Desktop far image read-write device with visual virtual image distance

Abstract

The utility model discloses a desktop far image read-write device with a visual virtual image distance, which comprises a far image optical system, a distance sensor, a controller, a distance measurement reference object and a display device, the distance measurement reference object is arranged on the desktop below the distance sensor or a plane with a fixed height from the desktop; the distance sensor is used for collecting the distance d from the bottom of the desktop remote image read-write equipment to the distance measurement reference object; and the controller is used for obtaining the virtual image distance l'of the remote image optical system according to the distance d from the bottom of the desktop remote image read-write equipment to the distance measurement reference object, and displaying the virtual image distance l 'through the display equipment. According to the desktop far image read-write device, the distance sensor, the distance measurement reference object and the display device are additionally arranged, and the distance from the desktop to the far image optical system is measured by using the unified distance measurement reference object, so that the influence of different desktop conditions on a measurement result is avoided, and the stability of a virtual image distance measurement result is ensured.

Description

Technical Field

[0001] This utility model relates to a desktop remote image reading and writing device. Background Technology

[0002] The problem of myopia among teenagers is becoming increasingly serious. The root cause is that teenagers' eyes spend most of their time focusing on close-up objects, causing their eyeballs to gradually lengthen in order to adapt to near-field imaging. To address this issue, various myopia prevention and control products have emerged on the market.

[0003] Desktop image reading and writing devices utilize optical means to extend near-field reading and writing to a distant image, and are primarily used in the field of myopia prevention and control among teenagers. These devices are generally designed for children and teenagers and are typically equipped with height-adjustable stands to accommodate users of different heights. However, when adjusting the stand height, the distances from the optical elements within the device to the desktop change, resulting in a corresponding change in the virtual image distance. For desktop image reading and writing devices with defocused optical paths, the degree of defocus also changes simultaneously.

[0004] For users who use desktop far-view reading and writing devices for myopia management, the virtual image distance of a single-focal-plane desktop far-view reading and writing device, as well as the virtual image distance and defocus of a far-viewing solution with a defocus optical path, are closely related to the myopia control effect and user comfort. These are important indicators that users pay close attention to, but currently there is no simple, intuitive solution that can accurately reflect changes in virtual image distance and defocus. Summary of the Invention

[0005] The primary technical problem to be solved by this utility model is to provide a desktop remote image reading and writing device with a visible virtual image distance for monitoring and displaying the virtual image distance.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0007] A desktop remote image reading and writing device with a visible virtual image distance includes a remote image optical system, a distance sensor, a controller, a ranging reference object, and a display device.

[0008] Among them, the far-image optical system is used to form a magnified virtual image of an object placed on a table;

[0009] The ranging reference object is set on a desktop below the distance sensor or on a plane at a fixed height from the desktop, and the area of ​​the ranging reference object is larger than the signal acquisition range of the distance sensor;

[0010] The distance sensor is used to collect the distance d from the bottom of the desktop image reader / writer to the ranging reference object;

[0011] The controller obtains the virtual image distance l' of the far-image optical system based on the distance d from the bottom of the desktop far-image reading and writing device to the ranging reference object, and displays the virtual image distance l' through the display device.

[0012] Preferably, the far-image optical system is also used to form a magnified, defocused image of an object placed on a table;

[0013] The controller obtains the defocus degree D corresponding to the image distance of the defocused image based on the distance d from the bottom of the desktop image reading and writing device to the ranging reference object, and displays the defocus degree D through the display device.

[0014] Preferably, the reflectivity of the ranging reference object is at least greater than 10%.

[0015] Preferably, the ranging reference object is a label, which includes an adhesive layer, a label body, and a surface protective layer.

[0016] Preferably, the ranging reference object is provided with prompts or markings related to the pasting information and / or ranging signal acquisition information.

[0017] Preferably, the thickness of the ranging reference object does not exceed 0.5 mm.

[0018] Preferably, the desktop image reading and writing device further includes:

[0019] The housing is used to house the far-image optical system and to secure the distance sensor, controller, and display device.

[0020] The stand, which is fixedly connected to the casing, is used to adjust the distance between the casing and the desktop.

[0021] Preferably, the distance sensor is positioned at the bottom of the housing, facing the desktop.

