Folding desktop far image read-write device
By using a damped hinge design and a folding structure for the coaxial optical path, the problem of the large size of desktop far-view reading and writing devices has been solved, and the folding and myopia prevention functions of the devices have been realized.
Patent Information
- Application Number
- CN202520176222.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-27
- Publication Date
- 2026-01-16
- Estimated Expiration
- 2035-01-27
AI Technical Summary
Existing desktop image reading and writing devices are large in size, occupying a significant amount of desktop space, and cannot effectively reduce their size when not in use.
The device employs a damped rotating shaft design, using a coaxial optical path composed of a planar beam splitter and a concave reflector, combined with a rotatable cover plate and back plate structure, to achieve folding and angle adjustment, ensuring imaging quality.
Without changing the virtual image distance, the height of the exit pupil relative to the desktop is adjusted to achieve device folding, reduce the size when not in use, and provide myopia prevention function.
Smart Images
Figure CN223808605U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a folding desktop far image reading and writing equipment. BACKGROUND
[0002] At present, the myopia problem of teenagers is increasingly serious, and the fundamental reason is that the eyes of teenagers focus on a relatively close range most of the time. In order to adapt to close-range imaging, the eye axis gradually becomes longer. In order to solve this problem, various myopia prevention and control products have emerged in the market.
[0003] Among them, the desktop far image reading and writing equipment is a device that uses optical means to image a close-range reading and writing at a distance. It is mainly used in the field of myopia prevention and control of teenagers. In order to ensure that the desktop far image reading and writing equipment has a large enough field of view, such as being able to image a fully opened A4-sized book, the overall volume of the desktop far image reading and writing equipment is relatively large, occupying a large space on the desktop. In order to reduce the volume of the desktop far image reading and writing equipment in the non-use state, a folding desktop far image reading and writing equipment is provided. SUMMARY
[0004] The technical problem to be solved by the utility model is to provide a folding desktop far image reading and writing equipment.
[0005] In order to achieve the above technical purpose, the utility model adopts the following technical scheme:
[0006] A folding desktop far image reading and writing equipment, comprising: a plane beam splitter, a concave mirror, a back plate, a cover plate and a damping shaft, wherein,
[0007] The damping shaft comprises a main shaft, a back plate fixing frame, a cover plate fixing frame and a plane beam splitter fixing frame which are respectively sleeved on the main shaft. The back plate fixing frame is fixedly connected with the main shaft. The cover plate fixing frame can rotate within 90° around the main shaft. The plane beam splitter fixing frame can rotate within a predetermined angle around the main shaft. The predetermined angle is less than 90°.
[0008] The concave mirror is fixedly arranged on the cover plate or the back plate. The concave mirror is kept in a horizontal or vertical position in the use state.
[0009] The cover plate, the back plate and the plane beam splitter are respectively fixed with the cover plate fixing frame, the back plate fixing frame and the plane beam splitter fixing frame.
[0010] The plane beam splitter is obliquely arranged between the cover plate and the back plate in the use state.
[0011] The light reflected by the desktop and the objects placed on the desktop is split by the plane mirror from below, then is split again by the plane mirror, reflected by the concave mirror, and split again by the plane mirror, and finally reaches the exit pupil position and forms a far image at a position not less than 3 meters.
[0012] Preferably, the back plate fixing frame is located between the cover plate fixing frame and the plane mirror fixing frame on the main shaft.
[0013] The damping rotating shaft further comprises a plurality of spacers sleeved on the main shaft and located between the cover plate fixing frame and the back plate fixing frame and between the back plate fixing frame and the plane mirror fixing frame.
[0014] Preferably, the damping rotating shaft further comprises a spacer, a first self-locking concave cam, a first self-locking convex cam, a disc spring, a spacer and a locking nut arranged on the main shaft and located outside the cover plate fixing frame, and the first self-locking concave cam and the first self-locking convex cam are used to limit the rotation of the cover plate fixing frame to 90°.
[0015] Preferably, the damping rotating shaft further comprises a spacer, a second self-locking concave cam, a second self-locking convex cam, a disc spring, a spacer and a locking nut arranged on the main shaft and located outside the plane mirror fixing frame, and the second self-locking concave cam and the second self-locking convex cam are used to limit the rotation of the plane mirror fixing frame to a predetermined angle.
