and is transmitted into the human eye. The reverse extension line of the light beam converges in front of the human eye to form a virtual image. The light beam emitted from the peripheral area of the observed object 6 reaches the beam splitter 2 through the object distance adjustment panel 4, and then is reflected by the beam splitter 2 to the retroreflective lens 32, and the retroreflected light beam is transmitted and converged by the beam splitter 2 behind the human eye to form a real image. In this way, the middle area of the picture seen by the human eye through the reading and writing table device is a virtual image, and the peripheral area is a real image, which can achieve the effect of myopia prevention and control.

[0069] It should be noted that: the observed object 6 can be a book or an electronic screen, and the light beam emitted by the observed object 6 refers to the light reflected by the natural environmental light acting on the book, or the light emitted by the internal light source of the electronic screen. The beam splitter 2, the eyepiece 3 and the object distance adjustment panel 4 are arranged in an isosceles right triangle after being connected and combined, where the beam splitter 2 is on the hypotenuse, and the eyepiece 3 and the object distance adjustment panel 4 are on the adjacent two right sides respectively.

[0070] Since different people have different acceptance degrees of defocus signals, in order to optimize the product structure and improve the comfort and durability of the human eye using the reading and writing table for viewing, a light shielding plate 5 is also provided on the upper plane of the object distance adjustment panel 4. The light shielding plate 5 is a sheet body in the shape of a square frame made of light shielding material. The light shielding plate 5 can be directly placed on the upper plane of the object distance adjustment panel 4, and the light shielding plate 5 is adapted to the size of the object distance adjustment panel 4.

[0071] A number of hollow bull's-eye patterns are evenly distributed on the light baffle 5, and the bull's-eye pattern is one of a cross shape or a clover shape. Specifically, each cross-shaped hollow pattern includes four sector holes with a central angle of 90°, and the four sector holes are evenly arranged in a circle. Each clover-shaped hollow pattern includes three sector holes with a central angle of 120°, and the three sector holes are evenly arranged in a circle.

[0072] With the cooperation of the light baffle 5 and the object distance adjustment panel 4, a small part of the light passing through the object distance adjustment panel 4 passes through the hollow part of the bull's-eye pattern and finally reaches the back of the human eye, forming myopic defocus. The remaining light passing through the object distance adjustment panel 4 is blocked by the light baffle 5, reducing the aberration and glare caused by defocus, avoiding visual fatigue caused by a large area of defocus signals, and improving the comfort and durability of use.

[0073] The present invention has a peripheral defocus function and has the effect of preventing myopia or delaying the development of myopia. In order to prevent the viewing field of the human eye from being blocked by the side wall of the housing 1, the included angle between the left or right side wall of the housing 1 and the eyepiece 3 needs to be determined. Based on the various parameters of the eyepiece 3, corresponding calculations can be performed to obtain the included angles between the left and right side walls of the housing 1 and the eyepiece 3. The housing 1 is manufactured according to the size of this included angle, so as to ensure that the housing 1 does not block the viewing field.

[0074] In this embodiment, the included angle between any left or right side wall of the housing 1 and the eyepiece 3 is expressed by the following formula:

[0075]

[0076] Among them, is the light exit angle of the edge of the concave mirror 31, H is the width of the concave mirror 31, with a value of 220 mm, x is the inner and outer margin of the retroreflective lens 32, with a value of 50 mm. Thus, according to the light exit angle of the edge of the concave mirror 31, the included angle between the side wall of the housing 1 and the eyepiece 3 is determined to achieve the viewing effect that the field of view is not blocked by the housing 1.

[0077] The light exit angle of the edge of the concave mirror 31 is expressed by the following formula:

[0078]

[0079] Among them, W is the length of the concave mirror 31, with a value of 260 mm; is the standard binocular distance, with a value of 65 mm; is the distance from the human eye to the center of the concave mirror 31, with a value of 400 mm; is the radius of curvature of the concave mirror 31, with a value of 1200 mm.

[0080] It should be noted that: , ;

[0081] According to the geometric relationship, it can be obtained that , that is ;

[0082] At the same time, it can be known from the cosine theorem that ;

[0083] Combined with the sine theorem, it can be known that , and after arrangement, the included angle between the side wall of the housing 1 and the eyepiece 3 is .

[0084] Substituting the above data into the formula for calculation, it can be obtained that is 9.7°, and at the same time, is 57.1 mm, and this value is greater than the width of the retroreflective lens 32, that is, at this time , the marginal rays will be blocked by the side wall of the housing 1. It is necessary to determine the included angle between the side wall of the housing 1 and the eyepiece 3 according to the emergence angle of the marginal rays. According to the calculation formula of, substituting the relevant parameter values, the included angle between the side wall of the housing 1 and the eyepiece 3 can be obtained is 90.7°, so as to determine the shape and size of the housing 1 and manufacture it. And when that is, the outermost marginal rays will not be blocked by the side wall of the housing 1, taking 90° is sufficient;

[0085] After determining the shape and size of the housing 1, the size of the beam splitter 2 also needs to be determined. Specifically, the upper side length of the beam splitter 2 is expressed by the following formula:

[0086]

[0087] The upper side length of the beam splitter 2 is the width of the side of the beam splitter 2 close to the upper end of the eyepiece 3;

[0088] The lower side length of the beam splitter 2 is expressed by the following formula:

[0089]

[0090] The lower side length of the beam splitter 2 is the width of the side of the beam splitter 2 close to the lower end of the eyepiece 3, and the height of the housing 1 is ;

[0091] The height of the beam splitter 2 is expressed by the following formula:

[0092]

[0093] Substituting the above data into the formula for calculation, it can be obtained that the upper side length of the beam splitter 2 is 360 mm, the lower side length is 368 mm, and the height of the beam splitter 2 is 453 mm. This makes the size of the beam splitter 2 match the housing 1, ensuring the reliability of the assembly of each component and enabling the normal and good use of the reading and writing table, so as to better meet the actual use requirements.

