White balance control device, control method and laser display equipment

Abstract

The present disclosure relates to the field of laser technology, and provides a white balance control device, a control method and a laser display device. The white balance control device includes: a sampling component, which is used to sample a laser light source to obtain a sampled light source; a first photoelectric sensing device, which is used to perform photoelectric sensing on the sampled light source to obtain first sensing data; a second photoelectric sensing device, which is used to perform photoelectric sensing on the sampled light source to obtain second sensing data, wherein the second photoelectric sensing device and the first photoelectric sensing device have different spectral response curves; a controller, which is connected to the first photoelectric sensing device and the second photoelectric sensing device, and is used to obtain the wavelength and power of the laser light source according to the first sensing data, the second sensing data and a pre-stored calibration coefficient, so as to adjust the driving current of the three-primary-color laser light source according to the wavelength and power of the three-primary-color laser light source to achieve white balance control.

Description

Technical Field

[0001] The present disclosure relates to the field of laser technology, and in particular to a white balance control device, a control method and a laser display apparatus. Background Art

[0002] In the related art, using three-primary-color narrow-spectrum lasers as the light source of laser display can greatly expand the color gamut of laser display and greatly improve the color saturation. However, due to factors such as device differences, different aging speeds, and different temperatures, the wavelength, bandwidth, and power of the three-primary-color laser light source may drift, which in turn causes the color coordinates of the synthetic white light to drift, resulting in color cast of the laser display screen.

[0003] In order to maintain the stability of the color coordinates of the laser light source, a three-color filter-type light sensor can be added to the optical path to detect the power of the three primary colors emitted by the light source, and feedback control can be performed based on the measured power to maintain the stability of the color coordinates of the light source. However, since the laser is a linear spectrum, wavelength drift has a great influence on the color coordinates of the light source, but the sensor cannot detect the wavelength drift of the light source very well, resulting in the white balance control effect of the traditional light feedback control scheme is not ideal. Summary of the invention

[0004] In view of this, the embodiments of the present disclosure provide a white balance control device, a control method and a laser display device to solve the problem in the prior art that the sensor cannot detect the wavelength drift of the light source.

[0005] To achieve the above objectives, the technical solution adopted by the present disclosure is:

[0006] On the one hand, an embodiment of the present disclosure provides a white balance control device, which includes: a sampling component, used to sample a laser light source to obtain a sampled light source; a first photoelectric sensing device, used to perform photoelectric sensing on the sampled light source to obtain first sensing data; a second photoelectric sensing device, used to perform photoelectric sensing on the sampled light source to obtain second sensing data, wherein the second photoelectric sensing device and the first photoelectric sensing device have different spectral response curves; a controller, connected to the first photoelectric sensing device and the second photoelectric sensing device, and used to obtain the wavelength and power of the laser light source according to the first sensing data, the second sensing data and a pre-stored calibration coefficient, so as to adjust the driving current of the three-primary-color laser light source according to the wavelength and power of the three-primary-color laser light source to achieve white balance control.

[0007] In one embodiment, the sampling assembly includes a semi-reflective semi-mirror or a scattering lens.

[0008] In one embodiment, the first photoelectric sensing device and the second photoelectric sensing device are photodetectors having different spectral response peaks.

[0009] In one embodiment, the first photoelectric sensing device and the second photoelectric sensing device include a photodetector and a pyroelectric detector.

[0010] On the other hand, an embodiment of the present disclosure provides a white balance control method using the white balance control device in the above technical solution, and the white balance control method includes: obtaining first sensing data obtained by sensing a current sampling light source using a first photoelectric sensing device, wherein the current sampling light source is obtained by sampling a current laser light source by a sampling component; obtaining second sensing data obtained by sensing the current sampling light source using a second photoelectric sensing device, wherein the second photoelectric sensing device and the first photoelectric sensing device have different spectral response curves; obtaining the wavelength and power of the current sampling light source according to the first sensing data and the second sensing data and a calibration coefficient obtained in advance; and adjusting the driving current of the three-primary-color laser light source according to the wavelength and power of the three-primary-color laser light source to achieve white balance control.

