Reading and writing table device with defocused periphery and unshielded visual field

Abstract

The read-write table device comprises a shell, a spectroscope, an eyepiece and an object distance adjusting panel, the shell is of a closed frame structure with an opening in the front side wall, the eyepiece is embedded in the rear side wall of the shell, and the eyepiece comprises a concave mirror and a retroreflection lens tightly surrounding the peripheral side of the concave mirror; a spectroscope is obliquely arranged in the shell between the opening of the shell and the eyepiece, an object distance adjusting panel is embedded in the lower side wall of the shell, and the size of the object distance adjusting panel is matched with that of the retroreflection lens, so that the middle area of a picture seen by human eyes through the read-write table device is a virtual image, the peripheral area is a real image, and the myopia prevention and control effect can be achieved. The included angle between the side wall of the shell and the eyepiece meets a certain relational expression, so that the included angle between the side wall of the shell and the eyepiece can be determined according to the emergent angle of the edge light, the viewing effect that the visual field is not shielded by the shell is achieved, and the use experience and the visual effect are improved.

Description

Technical Field

[0001] The invention relates to the technical field of reading and writing tables, and in particular to a reading and writing table device with peripheral defocusing and unobstructed visual field. Background Art

[0002] Myopia has become a major public health issue that affects people's health. Long-term close-up viewing and working are one of the important "culprits" in the formation of myopia. The optical system of the reading and writing table can image the desktop content in the air from a long distance, realizing the transformation from "near vision" to "far vision", thereby achieving the purpose of myopia prevention and control.

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

[0004] In addition, the side wall of the common reading and writing table shell is arranged perpendicular to the eyepiece. The lens in the reading and writing table that directly faces the eye and is directly seen by the human eye is the eyepiece, and the eyepiece in the reading and writing table is a concave mirror. As a result, the edge light emitted by the eyepiece will be blocked by the side wall of the shell, resulting in the side wall of the shell surrounding the screen viewed by the user, resulting in a viewing field obstruction problem, which seriously affects the user experience and visual effects. Figure 1 shown.

[0005] By attaching Figure 1 It can be seen from the blue light propagation path shown in that when the right eye observes the left edge of the eyepiece, the light emitted from the left edge of the eyepiece is directed toward the side wall of the shell, and the light will be blocked by the side wall, resulting in the above problem of limited viewing field. 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 shell is not considered, that is, the parameters of the eyepiece directly affect the shape and size of the shell. Only when the shape and size of the shell are compatible with the eyepiece can the side wall of the shell not block the viewing field. Summary of the invention

[0006] In order to solve the problem that some reading and writing desks have insufficient myopia prevention and control effects and the reading and writing desk shell is easy to block the viewing field, the present invention provides a reading and writing desk device with peripheral defocus and unblocked field of view, optimizes the eyepiece structure 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, calculation is performed according to data such as various parameters of the eyepiece to ensure that the angle between the side wall of the reading and writing desk shell and the eyepiece maintains a certain quantitative relationship, thereby ensuring that the viewing field is not blocked by the shell.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is: A reading and writing table device with peripheral defocusing and unobstructed visual field comprises a housing, a beam splitter, an eyepiece and an object distance adjustment panel, wherein the housing is a closed frame structure with an open front side wall, so that personnel can use the reading and writing table normally, and the eyepiece is embedded on the rear side wall of the housing, and the eyepiece comprises a concave mirror and a retroreflective lens tightly surrounding the concave mirror; A beam splitter is obliquely arranged in the shell between the shell opening and the eyepiece, so that the light beam emitted from the middle area of ​​the observed object enters the human eye after being reflected by the beam splitter, reflected by the concave mirror and transmitted by the beam splitter, thereby forming a virtual image; The object distance adjustment panel is embedded in the lower side wall of the housing. The object distance adjustment panel is a square frame surrounded by a plurality of inclined single-layer square lenses. The size of the object distance adjustment panel is adapted to the size of the retroreflective lens, so that the light beam emitted from the peripheral area of ​​the observed object enters 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, thereby forming a real image. The included angle between any left or right side wall of the shell and the eyepiece is preset angle one; the light emission angle at the edge of the concave mirror is preset angle two.

[0008] Furthermore, the shell opening, the beam splitter and the eyepiece are arranged in a straight line in front and back order, and the eyepiece is arranged vertically and perpendicular to the desktop.

