CN104991432A - Method for adjusting laser display brightness - Google Patents

Abstract

A method for adjusting the brightness of a laser display; the detection module detects changes in external environmental parameters; the area control part of the control center receives information from the detection module, calculates the projected area, and transmits it to the optical power control part to calculate the current optical power size. The optical power control part of the control center judges the calculated optical power according to the received area information and the light intensity of the external environment, combined with the algorithm flow chart, so that it can meet the comfortable brightness ratio and safe brightness value at the same time. The laser light source power control module controls the optical power of the projection laser light source according to the instructions of the control center, so as to output reasonable brightness. The projection method can detect the brightness of the environment through the detection module, and automatically adjust the laser brightness output, so that human eyes can get a clear sense of brightness. It can quickly adjust the brightness according to the change of the screen size, and at the same time automatically control the optical power within a safe range, which is fast and convenient.

Description

A method for adjusting the brightness of laser display

technical field

A method for adjusting laser display brightness belongs to the field of display technology, relates to a method for adjusting laser display brightness, and can be applied to laser projection.

Background technique

From the black-and-white display that emerged at the end of the 19th century to the advent of color TV in 1928 and the realization of color movies shot on film in 1935, the display technology has experienced a leap from black and white to color display technology. However, the color reproduction ability of existing displays is very low. Its color rendering range can only cover 33% of the color space that can be observed by human eyes, while the other 67% of the color space cannot be reproduced by digital display technology and existing display technology. An important idea of laser display technology is from the consideration of colorimetry, the display technology with red, green and blue three primary colors (RGB) laser as the light source can most truly reproduce the rich and gorgeous colors of the objective world, and provide more Shockingly expressive. Studies have found that the human eye is more sensitive to the contrast of brightness than to the absolute value of brightness. The luminance ratio within the field of view is increasingly becoming a major indicator for evaluating visual comfort. Regarding the optimal luminance ratio value, the Illuminating Engineering Society of North America (IESNA) gives a recommended value for the luminance ratio. The brightness ratio between the working surface and the adjacent area is 3:1 or 1:3. Practice has shown that projection brightness has a certain impact on people's emotions. Too dark can make people feel depressed and depressed; too bright can easily make people emotionally impetuous and unstable, and at the same time, too dark or too bright can cause damage to vision. Laser projection has the problems of excessive output light power resulting in excessive brightness and high temperature. Laser is a highly concentrated light with concentrated energy and high brightness. However, if the output light power is not controlled, the color of the image displayed on the laser display system will be too saturated or even color cast, which will easily hurt the eyes and cause eye fatigue. , and even lead to problems such as vision loss and headaches. Therefore, according to the existing environment and equipment performance, through scientific calculations, the projection brightness and projection size under ambient lighting can be reasonably set to obtain the best projection effect, that is, a soft, bright and clear image.

The display adjustment method provided by this method has the following advantages:

1. The laser has a high optical power output, and its high brightness can easily realize large-screen projection; at the same time, the laser light wave frequency is single, the transmission path is parallel and does not diverge, which makes laser projection a good choice for 3D projection.

2. The spectrum of the laser is a line spectrum, and the color that appears itself is the spectral color, and the laser has the characteristics of selectable wavelength and high spectral brightness, so the triangle formed by the three primary colors of the red, green and blue lasers as the light source The color gamut is larger and has high color saturation, which can cover more than 90% of the color space that the human eye can recognize.

3. This projection method can detect the brightness of the environment through the detection module, and automatically adjust the laser brightness output, so that the brightness ratio of the projection and the environment is 3:1, so that the human eye can get a clear sense of brightness.

4. The present invention calculates a reasonable brightness through the control center and at the same time intelligently regulates the output optical power of the semiconductor laser through the laser light source power control module, and projects appropriate brightness according to different projection screen sizes, thereby obtaining the most eye-safe display effect.

Contents of the invention

The purpose of the present invention is to combine the detection module, the control center and the laser light source power control module, monitor the parameters such as the external environment and distance through the monitoring module, and obtain the appropriate output optical power through calculation, so as to obtain the most suitable for human eye safety. brightness.