[0011] In one embodiment, before acquiring first sensing data obtained by sensing the current sampling light source using the first photoelectric sensing device, the method further includes: sampling the current laser light source using a sampling component.

[0012] In one embodiment, before obtaining the wavelength and power of the current sampling light source according to the first sensing data and the second sensing data and the calibration coefficient obtained in advance, the method also includes: respectively using the first photoelectric sensing device and the second photoelectric sensing device to sense the adjustable wavelength laser light source to obtain the first calibration sensing data and the second calibration sensing data; generating a spectral response curve and a calibration coefficient according to the first calibration sensing data and the second calibration sensing data.

[0013] In one embodiment, the driving current of the three-primary-color laser light source is adjusted according to the wavelength and power of the three-primary-color laser light source, including: calculating the power ratio of each primary-color laser light source at the wavelength of the corresponding primary-color laser light source according to the color mixing theorem, and adjusting the driving current according to the power ratio.

[0014] In one embodiment, adjusting the driving current according to the power ratio includes: determining the color temperature and color coordinates of the laser generated by the three-primary-color laser light source according to the wavelength and power of the three-primary-color laser light source; determining the standard color coordinates of the target color gamut according to the color temperature; and adjusting the driving current of the three-primary-color laser light source according to the color coordinates and the standard color coordinates of the target color gamut so that the laser generated by the three-primary-color laser light source forms the target white light.

[0015] On the other hand, an embodiment of the present disclosure provides a laser display device, including a laser light source, an optical machine and a projection lens, and the white balance control device in the above technical solution; wherein, the laser generated by the laser light source is sampled by a sampling component and partially enters the optical machine and the projection lens.

[0016] Compared with the prior art, the beneficial effects of the disclosed embodiment are: the dual photoelectric sensing device is calibrated in advance to obtain a calibration coefficient, and then the wavelength and power of the three-primary-color laser light source are determined according to the calibration coefficient and the response signal of the dual photoelectric sensing device to the sampling light source, so that the driving current of the three-primary-color laser light source can be adjusted according to the wavelength and power of the three-primary-color laser light source to achieve white balance control of the laser display. Compared with the prior art, not only the power of the laser light source can be detected, but also the wavelength drift of the laser light source can be detected, thereby improving the control accuracy of the white balance control of the laser display. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 is a structural schematic diagram of a white balance control device provided by an embodiment of the present disclosure;

[0019] Figure 2 is a schematic diagram of a spectral response curve of a calibration process of an embodiment of the present disclosure;

[0020] Figure 3 is a schematic diagram of the wavelength and power of the three-primary-color laser light source of the embodiment of the present disclosure;

[0021] Figure 4 is a schematic diagram of the wavelength and power of the output laser of the three-primary-color laser light source of the embodiment of the present disclosure;

[0022] Figure 5 It is a flowchart of the white balance control method provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure and are not used to limit the present disclosure.

[0024] The white balance control device, control method and laser display apparatus according to the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0025] Figure 1 is a schematic diagram of the structure of the white balance control device provided by the embodiment of the present disclosure; Figure 1 To describe the white balance control method provided by the embodiment of the present disclosure.

[0026] like Figure 1 As shown, an embodiment of the present disclosure provides a white balance control device, the white balance control device comprising:

[0027] The sampling component 102 is used to sample the laser light source to obtain a sampled light source.

[0028] Specifically, the sampling component is used to sample the laser light emitted by the laser light source. In the disclosed embodiment, after the laser light emitted by the laser light source passes through the sampling component, most of the optical power enters the optical machine and the projection lens, and a small part of the optical power reaches the first photoelectric sensing device and the second photoelectric sensing device.

[0029] The first photoelectric sensing device 105 is used to perform photoelectric sensing on the sampling light source to obtain first sensing data.

