Easel with painting assisting function

Abstract

The invention relates to the field of environment design tools, and discloses an easel with drawing assistance, the easel comprises a support frame and an adjusting frame, one end of the adjusting frame is hinged to the support frame and can be folded on the support frame, the easel further comprises a first clamping plate and a second clamping plate, the first clamping plate and the second clamping plate are arranged on one side of the adjusting frame and used for clamping drawing boards of different sizes, and the first clamping plate and the second clamping plate are arranged on the other side of the adjusting frame. The mounting frame is vertically arranged on the back face of the adjusting frame, and a projector is arranged on the mounting frame and used for projecting pictures to the back face of the drawing board. Displacement of the second clamping plate is monitored in real time through the displacement detection unit, the driving assembly can automatically adjust the distance between the mounting frame and the adjusting frame, the projection range of the projector is made to be proportional to the size of the drawing board, when the size of the drawing board changes, the horizontal moving distance of the mounting frame is dynamically matched with the size of the drawing board, and it is avoided that pictures overflow or are not covered; and the integrity and the accuracy of the projection picture are improved.

Description

Technical Field

[0001] The invention relates to the field of environmental design tools, in particular to an easel with painting assistance. Background Art

[0002] In residential design services, designers frequently conduct on-site surveys, plan development, and client presentations. Traditional easels only provide basic support and are unable to meet the diverse needs of intelligent assistance in these scenarios. With the advancement of digital design tools and the concept of green design, the integration of projectors with easels has enabled them to project auxiliary lines onto the canvas and support interactive virtual and real-world interactions. These tools can improve design efficiency and the accuracy of solution presentation.

[0003] Publication number CN216101304U discloses an intelligent interactive easel. Using a central axis track, a sliding mechanism, and a servo system, it enables features like height adjustment and remote teaching interaction. The solution integrates an information tablet and projection device, supporting remote instruction and resource access for teachers.

[0004] Existing easels use a fixed projection module, that is, the projector is fixed at a specific position on the easel. When changing to different sizes of drawing boards, the projection distance cannot be automatically adjusted as the drawing board size changes, resulting in image overflow or not covering the canvas area. Moreover, after changing the drawing board, the projection optical axis is misaligned with the geometric center of the drawing board, and the projected image is easily deviated from the center of the drawing board, affecting the accuracy of the design drawing. Summary of the Invention

[0005] In order to solve the problem that the above-mentioned easel adopts a fixed projection module, that is, the projector is fixed at a specific position of the easel, and when different-sized drawing boards are replaced, the projection distance cannot be automatically adjusted as the drawing board size changes, resulting in image overflow or not covering the canvas area, and after the drawing board is replaced, the projection optical axis is misaligned with the geometric center of the drawing board, and the projected image is easily deviated from the center of the drawing board, affecting the accuracy of the design drawing, the present invention is achieved through the following technical solutions.

[0006] An easel with a painting aid, comprising a supporting frame and an adjusting frame, wherein one end of the adjusting frame is hinged to the supporting frame and can be folded onto the supporting frame, and further comprising:

[0007] A first clamping plate and a second clamping plate are provided on one side of the adjustment frame and are used to clamp drawing boards of different sizes;

[0008] A mounting frame is vertically arranged on the back of the adjustment frame, and a projector is provided on the mounting frame for projecting an image onto the back of the drawing board;

[0009] At least two drive assemblies are installed on the adjustment frame, the drive assemblies are connected to the mounting frame, and the drive assemblies are used to adjust the distance between the mounting frame and the adjustment frame according to the displacement of the second clamping plate;

[0010] A displacement detection unit, mounted on the adjustment frame, for detecting the displacement of the second clamping plate;

[0011] The controller is installed on the adjustment frame. The drive component is connected to the displacement detection unit through the controller. The controller is used to receive signals from the displacement detection unit and control the drive component to adjust the position of the mounting frame so that the projection range and center position of the projector adapt to the current drawing board.

[0012] Preferably, the drive assembly includes:

[0013] A fixed plate, one end of which is fixed to the adjustment frame, a telescopic slot is provided on the mounting frame, and the other end of the fixed plate is connected to the telescopic slot;

[0014] Two adjustment arms, one end of the adjustment arm is connected to the adjustment frame through a movable seat, the movable seat is installed on the adjustment frame, and the movable seat moves along the vertical direction of the adjustment frame. The other end of the adjustment arm is connected to the mounting frame through a fixed block, and the two fixed blocks are respectively installed at the top and bottom of the mounting frame;

[0015] The second screw rod is installed on the adjustment frame, and the second screw rod passes through the two moving seats at the same time;

[0016] The power source is installed on the adjustment frame. The power shaft of the power source is connected to the second screw rod and is used to drive the second screw rod to rotate forward and reverse to control the spacing between the moving seats and adjust the distance between the mounting frame and the adjustment frame.

