A method for aligning a low-cost projection screen

Abstract

The present application relates to the field of projection technology, in particular to a kind of low-cost projection screen alignment method.The method will be mainly applied to the modification of screen, try not to change the original projector system structure.The four corners of the screen are provided with photosensitive sensors, comprising: controlling the projector to project the picture of specified wavelength color to the screen;The photosensitive sensor installed on the screen feeds back signal to the projector system;The projector system judges the position of the four sensors and then judges the picture range and position of the screen;The projector system corrects the projection picture through the judged picture range and position of the screen;Repeat the above steps until correction is completed.The photosensitive sensor provided on the screen realizes the automatic alignment of the projection screen, without manual intervention, with high picture accuracy and small deviation.Compared with the method of setting infrared emitter and receiver, the cost is more low.

Description

Technical Field

[0001] This invention relates to the technical field of projectors, and in particular to a low-cost method for aligning projection screens. Background Technology

[0002] A projector is a device that projects images or videos onto a screen. It serves as a display for computers, VCD players, DVD players, Blu-ray players, game consoles, DV cameras, and other devices that can output video. This device is widely used in homes, offices, schools, cinemas, and other places where sharing is required.

[0003] A projection screen is a screen that displays the image projected by a projector and is used to receive the image projected by the projector.

[0004] When using a projector, the projector projects an image onto a projection screen. However, the best effect is achieved when the image is completely within the screen and fills the entire screen.

[0005] Before using a projector system, the screen needs to be aligned for a good viewing experience. However, this step currently requires manual operation, which is tedious and lacks precision.

[0006] Many methods for automatically aligning the screen have emerged, but their high cost has prevented them from being widely adopted in a timely manner. Summary of the Invention

[0007] This invention provides a low-cost method for aligning projection screens, solving the problems of cumbersome and inaccurate manual screen operation and the high cost of other methods.

[0008] According to one aspect of the present invention, the following technical solution is provided:

[0009] A low-cost method for aligning a screen includes the following steps:

[0010] Step 1: Install photosensitive sensors at the four corners of the front of the screen;

[0011] Step two: Before starting the alignment process, receive a feedback signal from the photosensitive sensor once for signal calibration.

[0012] Step 3: The display control device controls the projector to face the screen and project a pure color image of a preset wavelength color onto the screen;

[0013] Step four: The display control device identifies the feedback signals transmitted by the photosensitive sensors at the four corners of the screen, thereby determining the relative position of each photosensitive sensor, and thus determining the screen's image range and relative position.

[0014] Step 5: The display control device corrects the projected image based on the determined current screen area and relative position.

[0015] Step six: Determine the screen's image range and relative position by acquiring feedback signals in real time; and repeat the steps to correct the projected image until the correction is complete.

[0016] Furthermore, in step four, if the photosensitive sensor receives an image of a specified wavelength color projected by the projector, the photosensitive sensor sends a signal back to the display control device to determine the position of the projected image relative to the photosensitive sensor.

[0017] Furthermore, the screen is divided into four regions by a horizontal center line and a vertical center line, and the photosensitive sensor is located at the corner of the screen corresponding to each region.

[0018] Furthermore, in step three, the position of the photosensitive sensor is gradually determined based on the feedback signal from the photosensitive sensor to the display control device. When the projected image completely covers all the photosensitive sensors, the boundary line of the projected image on one side of the corresponding separation area is adjusted to move towards the center of the screen, reducing the area of ​​the projected image. At the same time, the display control device records the change in area ΔS1. When the projected image cannot cover the photosensitive sensors, the boundary line of the projected image on one side of the corresponding separation area is adjusted to move in the opposite direction, increasing the area of ​​the projected image. At the same time, the display control device records the change in area ΔS2. The above steps are repeated until the change in area ΔSn recorded by the display control device is less than a preset threshold, at which point the loop exits. At this time, the horizontal and vertical positions of the four photosensitive sensors are measured to determine the final projection display range, thereby realizing the automatic positioning of the projection screen and completing the alignment of the screen.

[0019] Furthermore, the preset wavelength color is 455nm-360nm.

[0020] More preferably, the preset wavelength color is 400nm.

[0021] Furthermore, the photosensitive sensor is connected to the display control device via a data cable.

[0022] Beneficial effects

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. By adding a photosensitive sensor later, it is applicable to various ordinary screens, and the cost of later modification is relatively small.

[0025] 2. It achieves automatic alignment of the projection screen without manual intervention, resulting in high image accuracy and minimal deviation. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the curtain;

[0027] Figure 2 This is a schematic diagram of the overall structure of the screen and projector system;

[0028] Figure 3 This is a schematic diagram of the screen's divided areas;

[0029] Figure 4 This is a schematic diagram illustrating the principle of determining the sensor's position;

[0030] Figure 5 This is a flowchart illustrating the process of determining the sensor's position.

