CN110597001A - Automatic control method and system for white balance of RGB laser projector - Google Patents
Automatic control method and system for white balance of RGB laser projector Download PDFInfo
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- CN110597001A CN110597001A CN201910862858.1A CN201910862858A CN110597001A CN 110597001 A CN110597001 A CN 110597001A CN 201910862858 A CN201910862858 A CN 201910862858A CN 110597001 A CN110597001 A CN 110597001A
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- 238000003384 imaging method Methods 0.000 claims description 30
- 238000012937 correction Methods 0.000 claims description 12
- 238000001514 detection method Methods 0.000 claims description 12
- 230000003287 optical effect Effects 0.000 claims description 3
- 238000002834 transmittance Methods 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 6
- 239000003086 colorant Substances 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
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Classifications
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/14—Details
- G03B21/20—Lamp housings
- G03B21/2006—Lamp housings characterised by the light source
- G03B21/2013—Plural light sources
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/14—Details
- G03B21/20—Lamp housings
- G03B21/2006—Lamp housings characterised by the light source
- G03B21/2033—LED or laser light sources
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/14—Details
- G03B21/20—Lamp housings
- G03B21/2053—Intensity control of illuminating light
Abstract
The invention discloses an automatic white balance control method for an RGB laser projector. The actual white balance point coordinate is obtained by detecting the RGB brightness value of emergent light of the light source, the power offset of the laser light source is calculated according to the difference with the standard white balance point coordinate, the intensity proportion of the three-color laser is directly adjusted from the light source on the premise of ensuring the projection brightness by adjusting the PWM signal duty ratio of the laser light source to adjust the driving current of the laser light source, the color consistency of the projection system can be ensured, the stepless tuning of the coordinate of the white balance point can be realized, and the user experience is enhanced. The invention discloses an automatic white balance control system of an RGB laser projector.
Description
Technical Field
The invention relates to the technical field of laser projection, in particular to an automatic white balance control method and system for an RGB laser projector.
Background
The mainstream projection technology in the market at present comprises bulb projection, LED projection and laser projection, wherein the bulb projection comprises two light sources of a xenon lamp and a high-pressure mercury lamp, the problems of image yellowing, fast color decay and the like can occur in the using process, and the problems are gradually replaced by the laser projection. The three-primary-color laser projection is a future development direction, and has a color gamut and a service life larger than those of the two laser projection modes and the traditional projection technology, but the existing three-primary-color laser light source has the conditions of inconsistent efficiency and temperature coefficients and inconsistent attenuation rate, so that the drift of a white balance point can occur in long-term use, the user experience is influenced, and the dynamic adjustment of the white balance needs to be realized.
To achieve white balance adjustment, this is typically accomplished by adjusting the duty cycle of the DMD,this way of adjustmentThe heating problem is generated, and the service life is influenced.
Disclosure of Invention
In order to solve the technical problems in the background art, the invention provides an automatic control method and system for white balance of an RGB laser projector
The invention provides an automatic control method for white balance of an RGB laser projector, which comprises the following steps:
the method comprises the steps of obtaining an actual white balance point coordinate of emergent light of a laser light source by obtaining an RGB brightness value of the emergent light, calculating a power offset of the laser light source according to a comparison result of the actual white balance point coordinate and a preset standard white balance point coordinate, and finally adjusting a PWM signal duty ratio of the laser light source according to the power offset so as to adjust a driving current of the laser light source.
Preferably, the acquiring the RGB brightness value of the outgoing light of the RGB laser light source specifically includes: the method comprises the steps of dividing emergent light of an RGB laser light source into an imaging light beam and a detection light beam, and obtaining RGB brightness values of the detection light beam.
Preferably, when the power offset exceeds a preset threshold range, comparing an actual brightness value with an initial brightness value of the laser light source to obtain a brightness attenuation ratio value, performing logic correction on the brightness values of the other two laser light sources according to the actual brightness value with the maximum brightness attenuation ratio value to obtain a logic correction value, and adjusting the duty ratios of the PWM signals of the other two laser light sources according to the logic correction value.
The invention provides an automatic white balance control method of an RGB laser projector, which obtains an actual white balance point coordinate by detecting an RGB brightness value of emergent light of a light source, calculates the power offset of the laser light source according to the difference with a standard white balance point coordinate, adjusts the driving current of the laser light source by adjusting the PWM signal duty ratio of the laser light source, independently adjusts the light intensity of a three-color laser from the light source on the premise of ensuring the projection brightness, realizes the white balance coordinate control, improves the projection effect of a projection system and prolongs the service life of the projection system.
