Desktop remote image read-write device with contrast control and control method thereof

Abstract

The invention discloses a desktop remote image read-write device with contrast control and a control method thereof. The desktop remote image read-write device comprises a plane spectroscope, a concave reflector and a backlight plate. The light reflected by the desktop and an object placed on the desktop is emitted to the plane spectroscope from the lower part, and the light split by the plane spectroscope is reflected by the concave reflector, is split by the plane spectroscope again, is emitted to an exit pupil position, and forms a far image at a position not less than 1 meter; brightness of different areas of the backlight plate is different so as to change contrast of different areas of a far image. According to the desktop far image read-write device, when a user reads characters and other contents in a book, the peripheral low-contrast visual effect is provided, the growth of an eye axis is further inhibited, meanwhile, a certain effect is achieved on thickening of a choroid, and myopia prevention and control are achieved.

Description

Technical Field

[0001] The invention relates to a desktop telescopic image reading and writing device with contrast control, and also relates to a control method of the desktop telescopic image reading and writing device, belonging to the field of myopia prevention and control equipment. Background Art

[0002] At present, the myopia problem among teenagers is becoming increasingly serious. The fundamental reason is that teenagers' eyes 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 on the market.

[0003] Among them, desktop telephoto reading and writing equipment uses optical means to extend short-distance reading and writing to distant imaging, and is mostly used in the field of myopia prevention and control for young people. However, the effect of long-distance imaging achieved by a single optical path on myopia prevention and control is limited, so other auxiliary means need to be introduced to increase the effect of myopia prevention and control. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a desktop telescopic reading and writing device with contrast control.

[0005] Another technical problem to be solved by the present invention is to provide a control method for a desktop telescopic reading and writing device.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] According to one aspect of the present invention, a desktop telephoto reading and writing device with contrast control is provided, comprising: a plane beam splitter, a concave reflector and a backlight plate; wherein:

[0008] The concave reflector is kept in a horizontal or vertical position when in use; the plane beam splitter is tilted when in use;

[0009] The backlight plate and the concave reflector are arranged perpendicular to each other and are used to provide light to the exit pupil position;

[0010] The light reflected by the desktop and the object placed on the desktop is directed toward the plane beam splitter from below, and the light formed after the beam splitting by the concave reflector is reflected by the concave reflector, split by the plane beam splitter, and then directed toward the exit pupil position, and forms a distant image at a position not less than 1 meter; different areas of the backlight panel provide at least two lights of different brightness to the exit pupil position, wherein the brightness of the first light is lower than the brightness of the second light, so as to change the contrast of different areas of the distant image.

[0011] Preferably, the ratio of the brightness of the second light provided by the backlight panel to the exit pupil position to the average brightness of the distant image is not less than 1 / 9.

[0012] Preferably, the ratio of the brightness of the first light provided by the backlight panel to the exit pupil position to the average brightness of the distant image is less than 1 / 10.

[0013] As a preferred embodiment, an active light-emitting element is provided on the side surface of the backlight panel facing the exit pupil position, and the first light and the second light are provided to the exit pupil position in different regions by controlling the brightness of different regions in the active light-emitting element.

[0014] Preferably, the desktop telescopic reading and writing device further includes an eye tracking camera and a controller;

[0015] The eye tracking camera is arranged facing the exit pupil position and is used to collect images of human eyes;

[0016] The controller determines the gaze point of the human eye in the distant image according to the human eye image, and makes the brightness of the gaze area centered on the gaze point in the backlight plate lower than the brightness of the surrounding area of ​​the gaze area.

[0017] Preferably, the active light-emitting element is an array light source, the array light source covers the entire area of ​​the backlight panel, and the controller makes the light source in the attention area have low brightness or does not emit light.

[0018] Preferably, the active light-emitting element includes a fixed white board and a dark electrochromic film covering it, and the transmittance of the electrochromic film at different positions at different times is controlled by a logic timing circuit to change the brightness of different areas of the backlight panel.

[0019] Preferably, the active light-emitting element is a display screen, and the brightness of different areas of the backlight panel is changed by controlling pixels at different positions in the display screen for display.

[0020] Preferably, the active light emitting element is an array light source, and the array light source is distributed only in the peripheral area of ​​the backlight panel, or only in one or more local areas.

[0021] As another preferred embodiment, the backlight panel provides the at least two lights of different brightness to the exit pupil position through reflection sub-regions.

[0022] Preferably, the reflectivity of the central area of ​​the backlight plate is lower than 5%, and the peripheral area of ​​the backlight plate surrounding the central area has at least one area with a reflectivity of not less than 5%.

[0023] Preferably, the surface of the backlight plate is provided with a first area and a second area, wherein at least one of the material, color or surface microstructure of the first area and the second area is different, so that the second area has a higher reflectivity than the first area.

[0024] Preferably, the second area of ​​the backlight plate has a convex dot array or a concave pit array.

[0025] Preferably, the desktop telescopic reading and writing device also includes: a light source assembly for providing light source to the backlight panel; the surface of the backlight panel has the same reflectivity, and the light source assembly illuminates a local area of ​​the backlight panel to reflect the second light to the exit pupil position through the local area of ​​the backlight panel.

[0026] Preferably, the light source assembly includes a light source and a mask.

[0027] Preferably, the mask is a diffractive optical element.

[0028] Preferably, the desktop telescopic reading and writing device also includes: a first adjusting member, used to adjust the angle between the plane beam splitter and the concave reflector, and maintain the plane beam splitter at at least two positions where the angle between the plane beam splitter and the concave reflector is between 30° and 60°; the angle between the plane beam splitter and the concave reflector is adjusted by the first adjusting member to change the height of the exit pupil position relative to the desktop.

[0029] Preferably, the desktop telescopic reading and writing device also includes a fill light arranged on the lower surface of the plane beam splitter, the fill light is composed of a plurality of light sources arranged linearly, the plurality of light sources are arranged in a stepped manner, and when the plane beam splitter and the desktop are in use at an angle of 45°, the main light of each light source is perpendicular to the desktop.

[0030] According to another aspect of the present invention, a control method for a desktop telescopic reading and writing device is provided, characterized in that it comprises the following steps:

[0031] The desktop telescopic reading and writing device comprises: a plane beam splitter, a concave reflector and a backlight plate; wherein,

[0032] The light reflected by the desktop and the objects placed on the desktop is directed toward the plane beam splitter from below, and the light formed after the beam splitting by the concave reflector is reflected by the concave reflector, and then is directed toward the exit pupil position after the beam splitting by the plane beam splitter, and forms a distant image at a position not less than 1 meter; the backlight panel is arranged facing the exit pupil position and the brightness of different areas is different, so as to change the contrast of different areas of the distant image.

