Parameter adjustment method and projector applying same

Abstract

The present application provides a parameter adjustment method and a projector using the same. The parameter adjustment method comprises: obtaining a detection signal generated by an ambient light detector to obtain ambient light information; comparing the detection signal with a look-up table of a database to calculate a compensation parameter; and adjusting the amount of reflected light of a digital micro-mirror module according to the compensation parameter, so that the projector projects a corrected projection picture which is compensated according to the ambient light information. The parameter adjustment method and the projector provided by the present application can effectively achieve the purpose of correcting the projection picture without increasing the brightness of the projection light source, and have the advantages of saving energy, low working temperature, low operating noise, low equipment cost, and high color adjustment accuracy.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of projection display technology, and in particular to a parameter adjustment method and a projector using the same. BACKGROUND

[0002] Generally, projectors have been widely used in conference presentation, advertisement, exhibition and show, etc. The projectors use lens system to produce a wide range of projection pictures. The projectors can provide the most original picture color performance in the dark environment. However, in the partial light environment, the projection picture will be affected by the ambient light information and have the disadvantages of color fading and detail blurring.

[0003] In order to overcome the problem, the user usually tries to reduce the ambient brightness, but it is difficult to reduce to the dark environment. Another solution is to increase the light brightness of the projector. However, the increase of the projection brightness will increase the energy consumption, the body temperature, the fan speed, the mechanical noise and the equipment cost of the projector. In addition, the linearity of the change of the light brightness is very low. After increasing the light brightness, the color change of the projection picture cannot be calculated and preset. The conversion relationship between the color change and the increased light brightness needs to be tested one by one. The testing process is complicated and the accuracy is low.

[0004] Therefore, it is necessary to design a new type of parameter adjustment method and a projector using the same to overcome the above-mentioned defects. SUMMARY

[0005] The present application aims to provide a parameter adjustment method and a projector using the same, which can automatically correct the projection picture according to the ambient light information.

[0006] In order to achieve the above-mentioned purpose, the present application provides a parameter adjustment method applied to a projector having an ambient light detector, a database and a digital micro-mirror module. The parameter adjustment method comprises the following steps: obtaining the detection signal generated by the ambient light detector to obtain the ambient light information; comparing the ambient light information with the lookup table in the database to calculate the compensation parameter; and adjusting the reflection light quantity of the digital micro-mirror module according to the compensation parameter, so as to control the projector to project the corrected projection picture which is compensated according to the ambient light information.

[0007] Preferably, the method further comprises the following steps: selecting a key color ticket; obtaining the reference color parameter of the key color ticket when the ambient brightness of the projector is lower than the threshold value; measuring the original color parameter of the key color ticket under the ambient light information; and comparing the difference between the reference color parameter and the original color parameter to establish the lookup table.

[0008] Preferably, the color gamut coordinates of the key color ticket are located in the color gamut range of the original color parameter.

[0009] Preferably, the environment light information is lower than the threshold value includes that the projector is in an unlighted environment.

[0010] Preferably, the reference color parameter and the original color parameter each include at least one of a color gamut coordinate and a color brightness of the key color swatch.

[0011] Preferably, the method further comprises obtaining a plurality of original color brightnesses of the key color swatch under different environment light information; and listing a relationship between the plurality of original color brightnesses and corresponding gamma compensation values to be included in the lookup table; and / or listing a relationship between the plurality of original color brightnesses and corresponding saturation compensation values to be included in the lookup table.

[0012] Preferably, the method further comprises obtaining a plurality of original color gamut coordinates of the key color swatch under different environment light information and a comparison relationship of different light source types.

[0013] Preferably, the method further comprises listing a relationship between a plurality of light source types and corresponding white balance compensation values to be included in the lookup table; and / or listing a relationship between a plurality of light source types and corresponding hue compensation values to be included in the lookup table.

[0014] Preferably, the method further comprises analyzing the detection signal to determine whether the original projection image of the projector is affected by the environment light information; and if the original projection image is affected by the environment light information, performing the comparison between the detection signal and the lookup table by using the database.

[0015] Based on the above-mentioned parameter adjustment method, the present application further provides a projector with a parameter adjustment function, which comprises an environment light detector for generating a detection signal to obtain environment light information; a database for storing a lookup table; a digital micromirror module; and an operation processor electrically connected to the environment light detector, the database and the digital micromirror module for executing the above-mentioned parameter adjustment method.