[0030] The second photoelectric sensing device 106 is used to perform photoelectric sensing on the sampling light source to obtain second sensing data, wherein the second photoelectric sensing device and the first photoelectric sensing device have different spectral response curves.

[0031] Specifically, the spectral response curve can characterize the resolution capability of the photoelectric sensing device for different wavelengths. The first sensing data and the second sensing data are both detector response signals, which are output from the photoelectric sensing device and then enter the controller.

[0032] The controller 104 is connected to the first photoelectric sensing device and the second photoelectric sensing device, and is used to obtain the wavelength and power of the laser light source according to the first sensing data, the second sensing data and the pre-stored calibration coefficient, so as to adjust the driving current of the three-primary-color laser light source according to the wavelength and power of the three-primary-color laser light source to achieve white balance control.

[0033] Specifically, the controller has a calibration and control function, which can store the calibration coefficients of the first photoelectric sensing device and the second photoelectric sensing device, and calculate the wavelength and power of the primary color light emitted by the laser light source based on these calibration data, and perform feedback control of the optical power of the laser light source. The first photoelectric sensing device and the second photoelectric sensing device are calibrated in advance to obtain the calibration coefficients of the first photoelectric sensing device and the second photoelectric sensing device. In the calibration process, the first photoelectric sensing device and the second photoelectric sensing device can be irradiated with a known narrow-band primary color laser, and the response signals of the first photoelectric sensing device and the second photoelectric sensing device can be recorded respectively. The known narrow-band primary color laser is a single-color light source with adjustable wavelength. By recording the response signals of the photoelectric sensing device at different wavelengths respectively, different response signals of the photoelectric sensing device under the irradiation of laser light sources with different wavelengths can be obtained, thereby forming a spectral response curve of the photoelectric sensing device.

[0034] According to the wavelength of the irradiated laser light and the response signal of the first photoelectric sensor device, the following can be formed: Figure 2 The first spectral response curve η1 shown in FIG. 1 can be formed according to the wavelength of the irradiated laser and the response signal of the second photoelectric sensor device. Figure 2 The second spectral response curve η2 is shown. A lookup table or calibration coefficients can be generated according to the first spectral response curve η1 and the second spectral response curve η2.

[0035] After the calibration process is completed, the obtained calibration coefficient is stored in the controller, that is, the white balance control of the laser display can be performed based on the calibration coefficient in the subsequent white balance control process of the laser display.

[0036] In the disclosed embodiment, the laser display system first enters the white balance control process before working, such as Figure 3 As shown, the laser light source sequentially emits three primary colors, namely B (blue), G (green) and R (red), and each time a single primary color light is emitted, the response values ​​of the two photoelectric sensors to the sampled light source are obtained through the sampling component and the dual photoelectric sensors. Subsequently, the controller calculates the wavelength and power of the current primary color light through the ratio of the response values ​​of the two photoelectric sensors according to the calibration coefficient generated by the calibration process. After sequentially measuring the wavelength and power of the three primary colors emitted by the laser light source, the driving current of the three primary colors is adjusted according to the colorimetric principle and the target color gamut of the display system, and the power of the three primary colors is adjusted to obtain the following: Figure 4 The laser emitted by the three-primary-color laser light source shown realizes the color coordinate control of the target white field.

[0037] In the embodiment of the present disclosure, the measured wavelengths and powers of the three primary colors of light emitted by the laser light source are the relative values ​​of the wavelength and power of each primary color of light. According to the color mixing theorem, the power ratio of each primary color of light at the central wavelength at this moment can be calculated, and adjustments can be made based on the power ratio to achieve white balance control of the laser display.

[0038] In the embodiment of the present disclosure, the sampling component can use a half-reflective half-mirror or a scattering lens. Specifically, the half-reflective half-mirror refers to a lens with a transmittance and a reflectance of 50% each. The scattering lens refers to a lens with light scattering capability.