[0031] Attached icon number

[0032] Screen 100, display area 101, screen frame 102, photosensors (103, 104, 105, 106), projector projection image 201, data cables (202, 204), display control device 203, projector 205, horizontal center line 301, vertical center line 302, screen area (303, 304, 305, 306), lower right corner projection image 308, right boundary line 312, initial position of right boundary line 312a, position of right boundary line after first adjustment 312b, position of right boundary line after second adjustment 312c, final position of right boundary line after adjustment 312n. Detailed Implementation

[0033] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the alignment method of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Depend on Figures 1-5 As shown, the present invention provides a low-cost method for aligning a screen, comprising the following steps:

[0035] Step 1: Photosensitive sensors (103, 104, 105, 106) are installed at the four corners of the front of the screen 100.

[0036] Step two: Before starting the alignment process, the display control device 203 first receives feedback signals from the photosensitive sensors (103, 104, 105, 106) for calibration purposes.

[0037] Step 3: The display control device 203 controls the projector 205 to face the screen 100 and project a pure color image with a preset wavelength color onto the screen 100.

[0038] Step four: The display control device 203 identifies the feedback signals transmitted by the photosensitive sensors (103, 104, 105, 106) at the four corners of the screen 100, thereby determining the relative position of each photosensitive sensor (103, 104, 105, 106), and thus determining the screen 100's frame range and relative position.

[0039] Step 5: The display control device 203 corrects the projected image based on the determined current image area and relative position of the screen 100;

[0040] Step six: Determine the image area and relative position of screen 100 by acquiring feedback signals in real time; and repeat the steps to correct the projected image until the correction is complete.

[0041] Preferably, in step four, if the photosensitive sensors (103, 104, 105, 106) receive an image of a specified wavelength color projected by the projector system, the photosensitive sensors send a signal back to the display control device 203 to determine the position of the projected image relative to the sensors.

[0042] Preferably, the screen 100 is divided into four regions (303, 304, 305, 306) by a horizontal center line 301 and a vertical center line 302, and photosensitive sensors (103, 104, 105, 106) are respectively set at the corners of each region of the screen 100.

[0043] Preferably, in step three, the positions of the photosensitive sensors (103, 104, 105, 106) are gradually determined based on the feedback signals from the photosensitive sensors (103, 104, 105, 106) to the display control device 203 system. Specifically, when the projected image from the projector 205 completely covers all the photosensitive sensors (103, 104, 105, 106), the boundary line of the projected image on one side of the corresponding partition area is adjusted to move towards the center of the screen 100, reducing the area of ​​the projected image 201. Simultaneously, the display control device 203 records the change in area ΔS1. When the projected image 201 cannot cover the photosensitive sensors, the boundary line of the projected image on one side of the corresponding partition area is adjusted to move in the opposite direction, increasing the area of ​​the projected image. Simultaneously, the display control device records the change in area ΔS2. The above steps are repeated until the change in area ΔSn recorded by the display control device is less than a preset threshold, at which point the loop exits. At this point, the horizontal and vertical positions of the four sensors are measured, completing the alignment of the screen.

[0044] Preferably, the preset color wavelength for a solid color image is 455nm-360nm.

[0045] Further optimized, the preset color wavelength of the solid color image is 400nm.

[0046] Preferably, the photosensitive sensors (103, 104, 105, 106) are connected to the display control device 203 via data lines (202, 204).

[0047] Specifically, such as Figure 1 As shown, 100 is a screen with photosensitive sensors at each of the four corners, 101 is the projection content display area, 102 is the screen frame, and the photosensitive sensors (103, 104, 105, 106) are located between the projection content display area 101 and the screen frame 102.

[0048] In this figure, the photosensitive sensors (103, 104, 105, 106) are used to collect the graphic signals projected by the projector 205.

[0049] like Figure 2 As shown, 205 is the projector in this invention, and 201 is the projection range of the projector in this invention. The embodiments of this invention can be applied to various types of projectors without modifying the existing projector structure, and have good compatibility and low cost.

[0050] Specifically, the photosensitive sensors (103, 104, 105, 106) are connected to the display control device 203 (e.g., a computer) via data cable 202 (e.g., USB). The display control device 203 is connected to the projector 205 via data cable 204 (e.g., HDMI). The feedback signals from the photosensitive sensors (103, 104, 105, 106) are sent to the display control device 203. After processing, the display control device 203 outputs the processed image to the projector 205 via the data cable 204 connected to the projector 205. Finally, the projector 205 projects and displays the image.

[0051] In one example, such as Figure 3 As shown, the projection screen 100 is divided into four regions 303, 304, 305, and 306 by two dividing lines, the horizontal center line 301 and the vertical center line 302. At the same time, the projection area 201 of the projector is divided into four corresponding corner regions 308, and it is ensured that there is one and only one photosensitive sensor in each corner region 308.

[0052] After dividing the area, the position of each sensor is measured and determined individually. The position of each individual sensor is determined by measurements in both the horizontal and vertical directions.

[0053] Depend on Figure 4As shown, in this example, taking the measurement of the horizontal position of the photosensitive sensor 104 at the lower right corner of the projection screen as an example, 306 is the lower right corner area of ​​the projection screen. Before starting the measurement, the display control device 203 first receives a feedback signal transmitted from the photosensitive sensor 104 for signal calibration.