[0022] Preferably, the distance sensor is mounted away from the housing and bracket via a mounting component. Furthermore, preferably, the signal acquisition area of ​​the distance sensor does not overlap with the area below the telephoto optical system.

[0023] The desktop far-image reading and writing device provided by this utility model includes a far-image optical system, a distance sensor, a ranging reference object, a controller, and a display device. By placing the ranging reference object on a desktop or a plane with a fixed height, the distance sensor collects the distance from the bottom of the desktop far-image reading and writing device to the ranging reference object in real time, obtaining the virtual image distance of the far-image optical path. If a defocused optical path exists, the defocus degree of the defocused optical path can be obtained simultaneously. Then, the virtual image distance and defocus degree are displayed externally through the display device. By adding a distance sensor, a ranging reference object, and a display device to the desktop far-image reading and writing device, and using a uniform ranging reference object to measure the distance from the desktop to the far-image optical system, the influence of different desktop conditions on the measurement results is avoided, ensuring the stability and accuracy of the virtual image distance measurement results. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a desktop remote image reading and writing device provided by this utility model;

[0025] Figure 2 yes Figure 1 The diagram shows another three-dimensional structure of a desktop image reading and writing device.

[0026] Figure 3 yes Figure 1 A top view of the distance measuring reference object and the support;

[0027] Figure 4 This is a schematic diagram of yet another type of distance measurement reference.

[0028] Figure 5 yes Figure 1 The diagram shows the optical path principle and parameters of the desktop image reading and writing device.

[0029] Figure 6 This is a structural schematic diagram of another desktop remote image reading and writing device provided by this utility model;

[0030] Figure 7 yes Figure 6 The diagram shows the optical path of a desktop image reader / writer.

[0031] Figure 8 yes Figure 6 The diagram shows the parameters of a desktop image reading / writing device. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0034] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0035] This application provides a desktop remote image reading and writing device based on a coaxial optical system, including a remote image optical system. The remote image optical system may consist only of a remote image optical path for forming a magnified virtual image of an object placed on a desktop (e.g., a book or a display screen); or it may simultaneously include a remote image optical path and a defocus optical path for forming a magnified virtual image and a positive defocus image of the object placed on the desktop. Below, a first embodiment describes a desktop remote image reading and writing device that includes only a remote image optical path, and a second embodiment describes a desktop remote image reading and writing device that simultaneously includes a defocus optical path and a remote image optical path.

[0036] First Embodiment

[0037] The desktop remote image reader / writer 10 provided in the first embodiment includes only the remote image optical path. In this embodiment, a foldable desktop remote image reader / writer is used as an example for illustration. This technical solution is also applicable to a non-foldable fixed desktop remote image reader / writer that includes only the remote image optical path.

[0038] like Figure 1 and Figure 2As shown, the defocus-protected desktop far-image reading and writing device is based on the Birdbath (BB) optical path and includes a planar beam splitter 1 and a first reflector 2 disposed in the housing. Light rays (e.g., light rays 5 reflected by the desktop 4 and the book placed on the desktop 4) are incident on the planar beam splitter 1 from below and are split at the position of the planar beam splitter 1. The first light ray formed after being split by the planar beam splitter 1 is reflected by the first reflector 2, and then after being split by the planar beam splitter 1, it is incident on the exit pupil position. It forms an image at a virtual image position at a distance of not less than 3 meters from the exit pupil position in front of the human eye (i.e. in front of the exit pupil position) for normal human viewing. At this time, the light enters the human eye and forms an image on the human retina.

[0039] In this embodiment, the first reflecting mirror 2 for distant image imaging is horizontally arranged. The light transmitted through the plane beam splitter 1 is directed to the first reflecting mirror 2 and then reflected by the first reflecting mirror 2. It can be understood that in other embodiments, the first reflecting mirror 2 may also be vertically arranged. The light reflected by the plane beam splitter 1 is directed to the first reflecting mirror 2 and then reflected by the first reflecting mirror 2.

[0040] The desktop image reader / writer 10 is mounted on the desktop 4 via a bracket 15. The bracket 15 is connected to the outer casing of the desktop image reader / writer 10, and the distance between the desktop image reader / writer 10 and the desktop 4 is adjusted via the bracket 15. Alternatively, the desktop image reader / writer 10 can also be mounted on the desktop via a cantilever bracket, which also allows for adjustment of the distance between the desktop image reader / writer 10 and the desktop 4. Figure 5 As can be seen from the imaging principle shown, when the desktop image reading and writing device 10 moves up and down relative to the desktop 4, the object distance of the first reflecting mirror 2 changes, thereby affecting the virtual image distance l' of the image optical path.