[0009] Furthermore, the retroreflective lens in the eyepiece is a square frame made of a glass bead structure or a spherical lens with an embedded aperture structure, which facilitates the retroreflection of light; the size of the concave mirror in the eyepiece is compatible with the size of the central hollow area of ​​the object distance adjustment panel.

[0010] Furthermore, the object distance adjustment panel is arranged horizontally, the object distance adjustment panel is parallel to the desktop, the beam splitter is arranged above the object distance adjustment panel, and the vertical height of the eyepiece is equal to the horizontal width of the object distance adjustment panel; 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 from the inner circle to the outer circle, and the cross-sectional area of ​​the object distance adjustment panel decreases from top to bottom.

[0011] Furthermore, the adjustment amount of the focal length of the object distance adjustment panel is expressed according to the following formula: ;

[0012] in, D max is the maximum value of the optical power adjustment, D min is the minimum value of the optical power adjustment; The maximum and minimum values ​​of the focal length adjustment amount of the object distance adjustment panel are respectively expressed according to the following formulas: ; ;

[0013] in, is the focal length of a single-layer square lens, Adjust the vertical distance from the outer edge of the panel to the desktop for the object distance. Adjust the vertical distance from the inner edge of the panel to the desktop for object distance. 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, It is the horizontal distance from the human eye to the center of the beam splitter.

[0014] Furthermore, a light shield is provided on the upper plane of the object distance adjustment panel, the light shield is a square-shaped sheet, and a plurality of hollow bull's eye patterns are evenly distributed on the light shield, and the bull's eye pattern is a cross or clover-shaped one. The light shield improves the viewing comfort and durability of human eyes.

[0015] Furthermore, the preset angle 1 is expressed according to the following formula: ; in, is the light emission angle at the edge of the concave mirror, H is the concave mirror width, x The inner and outer margins of the retroreflective lens; The preset angle 2 is expressed by the following formula: ; in, 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.

[0016] Furthermore, the beam splitter is arranged at an angle of 45°; The length of the upper side of the beam splitter is expressed by the following formula: ;

[0017] The length of the lower side of the beam splitter is expressed by the following formula: ;

[0018] The beam splitter height is expressed by the following formula: .

[0019] Through the above technical solution, the beneficial effects of the present invention are: The present invention optimizes the eyepiece structure by arranging retroreflective lenses around a concave mirror, the concave mirror and the retroreflective lenses constitute the eyepiece, and then a light beam emitted by an observed object is reflected by a beam splitter to reach the concave mirror, and then is reflected by the concave mirror and transmitted through the beam splitter to enter a human eye, and a reverse extension line of the light beam converges in front of the human eye to form a virtual image; a light beam emitted from a peripheral area of ​​the observed object reaches the beam splitter through an object distance adjustment panel, and then is reflected by the beam splitter to the retroreflective lenses, and the retroreflected light beam is transmitted through the beam splitter and converges 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 myopia prevention and control.

[0020] The present invention proposes a relationship between the angle between the shell side wall and the eyepiece. The angle between the shell side wall and the eyepiece can be obtained according to a series of parameters of the eyepiece and by calculating the corresponding relationship. The shape and size of the shell are judged according to the angle to ensure that the shell side wall does not block the outgoing light from the edge of the concave mirror, thereby achieving a viewing effect in which the field of view is not blocked by the shell, improving the user experience and visual effect. At the same time, on the basis of determining the angle between the shell side wall and the eyepiece, a calculation relationship for the size of the spectroscope is also given, thereby ensuring that the manufactured spectroscope is compatible with the shell and ensuring the good use of the entire reading and writing table. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the state where the side wall of the reading and writing table shell blocks the light emitted from the edge of the eyepiece. In the figure, point A represents the right eye of the human body, and point B represents the center of curvature of the eyepiece.

[0022] Figure 2 It is an overall schematic diagram of a reading and writing table device with peripheral defocusing and unobstructed field of view of the present invention. Point A in the figure represents the position of the enlarged virtual image formed by the observed object passing through the reading and writing table, point B represents the position of the projected real image formed by the observed object passing through the reading and writing table, rectangular area C represents the imaging area of ​​the concave mirror on the table, and square area D represents the imaging area of ​​the retroreflective lens on the table.