[0016] Preferably, the back plate fixing frame, the cover plate fixing frame and the plane mirror fixing frame each comprise an L-shaped support composed of two connecting plates, one of which is perpendicular to the main shaft and has an extension extending from the rectangular plate body to the main shaft and sleeved on the main shaft, and the other of which is parallel to the main shaft.
[0017] Preferably, the plane mirror can be kept at at least two positions with an included angle between the plane mirror and the concave mirror of 30°-60°, so as to change the height of the exit pupil position relative to the desktop and the included angle between the exit pupil plane and the horizontal plane.
[0018] Preferably, the at least two positions with an included angle of 30°-60° include a position of 45° and at least one position other than 45°.
[0019] Preferably, in the non-use state, the plane mirror and the cover plate can be rotated until they coincide with the back plate.
[0020] Preferably, the folding desktop far image reading and writing device further comprises a sensor arranged on any one of the plane mirror, the back plate or the cover plate to detect the included angle between the plane mirror and the concave mirror.
[0021] Wherein preferably, the backboard is provided with a display for displaying information related to the device usage state.
[0022] Wherein preferably, the folding tabletop far-field read-write device further comprises a light supplement lamp arranged on the lower surface of the plane beam splitter in a stepped manner to provide uniform illumination to the tabletop vertically when the plane beam splitter is in the 45° inclination usage state.
[0023] Wherein preferably, the folding tabletop far-field read-write device further comprises a second concave mirror arranged on the backboard or the cover plate and kept in a position perpendicular to the concave mirror in the usage state and rotatable to coincide with the concave mirror in the non-usage state.
[0024] The light reflected by the tabletop and the object placed on the tabletop is shot to the plane beam splitter from below and split, shot to the second concave mirror, then reflected by the second concave mirror, split by the plane beam splitter and shot to the exit pupil position and imaged in a position further from the far-field image.
[0025] Wherein preferably, the folding tabletop far-field read-write device further comprises an active light emitting element or a passive light emitting element arranged on the backboard or the cover plate for emitting light to the exit pupil position to form a brightened light spot in at least a partial area of the far-field image to reduce the contrast of the image in the area where the far-field image coincides with the brightened light spot.
[0026] Wherein preferably, the lower surface of the plane beam splitter is provided with a contrast film or a surface microstructure to reduce the contrast of the whole area or partial area of the far-field image.
[0027] The folding tabletop far-field read-write device provided by the utility model uses coaxial optical system to image the reflected light of the tabletop and the object placed on the tabletop, wherein in the usage state, the concave mirror is located in a horizontal or vertical position and the plane beam splitter is arranged in an inclination, and the angle adjustment between the cover plate, the plane beam splitter and the backboard is realized through the damping pivot, on the one hand, the included angle between the plane beam splitter and the concave mirror can be adjusted to change the included angle between the chief ray of the exit pupil and the horizontal plane, thereby adjusting the height of the exit pupil position relative to the tabletop without changing the virtual image distance; on the other hand, the folding of the whole device can be realized. BRIEF DESCRIPTION OF DRAWINGS
[0028] Figure 1 is the structure schematic view of the folding tabletop far-field read-write device provided by the utility model;
[0029] Figure 2 is the three-dimensional structure schematic view of the damping pivot;
[0030] Figure 3 is a schematic diagram of a decomposed structure of a damping rotating shaft;
[0031] Figure 4 and Figure 5 is a schematic diagram of a contrast film under a plane beamsplitter. DETAILED DESCRIPTION
[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0033] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications also change accordingly.
[0034] In addition, if the embodiments of the present application involve descriptions of "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of the various embodiments can be combined with each other, but must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection required by the present application.
[0035] The folding desktop far vision reading and writing device provided by the present application comprises a coaxial light path composed of a plane beamsplitter and a concave mirror, the light reflected from the desktop and the objects on the desktop is reflected by the concave mirror, the magnification and long-distance projection of the image are realized, the folding of the light path is realized through the plane beamsplitter, and the magnification and long-distance projection of the desktop writing are realized by a device with a small volume, and the long-distance vision can be maintained for a long time. At the same time, in order to reduce the volume of the desktop far vision reading and writing device in the non-use state, a folding structure realized by using a damping rotating shaft is provided.