[0016] Compared with the prior art, the parameter adjustment method and the projector thereof provided by the present application first establish a look-up table for color gamut compensation of common light source types and different ambient brightness according to color ticket from high saturation to low saturation, that is, saturation sweeps; the gist of the present application is that only a few color tickets with saturation are selected for adjustment, so that the overall projection picture can be precisely adjusted. Then, the ambient light information obtained by the ambient light detector is compared with the look-up table, and the closest parameters are found out by interpolation or other calculation methods, and the white balance (WB, which can also be regarded as color temperature), hue, saturation, gain value (Gain, which can also be regarded as brightness), and gamma value (that is, the smoothness of transition between black and white blocks) of the projection picture are adjusted by controlling the amount of reflected light through the digital micromirror module, so that the original color parameters can be close to or overlap the reference color parameters. Compared with the prior art, the parameter adjustment method and the projector thereof provided by the present application can effectively correct the projection picture without increasing the brightness of the projection light source, and have the advantages of saving energy, low working temperature, low operating noise, low equipment cost, and high color adjustment accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The functional block diagram of the projector provided by the embodiment of the present application;

[0018] Figure 2 The assembly schematic diagram of the projector provided by the embodiment of the present application;

[0019] Figure 3 The flowchart of establishing the look-up table provided by the embodiment of the present application;

[0020] Figure 4 The flowchart of the parameter adjustment method provided by the embodiment of the present application;

[0021] Figure 5 The schematic diagram of the color space displayed by the parameter adjustment method provided by the embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to have a further understanding of the object, structure, features, and functions of the present application, the embodiments are described in detail as follows.

[0023] In the description and claims, some terms are used to refer to specific elements. Those skilled in the art should understand that manufacturers may use different names to refer to the same element. The description and claims of the present application do not distinguish elements by name, but by the functional difference between the elements. Throughout the description and claims, the term "comprising" is an open term, which should be interpreted as "comprising but not limited to".

[0024] Please refer to Figure 1 , Figure 1 A functional block diagram of a projector 10 according to an embodiment of the present application is shown in FIG. 1. The projector 10 can include a digital micro-mirror device 12, an ambient light detector 14, a database 16, and a processing unit 18. The ambient light detector 14 is used to generate a detection signal to obtain ambient light information, such as analyzing the brightness or other parameters of the detection signal to determine the ambient brightness. The database 16 is used to store a lookup table. The lookup table can be preset information established by the system in the database 16, or can be updated information stored in the database 16 by the projector 10 during operation. It should be noted that the source of the lookup table is not limited to this, and can be determined according to actual design requirements. The processing unit 18 can be electrically connected to the digital micro-mirror device 12, the ambient light detector 14, and the database 16. The projector 10 has a parameter adjustment function; the processing unit 18 can automatically adjust the amount of reflected light of the digital micro-mirror device 12 according to the ambient light information of the location where the projector 10 is located, so that the projection picture can maintain color consistency under various ambient brightness.

[0025] Please refer to Figures 2 to 5 , Figure 2 An assembly diagram of a projector 10 according to an embodiment of the present application is shown in FIG. 2, Figure 3 A flowchart of establishing a lookup table according to an embodiment of the present application is shown in FIG. 3, Figure 4 A flowchart of a parameter adjustment method according to an embodiment of the present application is shown in FIG. 4, Figure 5 A schematic diagram of a color space according to a parameter adjustment method of an embodiment of the present application is shown in FIG. 5. The projector 10 can project a complete color information projection picture on the projection screen 20 in an ambient light-free environment; however, in order to meet the viewing needs of the user, the projector 10 is usually applied in a place with some ambient brightness, and the ambient light information generated by the external light source 22 will affect the quality of the projection picture. Therefore, the parameter adjustment method provided by the present application can correspondingly improve the white balance, hue, saturation, gain value, and gamma value of the projection picture according to the ambient light information, so that the compensated projection picture can have better color performance.