[0033] Preferably, eye tracking camera is used to collect human eye images; the controller determines the gaze point of the human eye in the distant image based on the human eye image, and makes the brightness of the light source in the gaze area centered on the gaze point in the backlight panel lower than the brightness of the light source in the surrounding area of ​​the gaze area.

[0034] Preferably, the range of the gaze area is not larger than the size of the area in the array light source corresponding to the ±15° field of view of the human eye, and is not smaller than the size of the area in the array light source corresponding to the ±3° field of view of the human eye.

[0035] Preferably, the range of the gaze area is a circular area centered on the gaze point, and the diameter of the circular area is 6 to 8 centimeters.

[0036] Preferably, the brightness of the light source in the area outside the gaze area increases in steps with the gaze point as the center.

[0037] Preferably, the entire backlight panel presents a gradually increasing brightness from the center to the outside with the gaze point as the center.

[0038] The desktop telephoto reading and writing device with contrast control provided by the present invention uses a coaxial optical system to image the reflected light of the desktop and the objects placed on the desktop. At the same time, by adding a backlight panel and making different areas of the backlight panel provide light of different brightness to the exit pupil position, the contrast of different areas of the telephoto image is changed to achieve the purpose of myopia prevention and control. The desktop telephoto reading and writing device with contrast control introduces contrast control while forming a telephoto image. When the user reads the text and other contents in the book, it also gives the peripheral low-contrast visual effect, reduces retinal stimulation, further inhibits the growth of the eye axis, and has a certain effect on the thickening of the choroid, thereby achieving myopia prevention and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 1 is a schematic diagram of the structure of a desktop telescopic reading and writing device with contrast control provided in Example 1 of the present invention;

[0040] Figure 2 yes Figure 1 The schematic diagram of the optical path principle of the horizontal exit pupil of the desktop telephoto reading and writing device shown;

[0041] Figure 3A and Figure 3B yes Figure 1 The schematic diagram of two optical path principles of the desktop telephoto reading and writing device with tilted exit pupil is shown;

[0042] Figure 4 is a schematic diagram of the adjustment structure of the desktop telescopic reading and writing device shown in Example 1;

[0043] Figure 5 yes Figure 1 Schematic diagram of the arrangement of the array light source;

[0044] Figure 6 2 is a schematic diagram of the structure of a desktop telescopic reading and writing device with low contrast in the peripheral area provided by Embodiment 2 of the present invention;

[0045] Figure 7 is a schematic structural diagram of a desktop telescopic reading and writing device with contrast control provided by Embodiment 3 of the present invention;

[0046] Figure 8 yes Figure 7 The optical path principle diagram of the desktop telescopic reading and writing device shown;

[0047] Fig. 9A , Fig. 9B , Fig. 9C and Fig.9D They are schematic diagrams of the backlight panel surface;

[0048] Fig. 10A and Fig. 10B They are schematic diagrams of the structure of a desktop telescopic reading and writing device with contrast control provided by Embodiment 4 of the present invention;

[0049] Fig.11 It is a structural schematic diagram of a desktop telescopic reading and writing device with contrast control provided by Example 5 of the present invention. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0052] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0053] The present invention aims to provide a desktop far-image reading and writing device with contrast control implemented based on a coaxial optical system. The desktop far-image reading and writing device with contrast control includes: a backlight panel 3, a planar beam splitter 1, and a concave mirror 2; wherein, one end of the concave mirror 2 is connected to one end of the backlight panel 3 and is kept perpendicular to the backlight panel 3 in the usage state; the planar beam splitter 1 is inclined and arranged between the concave mirror 2 and the backlight panel 3 in the usage state; the surface of the backlight panel 3 facing the exit pupil side is provided with an active light-emitting element (for example, an array light source) or a passive light-emitting element for providing light to the exit pupil position. The light reflected by the desktop 4 and the object placed on the desktop is incident on the planar beam splitter 1 from below, the light split by the planar beam splitter 1 is incident on the concave mirror 2, then, after being reflected by the concave mirror 2 and split by the planar beam splitter 1 again, it is incident on the exit pupil position and forms a far image at a position not less than 1 meter. The surface of the backlight panel 3 facing the exit pupil side is provided with an active light-emitting element or a passive light-emitting element for providing light to the exit pupil position; different regions of the backlight panel 3 provide at least two kinds of light with different brightness to the exit pupil position, wherein, the brightness of the first kind of light is lower than that of the second kind of light, thereby changing the contrast of the overlapping region of the far image and the spot formed by the second kind of light, so that different regions of the far image have different contrasts.

[0054] The change of the brightness of the second kind of light above in the contrast of the local region of the far image reduces the contrast of the local region of the far image to less than 90% of the contrast of the original far image, for example, reduces it to between 30% and 90% of the contrast of the original far image. To meet the above contrast control, the brightness of the second kind of light should meet the following conditions: Define the contrast of the original far image as: wherein, I max represents the maximum brightness of the far image, I min represents the minimum brightness of the far image, I 均 represents the average brightness of the far image, Define the brightness of the second kind of light as I, then, the contrast of the local region of the far image overlapping with the spot is: Contrast’ < Contrast; To meet then: That is, the ratio of the brightness I of the second kind of light provided by the backlight panel 3 to the exit pupil position and the average brightness I 均 of the far image is not less than 1 / 9, preferably, lower than 7 / 3 or lower than 1. To reduce the influence of the first kind of light actively or passively provided by the backlight panel 3 on the far image, the ratio of the brightness of the first kind of light to the average brightness of the far image should be controlled below 1 / 10.

[0055] In the embodiment provided in the present application, the positions of the backlight plate 3 and the concave reflector 2 can be interchanged. Figure 1 As shown, the backlight panel 3 can be vertically arranged at the top of the bracket 9, and at this time, the concave reflector 2 is horizontally arranged when in use. It can be understood that the backlight panel 3 can also be horizontally arranged when in use, and the concave reflector 2 is vertically arranged at the top of the bracket. Because whether the setting positions of the backlight panel 3 and the concave reflector 2 are interchangeable has no effect on the imaging principle of the fixed desktop telescopic reading and writing device, the setting positions of the backlight panel 3 and the concave reflector 2 are not limited here. In the following, a desktop telescopic reading and writing device in which the backlight panel 3 is vertically arranged at the top of the bracket 9 and the concave reflector 2 is horizontally arranged when in use is introduced as an example.