[0036] Specifically, as Figure 1As shown in the drawings, a folding tabletop far-infrared reading and writing device comprises a support 1, a backboard 2, a plane beam splitter 3, a concave mirror, a cover plate 4 and a damping rotating shaft 5; wherein the support 1 is arranged on a tabletop, the backboard 2 is connected with the support 1 and the distance between the backboard 2 and the tabletop can be adjusted, and the backboard 2, the plane beam splitter 3 and the cover plate 4 are rotatably connected through the damping rotating shaft 5.
[0037] As shown in the drawings, Figure 2 and Figure 3 the damping rotating shaft 5 comprises a main shaft 50 and a backboard fixing frame 51, a cover plate fixing frame 52 and a plane beam splitter fixing frame 53 which are respectively sleeved on the main shaft 50, the backboard fixing frame 51 is fixedly connected with the main shaft 50, the cover plate fixing frame 52 can rotate around the main shaft 50 within a range of 90°, the cover plate fixing frame 53 can rotate around the main shaft 50 within a predetermined angle, and the predetermined angle is less than 90° (for example, 60°, 55° or 45°).
[0038] In the folding tabletop far-infrared reading and writing device, one end of the cover plate 4, one end of the backboard 2 and the top end of the plane beam splitter 3 are respectively fixed with the cover plate fixing frame 52, the backboard fixing frame 51 and the plane beam splitter fixing frame 53; the concave mirror is fixedly arranged on the cover plate 4 or the backboard 2, and the concave mirror is kept in a horizontal or vertical position in the use state; Figure 1 In the folding tabletop far-infrared reading and writing device, one end of the cover plate 4, one end of the backboard 2 and the top end of the plane beam splitter 3 are respectively fixed with the cover plate fixing frame 52, the backboard fixing frame 51 and the plane beam splitter fixing frame 53; the concave mirror is fixedly arranged on the cover plate 4 or the backboard 2, and the concave mirror is kept in a horizontal or vertical position in the use state;
[0039] Specifically, the structure of the damping rotating shaft can refer to Figure 3 the damping rotating shaft 5 comprises a main shaft 50 and a backboard fixing frame 51, a cover plate fixing frame 52 and a plane beam splitter fixing frame 53 which are respectively sleeved on the main shaft 50.
[0040] The back plate fixing frame 51 is located between the cover plate fixing frame 52 and the plane spectroscope fixing frame 53 on the main shaft 50, and the back plate fixing frame 51 is fixedly connected with the main shaft 50, and the cover plate fixing frame 52 and the plane spectroscope fixing frame 53 can independently rotate relative to the main shaft 50 and the back plate fixing frame 51 respectively. The back plate fixing frame 51, the cover plate fixing frame 52 and the plane spectroscope fixing frame 53 each comprise an L-shaped support composed of two connecting plates which are perpendicular to each other; one of the two connecting plates is perpendicular to the main shaft 50 and has an extension part extending from the one connecting plate to the main shaft 50 and sleeved on the main shaft 50; the other connecting plate is parallel to the main shaft, and the other connecting plate of the back plate fixing frame 51, the cover plate fixing frame 52 and the plane spectroscope fixing frame 53 is respectively used to realize the connection between the damping rotating shaft 5 and the back plate 2, the cover plate 4 and the plane spectroscope 3.
[0041] The damping rotating shaft 5 further comprises a plurality of spacers 60 sleeved on the main shaft 50 and located between the cover plate fixing frame 51 and the back plate fixing frame 52 and between the back plate fixing frame 51 and the plane spectroscope fixing frame 53.