[0026] Regarding the lookup table creation method, first, step S100 is executed to select a key color swatch within the color space. Generally, the key color swatch is selected from the three primary colors of light and the three primary colors of pigment, namely Red (R), Green (G), Blue (B), Cyan (C), Magenta (M), and Yellow (Y). Next, steps S102 and S104 are executed to obtain the reference color parameters of the key color swatch when the ambient brightness of the projector 10 is below a threshold value, and to measure the original color parameters of the key color swatch under ambient light information. The reference color parameters and original color parameters can be defined as the color coordinates of the key color swatch at a specific saturation level, such as 20%, 40%, 60%, 80%, and 100% saturation. It should be noted that the percentage of saturation and its interval difference are not limited to this and can be determined according to actual needs.

[0027] like Figure 5 As shown, when projector 10 is in a dark environment, its original color gamut is a solid triangle 24 within the color space. A dark environment can also be interpreted as an environment where the brightness of the surroundings is below a threshold value. If projector 10 is in a lit environment, meaning the brightness of the surroundings is above or equal to the threshold value, its original color gamut is a dashed triangle 26 within the color space. The color gamut coordinates of the key color swatch must be within the color gamut range of the original color parameters, meaning... Figure 5 The solid-line triangle 24 is shown; generally speaking, the color coordinates of the key color swatch at 100% saturation may fall outside the dashed-line triangle 26, so in actual implementation, the 100% saturation color coordinates are generally not selected. It should be noted that the selection of the key color swatch and its reference color parameters and original color parameters is not limited to this, and can be determined according to actual needs.

[0028] Next, step S106 is executed to obtain multiple original color luminance values ​​for each key color swatch under different ambient light conditions. This invention can predict the possible range of ambient brightness variation and define multiple illuminance intervals within this range. For example, this invention can preset the ambient brightness illuminance range to be between 0 and 350 lux, and can define multiple illuminance intervals in units of 50 lux. Then, step 108 is executed to list the relationships between multiple original color luminance values ​​and their corresponding gamma compensation values ​​and saturation compensation values ​​in a lookup table, as shown in Table 1 below.

[0029] Ambient color luminance (lux) Gamma compensation value Saturation compensation value 0～50 0 +0％ 50～100 -0.1 +3％ 100～150 -0.2 +6％ 150～200 -0.4 +9％ 200～250 -0.6 +12％ 250～300 -0.8 +15％ >350 -1.0 +18％

[0030] Table 1

[0031] Next, step S110 is performed to obtain the comparison relationship between the original color gamut coordinates (i.e. color temperature) of each key color ticket under different ambient light information and the plurality of light source types, and steps S112 and S114 are continued to list the relationship between the plurality of light source types and the corresponding white balance compensation value and hue compensation value to be included in the lookup table, as shown in Table 2 below. In particular, the reference color parameter and the original color parameter can be at least one or both of the color brightness and the color gamut coordinates of the corresponding key color ticket, i.e. Table 1 and Table 2 can be used as the lookup table, or the combination of Table 1 and Table 2 can be used as the lookup table required by the parameter adjustment method.

[0032]

[0033]

[0034] Table 2

[0035] After the lookup table is established, it can be applied to the parameter adjustment method provided by the present application. First, step S200 is performed to obtain the ambient light information using the detection signal generated by the ambient light detector 14. Next, step S202 is performed to analyze the detection signal to determine whether the original projection image of the projector 10 is affected by the ambient light information. If the original projection image is not affected by the ambient light information, it indicates that the ambient brightness is very low, or the projection light source brightness of the projector 10 is extremely high and is not disturbed, so step S204 is performed without adjusting the reflected light amount of the digital micromirror module 12. If the original projection image is affected by the ambient light information, for example, the ambient brightness is higher than a preset brightness threshold, or the ratio of the ambient brightness to the projection light source brightness is higher than a preset brightness threshold, steps S206 and S208 can be performed to connect to the database 16 to obtain the lookup table, and the detection signal is substituted into the lookup table to calculate the compensation parameter. Finally, step S210 is performed to adjust the reflected light amount of the digital micromirror module 12 according to the compensation parameter, so as to control the projector 10 to project a corrected projection image that is compensated according to the ambient light information.