[0041] To measure the distance d between the desktop image reader / writer 10 and the desktop 4, a distance sensor 20 is installed at the bottom of the desktop image reader / writer 10, and a display device 30 is installed on the desktop image reader / writer 10. The distance sensor 20 and the display device 30 are respectively connected to a controller installed inside the desktop image reader / writer 10. Furthermore, to standardize the measurement, a distance measurement reference object 40 is installed on the desktop 4 or a plane at a fixed height above the desktop. This ensures a unified measurement standard for different desktops, thereby eliminating measurement errors caused by inconsistent reflections of the distance measurement signal due to different desktop conditions.

[0042] The distance sensor 20 is positioned at the bottom of the desktop image reader / writer 10, facing the desktop. Specifically, it can be fixed to the lower edge of the housing, or it can be configured to extend from the lower edge of the housing to a position flush with the bottom of the desktop image reader / writer 10 via a mounting bracket. It is used to measure the distance d between the desktop image reader / writer 10 and the distance measurement reference object 40. To ensure the accuracy of the measurement results, during use of the desktop image reader / writer 10, objects such as books should not be placed under the distance sensor 20 to avoid errors in the distance measurement results. The distance sensor 20 can use signals such as infrared, millimeter wave, ultrasonic, laser, and LED for measurement, and can measure the real-time distance between the desktop image reader / writer 10 and the distance measurement reference object 40.

[0043] The controller is configured to receive signals collected by the distance sensor 20, obtain the virtual image distance l' corresponding to the distance d from the desktop image reader / writer 10 to the distance sensor 40, and display the virtual image distance l' externally through the display device 30. In practical applications, the controller can obtain the virtual image distance l' through real-time calculation. Alternatively, a mapping table of distance d and virtual image distance l' can be pre-stored in the controller, and then the virtual image distance l' corresponding to the distance d can be obtained from the mapping table during use. The aforementioned mapping table can be obtained through numerical calculation or actual measurement calibration.

[0044] Display device 30 uses a small-sized display screen, generally no larger than 5 inches, such as a 3.5-inch display screen. Display device 30 can also be a portion of a larger display screen. From a cost control perspective, monochrome or black-and-white e-ink screens can be used, such as monochrome electronic paper displays, industrial control screens, LCD dot matrix screens, LCD segment screens, etc. No restrictions are placed on the use of display device 30 here. To avoid prolonged exposure of the human eye to the display device 30, display device 30 preferably uses a display screen with an always-on function. The display screen is controlled by a controller and only lights up briefly after the virtual image distance l' is updated; otherwise, it remains in an always-on state.

[0045] The display device 30 is preferably positioned in front of the desktop image reading / writing device 10, emitting light towards the exit pupil, and is independent of the image path and defocus path, forming images in different areas of the human eye's field of vision; the display device 30 may also be positioned behind the desktop image reading / writing device 10 and facing the exit pupil area through the plane beam splitter 1 (e.g., Figure 1 As shown), the image of the display device 30 can be directly superimposed on the far-image optical path for display. The first reflector 2 has no optical effect on the light emitted by the display device 30 and does not have a magnification function for the image of the display device 30.

[0046] The controller is located inside the desktop remote image reader / writer 10. As the electronic control component of the desktop remote image reader / writer 10, it is preferable to centrally locate the distance sensor 20, the display device 30, and the controller in the same area of ​​the desktop remote image reader / writer 10. Since the use of the desktop remote image reader / writer 10 requires the use of a lighting source, the lighting source is usually located at the bottom of the desktop remote image reader / writer 10, and the distance sensor 20, the display device 30, and the controller can be located at the bottom of the desktop remote image reader / writer 10 near the lighting source.

[0047] Of course, in some specially designed desktop image reading and writing devices, the display device 30, controller, and distance sensor 20 can also be set separately. The distance sensor 20 is set at the bottom of the desktop image reading and writing device, and the position of the distance sensor 20 relative to the first reflector 2 remains unchanged; however, the setting positions of the display device 30 and the controller are not limited in this way, and the setting positions of the display device 30 and the controller can be changed relative to the first reflector 2 under different usage conditions.