[0023] Figure 3 The present invention is a light path diagram of a reading and writing table device with peripheral defocusing and unobstructed visual field. In the diagram, point A represents the lens, point B represents the retina, rectangular area C represents the imaging area of ​​the concave mirror on the table, square area D represents the imaging area of ​​the retroreflective lens on the table, and point E represents the position of the enlarged virtual image formed by the observed object passing through the reading and writing table.

[0024] Figure 4 It is a schematic diagram of the arrangement of various optical components of a reading and writing table device with peripheral defocusing and unobstructed visual field of the present invention, in which A represents a human eye.

[0025] Figure 5It is a light path diagram of a light beam of a reading and writing table device with peripheral defocusing and unobstructed field of view when passing through a retroreflective lens of the present invention. Diagram a shows the light path of the light beam when passing through a retroreflective lens with a glass bead structure, and diagram b shows the light path of the light beam when passing through a retroreflective lens with an aperture structure embedded in a spherical lens. Point A in the figure shows the light spot formed after the light beam passes through the retroreflective lens.

[0026] Figure 6 The present invention is a top view of an object distance adjustment panel of a reading and writing table device with peripheral defocusing and unobstructed visual field.

[0027] Figure 7 It is a top view of a light shielding plate of a reading and writing table device with peripheral defocusing and unobstructed visual field of the present invention, wherein diagrams a and b in the figure show two different types of light shielding plates.

[0028] Figure 8 The light emission angle of the edge of the concave mirror of the reading and writing table device with peripheral defocusing and unobstructed vision is φ The calculation principle diagram, point B represents the center of curvature of the concave mirror.

[0029] Fig. 9 The invention discloses a reading and writing table device with peripheral defocusing and unobstructed visual field. The top view of the shell.

[0030] Fig.10 The invention discloses a reading and writing table device with peripheral defocusing and unobstructed visual field. The top view of the shell.

[0031] The numbers in the accompanying drawings are: 1 housing, 2 beam splitter, 3 eyepiece, 31 concave mirror, 32 retroreflective lens, 4 object distance adjustment panel, 5 light shield, 6 observed object. DETAILED DESCRIPTION

[0032] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings: like Figure 2~Figure 10 As shown, a reading and writing table device with peripheral defocusing and unobstructed visual field 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 front side wall of the housing 1 is open and does not block the visual field, which is convenient for 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, and the open position of the housing 1 does not hinder the propagation of light.

[0033] An eyepiece 3 is embedded on the rear side wall 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 desktop. The eyepiece 3 includes a concave mirror 31 and a retroreflective lens 32 tightly surrounding the concave mirror 31. The concave mirror 31 is 260 mm long, 220 mm wide, and has a curvature radius of 1200 mm, forming a desktop field of view of 400 mm long and 300 mm wide.

[0034] The retroreflective lens 32 is an optical element that can reflect incident light back to the direction of the light source along the original path. The retroreflective lens 32 is a square frame made of a glass bead structure or a spherical lens with an embedded aperture 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 has a width of 60 mm, and the peripheral field of view closely surrounds the viewing field of the concave mirror 31. The incident angle of the light is equal to the exit angle after passing through the retroreflective lens 32, but the sign is opposite.

[0035] If the retroreflective lens 32 adopts a glass bead structure, then the retroreflective lens 32 is composed of densely arranged tiny glass beads, the diameter of the glass beads is 0.1 mm, the refractive index is 2, and the rear surface of the glass beads is coated with a reflective film, thereby achieving light reflection. If the retroreflective lens 32 adopts a ball lens embedded aperture structure, the ball lens embedded aperture means that an aperture aperture is set at the center of the ball lens, the aperture aperture is one tenth of the ball lens diameter, the ball lens diameter is 0.05 mm, the refractive index is 2, and the rear surface of the ball lens is coated with a reflective film.

[0036] The beam splitter 2 is tiltedly arranged in the housing 1 between the opening of the housing 1 and the eyepiece 3, and the beam splitter 2 is tilted at 45 degrees. The opening of the housing 1, the beam splitter 2 and the eyepiece 3 are arranged in a straight line in front and 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.