[0039] In the embodiment of the present disclosure, the first photoelectric sensing device and the second photoelectric sensing device have different spectral response curves, that is, the first photoelectric sensing device and the second photoelectric sensing device have different resolution capabilities for light of the same wavelength.

[0040] The photoelectric sensing device may be a photodetector. The working principle of the photodetector is to regard the effect of light radiation as the direct effect of the contained photons and the electrons inside the material. In the embodiment of the present disclosure, when the first photoelectric sensing device and the second photoelectric sensing device are both photodetectors, the first photoelectric sensing device and the second photoelectric sensing device have different spectral response peaks.

[0041] In addition, the photoelectric sensing device can also be a pyroelectric detector. The working principle of the pyroelectric detector is that the temperature of the receiving material increases under the action of light radiation, and the electrical properties of the receiving material change due to the temperature change.

[0042] In the embodiment of the present disclosure, one of the first photoelectric sensing device and the second photoelectric sensing device may be a photodetector, and the other may be a pyroelectric detector.

[0043] like Figure 1 As shown, an embodiment of the present disclosure also provides a laser display device, including a laser light source 101, an optical machine and a projection lens 103, and the white balance control device in the above technical solution; wherein, the laser generated by the laser light source is sampled by a sampling component and partially enters the optical machine and the projection lens.

[0044] like Figure 5 As shown, the embodiment of the present disclosure provides a white balance control method using the white balance control device in the above technical solution, and the white balance control method includes:

[0045] Step S501, obtaining first sensing data obtained by sensing a current sampling light source using a first photoelectric sensing device, wherein the current sampling light source is obtained by sampling a current laser light source by a sampling component.

[0046] Step S502 , obtaining second sensing data obtained by sensing the current sampling light source using a second photoelectric sensing device, wherein the second photoelectric sensing device and the first photoelectric sensing device have different spectral response curves.

[0047] Step S503, obtaining the wavelength and power of the current sampling light source according to the first sensing data, the second sensing data and the calibration coefficient obtained in advance.

[0048] Specifically, according to the calibration coefficient generated in the calibration process, the wavelength and power of the current primary color light can be calculated according to the ratio of the first sensing data to the second sensing data.

[0049] Step S504, adjusting the driving current of the three-primary-color laser light source according to the wavelength and power of the three-primary-color laser light source to achieve white balance control.

[0050] Specifically, after measuring the wavelength and power of the three primary colors of light emitted by the laser light source in turn, the driving current of the three primary colors of light is adjusted according to the principle of colorimetry and the target color gamut of the display system, thereby adjusting the color coordinates of the target white field.

[0051] In the technical solution of the embodiment of the present disclosure, by storing the calibration coefficients of the first photoelectric sensing device and the second photoelectric sensing device and calculating the wavelength and power of the primary color light emitted by the laser light source based on these calibration data, the optical power of the laser light source can be feedback controlled.

[0052] Before step S501, a sampling component may be used to sample the current laser light source. Specifically, the sampling component is used to sample the laser light emitted by the laser light source. In the disclosed embodiment, after the laser light emitted by the laser light source passes through the sampling component, most of the optical power enters the optical machine and the projection lens, and a small part of the optical power reaches the first photoelectric sensing device and the second photoelectric sensing device.

[0053] Before step S503, the first photoelectric sensing device and the second photoelectric sensing device can be calibrated, and the calibration process includes: using the first photoelectric sensing device and the second photoelectric sensing device to sense the adjustable wavelength laser light source respectively to obtain first calibration sensing data and second calibration sensing data; generating a spectral response curve and a calibration coefficient according to the first calibration sensing data and the second calibration sensing data.

[0054] Specifically, the spectral response curve can characterize the resolution capability of the photoelectric sensing device for different wavelengths. The first calibration sensing data and the second calibration sensing data are both detector response signals.