In order to achieve the above object, the present invention provides a laser display brightness adjustment method, the method is based on the laser display brightness adjustment structure, the adjustment includes projection laser light source, retractable lens, detection module, control center and laser light source power control module;

The retractable lens directly adjusts the projection focal length without adjusting the position of the projector, and changes the projection area.

The detection module includes a photosensitive sensor, a laser rangefinder and an angle detection module. Among them, the photosensitive sensor detects the brightness change of the external environment in real time; the laser range finder detects the distance between the projector and the projection screen; the angle detection module is connected with the retractable lens to detect the change of the projection angle in real time.

The control center includes two parts: area processing and laser light power processing. The area processing part is connected with the laser range finder and the angle detection module in the detection module, receives real-time distance and angle information, and obtains the projected area through calculation. At the same time, the area processing part is connected with the retractable lens, and according to the needs of users, combined with the measured projection distance, the projection angle is set to control the projection size. The laser light power processing part is connected with the area processing part and the photosensitive sensor in the detection module to judge the safety and comfort of the projection brightness and calculate the most suitable projection light power.

The laser optical power control module is connected with the laser optical power processing part of the control center, receives the instruction of the optical power from the control center, and controls the optical power output by adjusting the working current.

The projection laser light source is connected to the laser light power control module, including red semiconductor laser, green semiconductor laser, and blue semiconductor laser. These three semiconductor laser light sources are mixed in different proportions to generate laser images, and their power efficiency is known. The optical power is positively correlated with the operating current, and the output optical power is changed through the adjustment of the operating current by the laser optical power control module, thereby changing the projection brightness of the output image.

The projection laser light source is a semiconductor laser light source.

The detection module can monitor changes in parameters such as the brightness of the external environment and the distance between the lens and the screen.

The control center receives the parameter information from the monitoring module, and calculates the optical power that should be output.

The laser light source power control module controls the optical power of the projection laser light source according to the instructions of the control center, so as to output reasonable brightness.

Compared with the prior art, the present invention has the following beneficial effects.

1. The method for adjusting the brightness of the laser display provided by the present invention is simple in principle and low in cost.

2. This projection method can detect the brightness of the environment through the detection module, and automatically adjust the laser brightness output, so that the ratio of projection brightness and ambient brightness is higher than the minimum comfortable brightness ratio of 3:1, so that the human eye can get a clear sense of brightness.

3. The laser display brightness adjustment method provided by the present invention can quickly adjust the brightness according to the change of the screen size, and at the same time automatically control the optical power within a safe range, which is fast and convenient.

4. The laser display brightness adjustment method provided by the present invention can realize 3D and large-screen projection by utilizing the advantages of laser projection.

Description of drawings

Figure 1: The basic structural diagram of the method for adjusting the brightness of the laser display provided by the present invention;

Fig. 2: a projected side view of the method for adjusting the brightness of the laser display provided by the present invention;

Figure 3: a projected top view of the method for adjusting the brightness of a laser display provided by the present invention;

Fig. 4: The projected front view of the laser display brightness adjustment method provided by the present invention;

Fig. 5: the flow chart of the method for adjusting the brightness of the laser display provided by the present invention to automatically adjust the brightness as the area changes;

In the figure: 1. Retractable lens, 2. Photosensitive sensor, 3. Screen, 4. Laser rangefinder.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

The method for adjusting the brightness of laser display provided by the present invention is widely applicable to various laser projection and laser television systems. The following uses a laser projector as an example to illustrate its principle.

As shown in the figure, the method for adjusting the brightness of laser display provided by the present invention includes the following parts,

Step 101: The detection module detects changes in projection parameters such as the external environment light intensity E, the projection distance (that is, the distance between the projection lens and the screen) l, the projection elevation angle α and the horizontal angle β.

Step 102: The area control part of the control center receives the external ambient light intensity E, distance l, initial projection elevation angle α and horizontal angle β information from the detection module, calculates the projected area, and transmits it to the optical power control part to calculate The current optical power level.

Step 103: The optical power control part of the control center judges the calculated optical power according to the received area information and the light intensity of the external environment, combined with the algorithm flow chart, so that it can satisfy both a comfortable brightness ratio and a safe brightness value.

Step 104: The laser light source power control module controls the optical power of the projection laser light source according to the instruction of the control center, so as to output reasonable brightness.