[0037] The lower side wall of the housing 1 is embedded with an object distance adjustment panel 4, which is arranged horizontally and parallel to the desktop. The beam splitter 2 is arranged above the object distance adjustment panel 4, and the object distance adjustment panel 4 is a square frame surrounded by a plurality of inclined single-layer square lenses, so that the central area of ​​the object distance adjustment panel 4 is hollowed out, 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, and the lower side wall of the housing 1 does not block the central hollow area of ​​the object distance adjustment panel 4.

[0038] The "inclined" in the inclined single-layer square lens means that the longitudinal section of each single-layer square lens is a right-angled 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 of the single-layer square lens is the inner annular surface of the object distance adjustment panel 4. As a result, 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. The side length of the single-layer square lens is 93.5, the focal length is 385, and the angle with the normal line of the desktop is 60°.

[0039] 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, forming a real image. That is, the light beams passing through the single-layer square lens just reach the retroreflective lens 32, increasing the object distance, achieving a farther imaging distance, so that the image is formed behind the human eye, forming a myopic defocus of the peripheral area of ​​the retina.

[0040] The adjustment amount of the focal length of the object distance adjustment panel 4 is expressed according to the following formula:

[0041] in, D max is the maximum value of the optical power adjustment, D min It is the minimum value of the optical power adjustment.

[0042] The maximum and minimum values ​​of the focal adjustment amount of the object distance adjustment panel 4 are expressed according to the following formulas:

[0043]

[0044] in, is the focal length of a single-layer square lens, is the vertical distance from the outer edge of the object distance adjustment panel 4 to the desktop, where 346mm; is the vertical distance from the inner edge of the object distance adjustment panel 4 to the desktop. 300mm; is the vertical distance from the center of the beam splitter 2 to the outer edge of the object distance adjustment panel 4, where 160mm; is the vertical distance from the center of the beam splitter 2 to the inner edge of the object distance adjustment panel 4, where 206mm; is the horizontal distance from the human eye to the center of the beam splitter 2, here It is 245mm.

[0045] Substituting the above data into the formula, it is calculated that the focal adjustment amount of the object distance adjustment panel 4 is 900mm~3000mm, that is, the light beam emitted by the observed object 6 converges at a position 900mm~3000mm behind the human eye after passing through the object distance adjustment panel 4 and the retroreflective lens 32, forming a 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 to achieve clear imaging of the reading and writing table.

[0046] The present invention connects and fixes the beam splitter 2, the eyepiece 3 and the object distance adjustment panel 4 together through 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 achieved that: the light beam emitted from the middle area of ​​the observed object 6 is reflected by the beam splitter 2 to reach the concave mirror 31, and then reflected by the concave mirror 31 and transmitted through the beam splitter 2 to enter the human eye, and 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 reflected by the beam splitter 2 to the retroreflective lens 32, and the retroreflected light beam is transmitted through the beam splitter 2 and converges behind the human eye to form a real image. As a result, 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.

[0047] 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 ambient 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, wherein the beam splitter 2 is on the hypotenuse, and the eyepiece 3 and the object distance adjustment panel 4 are respectively on two adjacent right-angled sides.

[0048] Since different groups of people have different degrees of acceptance of defocus signals, in order to optimize the product structure and improve the comfort and durability of human eyes when using the reading and writing table, a light blocking plate 5 is also provided on the plane of the object distance adjustment panel 4. The light blocking plate 5 is a square-shaped sheet made of light-shielding material. The light blocking plate 5 can be directly placed on the plane of the object distance adjustment panel 4, and the size of the light blocking plate 5 is adapted to that of the object distance adjustment panel 4.

[0049] A plurality of hollow bull's-eye patterns are evenly distributed on the light shielding plate 5, and the bull's-eye pattern is a cross-shaped or clover-shaped one. Specifically, each cross-shaped hollow pattern includes four fan-shaped holes with a central angle of 90°, and the four fan-shaped holes are evenly arranged in a circle. Each clover-shaped hollow pattern includes three fan-shaped holes with a central angle of 120°, and the three fan-shaped holes are evenly arranged in a circle.

[0050] With the cooperation of the light blocking plate 5 and the object distance adjustment panel 4, a small amount of light passing through the object distance adjustment panel 4 is transmitted from the hollow part of the bull's eye pattern and finally reaches the back of the human eye, forming myopic defocus. The rest of the light passing through the object distance adjustment panel 4 is blocked by the light blocking plate 5, reducing the aberration and glare caused by defocus, avoiding visual fatigue caused by large-area defocus signals, and improving the comfort and durability of use.