[0048] In this embodiment, the thickness of the ranging reference object 40 does not exceed 0.5 mm. Thus, the distance d from the bottom of the desktop remote image reader / writer to the ranging reference object 40, measured by the distance sensor 20, can be approximated as the distance from the bottom of the desktop remote image reader / writer to the desktop 4. The shape of the ranging reference object 40 is not limited and can be, for example... Figure 3 The rectangle shown can also be as follows: Figure 4 The distance measuring reference object 40, whether circular or other shapes, should have an area larger than the signal acquisition range of the distance sensor 20. The material of the distance measuring reference object 40 is not limited; however, for similar products, it is recommended to use the same distance measuring reference object, such as a label, soft pad, soft cloth, or cardboard. The reflectivity of the distance measuring reference object 40 should be at least greater than 10% to ensure that the distance sensor 20 can receive sufficient reflected signals to complete distance detection.

[0049] like Figure 3 and Figure 4 The distance measuring reference 40 shown is a label. Preferably, the label includes an adhesive layer, a label body, and a surface protective layer. The label 40 can be adhered to the tabletop via the adhesive layer at the bottom, and any position on the surface of the label 40 can serve as a detection point 41. By adhering the label 40 below the distance sensor 20, the distance from the bottom of the desktop image reading and writing device to the distance measuring reference 40 can be detected.

[0050] To facilitate the pasting of the ranging reference object 40 on the desktop, prompts or labels 42 related to the pasting information and / or ranging signal acquisition information can be set on the ranging reference object 40. For example, the label can be easily set by aligning the label 40 with the fixed position of the bracket 15 and pasting it below the distance sensor.

[0051] The controller calculates the object distance u1 of the first reflecting mirror 2 based on the distance d from the bottom of the desktop far-image reading and writing device to the ranging reference object 40. It then combines this distance with the equivalent radius of curvature R1 of the first reflecting mirror 2 and the equivalent distance s2 from the first reflecting mirror 2 to the exit pupil position to calculate the virtual image distance of the far-image optical system. The expression used for the calculation is as follows:

[0052]

[0053] In the formula, all units are in meters (m).

[0054] l'—Virtual image distance;

[0055] d—The distance from the lower edge of the desktop image reading and writing device 10 to the ranging reference object 40;

[0056] s1—The equivalent distance from the first reflecting mirror 2 to the lower edge of the desktop image reading and writing device 10;

[0057] R1—Equivalent radius of curvature of the first reflecting mirror 2;

[0058] s2——The equivalent distance from the first reflecting mirror 2 to the exit pupil position.

[0059] Where u1 is the object distance of the first reflecting mirror 2, u1=d+s1; s1=δ1+δ2, δ1 is the distance from the first reflecting mirror 2 to the plane beam splitter 1, δ2 is the distance from the plane beam splitter 1 to the lower edge of the desktop image reading and writing device 10; s2=δ1+δ4, δ1 is the distance from the first reflecting mirror 2 to the plane beam splitter 1, δ4 is the distance from the plane beam splitter 1 to the exit pupil position.

[0060] When the ranging reference object 40 is set on a plane at a fixed height from the desktop, such as at a fixed position on the bottom bracket 15, the sum of the height d1 of the ranging reference object 40 from the desktop 4 and the distance d2 from the lower edge of the desktop image reading and writing device 10 to the ranging reference object 40 is equal to the distance d from the lower edge of the desktop image reading and writing device 10 to the ranging reference object 40 when the ranging reference object 40 is set on the desktop. Substituting the above result into the calculation formula, the virtual image distance l' is obtained.

[0061] Of course, the virtual image distance l' can also be obtained by looking up the built-in mapping table.

[0062] Furthermore, the distance sensor 20 can also be externally mounted on the lower part of the desktop far-image reading and writing device 10. The distance sensor 20 is mounted away from the housing and support via a mounting bracket, thus ensuring that the signal acquisition range of the distance sensor 20 avoids the bottom support and the area on the desktop where books are placed. For example, the distance sensor 20 can be mounted on the rear side of the housing at a predetermined distance from the housing (away from the exit pupil and away from the housing itself). In this case, the signal acquisition area of ​​the distance sensor 20 does not overlap with the area below the far-image optical system.