[0094] The above-described embodiments are only preferred embodiments of the present invention and do not limit the scope of implementation of the present invention. Therefore, any equivalent changes or modifications made according to the structure, features, and principles described in the scope of the present invention patent should be included within the scope of the patent application of the present invention.

Claims

1. A reading and writing table device with peripheral defocusing and unobstructed field of view, characterized in that: The invention comprises a housing (1), a beam splitter (2), an eyepiece (3) and an object distance adjustment panel (4); the housing (1) is a closed frame structure with an open front side wall; the eyepiece (3) is embedded on the rear side wall of the housing (1); the eyepiece (3) comprises a concave mirror (31) and a retroreflective mirror (32) tightly surrounding the concave mirror (31); A beam splitter (2) is obliquely arranged in the shell (1) between the opening of the shell (1) and the eyepiece (3), so that a light beam emitted from the middle area of ​​the observed object (6) enters the human eye after being reflected by the beam splitter (2), reflected by the concave mirror (31) and transmitted by the beam splitter (2), thereby forming a virtual image; The object distance adjustment panel (4) is embedded in the lower side wall of the housing (1); the object distance adjustment panel (4) is a square frame formed by a plurality of inclined single-layer square lenses; the size of the object distance adjustment panel (4) matches the size of the retroreflective lens (32), so that the light beam emitted from the peripheral area of ​​the observed object (6) enters the human eye after being transmitted through the object distance adjustment panel (4), reflected by the beam splitter (2), reflected by the retroreflective lens (32), and transmitted by the beam splitter (2), thereby forming a real image; The included angle between any left or right side wall of the housing (1) and the eyepiece (3) is a preset angle 1; the light emission angle at the edge of the concave mirror (31) is a preset angle 2; The preset angle 1 is expressed according to the following formula: in, is the light emission angle at the edge of the concave mirror (31), H is the width of the concave mirror (31), and x is the inner and outer margins of the retroreflective mirror (32); The preset angle 2 is expressed by the following formula: Wherein, W is the length of the concave mirror (31), ω is the standard binocular distance, L is the distance from the human eye to the center of the concave mirror (31), and R is the curvature radius of the concave mirror (31).

2. A reading and writing table device with peripheral defocus and unobstructed field of view according to claim 1, characterized in that: The open position of the shell (1), the beam splitter (2) and the eyepiece (3) are arranged in a straight line in front and back, and the eyepiece (3) is arranged vertically and perpendicular to the desktop.

3. A reading and writing table device with peripheral defocus and unobstructed field of view according to claim 1, characterized in that: The retroreflective lens (32) in the eyepiece (3) is a square frame made of a glass bead structure or a spherical lens embedded aperture structure; the size of the concave mirror (31) in the eyepiece (3) is compatible with the size of the central hollow area of ​​the object distance adjustment panel (4).

4. A reading and writing table device with peripheral defocus and unobstructed field of view according to claim 1, characterized in that: The object distance adjustment panel (4) is arranged horizontally, the object distance adjustment panel (4) is parallel to the desktop, and the beam splitter (2) is arranged above the object distance adjustment panel (4); The longitudinal section of each single-layer square lens in the object distance adjustment panel (4) is a right triangle, the thickness of the object distance adjustment panel (4) decreases from the inner circle to the outer circle, and the cross-sectional area of ​​the object distance adjustment panel (4) decreases from top to bottom.

5. A reading and writing table device with peripheral defocus and unobstructed field of view according to claim 4, characterized in that: The adjustment amount of the focal length of the object distance adjustment panel (4) is expressed according to the following formula: D∈{D|D min ≤D≤D max }; Among them, D max D is the maximum value of the optical power adjustment. min is the minimum value of the optical power adjustment; The maximum value and the minimum value of the focal length adjustment amount of the object distance adjustment panel (4) are respectively expressed according to the following formulas: Where, f is the focal length of a single-layer square lens, l 桌外 is the vertical distance from the outer edge of the object distance adjustment panel (4) to the desktop, l 桌内 is the vertical distance from the inner edge of the object distance adjustment panel (4) to the desktop, l′ 外 is the vertical distance from the center of the beam splitter (2) to the outer edge of the object distance adjustment panel (4), l′ 内 is the vertical distance from the center of the beam splitter (2) to the inner edge of the object distance adjustment panel (4), and z is the horizontal distance from the human eye to the center of the beam splitter (2).

6. A reading and writing table device with peripheral defocus and unobstructed field of view according to claim 4, characterized in that: A light blocking plate (5) is also provided on the upper plane of the object distance adjustment panel (4); the light blocking plate (5) is a sheet in a square frame shape, and a plurality of hollow bull's eye patterns are evenly distributed on the light blocking plate (5).

7. A reading and writing table device with peripheral defocus and unobstructed field of view according to claim 1, characterized in that: The beam splitter (2) is arranged at an angle of 45°; The length of the upper side of the beam splitter (2) is expressed by the following formula: <h2 style=";text-align:left;direction:ltr">l<h2 style=";text-align:left;direction:ltr"> u <h2 style=";text-align:left;direction:ltr"> (W+2x) The length of the lower side of the beam splitter (2) is expressed by the following formula: The height of the beam splitter (2) is expressed by the following formula:

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