[0056] Example 1

[0057] like Figure 1 The desktop telescopic reading and writing device with contrast control shown in the figure comprises: a plane beam splitter 1, a concave reflector 2, a backlight plate 3 and a bracket 9; wherein the bracket 9 is vertically arranged on the desktop 4, the backlight plate 3 is vertically arranged and connected to the top of the bracket 9; one end of the concave reflector 2 is connected to the top of the backlight plate 3, and is maintained at a position parallel to the desktop 4 when in use; the top of the plane beam splitter 1 can rotate around the top of the backlight plate 3, and the plane beam splitter 1 is tiltedly arranged between the concave reflector 2 and the backlight plate 3 when in use, and the light reflected by the desktop 4 and the object placed on the desktop is emitted from the bottom to the plane beam splitter 1, passes through the plane beam splitter 1 and then emits to the concave reflector 2 and is reflected at the position of the concave reflector 2; the light formed after reflection by the concave reflector 2 is reflected by the plane beam splitter 1 and then emitted to the exit pupil position; the light emitted to the exit pupil position forms a telescopic image at a virtual image position not less than 1 meter in front of the exit pupil position.

[0058] In the desktop telephoto reading and writing device, the surface of the concave reflector 2 used for imaging is covered with a total reflection film; the curvature radius of the concave reflector 2 ranges from 800mm to 1300mm. The pupil distance of the desktop telephoto reading and writing device is between 150mm and 350mm, and the pupil eye movement range is not less than The field of view angle is not less than 35° and not more than 50°.

[0059] Table 1 gives the surface parameters of a group of optical elements in the telephoto optical path of the desktop telephoto reading and writing device.

[0060] Table 1 Surface parameters of each optical element in the telephoto optical path

[0061] Surface marking Surface type Radius(mm) Thickness(mm) Alpha Tilt (°) Image plane Spherical unlimited -5000 0 Aperture 5 Spherical unlimited 200 0 2 Spherical -1150 195 0 1 Spherical unlimited 345 -45 4 Spherical unlimited 0 -45

[0062] As shown in Table 1, the specific optical design of the desktop telephoto reading and writing device with contrast control has an exit pupil distance of 200 mm and an exit pupil eye movement range of The horizontal field of view angle is ±19° and the vertical field of view angle is ±14°.

[0063] In order to adapt to people of different heights, the plane beam splitter 1 can also be rotated. By rotating the plane beam splitter 1, the direction of the light reflected by the plane beam splitter 1 and emitted to the exit pupil position can be changed, and the normal and height of the exit pupil position can be changed, so as to avoid changing the virtual image position due to adjusting the height of the device. Figure 2 , Figure 3A and 3B As shown, by changing the angle γ between the plane beam splitter 1 and the concave reflecting mirror 2 (γ is between 30° and 60°), the height of the exit pupil position relative to the desktop can be adjusted.

[0064] Among them, Figure 2 As shown, the plane beam splitter 1 is located at a position 45° to the horizontal line (desktop). At this time, the light reflected by the concave reflector 2 is reflected by the plane beam splitter 1 and then emitted to the exit pupil position 5 in a horizontal direction. At this time, the normal direction of the exit pupil position 5 is parallel to the desktop 4. This position corresponds to the horizontal exit pupil position and can be used as the initial exit pupil position. At this time, the exit pupil plane is a vertical plane.

[0065] like Figure 3A As shown, by lifting the plane beam splitter 1 upward, the angle between the plane beam splitter 1 and the horizontal line is less than 45°. At this time, the light formed by the reflection of the concave reflector 2 is reflected by the plane beam splitter 1 and emitted toward the exit pupil position 6A in an inclined upward direction. At this time, the normal direction of the exit pupil position 6A forms an acute angle with the desktop, the person's line of sight is slightly downward, the exit pupil position 6A is higher than the exit pupil position 5, the exit pupil position has a height change relative to the desktop, and the exit pupil plane is tilted relative to the horizontal plane and the vertical plane.

[0066] like Figure 3B As shown, by pressing down the plane beam splitter 1, the angle between the plane beam splitter 1 and the horizontal line is greater than 45°. At this time, the light formed by the reflection of the concave reflector 2 is reflected by the plane beam splitter 1 and emitted toward the exit pupil position 6B in an inclined downward direction. At this time, the normal direction of the exit pupil position 6B forms an acute angle with the desktop, the human line of sight is slightly upward, the exit pupil position 6B is lower than the exit pupil position 5, the exit pupil position has a height change relative to the desktop, and the exit pupil plane is inclined relative to the horizontal plane and the vertical plane.

[0067] It can be understood that in the adjustable desktop telescopic reading and writing device, the positions of the backlight panel and the concave reflector can be interchanged, wherein the concave reflector is vertically arranged, the backlight panel is horizontally arranged, and the backlight panel is maintained in a position parallel to the desktop when in use; one end of the backlight panel is connected to the top of the concave reflector, the top of the plane beam splitter is connected to the backlight panel or the concave reflector, and can rotate around the top of the concave reflector, and the plane beam splitter is tilted between the concave reflector and the backlight panel when in use.

[0068] like Figure 4 As shown, in the desktop telephoto reading and writing device, the backlight panel 3, the plane beam splitter 1, and the top of the concave reflector 2 can be rotatably connected through one or two rotating shafts. In order to achieve the angle adjustment of the plane beam splitter 1, the desktop telephoto reading and writing device is also provided with a first adjusting member 13, and the angle between the plane beam splitter 1 and the concave reflector 2 can be adjusted by the first adjusting member 13; one end of the first adjusting member 13 is connected to the plane beam splitter 1, and the other end is connected to the backlight panel 3 or the concave reflector 2; the first adjusting member 13 can be implemented using a rotating shaft with a limiting mechanism, or it can be an independently arranged adjusting member. For example, Figure 4 As shown, a retractable connecting rod is used to adjust the angle between the plane beam splitter 1 and the concave reflecting mirror 2.