[0042] The side of the cover plate fixing frame 52 facing the back plate fixing frame 51 is the inner side. The damping rotating shaft 5 further comprises a spacer 54, a first self-locking concave cam 55, a first self-locking convex cam 56, a disc spring 57, a spacer 58 and a locking nut 59 arranged on the main shaft 50 and located outside the cover plate fixing frame 52. When the cover plate 4 rotates, the cover plate fixing frame 52 drives the first self-locking concave cam 55 to rotate relative to the first self-locking convex cam 56, and the rotation of the cover plate fixing frame 52 to 90° is limited by the first self-locking concave cam 55 and the first self-locking convex cam 56, and the damping size when the cover plate rotates is controlled by the locking degree of the locking nut 59.
[0043] The side of the plane spectroscope fixing frame 53 facing the back plate fixing frame 51 is the inner side. The damping rotating shaft further comprises a spacer 61, a second self-locking concave cam 62, a second self-locking convex cam 63, a disc spring 64, a spacer 65 and a locking nut 66 arranged on the main shaft 50 and located outside the plane spectroscope fixing frame 53. When the plane spectroscope 3 rotates, the plane spectroscope fixing frame 53 drives the second self-locking concave cam 62 to rotate relative to the second self-locking convex cam 63, and the rotation of the plane spectroscope fixing frame 53 to a predetermined angle is limited by the second self-locking concave cam 62 and the second self-locking convex cam 63, and the damping size when the plane spectroscope 3 rotates is controlled by the locking degree of the locking nut 66.
[0044] Therefore, in the working state, the cover plate 4 can be rotated to a horizontal position perpendicular to the back plate 2, and the plane beam splitter 3 can be rotated to an inclined position between the cover plate 4 and the back plate 2; and in the non-working state, the cover plate 4 and the plane beam splitter 3 can be rotated to a vertical position coinciding with the back plate 2.
[0045] Meanwhile, the plane beam splitter 3 can also be kept at at least two positions with an included angle between the plane beam splitter 3 and the concave mirror of 30°-60°, so as to change the included angle between the light rays directed to the exit pupil position and the horizontal plane, change the height of the exit pupil position relative to the desktop, and change the included angle between the exit pupil plane and the horizontal plane. The at least two positions of 30°-60° include a position of 45° corresponding to the use state of the horizontal exit pupil, and at least one position other than 45° corresponding to the inclined upward or inclined downward exit pupil. Preferably, in the working state, the included angle of the plane beam splitter 3 relative to the back plate 1 varies between 35° and 55°. Thus, when adjusting the height of the exit pupil position, the variation of the virtual image distance can be avoided, and a constant virtual image distance far image can be provided for users of different heights, ensuring the nearsightedness prevention effect.
[0046] In order to enhance the imaging effect, a light supplement lamp is arranged at the bottom of the folding desktop far image reading and writing device. The light supplement lamp can be arranged at the bottom of the plane beam splitter 3 and / or the back plate 2, and is used to irradiate light to the desktop. For example, the light supplement lamp is arranged in a stepped manner on the lower surface of the plane beam splitter 3, so as to provide uniform illumination vertically to the desktop when the plane beam splitter 3 is in the use state of 45° inclination. A control member is further arranged at the lower part of the back plate 2, and controls the light supplement lamp, so as to adjust the brightness and color temperature.
[0047] In order to realize the parameter information visualization, the folding desktop far image reading and writing device further comprises a sensor arranged on any one of the plane beam splitter 3, the back plate 2 or the cover plate 4, so as to detect the included angle between the plane beam splitter 3 and the concave mirror. Meanwhile, a display 10 can also be arranged on the back plate 2, and is used to display information related to the use state of the device, such as time, angle, virtual image distance, defocus amount, etc. The angle information can be the inclination angle of the plane beam splitter 3 relative to the back plate 2 or the cover plate 4, or the included angle between the plane beam splitter 3 and the concave mirror.
