Non-touch display and writing system

Abstract

This invention discloses a non-touch display and a writing system, comprising a display and an electronic pen. The display has multiple dot matrix units arranged in rows and columns on a glass substrate facing the light-emitting side. Each dot matrix unit is divided into dot matrix squares, and each dot matrix square contains a metal coded dot attached to the glass substrate. The electronic pen includes a pen tip, a camera, and a data processing module. The camera is positioned facing the pen tip to capture images. The data processing module analyzes the images captured by the camera, obtains the positions of the coded dots covered by the pen tip at different times, calculates the absolute coordinates of the pen tip on the display, and combines multiple coordinates into a writing trajectory coordinate set, which is then displayed on the display. This invention eliminates the need for an additional sensing layer on the screen surface, achieving precise positioning through visual recognition using a metal dot matrix and pen tip obstruction. It does not affect the light transmittance or display quality of the display and has the advantages of strong anti-interference capability and high positioning accuracy.

Description

Technical Field

[0001] This invention relates to the field of display human-computer interaction technology, and more specifically, to a non-touch display and writing system based on infrared camera technology and dot matrix coding matrix. Background Technology

[0002] With the rapid development of display technology and human-computer interaction technology, large-size liquid crystal displays (LCD, LED, etc.) are increasingly widely used in education, conferencing, design, and other fields. In these application scenarios, users often need to perform operations such as writing, annotating, and drawing on the display. Existing touch writing technologies mainly include resistive touchscreens, capacitive touchscreens, infrared bezel touchscreens, and electromagnetic touchscreens.

[0003] However, existing technologies have many shortcomings: Resistive and capacitive touchscreens require an additional touch film or conductive glass layer to cover the display surface. This not only increases the thickness and manufacturing cost of the display but also reduces its light transmittance, affecting the display effect. Furthermore, the process of laying a capacitive touch film on large-size displays is extremely difficult and costly.

[0004] While infrared bezel touchscreens don't require a film layer on the screen surface, they rely on an array of infrared emitters and receivers mounted around the display. This structure results in a wider bezel, affecting aesthetics; it's also susceptible to interference from strong light, making it prone to failure in direct sunlight. Furthermore, infrared bezel technology cannot achieve high-precision pressure sensing and accurate tracking of fine pen tips.

[0005] While electromagnetic touchscreens offer high precision, they require an electromagnetic induction plate to be embedded behind the LCD panel. This not only significantly increases the overall thickness but also limits the development of thinner and lighter displays. Furthermore, electromagnetic pens typically require power, resulting in short battery life and a heavy pen body.

[0006] Traditional camera-based optical tracking technology typically calculates the position by capturing images of the pen tip on the screen using an external camera. This method is limited by the camera's angle of view and resolution, making it difficult to guarantee full-screen positioning accuracy on ultra-large screens. It is also susceptible to interference from screen surface reflections and changes in ambient light, making it impossible to accurately distinguish whether the pen tip is on the screen surface or suspended in the air.

[0007] In summary, there is an urgent need for a non-touch writing solution that does not affect the light transmittance and thickness of the display, does not require a complex bezel structure, and can achieve high precision, strong anti-interference ability, and adaptability to large-size screens. Summary of the Invention

[0008] The purpose of this invention is to provide a non-touch display and writing system to solve the problems of reduced light transmittance, complex frame structure, susceptibility to ambient light interference, and low positioning accuracy of large screens in existing touch technologies; at the same time, it also enables writing on traditional non-touch displays.

[0009] To achieve the above objectives, the present invention provides the following technical solution: A non-touch display writing system, comprising: The display has a plurality of dot matrix units disposed on a glass substrate facing the light-emitting side. The plurality of dot matrix units are arranged in rows and columns throughout the glass substrate. Each dot matrix unit is divided into rows and columns of dot matrix squares. Each dot matrix square is provided with at least one coding point. Each dot matrix unit has a plurality of coding points. The coding points are metal points attached to the glass substrate. An electronic pen, comprising a pen tip and a camera module disposed inside the electronic pen, the pen tip being used for writing on the display; wherein the camera module is directed toward the pen tip to capture images, and the area covered by the pen tip during writing is at least greater than one of the encoded points; The image captured by the camera module has a range greater than at least one dot matrix unit; the electronic pen is also equipped with a data processing module, which is used to analyze the image captured by the camera module to obtain the position of the coded point covered by the pen tip at different times, calculate the coordinates of the pen tip on the display based on the position of the coded point, and combine multiple coordinates at different times into a coordinate set to represent the writing trajectory. The display is used to show the writing trajectory according to the set of coordinates.

[0010] The display features a coded dot matrix of metal dots directly mounted on its glass substrate, completely eliminating the need for traditional touch films or infrared bezels. This allows the display to maintain its original high light transmittance and slim profile. The metal dots are so tiny that they are invisible or extremely difficult to detect with the naked eye, thus not affecting the visual experience.

[0011] From a technical principle and working process perspective: When the pen tip touches the screen, it obscures the metal coded dots within its coverage area. The internal camera module of the pen, facing the pen tip, captures real-time images of the coded dot matrix around the tip. Because the camera module's field of view is larger than a single dot matrix unit, the data processing module can always capture the complete dot matrix structure and the "blind spots" obscured by the pen tip in a single image. By comparing the differences between the images before and after obstruction, the system can accurately determine which coded dots the pen tip covers, thereby calculating the pen tip's local coordinates within the dot matrix unit, and ultimately mapping them to absolute coordinates on the entire display. This method of directly embedding physical codes onto the display panel fundamentally solves the problem of decreasing positioning accuracy on large screens as size increases, because each tiny area has an independent code as an absolute reference system.

[0012] Each dot matrix unit corresponds to a region code, and the multiple encoded points within a dot matrix unit are not completely identical; the position of the encoded point obscured by the pen tip corresponds to a specific coordinate under a region code, and the data processing module obtains multiple specific coordinates from multiple images and determines them sequentially to form a coordinate-based writing trajectory.

[0013] The dot matrix units possess both global uniqueness and local diversity. By assigning each dot matrix unit a unique region code, "grid-based" absolute positioning of the screen is achieved. This allows the electronic pen to quickly pinpoint the approximate area based on its current dot matrix unit, regardless of its location on the screen, significantly reducing the computational load of global searches. Furthermore, the coded points within the same unit are not entirely identical, forming a local micro-coordinate system that provides a high-precision relative positioning reference.