[0069] The desktop telescopic reading and writing device can be a fixed device or a folding device. In a fixed device, whether it is in use or not, the concave reflector 2 is always kept in a horizontal or vertical fixed state, and the concave reflector 2 is always perpendicular to the backlight plate 3. In a folding device, the concave reflector 2 and / or the backlight plate 3 can be rotated, so that the concave reflector 2 and the backlight plate 3 can be converted between mutually parallel and mutually perpendicular states, wherein when the concave reflector 2 and the backlight plate 3 are parallel to each other, it corresponds to the folded state of the desktop telescopic reading and writing device, that is, the idle state; and when the concave reflector 2 and the backlight plate 3 are perpendicular to each other, it corresponds to the open state of the desktop telescopic reading and writing device, that is, the use state; the above state transition can be achieved by the second adjusting member 14, and the second adjusting member 14 is used to keep the concave reflector 2 in a state parallel or perpendicular to the backlight plate 3, which can be achieved by using a rotating shaft with a limiting mechanism, or it can be an independently set adjusting member. For example, two ends of the second adjusting member 14 are connected to the backlight panel 3 and the concave reflector 2 respectively, and the state conversion of the concave reflector 2 relative to the backlight panel 3 is realized through the second adjusting member 14 .

[0070] In addition, it can be understood that when the first adjusting member 13 and the second adjusting member 14 are arranged at a position away from the top of the concave reflecting mirror 2 and the plane beam splitter 1, and only play the role of rotation adjustment and limiting, one or two rotating shafts need to be arranged between the plane beam splitter 1, the concave reflecting mirror 2 and the backlight panel 3 to realize the connection between the three, and the rotating shaft at this time can be a freely rotating movable shaft; when the first adjusting member 13 or the second adjusting member 14 is arranged at the end of the concave reflecting mirror 2 and the plane beam splitter 1, and the first adjusting member 13 or the second adjusting member 14 plays the role of connection, rotation adjustment and limiting at the same time, the first adjusting member 13 or the second adjusting member 14 can only use a damping rotating shaft with a limiting mechanism to realize the above functions, and at this time, there is no need to set up a movable shaft separately.

[0071] like Figure 1 As shown, the desktop telephoto reading and writing device provided by the present invention also has a contrast control function, by arranging an active light-emitting element on the side of the backlight plate 3 facing the exit pupil, which is used to provide a first light and a second light with different brightnesses to the exit pupil position in different regions; wherein the brightness of the second light provided by the active light-emitting element is higher than the brightness of the first light provided by other regions of the backlight plate 3, and the second light will form a light spot at the exit pupil position, thereby reducing the contrast of the area where the telephoto image and the light spot overlap, thereby changing the contrast of different areas of the telephoto image, and realizing contrast control.

[0072] In this embodiment, the active light emitting element includes an array light source 12. The light of the array light source 12 is emitted to the exit pupil position through the plane beam splitter 1. Figure 2 The exit pupil position shown is 5, or Figure 3A and Figure 3B At the exit pupil positions 6A and 6B shown, when viewing a distant image, the human eye can receive the second light emitted by the array light source. By controlling the brightness of different areas of the array light source, the contrast of different areas of the distant image can be changed.

[0073] Since the image size of the desktop telephoto reading and writing device is large, the human eye's focus point is variable and does not always converge on the center of the telephoto image. In order to improve the myopia prevention and control effect of contrast control, it is necessary to control the brightness of the local area of ​​the array light source in a targeted manner. Figure 1As shown, in the desktop telescopic image reading and writing device, an eye tracking camera 10 is also arranged at a position facing the human eye. For example, the eye tracking camera 10 is arranged on the upper surface of the plane beam splitter 1 or the front side of the concave reflector 2 facing the human eye when in use. The eye tracking camera 10 is used to collect the image of the human eye. The infrared light source in the eye tracking camera 10 illuminates the eye and provides a corneal reflection point, and the high-speed camera takes pictures to capture the movement of the human eye. The eye tracking camera 10 and the array light source are both electrically connected to the controller 8. The controller 8 obtains the gaze point of the human eye in the telescopic image according to the human eye image, and makes the brightness of the small area centered on the gaze point position in the array light source lower than the brightness of the surrounding area. The gaze area refers to the small area centered on the gaze point position. The range of the gaze area needs to be determined in combination with the size of the area corresponding to the small field of view of the backlight plate and the human eye, and should not be greater than the size of the area corresponding to the ±15° field of view of the human eye in the array light source, and should not be less than the size of the area corresponding to the ±3° field of view of the human eye in the array light source. For example, the controller 8 receives and processes images taken by the eye tracking camera 10, calculates the gaze position, analyzes the data, and then controls the light sources in other areas of the array light source except the gaze area (for example, a circular area centered on the gaze point, with a diameter of 6 to 8 cm).

[0074] By controlling the brightness of the backlight panel, low contrast control of the area around the gaze area is achieved. In this way, the brightness of the light source in the gaze area and the surrounding small area is low or does not emit light, and the brightness of the light source in other areas is higher than that of the gaze area, forming an effect of reducing the contrast of the peripheral image in the focus area, which is conducive to reducing the development of myopia.

[0075] The lighting control of the gaze area can be achieved by reducing the brightness of the light source in the gaze area or turning off the light source in the gaze area. The brightness of the light sources in other peripheral areas of the array light source far away from the gaze area can be the same as the brightness of the light sources in the surrounding areas of the gaze area, or lower than the brightness of the light sources in the surrounding areas of the gaze area, without limitation.

[0076] In this embodiment, the array light source may use an LED array, and the distribution of the array light source may refer to Figure 5 As shown, the array light source can completely cover the entire area of ​​the array light source and be evenly arranged to cover the entire imaging range of the telephoto image. In this way, combined with human eye tracking, targeted control of the local area of ​​the array light source can be achieved. In order to reduce the granularity of the array light source and reduce the impact of a single LED light source on the imaging quality, a light homogenizer 11 is provided in the array light source in the light emitting direction of the array light source. The light homogenizer may not be provided in the array light source, so that a dot-shaped low-contrast image is formed in the surrounding area of ​​the gaze area.

[0077] like Figure 5 As shown, the distribution of the LED array in the array light source can be honeycomb-shaped, with one LED distributed in the center of each hexagon, the spacing between adjacent LEDs is 5 to 15 mm, and the light-emitting surface is covered with a light-homogenizing plate 11 to make the light softer. The distribution of the LED array can also be arranged in other regular or irregular ways. In the direction of the exit pupil, a low-contrast picture with high-brightness backlight can be observed outside the non-attention area, and a high-contrast picture with low-brightness backlight or no backlight can be observed in the attention area. By controlling the contrast of the surrounding picture, the growth of the eye axis can be suppressed.