[0017] Preferably, nuts are installed through both movable seats, the threads of the two nuts are rotated in opposite directions, and the screw rod cooperates with the two nuts with opposite threads.

[0018] Preferably, the power source includes a first gear and a second gear, the first gear is mounted on a power shaft of the power source, the second gear is mounted on the second screw rod, and the first gear is meshed with the second gear.

[0019] Preferably, a movable groove is provided on the adjustment frame, a movable block is installed on the second clamping plate, the movable block is connected to the movable groove, the displacement detection unit is installed on the top wall of the movable groove, an elastic member is installed on the movable block, and one end of the elastic member is installed on the bottom wall of the movable groove.

[0020] Preferably, the driving assembly includes an electric slide, the mounting frame is fixed on the electric slide, and the mounting frame moves on the electric slide to adjust the distance between the mounting frame and the adjustment frame.

[0021] Preferably, the mounting frame is provided with a vertically extending electric slide rail, a storage plate is mounted on the electric slide rail, and the projector is mounted on the electric slide rail via the storage plate;

[0022] The controller controls the electric slide rail to rise and fall according to the signal of the displacement detection unit to adjust the height of the projector.

[0023] Preferably, the displacement detection unit is a laser distance sensor or a Hall sensor, which detects the movement of the second clamping plate in real time.

[0024] Preferably, the controller includes:

[0025] A sensor interface, the sensor interface receives a displacement signal from the displacement detection unit;

[0026] Processing unit with built-in adaptive algorithm to calculate the drawing board size, center coordinates and projection parameters;

[0027] The drive interface includes a motor drive circuit and a position feedback circuit. The motor drive circuit controls the start, stop and steering of the power source of the drive component. The position feedback circuit collects the displacement data of the mounting bracket in real time and feeds it back to the processing unit. The position feedback circuit includes an encoder or a Hall sensor installed on the power source output shaft of the drive component, which is used to detect the rotation angle of the power source and convert it into the actual displacement of the mounting bracket. The drive interface outputs control instructions to the drive component to adjust the position of the mounting bracket so that the projection range and center position of the projector adapt to the current drawing board.

[0028] Preferably, the adaptive algorithm includes:

[0029] Calculate the size and center coordinates of the drawing board according to the signal of the displacement detection unit;

[0030] Generate the target moving distance of the mounting frame based on the relationship between the drawing board size and the preset projection ratio;

[0031] Based on the center coordinates and the projector optical parameters, a height adjustment instruction for the projector is generated.

[0032] Preferably, two foldable support legs are provided at the bottom of the support frame, and the support legs are symmetrically arranged.

[0033] The present invention provides an easel with a drawing aid. Compared with existing technologies, it has the following advantages: a displacement detection unit monitors the displacement of the second clamping plate in real time, and a drive assembly automatically adjusts the distance between the mounting frame and the adjustment frame to ensure that the projector's projection range is proportional to the size of the drawing board. When the drawing board size changes, the horizontal movement distance of the mounting frame dynamically matches the drawing board size, preventing image overflow or under-coverage, thereby improving the integrity and accuracy of the projected image. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the three-dimensional structure proposed by the present invention.

[0035] Figure 2 This is a schematic diagram of a three-dimensional structure from another perspective proposed by the present invention.

[0036] Figure 3 This is a schematic diagram of the support frame and adjustment frame proposed in the present invention in the unfolded state.

[0037] Figure 4 This is a schematic diagram of the support frame and adjustment frame proposed in the present invention in a folded state.

[0038] Figure 5 This is a structural schematic diagram of the adjustment frame and mounting frame proposed in the present invention.

[0039] Figure 6 This is a structural schematic diagram of the adjustment frame, fixing plate, adjustment arm, support plate and projector proposed in the present invention.

[0040] Figure 7 This is a structural schematic diagram of the fixed plate, adjustment arm, movable seat, fixed block, second screw rod and power source proposed in the present invention.

[0041] Figure 8 This is a schematic diagram of the structure of the storage plate, electric slide rail and projector proposed in the present invention.