[0014] The data processing module first identifies the boundaries and feature codes of visible dot matrix units in the image, parsing out the region code of each unit (e.g., "5th row, 3rd column region"). Then, it searches for the coded points obscured by the pen tip within this region. Since each coded point has specific coordinates within the region (e.g., (2,3)), the system combines the region code with the local coordinates to generate a unique and precise location. By continuously capturing multiple frames of images, extracting the specific coordinates of each frame, and concatenating them in a time sequence, the movement trajectory of the pen tip is perfectly reconstructed.

[0015] The camera module includes an infrared generator and an infrared camera. The infrared generator emits infrared light toward the glass substrate, and the infrared camera receives the infrared light reflected from the glass substrate. When the infrared generator emits infrared light toward the shooting area, the coding point that is blocked by the pen tip cannot reflect infrared light, while the unblocked coding point reflects infrared light to the infrared camera, so that the position of the blocked coding point is shown in the captured image.

[0016] The active emission of infrared light significantly enhances the system's anti-interference capabilities and image recognition accuracy. In visible light environments, screen surface reflections, color variations, and uneven ambient lighting can severely interfere with image recognition by ordinary cameras. However, by using the infrared band, visible light noise can be completely shielded; the emitted infrared light is reflected back into the camera through unobstructed metal coding points, thus being recognized by the camera.

[0017] Specifically, the coding dots are metal dots (such as tiny particles of aluminum, silver, or copper) attached to a glass substrate. Metal contains a large number of free electrons. When an infrared generator actively emits infrared light of a specific wavelength (such as 850nm or 940nm) to illuminate the surface of the metal dots, the alternating electric field of the infrared light forces the free electrons in the metal to vibrate, forming a high-frequency oscillating current. According to electromagnetic theory, this oscillating current will re-radiate electromagnetic waves of the same frequency, resulting in strong reflection. Simultaneously, to further filter out visible light interference, a narrow-band filter is usually placed in front of the lens of an infrared camera, allowing only infrared light of that specific wavelength to enter the photosensitive element. Therefore, in the captured image, the unblocked metal dots appear as bright white dots.

[0018] The electronic pen's tip uses an infrared-blocking light-absorbing material (such as silicone mixed with carbon black or a special black resin), or its structural design prevents infrared light from penetrating. When the pen tip presses against the metal dot, the infrared light emitted by the infrared generator is physically blocked by the pen tip and cannot reach the metal dot below. Without incident light, the metal dot naturally cannot produce reflected light. Therefore, in the image captured by the infrared camera, the location of the blocked metal dot appears as a noticeable "black dot" or "hole".

[0019] Assume the electronic pen tip has a diameter of 2mm and covers 3 metal dots. An infrared camera captures 60 frames per second. In one frame, the data processing module observes that in an area that should have been a 5x5 matrix of bright spots, 3 bright spots in the center have become dark spots. Based on this, the system determines that these 3 dark spots are the coded points covered by the pen tip.

[0020] The electronic pen is equipped with a first communication module, which is connected to a data network. The display also includes a second communication module, which is connected to the data network. The first communication module sends the coordinates of the writing trajectory to the display through the second communication module. The display converts the coordinates into an image and displays the writing trajectory.

[0021] In this application, a wireless closed-loop communication system is formed between the electronic pen and the display. The advantage lies in achieving "zero-latency" real-time presentation of the writing trajectory, while decoupling computation and display. The data processing module performs complex coordinate calculations internally within the electronic pen, significantly reducing the computational burden on the display. Only lightweight coordinate data packets are transmitted via data networks (such as Wi-Fi or Bluetooth LAN), rather than large amounts of image data, ensuring low latency and high reliability in transmission.

[0022] During operation, the electronic pen calculates the current coordinates (X, Y) and broadcasts the coordinate packet via UDP or low-latency Bluetooth protocol through the first communication module. After receiving the packet, the second communication module on the display receives it and passes it to the display driver chip to draw color on the corresponding pixel, thereby tracing the user's handwriting on the screen in real time.

[0023] The smart terminal includes a third communication module, which is communicatively connected to the first communication module. The first communication module sends the writing trajectory coordinates to the smart terminal, and the smart terminal displays the writing trajectory. The smart terminal is also used to set additional information sent by the first communication module within the electronic pen via software. The additional information is sent along with the trajectory coordinates. The additional information includes writing color, writing thickness, and writing line type selection.

[0024] This application achieves multi-screen synchronous display and a high degree of personalization. The smart terminal not only serves as a second screen for real-time mirroring of written content, facilitating remote viewing or saving of records, but more importantly, users can flexibly control the writing effect through software on the smart terminal.

[0025] In the technical implementation and operation process: The smart terminal APP interface provides UI controls such as a color palette and a thickness slider. When the user selects "red, 0.5int thickness", the APP generates a corresponding data packet with accompanying information and sends it to the first communication module of the electronic pen. When the electronic pen subsequently sends a set of coordinates, it appends the accompanying information to the packet header. For example, the data frame sent is: [Header][Color:Red][Thickness:0.5][X:120][Y:340][Footer].

[0026] After the display and smart terminal parsed the frame, they both used a red brush with a thickness of 0.5 (120, 340) to render, achieving WYSIWYG customized writing.

[0027] In this embodiment, at least one of the dot matrix squares in each dot matrix unit is used to set a position coding point, which is used to mark the absolute position of the current dot matrix unit on the entire glass substrate; the absolute position is recorded with the center of the glass substrate as the origin of the coordinate system.

[0028] The coordinate system is established with the center of the screen as the origin, which makes the four quadrants of the screen symmetrical, the coordinate data structure clear, and facilitates the handling of negative coordinates, greatly facilitating matrix transformation operations such as mirroring and scaling of the display screen.

[0029] How to calculate absolute position coordinates and provide examples: Assume the entire glass substrate is divided into 100x100 dot matrix units. The center of the screen is (0,0).

[0030] Each dot matrix unit declares its absolute position through its internal "position code point". When the camera module captures a dot matrix unit, the data processing module first extracts the position code point information of that unit.