[0048] The folding desktop far image reading and writing equipment provided by the utility model can also be a desktop far image reading and writing equipment with a defocus function, for example, a second concave mirror is arranged on the back plate 2 or the cover plate 4, the second concave mirror and the concave mirror are arranged on the back plate 2 and the cover plate 4 respectively, and the second concave mirror and the concave mirror are kept perpendicular in the use state, and the second concave mirror can be rotated to coincide with the concave mirror in the non-use state. In the use state, the light reflected by the desktop and the object placed on the desktop is shot to the plane beam splitter 3 from below and is split, one part of the light is shot to the concave mirror, is reflected by the concave mirror, is split by the plane beam splitter 3, is shot to the exit pupil position, and forms a far image at a position of not less than 3 m, and the corresponding light enters the human eye and forms an image on the retina of the human eye; the other part of the light is shot to the second concave mirror, then is reflected by the second concave mirror, is split by the plane beam splitter, is shot to the exit pupil position, and forms an image at a position farther than the far image, the image is a defocus image, the corresponding light enters the human eye and forms an image in front of the retina of the human eye, positive defocus stimulation is provided, and the defocus prevention and control effect is realized.
[0049] In order to realize peripheral defocus stimulation, in the embodiment, the second concave mirror is partially coated with a total reflection film, or a light shielding plate is arranged in front of the second concave mirror, the light shielding plate is partially light-transmitting, and the second concave mirror is partially shielded by the light shielding plate, so that the peripheral part reflects light, and the central part does not reflect light, and only a defocus image is formed in the periphery of the field of view. The height of the exit pupil position of the far image light path can be adjusted by adjusting the rotation angle of the plane beam splitter, and at the same time, the position of the defocus image in the far image picture moves, but the defocus effect is not affected, and the myopia prevention and control still has an effect.
[0050] The folding desktop far image reading and writing equipment provided by the utility model can also be a desktop far image reading and writing equipment with a contrast control function. For example, active light emitting elements or passive light emitting elements are arranged on the back plate 2 or the cover plate 4, light is emitted to the exit pupil position, so that a bright spot is formed in at least a partial area of the far image, the contrast of the image of the area where the far image and the bright spot coincide is reduced, the contrast of the partial area of the far image is adjusted, and the stimulation to the retina is reduced. For another example, a contrast film or a surface microstructure is arranged on the lower surface of the plane beam splitter 3, so that the contrast of the whole area or the partial area of the far image is reduced. The contrast film can use an anti-glare protective film (AG film), and the anti-glare protective film scatters light through the micro concave-convex structure or special coating on the surface. Figure 4 or Figure 5The contrast film can be a complete plane film to cover the complete surface of the plane beam splitter 3, or a film with blank areas in the middle to cover only the peripheral area of the plane beam splitter 3. When the light passes through the lower surface of the plane beam splitter 3, the contrast film can regulate the contrast of different imaging areas passing through the plane beam splitter 3, and finally achieve the effect of reducing the contrast of the peripheral field of view. In addition, the glass etching, embossing or transfer process can be used to etch, emboss or transfer different distributed patterns on the peripheral area of the lower surface of the plane beam splitter 3, so as to slightly change the transmittance of the local area of the plane beam splitter 3, thereby realizing the effect of clear central field of view and reduced contrast of the edge field of view.
[0051] The folding table top far distance reading and writing device is described in detail above. Any obvious changes made to the folding table top far distance reading and writing device without departing from the essential content of the folding table top far distance reading and writing device will constitute an infringement of the folding table top far distance reading and writing device patent right and will bear the corresponding legal responsibility.
Claims
1. A folded tabletop far-field read-write apparatus, characterized by The equipment comprises: a plane beam splitter, a concave mirror, a back plate, a cover plate and a damping rotating shaft, wherein the damping rotating shaft comprises a main shaft, a back plate fixing frame, a cover plate fixing frame and a plane beam splitter fixing frame which are respectively sleeved on the main shaft, the back plate fixing frame is fixedly connected with the main shaft, the cover plate fixing frame can rotate within 90° around the main shaft, the plane beam splitter fixing frame can rotate within a predetermined angle around the main shaft, and the predetermined angle is less than 90°; the concave mirror is fixedly arranged on the cover plate or the back plate, and the concave mirror is kept in a horizontal or vertical position in a use state; the cover plate, the back plate and the plane beam splitter are respectively fixed with the cover plate fixing frame, the back plate fixing frame and the plane beam splitter fixing frame; the plane beam splitter is obliquely arranged between the cover plate and the back plate in a use state; light reflected by a desktop and an object placed on the desktop is split by the plane beam splitter after being shot to the plane beam splitter from below, then is shot to the concave mirror, is reflected by the concave mirror, is split by the plane beam splitter again, is shot to an exit pupil position, and forms a far image at a position not less than 3 meters.