[0078] Contrast can also be achieved by using different forms of backlight panels. For example, the backlight panel includes a fixed white panel that emits light as a whole and a dark electrochromic film covering it. A fixed white panel can be installed on the backlight panel, covered with a dark electrochromic film, and the transmittance of the electrochromic film at different times and positions can be controlled by a logic timing circuit to change the brightness of different areas of the backlight panel, thereby forming a contrast image that changes from time to time at the human eye. For another example, the backlight panel can be implemented using a high-pixel density display screen, which controls the display of pixels at different positions in the display screen to change the brightness of different areas of the backlight panel. By using a display screen to display different dot matrix images or other images, the contrast control of the local area of ​​the distant image can also be achieved, and the layout change of the luminous area of ​​the backlight panel is convenient. The display screen set on the backlight panel can also switch pictures to achieve the function of vision training, including gaze training, fusion training, and alternating training of near and far.

[0079] The desktop telephoto reading and writing device needs to be used in conjunction with a fill light 7. In order to ensure the desktop brightness in the area below the plane beam splitter 1, the fill light 7 is set on the frame of the lower surface of the plane beam splitter 1. Preferably, the fill light is composed of a plurality of light sources arranged linearly, and the plurality of light sources are arranged in a stepped manner. The plurality of light sources are arranged along the length direction of the plane beam splitter 1, and when the plane beam splitter 1 and the desktop are in a 45° angle of use, the main light of each light source is vertically downwardly projected toward the desktop. In order to meet the illumination uniformity of the desktop, the number of light sources distributed above can be greater than the number of light sources below, and the arrangement is dense. The fill light 7 is preferably set on the left and right frames of the lower surface of the plane beam splitter 1. The fill light 7 can also be set on the bottom frame of the plane beam splitter 1 and on the bottom surface of the backlight panel 3 at the same time, so as to provide light sources to the desktop at the same time.

[0080] The present invention also provides a control method for a desktop telescopic reading and writing device, wherein light reflected by a desktop 4 and an object placed on the desktop is directed toward a plane beam splitter 1 from below, and the light split by the plane beam splitter 1 is directed toward a concave reflector 2, and then, after being reflected by the concave reflector 2 and split by the plane beam splitter 1, it is directed toward an exit pupil position and forms a telescopic image at a position not less than 1 meter; at the same time, an array light source is arranged facing the exit pupil position and different areas have different brightness, thereby changing the contrast of different areas of the telescopic image to achieve contrast control.

[0081] As a preferred embodiment, the area where the array light source emits light changes according to the position of the human eye's gaze point; the controller 8 obtains the human eye's gaze point in the distant image in real time according to the human eye image, and makes the brightness of the light source in the small area centered on the gaze point position in the array light source lower than the brightness of the light source in the surrounding area. The gaze area refers to the small area centered on the gaze point position. The range of the gaze area needs to be determined in combination with the size of the area corresponding to the backlight plate and the small field of view of the human eye, and should not be larger than the size of the area corresponding to the ±15° field of view of the human eye in the array light source, and should not be smaller than the size of the area corresponding to the ±3° field of view of the human eye in the array light source. For example, the controller 8 receives and processes the picture taken by the eye tracking camera 10, calculates the gaze position, analyzes the data, and then controls the light sources in other areas of the array light source except the gaze area (eg: a circular area with a diameter of 6 to 8 cm centered on the gaze point) to emit light, and turns off the light source in the gaze area. The brightness of the light source in the area outside the gaze area can be increased in a step-by-step manner with the gaze point as the center. Of course, the controller 8 can also make the entire backlight panel centered on the gaze point, with the brightness gradually increasing from the center to the outside, to replace the above-mentioned on-off brightness control, wherein the ratio of the average brightness of the gaze area to the average brightness of the surrounding area should be lower than 40%.

[0082] By controlling the brightness of the backlight panel, low contrast control of the area around the gaze area is achieved. In this way, the brightness of the gaze area and the surrounding small area is low, and the brightness of other areas is higher than that of the gaze area, forming an effect of reducing the contrast of the peripheral image of the focus area, which is conducive to reducing the development of myopia.

[0083] Example 2

[0084] like Figure 6The desktop telescopic reading and writing device with contrast control provided by the illustrated embodiment comprises: a plane beam splitter 1, a concave reflector 2, a backlight plate 3 and a bracket 9; wherein the bracket 9 is vertically arranged on the desktop 4, the backlight plate 3 is vertically arranged and connected to the top of the bracket 9; one end of the concave reflector 2 is connected to the top of the backlight plate 3, and is maintained at a position parallel to the desktop 4 when in use; the top of the plane beam splitter 1 can rotate around the top of the backlight plate 3, and the plane beam splitter 1 is tiltedly arranged between the concave reflector 2 and the backlight plate 3 when in use, and the light reflected by the desktop 4 and the object placed on the desktop is emitted from the bottom to the plane beam splitter 1, passes through the plane beam splitter 1 and then emits to the concave reflector 2 and is reflected at the position of the concave reflector 2; the light formed after reflection by the concave reflector 2 is reflected by the plane beam splitter 1 and then emitted to the exit pupil position; the light emitted to the exit pupil position forms a telescopic image at a virtual image position not less than 1 meter in front of the exit pupil position.

[0085] In this embodiment, an active light-emitting element is provided on the side of the backlight plate 3 facing the exit pupil position, and the active light-emitting element adopts an array light source 15, wherein the array light source 15 is distributed in a local distribution manner. For example, the array light source 15 is provided only in the peripheral area of ​​the backlight plate 3, so as to form a light spot in the peripheral area of ​​the distant image, so as to reduce the contrast of the area where the peripheral area of ​​the distant image and the light spot overlap, and the contrast of the central area of ​​the distant image is not changed.

[0086] The array light sources may be symmetrically arranged only on the two side areas of the backlight panel 3, or may be arranged simultaneously on the entire peripheral area of ​​the backlight panel 3, thereby leaving a central area of ​​a circular, square or other symmetrical shape empty.

[0087] The array light source 15 may also be distributed in one or more local areas of the backlight panel 3 . The local areas may be arranged regularly or irregularly. Preferably, they are symmetrical about the center of the field of view or the axis of the field of view.

[0088] In addition, the backlight panel is replaceable, and the distribution of contrast in the distant image entering the eye can be changed by replacing the backlight panel, thereby changing the stimulation of the distant image to the human eye. In different backlight panels, the arrangement of the array light source is different.