[0042] The reference numerals in the figures are:

[0043] 100. Support frame; 101. Support legs;

[0044] 200, adjustment frame; 201, drawing board; 202, first clamping plate; 203, second clamping plate; 204, moving block; 205, moving slot; 206, displacement detection unit; 207, elastic member; 208, controller;

[0045] 300, mounting frame; 301, fixing plate; 302, adjusting arm; 303, moving seat; 304, fixing block; 305, second screw rod; 306, power source; 307, first gear; 308, second gear;

[0046] 400, storage board; 401, electric slide;

[0047] 500. Projector. DETAILED DESCRIPTION

[0048] The present invention is further described below with reference to specific examples. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of protection of the present invention.

[0049] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0050] Example 1: Reference Figures 1-8 , an easel with painting assistance, comprising a supporting frame 100 and an adjusting frame 200, one end of the adjusting frame 200 is hinged to the supporting frame 100 and can be folded onto the supporting frame 100; the adjusting frame 200 can be folded at the top of the supporting frame 100, and two foldable supporting legs 101 are provided at the bottom of the supporting frame 100, and the supporting legs 101 are symmetrically arranged, and a first clamping plate 202 and a second clamping plate 203 are installed on one side of the adjusting frame 200, the first clamping plate 202 is fixed, and the second clamping plate 203 is movable, moving on the adjusting frame 200, the first clamping plate 202 and the second clamping plate 203 can clamp and fix drawing boards 201 of different sizes, the drawing board 201 is a transparent acrylic board, and a microprismatic light-guiding layer is provided on the back thereof for directionally refracting projection light to the front of the drawing board 201, and the front is coated with a wide-band anti-reflection film, and the canvas or drawing paper is attached to the drawing board 201.

[0051] In this embodiment, if the projector 500 is located in front of the drawing board 201, the body, arms or drawing tools of the user may easily block the projection light beam when standing to draw, resulting in image interruption or shadows, affecting the integrity of the lines. However, if the projector 500 is located on the back of the drawing board 201, the light is projected onto the canvas or drawing paper through the transparent acrylic plate. The canvas or drawing paper also has a certain degree of light transmittance. The line drawing projected by the projector 500 has a high color contrast. The line drawing projected from the back can be used as a transparent base map, and the user can directly trace on the front of the medium. For scenes that require superimposing digital line drawings and physical brushstrokes, high-contrast projection can accurately locate the line position, avoiding the positioning deviation caused by human body obstruction in traditional front projection. When drawing architectural cross-sections, the projected axis and scale lines can penetrate the sulfuric acid paper, helping users to quickly align structural lines, which can provide assistance for painting.

[0052] Reference Figure 2 and Figure 5 The mounting frame 300 is mounted on the back of the adjusting frame 200, that is, the side of the adjusting frame 200 away from the drawing board 201. The mounting frame 300 is equipped with a projector 500. The projector 500 projects the auxiliary line draft onto the back of the drawing paper or canvas through the transparent acrylic plate, providing line assistance for the user when drawing. The mounting frame 300 is arranged perpendicular to the adjusting frame 200, and the distance between the mounting frame 300 and the adjusting frame 200 is adjustable, which can be adjusted specifically according to the position of the second clamping plate 203. When the distance between the second clamping plate 203 and the first clamping plate 202 is larger, the size of the clamped drawing board 201 is larger. At this time, it is necessary to increase the distance between the mounting frame 300 and the adjusting frame 200 to increase the size of the picture projected by the projector 500 on the drawing board 201; conversely, the distance between the second clamping plate 203 and the first clamping plate 202 is shortened, and the distance between the projector 500 and the adjusting frame 200 is smaller.

[0053] Reference Figure 6 and Figure 7 The specific adjustment method of the mounting frame 300 is as follows: there are two sets of drive components on the adjustment frame 200, both of which are connected to the mounting frame 300 and are symmetrically arranged. The position of the mounting frame 300 is driven by the drive components. In this embodiment, the drive components are composed of a fixed plate 301, two adjustment arms 302, a second screw rod 305 and a power source 306. One end of the fixed plate 301 is fixed to the adjustment frame 200, and the other end is connected to the mounting frame 300. A telescopic slot is provided on the mounting frame 300. The fixed plate 30 1 is connected to the telescopic slot. The function of the fixing plate 301 is to provide a linear moving path for the mounting frame 300. One end of the two adjusting arms 302 are both mounted on the adjusting frame 200. The other ends of the two adjusting arms 302 are respectively mounted on the top and bottom of the mounting frame 300. By adjusting the distance between the two adjusting arms 302 on one end of the adjusting frame 200, the mounting frame 300 can be driven to move closer to or away from the adjusting frame 200. When the ends of the two adjusting arms 302 close to the adjusting frame 200 are close to each other, the mounting frame 300 When the adjusting frame 200 is far away from each other, the mounting frame 300 is close to the adjusting frame 200, the movable seat 303 is installed on the adjusting frame 200, and the movable seat 303 moves in the vertical direction of the adjusting frame 200. One end of the adjusting arm 302 is rotatably connected to the movable seat 303. The two fixing blocks 304 are respectively installed at the top and bottom of the mounting frame 300. The other end of the adjusting arm 302 is connected to the fixing block 304. The second screw rod 305 is also installed on the adjusting frame 200. Nuts are installed on both movable seats 303. The threads of the two nuts rotate in opposite directions, and both nuts cooperate with the screw rod. In this way, when the second screw rod 305 rotates forward or reversely, the two movable seats 303 move closer to or away from each other. The second screw rod 305 is driven by a power source 306, and the power source 306 is installed on the adjustment frame 200. A first gear 307 is installed on the power shaft of the power source 306, and a second gear 308 is installed on the second screw rod 305. The second gear 308 is engaged with the first gear 307. The power source 306 adopts a servo motor, and can also adopt a stepping motor.