[0051] 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 shell 1, the angle between the left side wall or the right side wall of the shell 1 and the eyepiece 3 needs to be determined. The corresponding calculation is performed based on various parameters of the eyepiece 3 to obtain the angle between the left and right side walls of the shell 1 and the eyepiece 3. The shell 1 is manufactured according to the size of the angle, thereby ensuring that the shell 1 does not block the viewing field.

[0052] In this embodiment, the angle between any left or right side wall of the housing 1 and the eyepiece 3 is expressed by the following formula:

[0053] in, is the light emission angle at the edge of the concave mirror 31, H is the width of the concave mirror 31, the value is 220 mm, x The inner and outer margins of the retroreflective mirror 32 are 50 mm. Therefore, the angle between the side wall of the housing 1 and the eyepiece 3 is determined according to the light emission angle of the edge of the concave mirror 31, so as to achieve a viewing effect in which the visual field is not blocked by the housing 1.

[0054] The light emission angle at the edge of the concave mirror 31 is expressed by the following formula:

[0055] in, W is the length of the concave mirror 31, the value is 260 mm; The standard binocular distance is 65mm. The distance from the human eye to the center of the concave mirror 31 is 400 mm; is the curvature radius of the concave mirror 31, and its value is 1200 mm.

[0056] It should be noted that: , ; According to the geometric relationship, we can get , that is ; At the same time, from the cosine theorem, we know ; Combined with the sine theorem, we know , the angle between the side wall of the shell 1 and the eyepiece 3 is obtained by sorting .

[0057] Substituting the above data into the formula, we can get is 9.7°, and we get is 57.1 mm, which is greater than the width of the retroreflective lens 32. , the edge light will be blocked by the side wall of the shell 1, and the angle between the side wall of the shell 1 and the eyepiece 3 needs to be determined according to the angle of the edge light. Substituting the calculation formula into the relevant parameter values, the angle between the side wall of the shell 1 and the eyepiece 3 can be obtained. is 90.7°, thus determining the shape and size of the housing 1 and making it. That is, when the edge light is not blocked by the side wall of the housing 1, Just take 90°; After determining the shape and size of the housing 1, the size of the beam splitter 2 also needs to be determined. Specifically, the length of the upper side of the beam splitter 2 is expressed according to the following formula:

[0058] The length of the upper side 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; The length of the lower side of the beam splitter 2 is expressed by the following formula:

[0059] The length of the lower side of the beam splitter 2 is the width of the side of the beam splitter 2 near the lower end of the eyepiece 3, and the height of the housing 1 is ; The height of beam splitter 2 is expressed by the following formula:

[0060] Substituting the above data into the formula, it can be calculated 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 compatible with the housing 1, ensures the reliability of the assembly of each component, and realizes the normal and good use of the reading and writing table to better meet the actual use needs.

[0061] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes or modifications made according to the structures, features and principles described in the patent scope of the present invention should be included in 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 in the rear side wall of the housing (1); the eyepiece (3) comprises a concave mirror (31) and a retroreflective lens (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 a 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 preset angle one; and the light emission angle at the edge of the concave mirror (31) is preset angle two.

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 order, 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 defocusing and unobstructed field of view according to claim 4, characterized in that: The adjustment amount of the optical focal length of the object distance adjustment panel (4) is expressed according to the following formula: ； in, D max is the maximum value of the optical power adjustment, D 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: ； ； in, is the focal length of a single-layer square lens, is the vertical distance from the outer edge of the object distance adjustment panel (4) to the desktop, is the vertical distance from the inner edge of the object distance adjustment panel (4) to the desktop, is the vertical distance from the center of the beam splitter (2) to the outer edge of the object distance adjustment panel (4), is the vertical distance from the center of the beam splitter (2) to the inner edge of the object distance adjustment panel (4), 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 the shape of a square frame, 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 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), x The inner and outer margins of the retroreflective lens (32); The preset angle 2 is expressed by the following formula: ； in, W is the length of the concave mirror (31), is the standard binocular distance, is the distance from the human eye to the center of the concave mirror (31), is the radius of curvature of the concave mirror (31).

8. A reading and writing table device with peripheral defocus and unobstructed field of view according to claim 7, 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: ； 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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