[0089] exist Figure 6 In the embodiment shown, since the light source array in the backlight panel 15 is only provided in the peripheral area, in this embodiment, an eye tracking sensor may not be provided, and all light sources in the peripheral area may be directly lit to reduce the contrast of the peripheral area of ​​the distant image, thereby achieving the purpose of inhibiting the growth of the eye axis.

[0090] Example 3

[0091] like Figure 7The desktop telescopic reading and writing device with contrast control shown in the figure comprises: a plane beam splitter 1, a concave reflector 2, a backlight plate 3 and a bracket 9; wherein the bracket 9 is vertically arranged on the desktop 4, the backlight plate 3 is vertically arranged and connected to the top of the bracket 9; one end of the concave reflector 2 is connected to the top of the backlight plate 3, and is maintained at a position parallel to the desktop 4 when in use; the top of the plane beam splitter 1 can rotate around the top of the backlight plate 3, and the plane beam splitter 1 is tiltedly arranged between the concave reflector 2 and the backlight plate 3 when in use, and the light reflected by the desktop 4 and the object placed on the desktop is emitted from the bottom to the plane beam splitter 1, passes through the plane beam splitter 1 and then emits to the concave reflector 2 and is reflected at the position of the concave reflector 2; the light formed after reflection by the concave reflector 2 is reflected by the plane beam splitter 1 and then emitted to the exit pupil position; the light emitted to the exit pupil position forms a telescopic image at a virtual image position not less than 1 meter in front of the exit pupil position.

[0092] In the desktop telephoto reading and writing device, the surface of the concave reflector 2 used for imaging is covered with a total reflection film; the curvature radius of the concave reflector 2 ranges from 800mm to 1300mm. The pupil distance of the desktop telephoto reading and writing device is between 150mm and 350mm, and the pupil eye movement range is not less than The field of view angle is not less than 35° and not more than 50°.

[0093] like Figure 7 and Figure 8 As shown, the desktop telephoto reading and writing device provided by the present invention also has a contrast control function. In this embodiment, the surface of the backlight plate 3 facing the exit pupil position is not a mirror surface, which is used to provide at least two brightnesses of light to the exit pupil position through reflection. The first light has a lower brightness and its effect on the telephoto contrast can be ignored. The second light has a higher brightness and forms light spots in different areas of the telephoto, which can reduce the contrast of the area where the telephoto image and the light spot overlap, thereby achieving contrast control of different areas of the telephoto image.

[0094] The brightness of the second light provided by the backlight panel 3 to the exit pupil position through reflection should be no less than 1 / 9 of the average brightness of the distant image, and the purpose is to reduce the contrast of the local area of ​​the distant image, for example, to reduce the contrast of the local area of ​​the distant image to between 30% and 90% of the original contrast.

[0095] The reflection effect of the backlight plate 3 can be achieved by setting the surface of the backlight plate 3 facing the exit pupil to different areas and making them have different reflectivities. Among them, the surface reflectivity of at least a part of the area is greater than 5%, which is used to reflect and form the second light and form a light spot at the exit pupil position to reduce the contrast of the area where the distant image and the above light spot overlap; the surface reflectivity of the remaining area is less than 5% to absorb and reduce the reflected light as much as possible, so that the influence of the first light on the distant image can be ignored.

[0096] like Figure 7 As shown, as a preferred implementation, the reflectivity of the central area of ​​the backlight panel 3 is lower than 5%, and the peripheral area of ​​the backlight panel 3 surrounding the central area has at least one area with a reflectivity of not less than 5%, and the at least one area is called the second area, and other areas except the second area (including the central area and the peripheral area excluding the remaining part of the second area) constitute the first area, so that the second light is formed by reflection from the second area, and the second light forms a light spot at the exit pupil position to reduce the contrast of the area where the distant image overlaps with the light spot, thereby achieving the purpose of peripheral contrast control.

[0097] The reflection of the second area of ​​the backlight panel 3 is not limited to the peripheral reflection method as shown in the figure. The surface of the backlight panel 3 can be regularly or irregularly arranged with a first area and multiple second areas, wherein the first area is the area of ​​the surface of the backlight panel 3 excluding the second area, and any of the materials, colors or structures of the first area and the second area are different, so that the second area has a higher reflectivity than the first area.

[0098] For example, 9A to 9D As shown, the peripheral area of ​​the surface of the backlight plate 3 facing the exit pupil is distributed with several second areas that can provide scattering effect. The scattering area is approximately Lambertian scattering, with a reflectivity of 5% to 10%. The second area reflects the received light into the human eye. The light received by the second area is not limited to the light generated after the desktop is reflected to the plane beam splitter for splitting, but can also be the light directly reflected from the desktop to the backlight plate 3, or the light directly irradiated to the backlight plate 3 by the fill light. No matter what kind of light is reflected by the second area of ​​the backlight plate 3 and emitted to the exit pupil position, a light spot can be formed. The non-scattering area of ​​the backlight plate 3 is the first area. The texture of the non-scattering area is finer. For example, black matte or black light-absorbing material is used. The glare and scattered light are very small, which greatly reduces the impact on the distant image.

[0099] The scattering area of ​​the backlight plate 3 can be formed by different texture roughness (see Fig. 9A ) and texture morphology (see Fig. 9B ) to change the intensity of the scattered light, or by changing the color of the scattered area (see Fig.9D ) to change the scattered light intensity, or by changing the color and texture of the scattering area at the same time, thereby affecting the degree of change in peripheral contrast. Figure 9A-9D In the embodiment, the texture roughness of the scattering region is between VDI 27 and VDI 40, and the texture inside the scattering region can be ordered or random. In different backlight panels 3, the distribution of the second region can also be different, such as Fig. 9A , Fig. 9C and Fig.9DAs shown, although the second areas are distributed in the peripheral area of ​​the backlight plate 3, the sizes and distribution forms of the second areas are different in different backlight plates.

[0100] Specifically, in Figure 9A-9D In the figure, except for the central area of ​​the backlight plate 3 (300 mm in the longitudinal direction and 130-170 mm in the lateral direction), there is no scattering area distribution, and various scattering area patterns can be regularly or irregularly distributed in other areas. The spacing between the patterns is d, and the maximum size of the pattern is a, then a>4mm, d≥0.3a. Fig. 9B compared to Fig. 9A , the texture of the scattering region is changed to increase the surface roughness of the second region; Fig. 9C compared to Fig. 9A , there are differences in the distribution and number of scattering areas; Fig.9D and Fig. 9A , Fig. 9B , Fig. 9C In comparison, not only is the texture of the scattering area different, but the contrast of the distant image peripheral area is also changed by changing the color of the scattering area.