Regarding the method for adjusting the brightness of the laser display provided by the present invention, the present invention will be further described in detail below in conjunction with the basic structure diagram of the method for adjusting the brightness of the laser display.

The detection module described in the above-mentioned step 101 as shown in Figure 1, is made of three parts, the first part is a laser rangefinder (4), detects the distance l between the projection lens and the screen; the second part is an angle detection part, according to As shown in Fig. 2 and Fig. 3, the projected elevation angle α and horizontal angle β are detected according to the focal length change of the retractable lens (1); the third part is a photosensitive sensor (2), which detects the illuminance E of the external environment.

The above step 102 includes: the control center receives the parameter information from the detection module, ie the distance l between the projection lens and the screen, and the ambient illuminance E. After the projector is installed and debugged, the initial elevation angle α of the projection and the initial value of the horizontal angle β are given. Let the width of the projection area be w, the height be h, and the diagonal line of the projection area (called the projection size) be c. The unit is m. Then there are h=l×tanα, w=2l×tanβ. Then the area of the projection area is S=h×w=2l tanαtanβ, according to the brightness formula of the projector

${\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; A</span>}\mathrm{<span\; class="notranslate">\; N</span>}\mathrm{<span\; class="notranslate">\; S</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Equation (1) is the relationship between projector brightness and ambient lighting, relative illuminance, and projection size, where C _r is the contrast coefficient of the display object (text, graphics, images, etc.), and P is the gain coefficient of the screen, usually 3.0. The control center calculates the power of the projector according to formula (1) and the relationship between the power of the laser projector and the projection brightness.

Table 1 Contrast coefficients of display objects (text, graphics, images, etc.)

The above step 103 includes: according to the needs of the user, the control center can control the expansion and contraction of the lens to change the projection focal length, thereby changing the projected elevation angle α and the value of the horizontal angle β to change the projected area, and the detection module detects the new elevation angle α', horizontal angle The value of β' is fed back to the area processing part of the control center, and the control center calculates a new area value

S'=h'×w'=2l ² tanα'tanβ'

Then the laser power processing part of the control center uses the area of the row to calculate the new optical power, and then judges whether the power is within the safe value range, as shown in flow chart 5, when the area increases, the optical power increases, and the Whether it exceeds the maximum brightness acceptable to the human eye. If it is greater than the upper limit, reduce the optical power; when the area decreases and the optical power decreases, judge whether the projection brightness and the ambient brightness are less than the optimal brightness ratio of 3:1. If it is less than For this ratio, the optical power should be appropriately increased.

The above step 104: the laser light source power control module controls the optical power of the projection laser light source according to the instructions of the control center, according to the optical power formula of the laser that determines the power efficiency: P _em =η _p ·(I·V+I ² _rs ) pair The current of the laser light source of the projector is controlled and adjusted to change the brightness of the light source, so as to output a reasonable brightness.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only examples of the present invention and are not intended to limit the present invention. Within the spirit and principles of the present invention, any modifications, equivalent replacements, improvements, etc., shall fall within the protection scope of the present invention.

Claims (6)