[0054] First, the projected image 308 of the projector completely covers the lower right corner area 306 of the projection screen, causing a change in the state of the photosensor 104. In this state, the photosensor 104 sends a signal back to the control system of the display control device 203. At this time, the projected image 201 completely covers the photosensor 104.

[0055] When the projected image 201 does not cover the photosensitive sensor 104, the photosensitive sensor 104 does not send a signal back to the projector system. At this time, the projected image 201 does not cover or completely covers the area where the corresponding photosensitive sensor 104 is located.

[0056] Here, a method similar to the dichotomy is used to measure and determine the position of a single sensor in a certain direction.

[0057] Specifically, when the projector's projection screen 201 completely covers the photosensitive sensor 104, the position of the right boundary line 312 in the lower right corner of the projection screen 308 is 312a. By adjusting the right boundary line 312 in the lower right corner of the projection screen 308, the area of ​​the projection screen is reduced.

[0058] Specifically, the vertical length of the image remains fixed, while the right boundary line 312 is moved horizontally towards the center of the screen 100 or the vertical center line 302, until it is positioned midway between the vertical center line 302 and the original right boundary line 312a. It is important to note that when reducing the horizontal length of the image, only the position of the right boundary line 312 of the projected image 201 is adjusted.

[0059] After this operation, the right boundary line of the new projected image is 312b.

[0060] At the same time, the display and control equipment records the change in area ΔS1.

[0061] When the projected image 201 cannot cover the photosensitive sensor 104, adjust the right boundary line 312 of the projected image 308 in the lower right corner to expand the projected image area. Move the right boundary line 312 to the middle of position lines 312a and 313b. When expanding the horizontal length of the image, only adjust the position of the right boundary line 312 of the projected image.

[0062] After this operation, the right boundary of the new projected image is 314c.

[0063] At the same time, the display control device 201 records the change in area ΔS2.

[0064] The above steps are repeated continuously under relevant conditions until, after N rounds, the change in area ΔSn recorded by the display control device is less than the preset area change threshold, at which point the loop exits. At this point, the position 312n on the right side line can be considered the horizontal position of the photosensitive sensor 104 in the center of the lower right corner area 306 of the projection screen. Figure 5 This is a simplified flowchart of the above steps.

[0065] The method described in this example step allows for the sequential or simultaneous measurement of the horizontal and vertical positions of four photosensitive sensors (103, 104, 105, 106).

[0066] By measuring the horizontal and vertical positions of the four sensors, the final projection display range can be determined, thereby enabling automatic positioning of the projection screen.

[0067] The above description is merely a specific embodiment of the present invention and is not intended to limit the invention in any way. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the protection scope of the present invention.

[0068] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, embodiments of the present invention can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of the present invention can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0069] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

Claims

1. A low-cost method for aligning a screen, characterized in that, Includes the following steps: Step 1: Install photosensitive sensors at the four corners of the front of the screen; Step two: Before starting the alignment process, receive a feedback signal from the photosensitive sensor once for signal calibration. Step three: The display control device controls the projector to face the screen and project a pure color image of a preset wavelength onto the screen; the position of the photosensitive sensor is gradually determined based on the feedback signal from the photosensitive sensor to the display control device. When the projector's image completely covers all the photosensitive sensors, the boundary line of the projected image on one side of the corresponding separated area is adjusted to move towards the center of the screen, thereby reducing the area of ​​the projected image. At the same time, the display control device records the change in area ΔS1. When the projected image cannot cover the photosensitive sensor, the boundary line of the projected image on one side of the corresponding dividing area is adjusted to move in the opposite direction, so that the area of ​​the projected image is expanded. At the same time, the display control device records the change value ΔS2 of the area. Repeat the above steps until the display control device records a change in the current area ΔSn that is less than a preset threshold, then exit the loop. At this point, the horizontal and vertical positions of the four photosensitive sensors are measured to determine the final projection display range; Step four: The display control device identifies the feedback signals transmitted by the photosensitive sensors at the four corners of the screen, thereby determining the relative position of each photosensitive sensor, and thus determining the screen's image range and relative position. Step 5: The display control device corrects the projected image based on the determined current screen area and relative position. Step six: Determine the screen's image range and relative position by acquiring feedback signals in real time; and repeat the steps to correct the projected image until the correction is complete, thereby achieving automatic positioning of the projection screen and completing the alignment of the screen.

2. The method for aligning a low-cost screen according to claim 1, characterized in that, In step four, if the photosensitive sensor receives an image of a specified wavelength color projected by the projector, the photosensitive sensor sends a signal back to the display control device to determine the position of the projected image relative to the photosensitive sensor.

3. A low-cost screen alignment method according to any one of claims 1-2, characterized in that: The screen is divided into four areas by a horizontal center line and a vertical center line, and the photosensitive sensor is located at the corner of the screen corresponding to each area.

4. The low-cost screen alignment method according to claim 1, characterized in that: The preset wavelength color is 455nm-360nm.

5. The low-cost screen alignment method according to claim 4, characterized in that: The preset wavelength color is 400nm.

6. The method for aligning a low-cost screen according to claim 4, characterized in that: The photosensitive sensor is connected to the display control device via a data cable.

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