[0031] For example, if the information parsed from the position encoding point of the dot matrix unit is "9 rows from the bottom and 13 columns from the left," the data processing module directly knows that the center of the current dot matrix unit is located at (-13, -9) in the global coordinate system (assuming the unit size is 1). Based on this, and combined with the specific encoding point position (local micro-coordinates) obscured by the pen tip within the unit, for example, if the local coordinates are (0.2, 0.1), then the final absolute coordinates of the pen tip are (-13 + 0.2, -9 + 0.1). Through this two-level coordinate calculation of "macro positioning + micro positioning," the system can accurately lock the absolute physical position of the pen tip on the display within milliseconds.

[0032] Each of the dot matrix units includes a position encoding point, which is located in the top left corner dot matrix square of the dot matrix unit; each of the remaining dot matrix squares of the dot matrix unit contains an encoding point, and all the encoding points are metal points.

[0033] By fixing the position encoding point at the top left corner, a stable "anchor point" is provided for the image processing algorithm. In the image captured by the camera module, regardless of how the electronic pen rotates, as long as the position encoding point at the top left corner is included in the field of view, the algorithm can quickly perform image alignment and orientation correction. Each of the remaining squares contains one encoding point, and this uniform distribution ensures the consistency of local micro-positioning resolution.

[0034] The data processing module scans all bright spots in the image, identifies the location coding points with special structures (large points + small points), uses them as the origin (0,0) of the coordinate system to establish a local pixel grid to the right and down, and then the row and column numbers of the occluded coding points in this local grid are the local coordinates.

[0035] The location coding points include a first point with the largest diameter and a second point located in any one of the four directions above, below, left, and right of the first point; the diameter of the second point is smaller than the diameter of the first point; the straight-line distance between the second point and the first point represents the distance of the current dot matrix unit relative to the center point of the glass substrate through calculation; the angle between the line connecting the second point and the first point and the x-axis represents the row or column in which the dot matrix unit is located relative to the center of the glass substrate.

[0036] This application proposes a highly innovative polar coordinate encoding method. Its advantages are: using only two metal dots (one large and one small), it simultaneously encodes the absolute distance from the dot matrix unit to the center of the screen and the angle of its quadrant, resulting in extremely high information density and making it extremely difficult to forge or misread.

[0037] In this design, the first point (the larger point) is equivalent to the pole of polar coordinates, and the position of the second point (the smaller point) relative to the first point carries all the absolute position information.

[0038] Distance calculation: The straight-line distance *d* between the second point and the first point represents the distance from the current pixel unit to the center of the screen. Because it is scaled at a fixed ratio during manufacturing, for example, *d* = 1 μm corresponds to a physical distance of 1 mm from the screen. If the measured pixel distance between two points in the image is actually 50 μm after conversion, then the unit is 50 mm from the center of the screen.

[0039] Angle and Column Mapping: The second point has only four directions relative to the first point: up, down, left, and right. This means that the angle is quantified into four quadrant boundaries. If the second point is directly below the first point, the included angle is 270 degrees, which means that the unit is located directly below the center of the screen (i.e., the corresponding column is the center column, and the row is below); if it is to the left, the included angle is 180 degrees, which means it is directly to the left.

[0040] Coordinate system transformation: Obtain the pixel coordinates (x1, y1) and (x2, y2) of the first and second points through image recognition. Calculate the vector. Modulus length Converted to physical distance R, argument By looking up a table or using a preset step algorithm, R is mapped to row or column numbers. The quadrant and row / column affiliation of the cell are determined, ultimately yielding the integer coordinate region of the cell in the global Cartesian coordinate system.

[0041] Wherein, when the included angle represents the row where the dot matrix unit is located relative to the center of the glass substrate, the display is set to have a rows in total, and the row below the center point has a / 2 rows, as a minimum step value, and the corresponding row number is determined according to the step value range of the included angle.

[0042] This implementation provides a highly robust discretized position analysis method. Since the camera module's shooting angle may be slightly tilted, the angle between the line connecting the second point and the first point may not be an absolute 90 degrees or 270 degrees, but rather a deviation. By using a stepped fault tolerance range, the system allows for a certain degree of angular error, improving the fault tolerance rate.

[0043] Example of the calculation process: Assume the monitor has 100 rows (a=100), with 50 rows below the center point. Set the step values. Degrees / rows. However, in actual engineering, we divide the 90-degree area into 50 steps, with each step representing one row. The tolerance range for each step is 90 / 50 = 1.8 degrees.

[0044] When the system determines the angle direction to be "directly downwards" (reference angle 270 degrees) and measures the actual angle to be 272 degrees, the system calculates the deviation: 272 - 270 = 2 degrees. This 2-degree deviation falls within the first and second step intervals, which the system identifies as the first or second row below the center point. Fine-tuning is then performed based on the measured straight-line distance to ultimately pinpoint the exact row number. This step-based fault-tolerant algorithm perfectly solves the problem of image distortion recognition caused by stylus tilt.

[0045] Wherein, when the included angle represents the column where the dot matrix unit is located relative to the center of the glass substrate, the display is set to have a total of b columns, with b / 2 columns located on one side of the center point, as a minimum step value, and the corresponding number of columns is determined according to the step value range of the included angle.

[0046] When the row directions are consistent, they together form a complete two-dimensional plane positioning reference, ensuring that the system can accurately resolve the absolute coordinates whether writing horizontally or vertically, thus fundamentally eliminating accumulated errors.

[0047] Finally, the present invention also discloses a non-touch display that runs the above-described writing system. Attached Figure Description

[0048] Figure 1 This is an overall architecture diagram of the non-touch display writing system of the present invention; Figure 2 This is a schematic diagram of the modules of the non-touch display writing system of the present invention; Figure 3This is a schematic diagram of the dot matrix unit distribution on the glass substrate of a display. Figure 4 This is a schematic diagram of the internal structure of an electronic pen and the principle of infrared light reflection. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0050] like Figures 1 to 4 This invention provides a non-touchscreen display writing system that completely overturns the traditional design concept of touchscreens that rely on sensing layers or infrared bezels. It adopts an innovative architecture of "micro-nano metal dot matrix solidified on the display panel + active infrared pen tip occlusion visual recognition." The following provides a detailed analysis of the various components and characteristics of the system.

[0051] Display (10) The display (10) is the display output carrier and writing physical medium of the system. Traditional touch displays usually have a layer of resistive sensing film or capacitive sensing glass attached to the light-emitting side (i.e., the side facing the user). However, the display (10) of the present invention does not have any thick sensing layer on the glass substrate (11) facing the light-emitting side, but instead directly sets an encoding matrix composed of multiple dot matrix units (12). That is to say, an encoding matrix is ​​added to the basis of a normal non-touch display.