[0036] As shown in Figure 5 the case where the ambient brightness of the projector 10 is higher than or equal to the threshold value, the color coordinates of the key color tickets (including red R, green G, blue B, cyan C, magenta M, and yellow Y) of various saturations are circular marks in the color space, located inside the dashed triangle 26; and after the reflected light amount of the digital micromirror module 12 is adjusted by the parameter adjustment method provided by the present application, the color coordinates of the key color tickets of various saturations can be corrected to rectangular marks in the color space, i.e. the key color tickets of various saturations can be corrected to positions close to the solid triangle 24, so that the projection image provided by the projector 10 under high ambient brightness can have the same or similar performance as the projection image under low ambient brightness.

[0037] In summary, the parameter adjustment method and the projector thereof provided by the present application first establish a look-up table for color gamut compensation according to the color chart from high saturation to low saturation, i.e. saturation sweeps, for common light source types and different ambient brightness. The key point of the present application is that only a few color chart saturations need to be selected for adjustment, and the overall projection picture can be precisely adjusted. Then, the ambient light information obtained by the ambient light detector is compared with the look-up table, and the closest parameters are found out by interpolation or other calculation methods, and the amount of reflected light is controlled by the digital micro-mirror module to adjust the white balance (WB, which can also be regarded as color temperature), hue, saturation, gain value (Gain, which can also be regarded as brightness), gamma value (i.e. the smoothness of the transition between black and white blocks) of the projection picture, so that the original color parameters can be close to or overlap the reference color parameters. Compared with the prior art, the parameter adjustment method and the projector thereof provided by the present application can effectively correct the projection picture without increasing the brightness of the projection light source, and have the advantages of saving energy, low working temperature, low operating noise, low equipment cost, and high color adjustment accuracy.

[0038] The present application has been described by the above-mentioned related embodiments, however, the above-mentioned embodiments are only examples for implementing the present application. It must be pointed out that the disclosed embodiments do not limit the scope of the present application. On the contrary, modifications and improvements made without departing from the spirit and scope of the present application are within the scope of the patent protection of the present application.

Claims

1. A parameter adjustment method applied to a projector having an ambient light detector, a database and a digital micro-mirror module, characterized in that, The parameter adjustment method comprises: obtaining a detection signal generated by the ambient light detector to obtain ambient light information; selecting a key color chart, and obtaining reference color parameters of the key color chart when ambient brightness of a projection environment where the projector is located is lower than a threshold value; measuring original color parameters of the key color chart under the ambient light information, and comparing differences between the reference color parameters and the original color parameters to establish a lookup table; comparing the ambient light information with the lookup table in the database to calculate compensation parameters; and adjusting the amount of reflected light of the DMD according to the compensation parameters, so as to control the projector to project a corrected projection image compensated by the ambient light information.

2. The parameter adjustment method of claim 1, wherein, The color gamut coordinates of the key color chart are located within a color gamut range of the original color parameters.

3. The parameter adjustment method of claim 1, wherein, The ambient brightness lower than the threshold value includes that the projector is located in an unlighted environment.

4. The parameter adjustment method of claim 1, wherein, The reference color parameters and the original color parameters each include at least one of color gamut coordinates and color brightness of the key color chart.

5. The parameter adjustment method of claim 1, wherein The method further comprises: obtaining a plurality of original color brightnesses of the key color chart under different ambient light information; and listing a relationship between the plurality of original color brightnesses and corresponding gamma compensation values to be included in the lookup table; and / or listing a relationship between the plurality of original color brightnesses and corresponding saturation compensation values to be included in the lookup table. The method further comprises:

6. The parameter adjustment method of claim 1, wherein, obtaining a comparison relationship between a plurality of original color gamut coordinates of the key color chart under different ambient light information and different light source types. The method further comprises:

7. The parameter adjustment method of claim 6, wherein listing a relationship between a plurality of light source types and corresponding white balance compensation values to be included in the lookup table; and / or listing a relationship between a plurality of light source types and corresponding hue compensation values to be included in the lookup table. The method further comprises: analyzing the detection signal to determine whether original projection images of the projector are affected by the ambient light information; and 8. The parameter adjustment method of claim 1, wherein, if the original projection images are affected by the ambient light information, performing comparison between the detection signal and the lookup table by using the database. The projector comprises: an ambient light detector configured to generate a detection signal to obtain ambient light information; 9. A projector having a parameter adjustment function, characterized by comprising: a database configured to store a lookup table; a DMD; and an operation processor electrically connected to the ambient light detector, the database, and the DMD, and configured to execute the parameter adjustment method according to any one of claims 1 to 8. ​ ​ ​

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