[0054] Reference Figure 5 and Figure 6A moving groove 205 is provided on the adjustment frame 200, and a moving block 204 is installed on the second clamping plate 203. The moving block 204 is connected to the moving groove 205. The displacement detection unit 206 is installed on the top wall of the moving groove 205. An elastic member 207 is installed on the moving block 204. One end of the elastic member 207 is installed on the bottom wall of the moving groove 205. The elastic member 207 is a spring or an elastic rope. The elastic member 207 provides clamping force for the second clamping plate 203. The displacement detection unit 206 is a laser distance sensor or a Hall sensor, which detects the movement of the second clamping plate 203 in real time and is used to monitor the moving position or distance of the moving block 204. When it is detected that the distance of the moving block 204 changes, the distance sensor sends data and controls the power source 306 to start, driving the mounting frame 300 and the projector 500 to move and adjust to the corresponding position.

[0055] Reference Figure 6 , controller 208, is installed on the adjustment frame 200, and the driving component is connected to the displacement detection unit 206 through the controller 208. The controller 208 is used to receive the signal of the displacement detection unit 206 and control the driving component to adjust the position of the mounting frame 300 so that the projection range and center position of the projector 500 adapt to the current drawing board 201.

[0056] The controller 208 includes: a sensor interface, which receives the displacement signal of the displacement detection unit 206; a processing unit, which has a built-in adaptive algorithm to calculate the size, center coordinates and projection parameters of the drawing board 201; a drive interface, which includes a motor drive circuit and a position feedback circuit. The motor drive circuit controls the start, stop and steering of the power source 306 of the drive component. The position feedback circuit collects the displacement data of the mounting frame 300 in real time and feeds it back to the processing unit. The position feedback circuit includes an encoder or a Hall sensor installed on the output shaft of the power source 306 of the drive component, which is used to detect the rotation angle of the power source 306 and convert it into the actual displacement of the mounting frame 300. The drive interface outputs control instructions to the drive component to adjust the position of the mounting frame 300 so that the projection range and center position of the projector 500 are adapted to the current drawing board 201.

[0057] The adaptive algorithm includes: calculating the size and center coordinates of the drawing board 201 based on the signal of the displacement detection unit 206; generating the target movement distance of the mounting frame 300 based on the relationship between the size of the drawing board 201 and the preset projection ratio; and generating a height adjustment instruction for the projector 500 based on the center coordinates and the optical parameters of the projector 500.

[0058] The mounting frame 300 is provided with a vertically extending electric slide rail 401, on which a storage plate 400 is installed, and the projector 500 is installed on the electric slide rail 401 through the storage plate 400; the controller 208 controls the electric slide rail 401 to rise and fall to adjust the height of the projector 500 according to the signal of the displacement detection unit 206. When the displacement sensor or the distance sensor detects that the moving position or distance of the moving block 204 has changed, it indicates that the second clamping plate 203 is currently displaced, that is, the size of the drawing board 201 has changed, and the center position of the drawing board 201 has changed. At this time, the signal and data are sent to the controller 208, and the electric slide rail 401 is controlled to move. The electric slide rail 401 drives the projector 500 to rise and fall, and the projector 500 can be adjusted to the center position of the current drawing board 201.

[0059] After the displacement detection unit 206 detects the movement of the second clamping plate 203, the controller 208 controls the power source 306 and the electric slide rail 401 and adjusts the position of the projector 500.