1. A method for adjusting laser display brightness, characterized in that: the method comprises the following steps, Step 101: The detection module detects changes in projection parameters such as the external environment light intensity E, the projection distance (that is, the distance between the projection lens and the screen) l, the projection elevation angle α and the horizontal angle β; Step 102: The area control part of the control center receives the external ambient light intensity E, distance l, initial projection elevation angle α and horizontal angle β information from the detection module, calculates the projected area, and transmits it to the optical power control part to calculate The current optical power; Step 103: The optical power control part of the control center judges the calculated optical power according to the received area information and the light intensity of the external environment, combined with the algorithm flow chart, so that it can satisfy both a comfortable brightness ratio and a safe brightness value; Step 104: The laser light source power control module controls the optical power of the projection laser light source according to the instructions of the control center, so as to output reasonable brightness; The detection module described in the above step 101 is composed of three parts, the first part is a laser range finder (4), which detects the distance l between the projection lens and the screen; The elevation angle α and the horizontal angle β of the projection are detected by the focal length change; the third part is a photosensitive sensor (2), which detects the external environment illuminance E; The above step 102 includes: the control center receives the parameter information from the detection module, that is, the distance l between the projection lens and the screen, and the ambient illuminance E; after the projector is installed and debugged, the initial elevation angle α and the initial value of the horizontal angle β of the projection are given, Suppose the width of the projection area is w, the height is h, the diagonal line of the projection area is c, and the unit of the three is m; then h=l×tanα, w=2l×tanβ; then the area of the projection area is S=h× w=2ltanαtanβ, according to the brightness formula of the projector $L_{ANS}=\frac{1}{2}{C}_r*S*\mathrm{E.}/P---\left(1\right)$ Equation (1) is the relationship between the brightness of the projector and the ambient lighting, relative illuminance and projection size, where C _r is the contrast coefficient of the display object (text, graphics, image, etc.), and P is the gain coefficient of the screen, usually 3.0; the control center Calculate the power of the projector according to formula (1) and the relational expression of laser projector power and projection brightness; Table 1 Contrast coefficients of display objects (text, graphics, images, etc.) The above step 103 includes: according to the needs of the user, the control center can control the expansion and contraction of the lens to change the projection focal length, thereby changing the projected elevation angle α and the value of the horizontal angle β to change the projected area, and the detection module detects the new elevation angle α', horizontal angle The value of β' is fed back to the area processing part of the control center, and the control center calculates a new area value S'=h'×w'=2l ² tanα'tanβ' Then the laser power processing part of the control center uses the area of the row to calculate the new optical power, and then judges whether the power is within the safe value range. If the maximum brightness is greater than the upper limit, reduce the optical power; when the area decreases and the optical power decreases, judge whether the projection brightness and the ambient brightness are less than the optimal brightness ratio of 3:1, if it is less than this ratio, adjust the light appropriately power; The above step 104: the laser light source power control module controls the optical power of the projection laser light source according to the instructions of the control center, according to the optical power formula of the laser that determines the power efficiency: P _em =η _p ·(I·V+I ² _rs ) pair The current of the laser light source of the projector is controlled and adjusted to change the brightness of the light source, so as to output a reasonable brightness. 2. An adjustment structure for laser display brightness, characterized in that: the adjustment structure includes a projection laser light source, a retractable lens, a detection module, a control center and a laser light source power control module; The retractable lens directly adjusts the projection focal length without adjusting the position of the projector to change the projection area; The detection module includes a photosensitive sensor, a laser rangefinder and an angle detection module; wherein the photosensitive sensor detects the brightness change of the external environment in real time; the laser rangefinder detects the distance between the projector and the projection screen; the angle detection module is connected with the retractable lens, Real-time detection of changes in projection angle; The control center includes two parts of area processing and laser light power processing; the area processing part is connected with the laser range finder and the angle detection module in the detection module, receives real-time distance and angle information, and obtains the projected area through calculation; at the same time, the area processing The part is connected with the retractable lens, according to the needs of the user, combined with the measured projection distance, the projection angle is set to control the projection size; the laser light power processing part is connected with the area processing part and the photosensitive sensor in the detection module, and the projection brightness is controlled. Make a judgment on safety and comfort, and calculate the most suitable projection light power; The laser optical power control module is connected with the laser optical power processing part of the control center, receives the instruction of the optical power from the control center, and controls the optical power output by adjusting the working current; The projection laser light source is connected to the laser light power control module, including red semiconductor laser, green semiconductor laser, and blue semiconductor laser. These three semiconductor laser light sources are mixed in different proportions to generate laser images, and their power efficiency is known. The optical power is positively correlated with the operating current, and the output optical power is changed through the adjustment of the operating current by the laser optical power control module, thereby changing the projection brightness of the output image. 3. A laser display brightness adjustment structure according to claim 2, characterized in that the projection laser light source is a semiconductor laser light source. 4. A laser display brightness adjustment structure according to claim 2, characterized in that the detection module can monitor changes in parameters such as the brightness of the external environment and the distance between the lens and the screen. 5. A laser display brightness adjustment structure according to claim 2, characterized in that: the control center receives the parameter information from the monitoring module and calculates the output optical power. 6. A laser display brightness adjustment structure according to claim 2, characterized in that: the laser light source power control module controls the optical power of the projection laser light source according to the instructions of the control center, so as to output a reasonable brightness.