[0063] Second Embodiment

[0064] The second embodiment provides a desktop remote image reader / writer 10 with defocus control function.

[0065] like Figure 6 and Figure 7 As shown, the defocus-protected desktop image reading and writing device is based on the Birdbath (BB) optical path and includes two BB optical paths. The two BB optical paths share a plane beam splitter 1. The light 5, after being reflected by the desktop 4 (and objects placed on the desktop 4, such as books), is directed from below to the plane beam splitter 1 and is split at the plane beam splitter 1. The first light ray formed after being split by the plane beam splitter 1 (shown as light 51 reflected by the plane beam splitter 1) is reflected by the first mirror 2 and then passes through the plane beam splitter 1 to the exit pupil. The second light ray formed after being split by the plane beam splitter 1 (shown as light 52 passing through the plane beam splitter 1) is reflected by the second mirror 3 and then reflected again by the plane beam splitter 1 to the exit pupil. The first light ray and the second light ray form different optical paths, and the light rays in the two optical paths form images in the human eye. Each optical path has an independent focal plane, and the two focal planes are located at different positions.

[0066] The first ray of light, after being reflected by the first reflecting mirror 2, is projected onto a virtual image position at a distance of no less than 3 meters in front of the eye (i.e., in front of the exit pupil position), which is used for normal viewing. At this time, the light enters the eye and is projected onto the retina. The light path corresponding to the first reflecting mirror 2 is the far image light path. The second ray of light, after being reflected by the second reflecting mirror 3, is projected onto the exit pupil position on the opposite side (i.e., behind the exit pupil position) relative to the exit pupil position, forming a defocused image, thus forming a positive defocus light path. The diopter corresponding to the positive defocus light path can be controlled between +1D and +5D. The light in the positive defocus light path is projected onto the retina in front of the eye, presenting a myopic defocus state, thereby achieving defocus stimulation, which helps in myopia prevention and control.

[0067] To achieve different focal plane positions for the two optical paths, the first reflecting mirror 2 and the second reflecting mirror 3 can have the same surface parameters but different distances from the plane beam splitter 1; alternatively, the first reflecting mirror 2 and the second reflecting mirror 3 can have the same distance from the plane beam splitter 1, but different equivalent radii of curvature. No restrictions are placed on the methods for achieving distant image imaging and positive defocus imaging using the two optical paths.

[0068] In the above embodiment, the first reflecting mirror 2 for distant image imaging is vertically arranged, and the light reflected by the plane beam splitter 1 is directed toward the first reflecting mirror 2. The second reflecting mirror 3 for defocus imaging is horizontally arranged, and the light transmitted through the plane beam splitter 1 is directed toward the second reflecting mirror 3. It can be understood that in other embodiments, the first reflecting mirror 2 may also be horizontally arranged, while the second reflecting mirror 3 may be vertically arranged.

[0069] like Figure 6 As shown, the desktop image reader / writer 10 is mounted on the desktop 4 via a bracket 15, and the position of the desktop image reader / writer 10 relative to the desktop 4 is adjustable. Figure 7 As can be seen from the imaging principle shown, when the desktop image reading and writing device 10 moves up and down relative to the desktop 4, the object distance between the first reflecting mirror 2 and the second reflecting mirror 3 changes, thereby affecting the virtual image distance l' of the far image optical path and the defocus degree D of the defocus optical path.

[0070] To measure the distance d between the desktop image reader / writer 10 and the desktop 4, a distance sensor 20 is installed at the bottom of the desktop image reader / writer 10, and a display device 30 is installed on the desktop image reader / writer 10. The distance sensor 20 and the display device 30 are respectively connected to a controller installed inside the desktop image reader / writer 10. Furthermore, to standardize the measurement, a distance measurement reference object 40 is installed on the desktop 4 or a plane at a fixed height above the desktop. This ensures a unified measurement standard for different desktops, thereby eliminating measurement errors caused by inconsistent reflections of the distance measurement signal due to different desktop conditions.