[0060] 1. Displacement detection and signal transmission

[0061] The displacement detection unit 206 (a laser distance sensor or a Hall sensor) monitors the position change of the second clamping plate 203 in the movable groove 205 in real time: when the user adjusts the distance between the second clamping plate 203 and the first clamping plate 202 (for example, to clamp a larger or smaller drawing board 201), the movable block 204 moves with the second clamping plate 203, triggering the displacement detection unit 206 to collect the movement distance ΔL and the current position coordinate X;

[0062] The sensor converts the displacement data (such as distance change, coordinate values) into an electrical signal and transmits it to the processing unit of the controller 208 through the sensor interface.

[0063] 2. Adaptive Algorithm Logic of the Processing Unit

[0064] The processing unit analyzes the displacement data using a built-in adaptive algorithm and calculates the adjustment parameters required for the projector 500:

[0065] 1. Calculate the size and center coordinates of the drawing board 201

[0066] Drawing board 201 size W: According to the initial position of the displacement detection unit 206 (corresponding to the minimum drawing board 201 size) and the current displacement ΔL, the actual clamped drawing board 201 size is calculated: W=W0+2×ΔL (assuming symmetrical movement on both sides, W0 is the minimum size).

[0067] Coordinates of the center of drawing board 201 (Xc, Yc):

[0068] Horizontal center coordinate: Xc=X0+ΔL (X0 is the initial center coordinate).

[0069] The vertical center coordinate: Yc is the midpoint of the height of the drawing board 201 , assuming that the height of the drawing board 201 is fixed or obtained through preset parameters.

[0070] 2. Generate horizontal movement instructions for mounting frame 300

[0071] Projection range matching: The projection screen size of the projector 500 needs to be proportional to the width W of the drawing board 201 (preset projection ratio K, such as 1:1), so the distance D between the mounting bracket 300 and the adjustment bracket 200 needs to satisfy: D=K×W.

[0072] Target moving distance ΔD: Calculate the distance to be adjusted based on the current distance D_current and the target distance D_target: ΔD = D_target - D_current.

[0073] Drive component control logic: If ΔD>0, the drive component needs to move the mounting bracket 300 away from the adjustment bracket 200; if ΔD<0, the drive component needs to move the mounting bracket 300 closer to the adjustment bracket 200.

[0074] Precise movement is achieved by the rotation direction and number of turns of the second screw 305: the screw pitch is P, and the required number of turns is N=ΔD / P.

[0075] The power source 306 drives the screw through the gear transmission, and the number of motor rotations N_motor=N×i.

[0076] 3. Generate projector 500 vertical height adjustment instructions

[0077] Center alignment logic: The optical center of the projector 500 needs to be aligned with the center coordinates (Xc, Yc) of the drawing board 201. Therefore, the height H of the projector 500 needs to be adjusted vertically so that the center axis of the projection beam passes through Yc.

[0078] The moving distance ΔH of the electric slide rail 401 is calculated based on the vertical center coordinate Yc of the drawing board 201 and the current height H_current of the projector 500: ΔH=Yc-H_current.

[0079] Motor control parameters: The stepping motor of the electric slide 401 moves a distance S per step, and the required number of steps M = ΔH / S.

[0080] 3. Execution Control of Driver Interface

[0081] 1. Drive component (horizontal movement) control

[0082] Power source 306 (motor) start, stop and steering:

[0083] The processing unit sends a forward / reverse signal through the motor driving circuit to control the power source 306 to drive the first gear 307 to rotate.

[0084] The first gear 307 is meshed with the second gear 308 to drive the second screw rod 305 to rotate. Since the threads of the two nuts rotate in opposite directions, the two moving seats 303 will move synchronously in opposite directions:

[0085] When the screw rotates forward, the movable seats 303 move away from each other, and the adjustment arm 302 drives the mounting frame 300 closer to the adjustment frame 200 (ΔD decreases);

[0086] When the screw rod is reversed, the movable seats 303 move closer to each other, and the mounting frame 300 moves away from the adjustment frame 200 (ΔD increases).

[0087] Position feedback and closed-loop control:

[0088] The encoder detects the rotation angle of the output shaft of the power source 306 in real time, converts it into the actual displacement ΔD_real of the mounting bracket 300, and feeds it back to the processing unit.

[0089] The processing unit compares ΔD_real and ΔD_target. When the error exceeds the threshold, the number of motor revolutions is automatically adjusted to achieve precise positioning.

[0090] 2. Electric slide 401 (vertical movement) control

[0091] Height adjustment execution: The processing unit sends a pulse signal to the stepper motor of the electric slide 401 through the motor drive circuit, controls the motor to rotate in steps M, and drives the projector 500 to rise and fall a distance ΔH along the slide.