[0101] Example 4

[0102] like Fig. 10A and Fig. 10B The desktop telescopic reading and writing device with contrast control shown in the figure comprises: a plane beam splitter 1, a concave reflector 2, a backlight plate 3 and a bracket 9; wherein the bracket 9 is vertically arranged on the desktop 4, the backlight plate 3 is vertically arranged and connected to the top of the bracket 9; one end of the concave reflector 2 is connected to the top of the backlight plate 3, and is maintained at a position parallel to the desktop 4 when in use; the top of the plane beam splitter 1 can rotate around the top of the backlight plate 3, and the plane beam splitter 1 is tiltedly arranged between the concave reflector 2 and the backlight plate 3 when in use, and the light reflected by the desktop 4 and the object placed on the desktop is emitted from the bottom to the plane beam splitter 1, passes through the plane beam splitter 1 and then emits to the concave reflector 2 and is reflected at the position of the concave reflector 2; the light formed after reflection by the concave reflector 2 is reflected by the plane beam splitter 1 and then emitted to the exit pupil position; the light emitted to the exit pupil position forms a telescopic image at a virtual image position not less than 1 meter in front of the exit pupil position.

[0103] In this embodiment, if Fig. 10A As shown, a pit array 17 is provided on the surface of the backlight plate 3 facing the exit pupil position to realize partial reflection of the backlight plate 3. When the pit area reflects light, the pit area forms a second light through reflection, and the second light directed toward the exit pupil position forms a light spot, and the contrast of the area where the distant image overlaps with the light spot decreases. By changing the reflectivity and distribution of the scattering area, the brightness and display position of the light spot can be changed, thereby adjusting the contrast strength and layout of the distant image.

[0104] Similarly, if Fig. 10B As shown, a convex dot array 18 is provided on the surface of the backlight plate 3 facing the exit pupil position to realize partial reflection of the backlight plate 3. When the convex dot area reflects light, the convex dot area forms a second light through scattering, and the second light directed to the exit pupil position forms a light spot, and the contrast of the area where the distant image overlaps with the light spot decreases. By changing the reflectivity and distribution of the scattering area, the brightness and display position of the above light spot can be changed, thereby adjusting the contrast strength and layout of the distant image.

[0105] Example 5

[0106] like Fig.11 The desktop telescopic reading and writing device with contrast control shown in the figure comprises: a plane beam splitter 1, a concave reflector 2, a backlight plate 3 and a bracket 9; wherein the bracket 9 is vertically arranged on the desktop 4, the backlight plate 3 is vertically arranged and connected to the top of the bracket 9; one end of the concave reflector 2 is connected to the top of the backlight plate 3, and is maintained at a position parallel to the desktop 4 when in use; the top of the plane beam splitter 1 can rotate around the top of the backlight plate 3, and the plane beam splitter 1 is tiltedly arranged between the concave reflector 2 and the backlight plate 3 when in use, and the light reflected by the desktop 4 and the object placed on the desktop is emitted from the bottom to the plane beam splitter 1, passes through the plane beam splitter 1 and then emits to the concave reflector 2 and is reflected at the position of the concave reflector 2; the light formed after reflection by the concave reflector 2 is reflected by the plane beam splitter 1 and then emitted to the exit pupil position; the light emitted to the exit pupil position forms a telescopic image at a virtual image position not less than 1 meter in front of the exit pupil position.

[0107] Among them, Fig.11 As shown, by adding an additional light source on the lower surface of the plane beam splitter 1, the light source provides illumination to different areas of the backlight plate 3, and a light spot is formed by reflection of a local area of ​​the backlight plate 3 to reduce the contrast of the area where the distant image and the light spot overlap.

[0108] like Fig.11 In the embodiment shown, the surface of the backlight panel 3 facing the exit pupil position is non-mirror and has the same reflectivity (preferably: between 3% and 8%). In combination with a light source assembly arranged opposite the backlight panel 3, the light source assembly illuminates a local area of ​​the backlight panel to reflect light toward the exit pupil position through the local area of ​​the backlight panel, thereby achieving the effect of reducing the contrast of the local area of ​​the distant image.

[0109] The light source assembly includes a light source and a mask, and the mask can be a diffractive optical element. The shape and intensity of the light are regulated by installing a micro laser and a diffractive optical element (DOE) in the groove below the plane reflector 1, so that the light is projected onto the backlight plate 3, forming light spots or lines of different layouts on it, making the layout more diverse. The optical path is shown in FIG. Fig.11 The light hitting the backlight panel 3 is scattered by the backlight panel 3 and directly enters the human eye through the plane reflector 1, thereby reducing the contrast of the corresponding position of the distant image.

[0110] In order to fully utilize the bonus period of contrast control, the position of the light spot can be changed regularly, for example, by regularly replacing different backlight panels 3 or regularly changing the light source signal directed to the backlight panel 3 to achieve the above purpose.

[0111] In summary, the desktop telephoto reading and writing device with contrast control provided by the present invention uses the birdbath coaxial optical system to magnify and project objects such as books placed on the desktop, achieving an imaging effect similar to that of a telescope. This structure can obtain a high-definition image with almost no distortion without introducing a free-form surface, while reducing the difficulty of processing and adjustment. In addition, the desktop telephoto reading and writing device also introduces contrast control. When the user reads text and other content in a book, the contrast of the image outside the gaze area is reduced, reducing retinal stimulation and inhibiting the growth of the eye axis. At the same time, it may have a certain effect on the thickening of the choroid, thereby achieving myopia prevention and control.

[0112] The above is a detailed description of a desktop telephoto reading and writing device with contrast control and a control method thereof provided by the present invention. For a person skilled in the art, any obvious changes made to it without departing from the essence of the present invention will constitute an infringement of the patent right of the present invention and will bear corresponding legal responsibilities.