[0052] Specifically, multiple dot matrix units (12) are arranged in rows and columns across the entire glass substrate (11), covering the entire display area. Each dot matrix unit (12) is virtually divided into rows and columns of dot matrix squares (13) (e.g., 5×5 or 10×10 as one dot matrix unit (12)), and each dot matrix square (13) contains at least one coded point (14). These coded points (14) are metal points attached to the glass substrate (11). The metal points can be made of aluminum, silver, copper, or their alloys, and are directly solidified onto the surface of the glass substrate (11) by magnetron sputtering, photolithography, or nanoscale inkjet printing, and then covered with standard liquid crystal display panel protective glass or polarizer. Since the diameter of the metal points is in the micrometer range (e.g., 10-50 micrometers), they are almost invisible to the naked eye at normal viewing distances, and therefore do not affect the light transmittance and display quality of the display (10) at all.

[0053] Each dot matrix unit (12) corresponds to a region code, and the multiple coding points (14) within a dot matrix unit (12) are not completely identical.

[0054] To achieve global absolute positioning, at least one dot matrix square (13) in each dot matrix unit (12) is used to set a position coding point (141). The position coding point (141) is used to mark the absolute position of the current dot matrix unit (12) on the entire glass substrate (11), and the absolute position is recorded with the center of the glass substrate (11) as the origin of the coordinate system.

[0055] In the specific dot matrix layout, each dot matrix unit (12) includes a position coding point (141), which is located in the upper left corner dot matrix square (13) of the dot matrix unit (12); each dot matrix square (13) of the remaining dot matrix squares (13) of the dot matrix unit (12) contains a normal coding point (14), and all coding points (14) are metal points.

[0056] The location coding point (141) adopts a highly creative two-point polar coordinate structure: it includes a first point (142) with the largest diameter and a second point (143) located in any one of the four directions of the first point (142), namely, above, below, left, and right; the diameter of the second point (143) is smaller than the diameter of the first point (142).

[0057] The characteristic of this design is: The first point (142) serves as the anchor point (origin) of the polar coordinates, and the orientation of the second point (143) serves as the information carrier of the quadrant. The straight-line distance between the second point (143) and the first point (142) is calculated to represent the distance of the current lattice unit (12) relative to the center point of the glass substrate (11); the angle between the line connecting the second point (143) and the first point (142) and the x-axis represents the row or column in which the lattice unit (12) is located relative to the center of the glass substrate (11).

[0058] Since the second point (143) is only in the four directions of up, down, left, and right of the first point (142), this is equivalent to discretizing the polar coordinate angle into the reference directions of the four quadrants. The distance is directly mapped by the physical distance between the two points, for example, 5 times the distance between the two points is the actual distance. This design uses only two tiny metal points to encode both distance and direction (row / column affiliation) simultaneously, resulting in extremely high information density. Furthermore, since it does not require a complex matrix QR code, it greatly saves the surface space of the glass substrate (11) and reduces the obstruction of visible light.

[0059] Electronic pen (20) The electronic pen (20) is the core data acquisition and processing terminal of the system. The electronic pen (20) includes a pen tip (21), a camera module (22), a data processing module (23), a first communication module (24), and a power management module.

[0060] The pen tip (21) is used for writing on the display (10), and its material needs to have two key characteristics: first, it needs to have a certain friction to simulate the real writing feel; second, it needs to have a strong absorption or blocking effect on infrared light. The pen tip (21) can be made of special silicone or polyoxymethylene (POM) material mixed with carbon black.

[0061] The camera module (22) is located inside the electronic pen (20) and faces the pen tip (21) to take pictures. The field of view (FOV) of the camera module (22) is carefully designed so that the range of the picture it captures is greater than at least one dot matrix unit (12). At the same time, the area covered by the pen tip (21) when writing is at least greater than one coding point (14) to ensure that sufficient occlusion features are generated for the algorithm to recognize.

[0062] The camera module (22) of the system includes an infrared generator (221) and an infrared camera (222). The infrared generator (221) emits infrared light toward the glass substrate (11), and the infrared camera (222) receives the infrared light reflected by the glass substrate (11). The infrared generator (221) is an infrared LED (e.g., with a wavelength of 850nm or 940nm). The infrared generator (221) and the infrared camera (222) are integrated together, and a narrowband filter is arranged in front of the lens after integration.

[0063] In this process, visible light from the environment (such as lamplight and sunlight) is filtered out by a narrow-band filter, allowing only infrared light of a specific wavelength to enter the photosensitive element. When the infrared generator (221) emits infrared light toward the shooting area, the metal dots (encoding dots (14)) attached to the glass substrate (11) strongly reflect the infrared light due to the resonance effect of the free electrons in the metal, forming bright white dots in the image. The encoding dots (14) that are blocked by the pen tip (21) cannot produce reflected light because the pen tip (21) material absorbs or blocks the incident light, and appear as dark spots or black dots in the image. This active infrared imaging technology enables the "blocked encoding dots (14)" to exhibit extreme contrast in the captured image, completely eliminating the interference of changes in ambient light and screen color on image recognition.

[0064] The data processing module (23) is the brain of the electronic pen (20), and is usually composed of a low-power DSP (digital signal processor) or ARM microcontroller. Its core function is to analyze the images captured by the camera module (22) in real time and calculate the absolute coordinates of the pen tip (21).

[0065] Its computational logic is divided into two levels: The first level is "macro positioning": by identifying the location coding points (141) (first point (142) and second point (143)) in the image, the region code (absolute row and column number) of the current lattice unit (12) in the global coordinate system is parsed.

[0066] The second level is "micro-positioning": After determining the region code, the distribution of ordinary coding points (14) occluded by the pen tip (21) in the image is analyzed. Since each ordinary coding point (14) has a fixed relative coordinate within the dot matrix unit (12), the data processing module (23) calculates the local pixel coordinates of the center of the occluded region through the centroid algorithm or template matching algorithm, and maps them to the micro coordinates within the dot matrix unit (12).

[0067] Finally, the absolute coordinates of the region and the local micro coordinates are weighted and fused to calculate the high-precision absolute coordinates of the pen tip (21) on the display (10). The data processing module (23) takes multiple pictures per second (e.g., no less than 25 frames or up to 120 frames) and combines the multiple coordinates at different times into a set of coordinates to represent the writing trajectory.