[0092] Limit protection: limit switches are provided at both ends of the slide rail. When the projector 500 reaches the limit position, a switch signal is triggered to the controller 208 to stop the motor movement.

[0093] 4. Key Parameters and Calibration of Adaptive Algorithms

[0094] Preset projection ratio K: needs to be calibrated during system initialization and is determined by measuring the optimal projection distance of the projector 500 under different drawing board 201 sizes (e.g., K=1 means that a drawing board 201 width of 10 cm corresponds to a projection distance of 10 cm).

[0095] Optical parameter compensation: The processing unit takes into account the keystone correction parameters and focal length parameters of projector 500 to prevent distortion of the projected image due to movement of mounting bracket 300. For example, when mounting bracket 300 moves away from adjustment bracket 200, the keystone correction coefficient of projector 500 is automatically adjusted to maintain a rectangular image.

[0096] Multi-device collaborative control: If the system integrates multiple projectors 500 or sensors, the processing unit ensures the real-time performance of displacement detection and projection adjustment through a time synchronization algorithm.

[0097] A shading plate or a shading cloth / cover can be installed between the adjustment frame 200 and the mounting frame 300. When the easel is used outdoors in an environment with strong light, the projection effect of the projector 500 is poor. At this time, the four sides of the adjustment frame 200 and the mounting frame 300 can be used as installation points or anchor points. Installing a shading plate or a shading cloth / cover can reduce the impact of ambient light on the projection.

[0098] Example 2: The difference between this example and Example 1 is that the driving assembly is composed of an electric slide, the mounting frame 300 is installed on the electric slide, and the mounting frame 300 is directly driven to move by the electric slide. The electric slide is not shown in the accompanying drawings. The electric slide adopts the KA series high-precision electric linear slide produced by Zhuoli Hanguan. The linear motor slide is a high-precision, high-speed, and high-load capacity electric linear slide driven by a linear motor, guided by a linear slider guide, and uses a closed-loop device (usually a grating scale) for position control.

[0099] During use, the projector 500 is fixed on the electric slide rail 401 and the storage plate 400 of the mounting frame 300 , and is connected to the controller 208 , the displacement detection unit 206 , and the driving assembly.

[0100] The controller 208 presets system parameters such as projection ratio parameter K (eg 1:1, i.e. the ratio of the width of the drawing board 201 to the projection distance), screw pitch P, and step accuracy S of the electric slide rail 401 .

[0101] In the initial calibration state, when the distance between the second clamping plate 203 and the first clamping plate 202 is at the minimum, adjust the mounting frame 300 until the projection image of the projector 500 completely covers the minimum drawing board 201, and record the position of the mounting frame 300 (D0) and the height of the projector 500 (H0) at this time.

[0102] The user manually moves the second clamping plate 203 according to the size of the drawing board 201, changes the distance (ΔL) between it and the first clamping plate 202, and clamps transparent acrylic drawing boards 201 of different sizes. The second clamping plate 203 slides in the moving groove 205 of the support frame 100 through the moving block 204, triggering the displacement detection unit 206 to collect the moving distance ΔL and the current position coordinate X in real time.

[0103] Signal acquisition and transmission: The displacement detection unit 206 converts the physical displacement into an electrical signal (such as laser pulse time difference, Hall effect voltage change) and transmits it to the processing unit of the controller 208 through the sensor interface.

[0104] Generate projection adjustment instructions:

[0105] The horizontal movement distance ΔD of the mounting frame 300 is: ΔD = K × W - D_current (D_current is the current distance of the mounting frame 300, the initial value is D0); if ΔD>0, the mounting frame 300 needs to be moved away from the adjustment frame 200; if ΔD<0, it needs to be moved closer.

[0106] The vertical height ΔH of the projector 500 is: ΔH=Yc-H_current (H_current is the current height of the projector 500, the initial value is H0); if ΔH>0, the electric slide rail 401 needs to rise; if ΔH<0, it needs to fall.