The invention also provides a control system for realizing the automatic white balance control method of the RGB laser projector, which is characterized by comprising the following steps:
the RGB laser light source is used for emitting RGB three-color laser;
the laser driving circuit is used for driving the RGB laser light source to work;
the photoelectric sensor is used for detecting the light intensity of RGB three-color laser;
an imaging unit for imaging according to RGB three-color laser;
and the control unit is used for controlling the laser driving circuit to adjust the driving current of the RGB laser light source according to the detection light intensity of the photoelectric sensor.
Preferably, the method further comprises the following steps: and the light splitting unit is used for splitting the emergent light of the RGB laser light source into an imaging light beam and a detection light beam.
Preferably, the light splitting unit adopts a dielectric reflector for splitting the emergent light of the RGB laser light source into a reflected light beam and a transmitted light beam.
Preferably, the transmittance of the dielectric mirror is 5% or less.
Preferably, the photosensor is used for detecting the RGB light intensity of the transmitted light beam, and the imaging unit is used for imaging the reflected light beam.
Preferably, the method further comprises the following steps: and the dodging collimation unit is used for carrying out dodging calibration on emergent light of the RGB laser light source.
Preferably, the imaging unit includes an imaging lens and a spatial light modulator, and the spatial light modulator is located on an optical path between the imaging lens and the light splitting unit.
The method and the system for automatically controlling the white balance of the RGB laser projector can ensure the color consistency of a projection system, realize the coordinate stepless tuning of white balance points and enhance the user experience.
Drawings
Fig. 1 is a schematic structural diagram of an automatic white balance control system of an RGB laser projector according to the present invention.
Fig. 2 is a schematic control flow diagram of an automatic white balance control method for an RGB laser projector according to the present invention.
Fig. 3 is a layout diagram of a three-color photosensor array structure of an RGB laser projector white balance automatic control system according to the present invention.
Fig. 4 is a response spectrum graph of a three-color photosensor array structure of an RGB laser projector white balance automatic control system according to the present invention.
Detailed Description
As shown in fig. 1 to 4, fig. 1 is a schematic structural diagram of an automatic white balance control system of an RGB laser projector according to the present invention, fig. 2 is a schematic control flow diagram of an automatic white balance control method of an RGB laser projector according to the present invention, fig. 3 is a layout diagram of a three-color photosensor array structure of an automatic white balance control system of an RGB laser projector according to the present invention, and fig. 4 is a response spectrum graph of a three-color photosensor array structure of an automatic white balance control system of an RGB laser projector according to the present invention. .
The invention provides an automatic control method for white balance of an RGB laser projector, which comprises the following steps:
the method comprises the steps of obtaining an actual white balance point coordinate of emergent light of a laser light source by obtaining an RGB brightness value of the emergent light, calculating a power offset of the laser light source according to a comparison result of the actual white balance point coordinate and a preset standard white balance point coordinate, and finally adjusting a PWM signal duty ratio of the laser light source according to the power offset so as to adjust a driving current of the laser light source.
Referring to fig. 1, the present embodiment provides an automatic white balance control system for an RGB laser projector, including:
the RGB laser light source is used for emitting RGB three-color laser;
the laser driving circuit 4 is used for driving the RGB laser light source to work;
a photosensor 7 for detecting the light intensity of the RGB three-color laser light;
an imaging unit 8 for imaging according to RGB three-color laser light;
and the control unit 9 is used for controlling the laser driving circuit 4 to adjust the driving current of the RGB laser light source according to the detected light intensity of the photoelectric sensor 7.
In the specific working process of the automatic white balance control method and system of the RGB laser projector of the embodiment, RGB laser is used as a light source, and the emitted RGB three-color laser is incident on the imaging unit for imaging; the photoelectric sensor respectively detects the light intensity of three colors in the transmitted light on the emergent light path, the control unit calculates the actual white balance point coordinate according to the RGB brightness value, then compares the actual white balance point coordinate with the preset standard white balance point coordinate, calculates the power offset of the laser light source, and controls the laser driving circuit to adjust the PWM signal duty ratio of the laser light source according to the power offset so as to adjust the driving current of the laser light source and correspondingly adjust the luminous intensity of the three lasers, thereby realizing the automatic control of white balance.
In this embodiment, the proposed method and system for automatically controlling white balance of an RGB laser projector obtain an actual white balance point coordinate by detecting an RGB brightness value of light emitted from a light source, calculate a power offset of the laser light source according to a difference from a standard white balance point coordinate, adjust a driving current of the laser light source by adjusting a PWM signal duty ratio of the laser light source, and independently adjust light intensity of a three-color laser from the light source on the premise of ensuring projection brightness, thereby achieving white balance coordinate control, improving a projection effect of the projection system, and prolonging a service life of the projection system.