[0071] The setup of the distance sensor 20, display device 30, and ranging reference 40 is the same as in the first embodiment and will not be described again here. Unlike the first embodiment, in this embodiment, the controller is configured to receive the signal collected by the distance sensor 20, obtain the virtual image distance l' and defocus degree D corresponding to the distance d from the desktop image reader / writer 10 to the ranging reference 40, and display the virtual image distance l' and defocus degree D externally through the display device 30. In practical applications, the controller can obtain the virtual image distance l' and defocus degree D through real-time calculation. Alternatively, a mapping table of distance d, virtual image distance l', and defocus degree D can be pre-stored in the controller, and then, during use, the virtual image distance l' and defocus degree D corresponding to the distance d can be obtained from the mapping table through data lookup. The mapping table can be obtained through numerical calculation or through actual measurement.

[0072] The following is combined with Figure 7 and Figure 8 The calculation process of virtual image distance l' and defocusing degree D is introduced.

[0073] In the process of calculating the virtual image distance l' and defocus D of the desktop image reading and writing device provided by this utility model, only the distance d between the desktop image reading and writing device 10 and the ranging reference object 40 is a variable. The object distance u1 of the first reflecting mirror 2 and the object distance u2 of the second reflecting mirror 3 change with the change of d. The equivalent distance s2 from the first reflecting mirror 2 to the exit pupil position and the equivalent distance s4 from the second reflecting mirror 3 to the exit pupil position are unrelated to the distance d between the desktop image reading and writing device 10 and the desktop 4 and do not change.

[0074] Specifically, the controller calculates the object distance u1 of the first reflecting mirror 2 based on the distance d from the bottom of the desktop far-image reading and writing device to the ranging reference object 40, and calculates the virtual image distance of the far-image optical system by combining the equivalent radius of curvature R1 of the first reflecting mirror 2 and the equivalent distance s2 from the first reflecting mirror 2 to the exit pupil position. The expression used for the calculation is as follows:

[0075]

[0076] In the formula, all units are in meters (m).

[0077] l'—Virtual image distance;

[0078] d—The distance from the lower edge of the desktop image reading and writing device 10 to the ranging reference object 40;

[0079] s1—The equivalent distance from the first reflecting mirror 2 to the lower edge of the desktop image reading and writing device 10;

[0080] R1—Equivalent radius of curvature of the first reflecting mirror 2;

[0081] s2——The equivalent distance from the first reflecting mirror 2 to the exit pupil position.

[0082] Where u1 is the object distance of the first reflecting mirror 2, u1=d+s1; s1=δ1+δ2, δ1 is the distance from the first reflecting mirror 2 to the plane beam splitter 1, δ2 is the distance from the plane beam splitter 1 to the lower edge of the desktop image reading and writing device 10; s2=δ1+δ4, δ1 is the distance from the first reflecting mirror 2 to the plane beam splitter 1, δ4 is the distance from the plane beam splitter 1 to the exit pupil position.

[0083] The controller calculates the object distance u2 of the second reflector 3 based on the distance d from the bottom of the desktop far-viewing device 10 to the ranging reference object, and calculates the defocus degree D corresponding to the image distance of the defocused image by combining the equivalent radius of curvature R2 of the second reflector 3 and the equivalent distance s4 from the second reflector 3 to the exit pupil position. The defocus degree D is the reciprocal of the image distance of the defocused optical path.

[0084] Calculate the defocus D using the following expression:

[0085]

[0086] In the formula, all units are in meters (m).

[0087] D – Defocus;

[0088] R2—Equivalent radius of curvature of the second reflecting mirror 3;

[0089] s3 — the equivalent distance from the second reflecting mirror 3 to the lower edge of the desktop image reading and writing device 10;

[0090] s4 — The equivalent distance from the second reflecting mirror 3 to the exit pupil position.

[0091] Where u2 is the object distance of the second reflecting mirror 3, u2=d+s3; s3=δ2+δ3, δ2 is the distance from the plane beam splitter 1 to the lower edge of the desktop image reading and writing device 10, δ3 is the distance from the second reflecting mirror 3 to the plane beam splitter 1; s4=δ3+δ4, δ3 is the distance from the second reflecting mirror 3 to the plane beam splitter 1, δ4 is the distance from the plane beam splitter 1 to the exit pupil position.

[0092] During the above calculation process, the controller collects the distance d between the lower edge of the desktop image reading and writing device 10 and the ranging reference object 40, and calls the parameters R1, R2, δ1, δ2, δ3 and δ4 stored in the controller in advance to calculate the virtual image distance l' and defocus degree D.