[0107] Drive parameter conversion:

[0108] Number of screw rotations N: N = ΔD / P (P is the screw pitch, such as P = 2mm / turn, then ΔD = 20mm corresponds to N = 10 turns);

[0109] Number of steps M of the electric slide 401: M = ΔH / S (S is the step accuracy, such as S = 0.5mm / step, then ΔH = 10mm corresponds to M = 20 steps);

[0110] The controller 208 sends instructions through the drive interface, and the power source 306 drives the first gear 307 to rotate, engaging the second gear 308 to drive the second screw rod 305 to rotate. Since the two nut threads rotate in opposite directions, when the screw rod rotates, the two movable seats 303 move closer to or away from each other in the vertical direction of the adjustment frame 200, and the mounting frame 300 is pulled by the adjustment arm 302. When the screw rod rotates forward, the movable seat 303 moves away, the angle of the adjustment arm 302 increases, and the mounting frame 300 moves closer to the adjustment frame 200 (ΔD decreases); when the screw rod reverses, the movable seat 303 moves closer, the angle of the adjustment arm 302 decreases, and the mounting frame 300 moves away from the adjustment frame 200 (ΔD increases), and the fixed plate 301 slides in the telescopic slot of the mounting frame 300 to ensure that the mounting frame 300 moves linearly in the horizontal direction to avoid shaking.

[0111] The controller 208 sends a pulse signal to the stepper motor of the electric slide 401, driving the storage plate 400 to rise and fall along the slide, driving the projector 500 to move a distance ΔH, so that the optical center of the projector 500 is aligned with the vertical center Yc of the drawing board 201. The encoder installed on the output shaft of the power source 306 monitors the motor rotation angle in real time and converts it into the actual displacement ΔD_real of the mounting frame 300. The processing unit compares ΔD_real with ΔD_target. If the error exceeds a threshold (such as ±0.5mm), a pulse command is automatically triggered to adjust the number of motor rotations until the positions are accurately matched. The projector 500 automatically adjusts the keystone correction parameters and focal length according to the new mounting frame 300 spacing D and height H to ensure that the projected image covers the entire drawing board 201 without distortion. If the ambient light is strong, the user can manually or through the controller 208 command install a sunshade / cloth around the adjustment frame 200 and the mounting frame 300 to reduce ambient light interference.

[0112] In summary, compared with the existing technology, it has the following beneficial effects:

[0113] By real-time monitoring of the displacement of the second clamping plate 203 through the displacement detection unit 206, the driving component can automatically adjust the distance between the mounting frame 300 and the adjustment frame 200 so that the projection range of the projector 500 is proportional to the size of the drawing board 201. When the size of the drawing board 201 changes, the horizontal movement distance of the mounting frame 300 dynamically matches the size of the drawing board 201, avoiding image overflow or uncoveredness, thereby improving the integrity and accuracy of the projected image.

[0114] The controller 208 controls the electric slide 401 to adjust the vertical height of the projector 500 according to the center coordinates of the drawing board 201 and the optical parameters of the projector 500, so that the central axis of the projection light beam is precisely aligned with the geometric center of the drawing board 201, ensuring that the horizontal spacing and vertical height of the projector 500 are adjusted synchronously, which is suitable for environmental design scenarios with high requirements for line positioning.

[0115] The user only needs to manually adjust the distance between the clamping plates, the displacement detection unit 206 automatically collects data, the built-in algorithm of the processing unit generates driving instructions, and the driving component synchronously performs horizontal and vertical adjustments, without the need for manual adjustment of the projector 500 position.

[0116] The support frame 100 is provided with foldable symmetrical support legs 101 at the bottom, and the adjustment frame 200 is hinged to the support frame 100 and can be folded at the top, which is convenient for carrying and storage, and is suitable for mobile scenes such as on-site surveys and outdoor design.

[0117] Thus, although the invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are contemplated within the foregoing disclosure, and it should be understood that in some cases, some features of the invention will be employed without the corresponding use of other features without departing from the scope and spirit of the claimed invention. Thus, many modifications may be made to adapt a particular environment or material to the true scope and spirit of the invention. The invention is not intended to be limited to the specific terminology used in the claims below and / or to the specific embodiments disclosed as the best mode contemplated for carrying out the invention, but the invention is intended to include any and all embodiments and equivalents falling within the scope of the appended claims. Thus, the scope of the invention will be determined solely by the appended claims.

Claims

1. An easel with a painting aid, comprising a support frame (100) and an adjustment frame (200), wherein one end of the adjustment frame (200) is hinged to the support frame (100) and can be folded onto the support frame (100), characterized in that: Also includes: A first clamping plate (202) and a second clamping plate (203) are provided on one side of the adjustment frame (200) and are used to clamp drawing boards (201) of different sizes; A mounting frame (300) is vertically arranged on the back of the adjustment frame (200), and a projector (500) is provided on the mounting frame (300) for projecting an image onto the back of the drawing board (201); At least two drive assemblies are installed on the adjustment frame (200), the drive assemblies are connected to the mounting frame (300), and the drive assemblies are used to adjust the distance between the mounting frame (300) and the adjustment frame (200) according to the displacement of the second clamping plate (203); A displacement detection unit (206) is installed on the adjustment frame (200) and is used to detect the displacement of the second clamping plate (203); The controller (208) is mounted on the adjustment frame (200), and the driving component is connected to the displacement detection unit (206) through the controller (208). The controller (208) is used to receive a signal from the displacement detection unit (206) and control the driving component to adjust the position of the mounting frame (300) so that the projection range and center position of the projector (500) are adapted to the current drawing board (201).