[0068] The electronic pen (20) contains a first communication module (24), which supports wireless communication protocols such as Wi-Fi, Bluetooth (BLE), or Ultra Wideband (UWB). The first communication module (24) is connected to a data network to transmit the processed coordinate set with extremely low latency.

[0069] The communication feature of this system is "decoupling of computation and rendering". The electronic pen (20) completes all the heavy-load image computation and only sends lightweight coordinate data packets (such as X, Y coordinate values ​​and timestamps) to the network. This design greatly saves wireless bandwidth, so that even in high-concurrency scenarios where multiple electronic pens (20) are writing at the same time, there will be no network congestion, and the real-time synchronization of the writing trajectory is guaranteed.

[0070] The system also includes a smart terminal (30), such as a smartphone, tablet, or personal computer. The smart terminal (30) includes a third communication module (31), which is communicatively connected to the first communication module (24).

[0071] The intelligent terminal (30) is characterized by being both a "display mirror" and a "control and configuration terminal".

[0072] As the display end, the first communication module (24) sends the writing trajectory coordinates to the smart terminal (30), and the smart terminal (30) displays the writing trajectory on its screen in real time, realizing dual-screen synchronization. This is extremely valuable in remote teaching and video conferencing, as participants can see the speaker's annotations in real time on their own devices.

[0073] As a configuration terminal, the smart terminal (30) sets the attached information sent by the electronic pen (20) through the first communication module (24) via a dedicated software APP. The attached information is sent along with the trajectory coordinates, including writing color (RGB color), writing thickness (0.1int-2int), and writing line type selection (discontinuous line, dotted line, straight line, etc.). The user adjusts the pen attributes on the smart terminal (30), and the configuration command is sent to the electronic pen (20). The electronic pen (20) includes these attribute information in the coordinate packets sent in the subsequent messages. After receiving the coordinates, the display (10) and the smart terminal (30) render and display the coordinates according to the set color, thickness, and line type, realizing flexible and personalized interaction.

[0074] The overall operation of this system involves the close coordination of multiple aspects, including optics, image processing, communication transmission, and graphics rendering. The following details the complete working process of the system from the moment the user puts a pen to the moment the trajectory is displayed on the screen.

[0075] Step 1: System Initialization and Network Connection Establishment When the monitor (10) and the electronic pen (20) are powered on, the second communication module (15) of the monitor (10) broadcasts a service discovery message within the local area network. After receiving the message, the first communication module (24) of the electronic pen (20) establishes a low-latency wireless data channel with the monitor (10). At the same time, the smart terminal (30) also joins the network and establishes a pairing connection with the electronic pen (20). The user sets the initial additional information (such as black, 0.5int thickness, solid line) through the smart terminal (30) APP and sends it to the electronic pen (20).

[0076] Step 2: Pen tip contact and infrared image acquisition The user holds the electronic pen (20) and presses the pen tip (21) onto the glass substrate (11) of the display (10). The pen tip (21) physically covers at least one coding point (14). The camera module (22) inside the electronic pen (20) operates continuously at a high frame rate (e.g., 60fps) and actively emits infrared light into the glass substrate (11) around the pen tip (21).

[0077] Infrared light is irradiated onto the micro-nano metal dot array on the surface of the glass substrate (11). The metal dots not blocked by the pen tip (21) strongly reflect the infrared light, which penetrates the narrow-band filter in front of the lens and enters the CMOS image sensor, forming bright pixels; the metal dots blocked by the pen tip (21) cannot reflect light due to the lack of incident light, forming dark areas in the image. The infrared camera (222) in the camera module (22) captures this high-contrast infrared grayscale image in real time and transmits it to the data processing module (23).

[0078] Step 3: Image preprocessing and raster feature extraction After receiving the infrared image, the data processing module (23) first performs Gaussian filtering to remove noise caused by minor scratches or dust on the screen surface. Then, it uses an adaptive threshold segmentation algorithm (such as Otsu's method) to binarize the image, converting metal points into white pixel blocks and background and occluded points into black.

[0079] Next, the algorithm performs connected component detection on the binarized image, extracting the bounding rectangles and centroid coordinates of all bright spot blobs. In order to filter out effective coding points (14), the algorithm filters out noisy connected components with excessively large or small areas, retaining the set of bright spots that conform to the size characteristics of metallic points.

[0080] Step 4: Fault-tolerant reading and absolute coordinate calculation (1) Header identification and region delimitation: The algorithm can determine the boundary of the content data section by identifying the location encoding point (141) in the bright spot set.

[0081] (2) Fault-tolerant calculation: If some location coding points (141) are missing due to occlusion by the pen tip (21), the algorithm activates the cross-image index fault tolerance mechanism. Using the location coding points (141) of the currently visible adjacent dot matrix units (12), the missing data is calculated based on the preset mathematical relationship (such as coordinate difference) to restore the complete region code.

[0082] (3) Analysis of position encoding point (141): The algorithm scans the top left corner dot matrix grid (13) and identifies the first point (142) with the largest diameter and the second point (143) with the smaller diameter. Calculate the vector of the second point (143) relative to the first point (142). If the vector direction is directly downward, it is determined that the dot matrix unit (12) is located below the center of the screen; by calculating the pixel distance between the two points and converting it to physical distance, the number of rows of the unit from the center is obtained by looking up the table. Furthermore, using the step value fault tolerance algorithm, the screen is set to have a rows, and there are a / 2 rows below. The minimum step value is (a / 2) / 90. Based on the degree of deviation of the vector angle from the reference angle, it is determined that it falls into the step interval, and the exact number of rows is corrected and determined. Similarly, if the vector direction is left / right, the number of columns is determined. Thus, the global absolute coordinates of the current dot matrix unit (12) with the center of the screen as the origin are obtained.

[0083] (4) Calculation of local micro-coordinates: After the global coordinates are determined, the algorithm analyzes the position of the dark area occluded by the pen tip (21). The dot matrix square (13) where the dark area is located has a fixed row and column index inside the dot matrix unit (12). By mapping the centroid coordinates of the dark area to the local coordinate system of the square, the sub-pixel level local offset is calculated.

[0084] (5) Coordinate fusion: The global absolute reference coordinates of the dot matrix unit (12) are added to the local offset to obtain the high-precision absolute coordinates (X, Y) of the pen tip (21) on the display (10) in the current frame.