[0093] In the above process, the virtual image distance l' and defocus D are obtained in the same step. When the distance d from the bottom of the desktop far image reading and writing device 10 to the desktop 4 or the object placed on the desktop changes, both the virtual image distance l' and the defocus D will change. However, for the desktop far image reading and writing device 10 that only includes the far image optical path, only the acquisition, comparison and display of the virtual image distance l' are involved.

[0094] It is understandable that, in order to reduce the data processing of the controller, the comparison step can be moved forward. By judging whether the distance d from the bottom of the desktop far-view reading and writing device to the ranging reference object has changed compared with the previous distance, it can be determined whether to obtain the virtual image distance l' and defocus D, and whether to update and display the virtual image distance l' and defocus D.

[0095] In summary, the desktop far-image reading and writing device provided by this utility model acquires the virtual image distance of the far-image optical path in real time by using a distance sensor to collect the distance from the bottom of the device to the ranging reference. If a defocused optical path exists, the defocus degree of that path can also be acquired. Then, the virtual image distance and defocus degree are displayed externally through a display device. By adding a distance sensor and a display device to the desktop far-image reading and writing device, the real-time display function of virtual image distance and defocus degree is added, thus solving the problem that current desktop far-image reading and writing devices cannot intuitively and accurately reflect the changes in virtual image distance and defocus degree of the far-image optical system. Furthermore, by acquiring and displaying virtual image distance and defocus degree after real-time distance data acquisition, a basis is provided for users to adjust the desktop far-image reading and writing device to a suitable height. Moreover, by adding a distance sensor, a ranging reference, and a small display device to the desktop far-image reading and writing device, and using a uniform ranging reference to measure the distance from the desktop to the far-image optical system, the influence of different desktop conditions on the measurement results is avoided, ensuring the stability of the virtual image distance measurement results.

[0096] The foregoing has provided a detailed description of the desktop image reading and writing device with a visible virtual image distance provided by this utility model. Any obvious modifications made by those skilled in the art without departing from the essential content of this utility model will constitute an infringement of the patent rights of this utility model and will incur corresponding legal liability.

Claims

1. A desktop image reading and writing device with a visible virtual image distance, characterized in that... Includes a far-viewing optical system, a distance sensor, a controller, a ranging reference, and a display device: The distant image optical system is used to form a magnified virtual image of an object placed on a table. The ranging reference object is set on a desktop below the distance sensor or on a plane at a fixed height from the desktop. The area of ​​the ranging reference object is larger than the signal acquisition range of the distance sensor, and the surface reflectivity of the ranging reference object is at least greater than 10%. The ranging reference object is a label, which includes an adhesive layer, a label body, and a surface protective layer. The label is attached to the desktop by the bottom adhesive layer, and the position of the label surface serves as a detection point. The distance sensor is used to collect the distance from the bottom of the desktop image reader / writer to the ranging reference object. d ; The controller determines the distance from the bottom of the desktop image reader / writer to the ranging reference object. d To obtain the virtual image distance of the far-image optical system l’ and the virtual image distance l’ Displayed via the display device.

2. The desktop image reading and writing device as described in claim 1, characterized in that: The telephoto optical system is also used to form a magnified, defocused image of an object placed on a table. The controller determines the distance from the bottom of the desktop image reading and writing device to the ranging reference object. d Obtain the defocus degree corresponding to the image distance of the defocused image. D and the defocus D Displayed via the display device.

3. The desktop image reading and writing device as described in claim 1 or 2, characterized in that: The ranging reference object is provided with prompts or markings related to the pasted information and / or ranging signal acquisition information.

4. The desktop image reading and writing device as described in claim 1 or 2, characterized in that: The thickness of the ranging reference object does not exceed 0.5 mm.

5. The desktop image reading and writing device as described in claim 1, characterized in that... Also includes: The housing is used to house the far-image optical system and to secure the distance sensor, controller, and display device. The stand, which is fixedly connected to the casing, is used to adjust the distance between the casing and the desktop.

6. The desktop image reading and writing device as described in claim 5, characterized in that: The distance sensor is positioned at the bottom of the casing, facing the desktop.

7. The desktop image reading and writing device as described in claim 5, characterized in that: The distance sensor is mounted away from the housing and bracket via a mounting component.

8. The desktop image reading and writing device as described in claim 7, characterized in that: The signal acquisition area of ​​the distance sensor does not overlap with the area below the far-image optical system.

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