2. The folding desktop far image reading and writing equipment according to claim 1, wherein the back plate fixing frame is located between the cover plate fixing frame and the plane beam splitter fixing frame on the main shaft; the damping rotating shaft further comprises a plurality of spacers which are sleeved on the main shaft and are located between the cover plate fixing frame and the back plate fixing frame and between the back plate fixing frame and the plane beam splitter fixing frame.
3. The folding desktop far image reading and writing equipment according to claim 2, wherein the damping rotating shaft further comprises a spacer, a first self-locking concave cam, a first self-locking convex cam, a disc spring, a spacer and a locking nut which are arranged on the main shaft and are located outside the cover plate fixing frame, and the first self-locking concave cam and the first self-locking convex cam are used to limit the rotation of the cover plate fixing frame to 90°.
4. The folding desktop far image reading and writing equipment according to claim 2, wherein the damping rotating shaft further comprises a spacer, a second self-locking concave cam, a second self-locking convex cam, a disc spring, a spacer and a locking nut which are arranged on the main shaft and are located outside the plane beam splitter fixing frame, and the second self-locking concave cam and the second self-locking convex cam are used to limit the rotation of the plane beam splitter fixing frame to the predetermined angle.
5. The folding desktop far image reading and writing equipment according to claim 1, wherein the back plate fixing frame, the cover plate fixing frame and the plane beam splitter fixing frame respectively comprise an L-shaped support which is composed of two connecting plates, the two connecting plates are perpendicular to each other, one of the connecting plates is perpendicular to the main shaft and has an extension which extends to the main shaft and is sleeved on the main shaft, and the other connecting plate is parallel to the main shaft.
6. The folding desktop far image reading and writing equipment according to any one of claims 1-5, wherein the plane beam splitter can be kept in at least two positions in which the included angle between the plane beam splitter and the concave mirror is between 30° and 60°, so as to change the height of the exit pupil position relative to the desktop and change the included angle between the exit pupil plane and the horizontal plane.
7. The folding table-top far-field read-write apparatus of claim 6, wherein: the at least two positions between 30° and 60° include a 45° position and at least one non-45° position.
8. The folding table-top far-field read-write apparatus of any one of claims 1-5, wherein: in the non-use state, the flat beam splitter and the cover plate are rotatable to coincide with the back plate.
9. The folded tabletop far-field read-write apparatus of any of claims 1-5, wherein Further comprising: a sensor disposed on any one of the flat beam splitter, the back plate or the cover plate to detect the included angle between the flat beam splitter and the concave mirror.
10. The folding table-top far-field read-write apparatus of any one of claims 1-5, wherein: a display is disposed on the back plate to display information related to the use state of the apparatus.
11. The folded tabletop far-field read-write apparatus of any of claims 1-5, wherein Further comprising: a light supplement disposed on the lower surface of the flat beam splitter in a stepped manner to provide uniform illumination to the table top in the use state of the flat beam splitter at 45° inclination.
12. The folded tabletop far-field read-write apparatus of any of claims 1-5, wherein Further comprising: a second concave mirror disposed on the back plate or the cover plate and kept at a position perpendicular to the concave mirror in the use state and rotatable to coincide with the concave mirror in the non-use state; light reflected by the table top and an object placed on the table top is downwardly directed to the flat beam splitter and split, directed to the second concave mirror, then reflected by the second concave mirror, split by the flat beam splitter and directed to the exit pupil position and imaged at a position further from the far-field image.
13. The folded tabletop far-field read-write apparatus of any of claims 1-5, wherein Further comprising: an active or passive light emitting element disposed on the back plate or the cover plate to emit light to the exit pupil position to form a brightened spot in at least a partial area of the far-field image to reduce the contrast of the image in the area where the far-field image and the brightened spot coincide.
14. The folding table-top far-field read-write apparatus of any one of claims 1-5, wherein: a contrast film or surface microstructure is disposed on the lower surface of the flat beam splitter to reduce the contrast of the far-field image in the whole area or a partial area of the far-field image.