Claims

1. A desktop telescopic reading and writing device with contrast control, characterized in that: include: A plane beam splitter, a concave reflector and a backlight plate; wherein, The concave reflector is kept in a horizontal or vertical position when in use; the plane beam splitter is tilted when in use; The backlight plate and the concave reflector are arranged perpendicular to each other and are used to provide light to the exit pupil position; The light reflected by the desktop and the object placed on the desktop is directed toward the plane beam splitter from below, and the light formed after the beam splitting by the concave reflector is reflected by the concave reflector, split by the plane beam splitter, and then directed toward the exit pupil position, and forms a distant image at a position not less than 1 meter; different areas of the backlight panel provide at least two lights of different brightness to the exit pupil position, wherein the brightness of the first light is lower than the brightness of the second light, so as to change the contrast of different areas of the distant image.

2. The desktop telescopic reading and writing device according to claim 1, characterized in that: The ratio of the brightness of the second light provided by the backlight panel to the exit pupil position to the average brightness of the distant image is not less than 1 / 9.

3. The desktop telescopic reading and writing device according to claim 1, characterized in that: The ratio of the brightness of the first light provided by the backlight panel to the exit pupil position to the average brightness of the distant image is less than 1 / 10.

4. The desktop telescopic reading and writing device according to claim 1, characterized in that: The side surface of the backlight plate facing the exit pupil position is provided with an active light-emitting element, and the first light and the second light are provided to the exit pupil position in different regions by controlling the brightness of different regions in the active light-emitting element.

5. The desktop telescopic reading and writing device as claimed in claim 4, characterized in that Also included is an eye-tracking camera and controller; The eye tracking camera is arranged facing the exit pupil position and is used to collect images of human eyes; The controller determines the gaze point of the human eye in the distant image according to the human eye image, and makes the brightness of the gaze area centered on the gaze point in the backlight plate lower than the brightness of the surrounding area of ​​the gaze area.

6. The desktop telescopic reading and writing device according to claim 5, characterized in that: The active light emitting element is an array light source, which covers the entire area of ​​the backlight panel. The controller makes the light source in the attention area have low brightness or does not emit light.

7. The desktop telescopic reading and writing device according to claim 5, characterized in that: The active light-emitting element includes a fixed white board and a dark electrochromic film covering it. The transmittance of the electrochromic film at different positions at different times is controlled by a logic timing circuit to change the brightness of different areas of the backlight board.

8. The desktop telescopic reading and writing device according to claim 5, characterized in that: The active light-emitting element is a display screen, which displays by controlling pixels at different positions in the display screen to change the brightness of different areas of the backlight panel.

9. The desktop telescopic reading and writing device according to claim 4, characterized in that: The active light emitting element is an array light source, and the array light source is distributed only in the peripheral area of ​​the backlight plate, or only in one or more local areas.

10. The desktop telescopic reading and writing device according to claim 1, characterized in that: The backlight panel provides the at least two lights of different brightness to the exit pupil position through reflection sub-areas.

11. The desktop telescopic reading and writing device according to claim 10, characterized in that: The reflectivity of the central area of ​​the backlight plate is lower than 5%, and the reflectivity of at least one area in the peripheral area of ​​the backlight plate surrounding the central area is not less than 5%.

12. The desktop telescopic reading and writing device according to claim 10, characterized in that: The surface of the backlight plate is provided with a first area and a second area, wherein at least one of the material, color or surface microstructure of the first area and the second area is different, so that the second area has a higher reflectivity than the first area.

13. The desktop telescopic reading and writing device according to claim 12, characterized in that: The microstructure of the second area of ​​the backlight plate is a convex dot array or a concave pit array.

14. The desktop telescopic reading and writing device according to claim 10, characterized in that Also includes: The light source assembly is used to provide light source to the backlight panel; the surface of the backlight panel has the same reflectivity, and the light source assembly illuminates a local area of ​​the backlight panel to reflect the second light to the exit pupil position through the local area of ​​the backlight panel.

15. The desktop telescopic reading and writing device according to claim 14, characterized in that: The light source assembly includes a light source and a mask.

16. The desktop telescopic reading and writing device according to claim 15, characterized in that: The mask is a diffractive optical element.

17. The desktop telescopic reading and writing device according to claim 1, characterized in that: Also includes: The first adjusting member is used to adjust the angle between the plane beam splitter and the concave reflecting mirror, and to keep the plane beam splitter at at least two positions where the angle between the plane beam splitter and the concave reflecting mirror is between 30° and 60°; the angle between the plane beam splitter and the concave reflecting mirror is adjusted by the first adjusting member to change the height of the exit pupil position relative to the desktop.

18. The desktop telescopic reading and writing device according to claim 1, characterized in that Also includes: The fill light is arranged on the lower surface of the plane beam splitter, and the fill light is composed of a plurality of light sources arranged linearly, the plurality of light sources are arranged in a stepped manner, and when the plane beam splitter and the desktop are in a use state with an angle of 45 degrees, the main light of each light source is perpendicular to the desktop.

19. A control method for a desktop telescopic reading and writing device, characterized in that The steps include: The desktop telescopic reading and writing device comprises: a plane beam splitter, a concave reflector and a backlight plate; wherein, The light reflected by the desktop and the objects placed on the desktop is directed toward the plane beam splitter from below, and the light formed after the beam splitting by the concave reflector is reflected by the concave reflector, and then is directed toward the exit pupil position after the beam splitting by the plane beam splitter, and forms a distant image at a position not less than 1 meter; the backlight panel is arranged facing the exit pupil position and the brightness of different areas is different, so as to change the contrast of different areas of the distant image.

20. The control method of the desktop telescopic reading and writing device according to claim 19, characterized in that: Use eye tracking camera to collect human eye images; The controller determines the gaze point of the human eye in the distant image according to the human eye image, and makes the brightness of the gaze area centered on the gaze point in the backlight panel lower than the brightness of the surrounding area of ​​the gaze area.

21. The control method of the desktop telescopic reading and writing device according to claim 20, characterized in that: The range of the gaze area is not larger than the size of the area in the backlight plate corresponding to the ±15° visual field of the human eye, and is not smaller than the size of the area in the backlight plate corresponding to the ±3° visual field of the human eye.

22. The control method of the desktop telescopic reading and writing device according to claim 20, characterized in that: The range of the gaze area is a circular area centered on the gaze point, and the diameter of the circular area is 6 to 8 centimeters.

23. The control method of the desktop telescopic reading and writing device according to claim 20, characterized in that: The brightness of the area outside the fixation area increases in steps with the fixation point as the center.

24. The control method of the desktop telescopic reading and writing device according to claim 20, characterized in that: The entire backlight panel is centered on the gaze point and the brightness gradually increases from the center to the outside.

Images