2. The easel according to claim 1, wherein: The drive assembly includes: A fixing plate (301) is fixed to the adjustment frame (200) at one end, a telescopic slot is provided on the mounting frame (300), and the other end of the fixing plate (301) is connected to the telescopic slot; Two adjusting arms (302), one end of the adjusting arm (302) is connected to the adjusting frame (200) through a movable seat (303), the movable seat (303) is installed on the adjusting frame (200), the movable seat (303) moves along the vertical direction of the adjusting frame (200), the other end of the adjusting arm (302) is connected to the mounting frame (300) through a fixed block (304), and the two fixed blocks (304) are respectively installed at the top and bottom of the mounting frame (300); The second screw rod (305) is installed on the adjustment frame (200), and nuts are installed through the two movable seats (303). The threads of the two nuts are rotated in opposite directions, and the screw rod cooperates with the two nuts with opposite threads; A power source (306) is mounted on the adjustment frame (200), and a power shaft of the power source (306) is connected to the second screw rod (305) for driving the second screw rod (305) to rotate forward and reverse to control the spacing of the movable seat (303) and adjust the distance between the mounting frame (300) and the adjustment frame (200).

3. The easel according to claim 2, characterized in that The power source (306) includes a first gear (307) and a second gear (308). The first gear (307) is mounted on a power shaft of the power source (306). The second gear (308) is mounted on a second screw rod (305). The first gear (307) and the second gear (308) are meshed.

4. The easel according to claim 1, wherein: The adjusting frame (200) is provided with a moving groove (205), a moving block (204) is installed on the second clamping plate (203), the moving block (204) is connected in the moving groove (205), a displacement detection unit (206) is installed on the top wall of the moving groove (205), an elastic member (207) is installed on the moving block (204), and one end of the elastic member (207) is installed on the bottom wall of the moving groove (205).

5. The easel according to claim 1, wherein: The driving assembly includes an electric slide, the mounting frame (300) is fixed on the electric slide, and the mounting frame (300) moves on the electric slide to adjust the distance between the mounting frame (300) and the adjustment frame (200).

6. The easel according to claim 1, wherein: The mounting frame (300) is provided with a vertically extending electric slide rail (401), a storage plate (400) is installed on the electric slide rail (401), and the projector (500) is installed on the electric slide rail (401) via the storage plate (400); The controller (208) controls the electric slide rail (401) to move up and down to adjust the height of the projector (500) according to the signal of the displacement detection unit (206).

7. The easel according to claim 6, characterized in that The displacement detection unit (206) is a laser distance sensor or a Hall sensor, and detects the movement amount of the second clamping plate (203) in real time.

8. The easel according to claim 6, characterized in that The controller (208) includes: a sensor interface, the sensor interface receiving a displacement signal from a displacement detection unit (206); A processing unit having a built-in adaptive algorithm for calculating the size, center coordinates and projection parameters of the drawing board (201); A drive interface, the drive interface includes a motor drive circuit and a position feedback circuit, the motor drive circuit controls the start, stop and direction of the power source (306) of the drive component, the position feedback circuit collects displacement data of the mounting frame (300) in real time and feeds it back to the processing unit, the position feedback circuit includes an encoder or a Hall sensor installed on the output shaft of the power source (306) of the drive component, and is used to detect the rotation angle of the power source (306) and convert it into the actual displacement of the mounting frame (300), and the drive interface outputs a control instruction to the drive component to adjust the position of the mounting frame (300) so that the projection range and center position of the projector (500) are adapted to the current drawing board (201).

9. The easel according to claim 8, characterized in that The adaptive algorithm includes: Calculating the size and center coordinates of the drawing board (201) based on a signal from the displacement detection unit (206); Based on the relationship between the size of the drawing board (201) and the preset projection ratio, a target moving distance of the mounting frame (300) is generated; Based on the center coordinates and the optical parameters of the projector (500), a height adjustment instruction for the projector (500) is generated.

10. The easel according to claim 1, wherein: Two foldable support legs (101) are provided at the bottom of the support frame (100), and the support legs (101) are symmetrically arranged.

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