[0085] Step 5: Track data encapsulation and wireless transmission The data processing module (23) timestamps the calculated absolute coordinates (X, Y) and reads the accompanying information (color, thickness, line type) from the cache, encapsulating it into a data frame. For example, the data frame format is: [frame header][timestamp][X coordinate][Y coordinate][color RGB][thickness][line type][checksum][frame tail]. The first communication module (24) broadcasts the data frame to the data network via the UDP protocol. Compared with TCP, the UDP protocol has lower latency and is suitable for real-time writing scenarios. Even if frames are occasionally lost, the coordinates of subsequent frames can be smoothly transitioned due to the continuity of the writing trajectory.

[0086] Step 6: Multi-device collaborative rendering and display After receiving the data frame, the second communication module (15) of the display (10) hands it over to the graphics rendering engine on the display motherboard. The rendering engine parses the coordinates and accompanying information, and draws points or line segments with specified colors and thicknesses at the corresponding pixel positions in the video memory. Since the display refresh rate is usually 60Hz, the continuous coordinates of the pen tip (21) movement are connected on the screen in real time, forming a visually delay-free writing trajectory.

[0087] At the same time, the third communication module (31) of the smart terminal (30) also receives the data frame. The APP uses the OpenGL or Canvas drawing interface to perform synchronous rendering on the screen of the smart terminal (30), realizing a consistent writing experience across multiple terminals.

[0088] This invention also provides a non-touch display writing method, which uses the aforementioned non-touch display writing system (1). The following is a detailed technical description of each step of the method.

[0089] Step S1: A plurality of dot matrix units (12) arranged in rows and columns are provided on the glass substrate (11) of the display (10) facing the light-emitting side. Each dot matrix unit (12) is divided into dot matrix squares (13) arranged in rows and columns, and at least one coding point (14) composed of metal dots is provided in each dot matrix square (13).

[0090] This step is fundamental to the system construction. A metal dot array is formed on the glass substrate (11) using photolithography. Since the division of the dot grid (13) is logical, only micron-sized metal dots exist physically. The adhesion process of the metal dots must ensure their bonding force with the glass while not compromising the sealing of the liquid crystal cell. The technical value of this step lies in achieving information solidification with a zero-thickness physical structure, laying the physical foundation for non-touch detection.

[0091] Step S2: Use the tip (21) of the electronic pen (20) to write on the display (10), and the area covered by the pen tip (21) during writing is at least greater than one coding point (14).

[0092] This step defines the interactive input action. The area covered by the pen tip (21) being larger than one encoding point (14) is a necessary condition to ensure the recognizability of image features. If the pen tip (21) is too small, only half of the encoding point (14) will be obscured, and reflected light will still exist, making it difficult to form a clear dark area in the image. By limiting the size of the pen tip (21), the salience of the obscured features is guaranteed.

[0093] Step S3: Take a picture of the image taken by the camera module (22) inside the electronic pen (20) toward the pen tip (21), wherein the area of ​​the captured image is larger than at least one dot matrix unit (12).

[0094] This step clarifies the field of view requirements for visual acquisition. The field of view of the camera module (22) is larger than one dot matrix unit (12) to ensure that there is always a complete region code available for parsing in the image under any writing posture. If the field of view is too small, a slight tilt of the pen tip (21) may cause the entire field of view to be occluded dark areas, and the algorithm will fail. The design of being larger than one dot matrix unit (12) provides sufficient redundancy for fault-tolerant calculation and global localization.

[0095] Step S4: The captured image is analyzed by the data processing module (23) inside the electronic pen (20) to obtain the position of the coding point (14) covered by the pen tip (21) at different times, and the coordinates of the pen tip (21) on the display (10) are calculated based on the position of the coding point (14).

[0096] This step is the core computational component of the method, and it specifically includes the following sub-steps: S41: Image binarization and connected component extraction. High-contrast images are acquired using infrared active illumination to separate metal points from the background.

[0097] S42: Identification of position coding point (141). Find the large point (first point (142)) and the small point (second point (143)) in the upper left corner. Calculate the modulus and argument of the line connecting the two.

[0098] S43: Determine the row and column of the step value. Determine the direction (up, down, left, right) based on the argument and the base distance based on the modulus. Use the minimum step value (e.g., (a / 2) / 90) to divide the angle tolerance range, and place the argument into the corresponding step to determine the absolute number of rows or columns.

[0099] S44: Local micro-coordinate calculation. The local offset is calculated based on the distribution of the occluded dark points in the dot matrix (13).

[0100] S45: Coordinate Blending. Blends absolute row / column coordinates with local offsets to output the final absolute coordinates (X, Y).

[0101] Step S5: Combine multiple coordinates at different times into a coordinate set to represent the writing trajectory.

[0102] This step serializes discrete coordinate points into a trajectory. The data processing module (23) sorts the coordinates by timestamp. To smooth the trajectory, Bézier curves or spline interpolation algorithms can be used to smooth adjacent coordinate points, eliminating the jagged edges caused by hand tremors or uneven sampling.

[0103] Step S6: The display (10) shows the writing trajectory based on the coordinate set.

[0104] This step involves graphics rendering. The display receives the coordinate set and accompanying information (color, thickness), executes a line drawing algorithm (such as the Bresenham algorithm) in the video memory, draws the trajectory, and outputs it to the LCD panel for display.

[0105] Step S7: Set a region code for each dot matrix unit (12) in a one-to-one correspondence, and make the multiple coding points (14) in a dot matrix unit (12) not completely the same.

[0106] This step defines the logical encoding rules for the dot matrix. The uniqueness of the region code ensures the accuracy of global positioning, while the difference in the encoded points (14) within the unit ensures the distinguishability of local micro-coordinates.

[0107] Step S8: The camera module (22) actively emits infrared light to illuminate the shooting area. The coding point (14) blocked by the pen tip (21) cannot reflect infrared light, while the unblocked coding point (14) reflects infrared light to the camera module (22), thereby identifying the position of the blocked coding point (14) in the captured image.

[0108] This step explains the principle of optical imaging. Infrared active illumination, combined with metal point reflection and light-absorbing pen tip (21) blocking, constitutes an imaging model with an extremely high signal-to-noise ratio, which is a prerequisite for the efficient operation of all subsequent image processing algorithms.