In order to balance the light intensity requirements of imaging and detection, the automatic control system of the embodiment further comprises: the light splitting unit is used for splitting emergent light of the RGB laser light source into an imaging light beam and a detection light beam, and the photoelectric sensor obtains RGB brightness values of the detection light beam.
In a specific embodiment, the light splitting unit adopts a dielectric reflector 6 for splitting the outgoing light of the RGB laser light source into a reflected light beam and a transmitted light beam, and preferably, the transmittance of the dielectric reflector 6 is less than or equal to 5%; during operation, the tricolor laser of RGB laser light source outgoing incides on the medium speculum, and the medium speculum splits emergent light into reflected light beam and transmission light beam, and imaging element 8 will the reflected light beam formation of image is with a small part light transmission simultaneously, and photoelectric sensor 7 is the tricolor photoelectric sensor, is a detector array that can detect the tricolor light intensity simultaneously, is used for detecting respectively the RGB light intensity of transmission light beam.
In another specific implementation, the control system of this embodiment further includes: and the dodging collimation unit 5 is used for dodging and calibrating the emergent light of the RGB laser light source, so that the uniformity of the emergent light of the light source is improved.
In a specific design of the imaging unit, the imaging unit 8 includes an imaging lens and a spatial light modulator, and the spatial light modulator is located on an optical path between the imaging lens and the dielectric mirror 6.
In a specific design of the RGB laser light source, it includes a red laser diode 1, a green laser diode 2, and a blue laser diode 3.
In a specific selection mode of the control unit, the control unit 9 adopts a single chip microcomputer.
In other specific embodiments of the control method of this embodiment, when the power offset exceeds a preset threshold range, comparing an actual brightness value with an initial brightness value of the laser light source to obtain a brightness attenuation ratio value, performing logic correction on brightness values of the other two laser light sources according to an actual brightness value with a maximum brightness attenuation ratio value to obtain a logic correction value, and adjusting the duty ratios of PWM signals of the other two laser light sources according to the logic correction value.
Referring to fig. 2, in order to illustrate specific technical effects of the above embodiments, a control process in an embodiment of the present system is described in detail below.
In a specific working mode, three-color laser emitted by the red laser diode 1, the green laser diode 2 and the blue laser diode 3 enters the dodging collimating device for dodging and calibrating, and then the three-color laser enters the medium reflector, the medium reflector reflects most of light to the imaging unit for imaging, a small part of light is transmitted, and the photoelectric sensor detects the light intensity of three colors in the transmitted light respectively.
In a specific control mode, the photoelectric sensor sends the detected brightness signals of the three-color laser to the single chip microcomputer; the single chip microcomputer calculates the actual white balance point coordinate of the RGB three-color laser according to the brightness value of the RGB three-color laser in the transmission beam, then the difference between the calculated actual white balance point coordinate and the standard white balance point coordinate prestored in the single chip microcomputer is compared, if the white balance coordinate is consistent with the white balance coordinate set by the standard, the light source white balance point is not deviated, and the laser driving circuit keeps the driving current unchanged; if the coordinate of the actual white balance point is inconsistent with the coordinate of the standard white balance point, firstly comparing the detection brightness value with the initial brightness value, determining the primary color with the maximum power offset amplitude, taking the primary color as a reference value, carrying out logic correction on the brightness of the other two primary colors according to the coordinate of the standard white balance point to obtain a correction value, then outputting the correction value to a laser driving circuit by a singlechip, calibrating the driving current of the other two primary colors by reducing the duty ratio of PWM signals of the other two primary colors on the laser driving circuit, realizing the maintenance of the white balance point of the three-color mixed laser, further realizing the stepless tuning of the coordinate of the white balance point and enhancing the user experience. .
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.
Claims (10)
1. An automatic control method for white balance of an RGB laser projector is characterized by comprising the following steps: the method comprises the steps of obtaining an actual white balance point coordinate of emergent light of a laser light source by obtaining an RGB brightness value of the emergent light, calculating a power offset of the laser light source according to a comparison result of the actual white balance point coordinate and a preset standard white balance point coordinate, and finally adjusting a PWM signal duty ratio of the laser light source according to the power offset so as to adjust a driving current of the laser light source.
2. The method as claimed in claim 1, wherein the obtaining of the RGB brightness values of the light emitted from the RGB laser sources specifically comprises: the method comprises the steps of dividing emergent light of an RGB laser light source into an imaging light beam and a detection light beam, and obtaining RGB brightness values of the detection light beam.
3. The RGB laser projector white balance automatic control method of claim 1, wherein when the power offset exceeds a preset threshold range, comparing an actual RGB brightness value with an initial laser light source brightness value to obtain a brightness attenuation ratio value, performing a logic correction on brightness values of other two laser light sources according to an actual brightness value with a maximum brightness attenuation ratio value to obtain a logic correction value, and adjusting PWM signal duty ratios of the other two laser light sources according to the logic correction value.
4. A control system for implementing the automatic white balance control method for the RGB laser projector according to any one of claims 1 to 3, comprising:
the RGB laser light source is used for emitting RGB three-color laser;
the laser driving circuit (4) is used for driving the RGB laser light source to work;
a photoelectric sensor (7) for detecting the light intensity of the RGB three-color laser;
an imaging unit (8) for imaging according to RGB three-color laser light;
and the control unit (9) is used for controlling the laser driving circuit (4) to adjust the driving current of the RGB laser light source according to the detection light intensity of the photoelectric sensor (7).
5. The RGB laser projector white balance automatic control system of claim 4, further comprising: and the light splitting unit is used for splitting the emergent light of the RGB laser light source into an imaging light beam and a detection light beam.
6. The automatic white balance control system for RGB laser projector as claimed in claim 5, wherein said beam splitting unit employs a dielectric reflector (6) for splitting the outgoing light from RGB laser source into reflected beam and transmitted beam.
7. The RGB laser projector white balance automatic control system of claim 6, wherein the transmittance of the dielectric mirror (6) is preferably 5% or less.
8. The automatic white balance control system for an RGB laser projector according to claim 6, wherein the photo sensors (7) are used to detect the RGB light intensities of the transmitted beams, respectively, and the imaging unit (8) is used to image the reflected beams.
9. The RGB laser projector white balance automatic control system of claim 4, further comprising: and the dodging collimation unit (5) is used for dodging and collimating the emergent light of the RGB laser light source.
10. The RGB laser projector white balance automatic control system according to claim 4, wherein the imaging unit (8) includes an imaging lens and a spatial light modulator, the spatial light modulator is located on the optical path between the imaging lens and the dielectric reflector (6).
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| Application Number | Priority Date | Filing Date | Title |
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| CN201910862858.1A CN110597001A (en) | 2019-09-12 | 2019-09-12 | Automatic control method and system for white balance of RGB laser projector |
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| CN201910862858.1A CN110597001A (en) | 2019-09-12 | 2019-09-12 | Automatic control method and system for white balance of RGB laser projector |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112637576A (en) * | 2020-12-15 | 2021-04-09 | 青岛海信激光显示股份有限公司 | Projection apparatus and projection control method |
| CN113140957A (en) * | 2021-04-16 | 2021-07-20 | 杭州中科极光科技有限公司 | Laser display white balance control system, control method and laser display equipment |
| CN113376942A (en) * | 2020-03-09 | 2021-09-10 | 青岛海信激光显示股份有限公司 | Laser projection device |
| CN114339175A (en) * | 2021-12-20 | 2022-04-12 | 歌尔科技有限公司 | Color correction method and apparatus, projector, and storage medium |
| US11543742B2 (en) | 2021-02-09 | 2023-01-03 | Delta Electronics, Inc. | Light source module and projection device |
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| CN106154720A (en) * | 2016-06-30 | 2016-11-23 | 海信集团有限公司 | A kind of projection light source wwhite balance control circuit |
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| CN106154720A (en) * | 2016-06-30 | 2016-11-23 | 海信集团有限公司 | A kind of projection light source wwhite balance control circuit |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113376942A (en) * | 2020-03-09 | 2021-09-10 | 青岛海信激光显示股份有限公司 | Laser projection device |
| CN113376942B (en) * | 2020-03-09 | 2022-08-19 | 青岛海信激光显示股份有限公司 | Laser projection equipment |
| CN112637576A (en) * | 2020-12-15 | 2021-04-09 | 青岛海信激光显示股份有限公司 | Projection apparatus and projection control method |
| US11543742B2 (en) | 2021-02-09 | 2023-01-03 | Delta Electronics, Inc. | Light source module and projection device |
| CN113140957A (en) * | 2021-04-16 | 2021-07-20 | 杭州中科极光科技有限公司 | Laser display white balance control system, control method and laser display equipment |
| CN114339175A (en) * | 2021-12-20 | 2022-04-12 | 歌尔科技有限公司 | Color correction method and apparatus, projector, and storage medium |
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