[0109] Step S9: The electronic pen (20) sends the coordinates of the writing trajectory to the data network through the first communication module (24), and then transmits them to the display (10) through the second communication module (15) connected to the data network. The display (10) converts the coordinates into an image and displays the writing trajectory.

[0110] This step defines the low-latency communication link. By leaving computationally intensive tasks to the pen and allowing the display to perform only lightweight rendering, end-to-end ultra-low latency data transmission is achieved.

[0111] Step S10: The electronic pen (20) sends the writing trajectory coordinates to the third communication module (31) of the smart terminal (30) through the first communication module (24), and the smart terminal (30) displays the writing trajectory; and sends the accompanying information along with the trajectory coordinates through the software settings of the smart terminal (30). The accompanying information includes writing color, writing thickness and writing line type selection.

[0112] This step expands multi-terminal collaboration and personalized configuration. The involvement of smart terminals (30) makes writing no longer limited to in front of a physical screen, enabling remote collaboration and digital recording.

[0113] Step S11: Set a position coding point (141) in at least one dot grid (13) of each dot grid unit (12), and use the position coding point (141) to mark the absolute position of the current dot grid unit (12) on the entire glass substrate (11). The absolute position is recorded with the center of the glass substrate (11) as the origin of the coordinate system.

[0114] This step establishes an absolute coordinate system. Using the center as the origin not only conforms to the aesthetics of symmetry but also optimizes matrix transformations at the underlying algorithm level, allowing screen rotation or mirroring operations to be achieved simply by reversing the signs.

[0115] Step S12: Set a position coding point (141) in the top left corner dot matrix square (13) of each dot matrix unit (12), and each dot matrix square (13) in the remaining dot matrix squares (13) of the dot matrix unit (12) contains a coding point (14), and all coding points (14) are metal points.

[0116] This step standardizes the internal structure of the dot matrix. The design of a fixed anchor point (top left corner) simplifies the complexity of the image registration algorithm and improves the speed of feature extraction.

[0117] Step S13: The position encoding point (141) includes the first point (142) with the largest diameter and the second point (143) located in any one of the four directions of the first point (142), namely, above, below, left and right. The diameter of the second point (143) is smaller than the diameter of the first point (142). The distance between the second point (143) and the first point (142) is calculated to represent the distance of the current dot matrix unit (12) relative to the center point of the glass substrate (11). The angle between the line connecting the second point (143) and the first point (142) and the x-axis represents the row or column in which the dot matrix unit (12) is located relative to the center of the glass substrate (11).

[0118] This step defines the polar coordinate encoding mechanism in detail. By using a dual mapping of distance and angle between two points, high-dimensional positional information is encoded with minimal physical resources, greatly reducing manufacturing costs and visual interference.

[0119] Step S14: When the included angle represents the row where the dot matrix unit (12) is located relative to the center of the glass substrate (11), the display (10) is set to have a rows in total, and the row below the center point is a / 2 rows, as a minimum step value. The corresponding row number is determined according to the step value range where the included angle is located.

[0120] This step introduces a stepped fault-tolerant algorithm. Continuous angles are discretized into stepped intervals, allowing the electronic pen (20) to have a certain angle error when writing at an angle without affecting the accurate determination of line numbers. For example, setting a=100, a / 2=50, the step value is approximately 0.55 degrees. When the angle deviation is within ±0.55 degrees, the system can still stably output the same line number, significantly improving the robustness of the system.

[0121] Step S15: When the included angle represents the column where the dot matrix unit (12) is located relative to the center of the glass substrate (11), the display (10) is set to have a total of b columns, and the column located on one side of the center point has b / 2 columns, as a minimum step value. The corresponding number of columns is determined according to the step value range where the included angle is located.

[0122] This step is similar to step S14, completing the fault tolerance determination in the column direction, which together with the row direction forms a complete two-dimensional high fault tolerance positioning grid.

[0123] Through a detailed discussion of the above-described system operation and method steps, the following significant technical advantages of this invention can be summarized: 1. Unlimited cascading positioning capability that overcomes physical size limitations Traditional infrared bezel touchscreens rely on an infrared grid emitted from the edges. The larger the screen, the more emitters are needed, increasing the load on the edge processor. Furthermore, light divergence over long distances leads to a sharp decrease in accuracy. The method of this invention directly encodes absolute position information into every tiny area of ​​the screen surface. Each dot matrix unit is an independent absolute coordinate anchor point. This means that regardless of the screen size (even a multi-inch spliced ​​screen), as long as the encoding matrix is ​​laid on the glass substrate, the electronic pen can obtain the full-screen absolute coordinates through local image recognition. The system's positioning accuracy is completely decoupled from the screen size, achieving true "infinitely cascaded precise positioning."

[0124] 2. Extreme resistance to ambient light interference and high signal-to-noise ratio imaging Traditional visible light-based camera optical positioning systems are highly susceptible to interference from factors such as changes in ambient lighting, screen color content, and user shadows, leading to image feature extraction failures. This method employs active infrared illumination combined with narrowband filter technology to completely shield visible light noise. The strong reflectivity of the metal dots to specific infrared bands, combined with the strong occlusion properties of the light-absorbing pen tip, results in a nearly "black and white" binary image. This extremely high image signal-to-noise ratio not only ensures the accuracy of feature extraction but also significantly reduces the computational power consumption of the data processing module, enabling the electronic pen to achieve high frame rate real-time processing using low-power chips.

[0125] 3. Coding scheme with ultra-high information density and extremely low visual interference This method employs polar coordinate positioning encoding points of "large dots + small dots," achieving globally unique identification within an extremely small microscopic area (such as a 0.5mm × 0.5mm dot matrix unit). Compared to traditional printed QR codes or DMC codes, the metal dot matrix of this invention eliminates the need for large blank areas or seeker patterns; the diameter of the metal dots is on the micrometer scale, invisible to the naked eye. This not only fully preserves the display's high light transmittance and high contrast but also achieves "invisible encoding," endowing the display with high-precision interactive capabilities without altering its original industrial design and visual appearance.

[0126] 4. Highly robust fault-tolerant reading and frame loss prevention mechanism When writing rapidly or with a significant pen tilt, the camera module's field of view often misses some dot matrix information. This method introduces a cross-image index fault-tolerant estimation mechanism based on mathematical correlation. When the data of the current dot matrix unit is incomplete, the algorithm can use data from adjacent units to perform real-time estimation and completion. Simultaneously, a step value fault-tolerant algorithm is introduced in row and column discrimination, allowing for a certain degree of distortion in the angle vector. This dual fault-tolerant mechanism completely solves the problems of "dropped dots" and "frame skipping" when the stylus is in high-speed motion or unconventional grip, ensuring the continuity and smoothness of the writing trajectory.

[0127] 5. Ultra-low latency communication architecture decoupling computation and rendering Traditional interactive systems often transmit raw video streams or large amounts of raw data to the host computer for processing, resulting in significant transmission latency. In this method, the data processing module at the electronic pen directly handles the entire process from image acquisition to absolute coordinate calculation, sending only lightweight coordinate data packets and accompanying information packets to the network. This "edge computing" model reduces the amount of communication data by several orders of magnitude. The display and smart terminal only need to execute simple line drawing and rendering commands, greatly reducing end-to-end latency and making digital writing as responsive as writing with real pen and paper.

[0128] 6. Flexible multi-device collaboration and personalized configuration experience This method, by introducing smart terminals, not only achieves real-time mirroring and synchronization of written content across multiple devices, but more importantly, enables dynamic control of writing attributes. Additional information (color, thickness, line type) is broadcast along with the coordinate data, allowing users to switch between different writing effects at any time via software without changing the physical pen tip. This provides significant convenience for scenarios such as educational whiteboards and remote design reviews, enabling one person to write while multiple devices synchronize, with attributes adjustable in real time, greatly enriching the dimensions of human-computer interaction.

[0129] In summary, the non-touch display writing system and method provided by this invention, through the integration and innovation of technologies such as micro-nano metal dot matrix, infrared active visual recognition, polar coordinate fault-tolerant coding, and edge computing communication, successfully overcomes many defects of existing touch technology. While maintaining the ultimate visual experience of the display, it achieves high-precision, low-latency, and highly robust non-touch writing interaction, which has significant industrial application value.

[0130] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A non-touchscreen display writing system, characterized in that, The system includes: The display (10) has a plurality of dot matrix units (12) disposed on a glass substrate (11) facing the light-emitting side. The plurality of dot matrix units (12) are arranged in rows and columns on the entire glass substrate (11). Each dot matrix unit (12) is divided into dot matrix squares (13) arranged in rows and columns. Each dot matrix square (13) is provided with at least one coding point (14). Each dot matrix unit (12) has a plurality of coding points (14). The coding points (14) are metal points attached to the glass substrate (11). An electronic pen (20) includes a pen tip (21) and a camera module (22) disposed inside the electronic pen (20). The pen tip (21) is used for writing on the display (10). The camera module (22) is directed toward the pen tip (21) to take pictures. The area covered by the pen tip when writing is at least greater than one of the coding points (14). The camera module (22) captures images with a range greater than at least one dot matrix unit (12). The electronic pen (20) is also equipped with a data processing module (23). The data processing module (23) is used to analyze the images captured by the camera module (22) to obtain the position of the coding point (14) covered by the pen tip (21) at different times, and calculate the coordinates of the pen tip (23) on the display (10) based on the position of the coding point (14), and combine multiple coordinates at different times into a coordinate set for representing the writing trajectory. The display is used to show the writing trajectory according to the set of coordinates.

2. The non-touch display writing system according to claim 1, characterized in that, Each of the dot matrix units (12) corresponds to a region code, and the multiple coding points (14) within a dot matrix unit (12) are not completely identical.

3. The non-touch display writing system according to claim 2, characterized in that, At least one of the dot matrix squares (13) in each of the dot matrix units (12) is used to set a position coding point (141), which is used to mark the absolute position of the current dot matrix unit (12) on the entire glass substrate (11); the absolute position is recorded with the center of the glass substrate (11) as the origin of the coordinate system.

4. The non-touch display writing system according to claim 3, characterized in that, The position coding point (141) is located in the upper left corner dot matrix square (13) of the dot matrix unit (12); each dot matrix square (13) of the remaining dot matrix squares (13) of the dot matrix unit (12) contains one coding point (14), and all coding points (14) are metal points.

5. The non-touch display writing system according to claim 4, characterized in that, The position coding point (141) includes a first point (142) with the largest diameter and a second point (143) located in any one of the four directions of the first point (142): up, down, left, and right. The diameter of the second point (143) is smaller than that of the first point (142). The straight-line distance between the second point (143) and the first point (142) is calculated to represent the distance of the current dot matrix unit (12) relative to the center point of the glass substrate (11). The angle between the line connecting the second point (143) and the first point (142) and the x-axis represents the row or column in which the dot matrix unit (12) is located relative to the center of the glass substrate (11).

6. The non-touch display writing system according to claim 5, characterized in that, When the included angle represents the row where the dot matrix unit (12) is located relative to the center of the glass substrate (11), the display (10) is set to have a rows in total, and the row below the center point has a / 2 rows. (a / 2) / 90 is used as a minimum step value, and the corresponding row number is determined according to the step value range where the included angle is located.

7. The non-touch display writing system according to claim 1, characterized in that, The position of the coding point (14) obscured by the pen tip (21) corresponds to a specific coordinate under a region code. The data processing module (23) obtains multiple specific coordinates from multiple images and determines them sequentially to form a coordinate-based writing trajectory.

8. The non-touch display writing system (1) according to claim 1, characterized in that, The camera module (22) includes an infrared generator (221) and an infrared camera (222). The infrared generator (221) is used to emit infrared light toward the glass substrate (11), and the infrared camera (222) is used to receive the infrared light reflected by the glass substrate (11). When the infrared generator (221) emits infrared light toward the shooting area, the coding point (14) blocked by the pen tip (21) cannot reflect infrared light, and the unblocked coding point (14) reflects infrared light to the infrared camera (222), so that the position of the blocked coding point (14) is shown in the captured image.

9. The non-touch display writing system according to claim 1, characterized in that, The electronic pen (20) is provided with a first communication module (24), which is connected to a data network; the display (10) also includes a second communication module (15), which is connected to the data network. The first communication module (24) sends the coordinates of the writing trajectory to the display (10) through the second communication module (15), and the display (10) converts the coordinates into an image and displays the writing trajectory.

10. A non-touch display, characterized in that, For use in operating the non-touch display writing system as described in claim 1.

Images