[0055] Before the laser display system starts working, it first enters the white balance control process. The laser light source emits three primary colors of light in sequence, and each time a single primary color light is emitted, the sampling component and the dual photoelectric sensing device obtain the response value of the two photoelectric sensing devices to the sampled light source. Subsequently, the controller calculates the wavelength and power of the current primary color light through the ratio of the response values ​​of the two photoelectric sensing devices based on the calibration coefficient generated by the calibration process. After measuring the wavelength and power of the three primary colors of light emitted by the laser light source in turn, according to the principle of colorimetry and the target color gamut of the display system, the driving current of the three primary colors of light is adjusted, and then the power of the three primary colors of light is adjusted to achieve color coordinate control of the target white field.

[0056] In the embodiment of the present disclosure, the measured wavelengths and powers of the three primary colors of light emitted by the laser light source are the relative values ​​of the wavelength and power of each primary color of light. According to the color mixing theorem, the power ratio of each primary color of light at the central wavelength at this moment can be calculated, and adjustments can be made based on the power ratio to achieve white balance control of the laser display.

[0057] In step S504, the power ratio of each primary color laser light source at the wavelength of the corresponding primary color laser light source is calculated according to the color mixing theorem, and the driving current is adjusted according to the power ratio.

[0058] Further, in step S504, the color temperature and color coordinates of the laser generated by the three-primary-color laser light source are determined according to the wavelength and power of the three-primary-color laser light source; the standard color coordinates of the target color gamut are determined according to the color temperature; and the driving current of the three-primary-color laser light source is adjusted according to the color coordinates and the standard color coordinates of the target color gamut so that the laser generated by the three-primary-color laser light source forms the target white light.

[0059] Specifically, laser display requires white balance control. The wavelength and power of each primary color determine the tristimulus value, which in turn determines the color temperature and color coordinates of the primary color and the mixed color. According to the color temperature, the standard color coordinates of the target color gamut can be determined, and then according to the color coordinates and the standard color coordinates of the target color gamut, the driving current of the three-primary color laser light source can be adjusted to perform white balance control of the laser display.

[0060] According to the white balance control device, control method and laser display equipment provided by the embodiments of the present disclosure, the dual photoelectric sensing device is calibrated in advance to obtain a calibration coefficient, and then the wavelength and power of the three-primary color laser light source are determined according to the calibration coefficient and the response signal of the dual photoelectric sensing device to the sampling light source. Therefore, the driving current of the three-primary color laser light source can be adjusted according to the wavelength and power of the three-primary color laser light source to realize the white balance control of the laser display. Compared with the prior art, not only the power of the laser light source can be detected, but also the wavelength drift of the laser light source can be detected, thereby improving the control accuracy of the white balance control of the laser display.

[0061] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A white balance control device, characterized in that: The control device comprises: A sampling component, used for sampling the laser light source to obtain a sampled light source; A first photoelectric sensing device, used for performing photoelectric sensing on the sampling light source to obtain first sensing data, wherein the light emitted by the laser light source is a single primary color light among the three primary colors; A second photoelectric sensing device, used for performing photoelectric sensing on the sampling light source to obtain second sensing data, wherein the second photoelectric sensing device and the first photoelectric sensing device are photoelectric detectors with different spectral response curves; A controller is connected to the first photoelectric sensing device and the second photoelectric sensing device, and is used to obtain the wavelength and power of the laser light source according to the first sensing data, the second sensing data and a pre-stored calibration coefficient, so as to adjust the driving current of the three-primary-color laser light source according to the wavelength and power of the three-primary-color laser light source to achieve white balance control, wherein the calibration coefficient is generated according to the wavelength and response signal of the irradiating laser of the first photoelectric sensing device and the second photoelectric sensing device.

2. The white balance control device according to claim 1, characterized in that: The sampling component includes a semi-reflective semi-mirror or a scattering lens.

3. The white balance control device according to claim 1, characterized in that: The first photoelectric sensing device and the second photoelectric sensing device include a photodetector and a pyroelectric detector.

4. A white balance control method using the white balance control device according to any one of claims 1 to 3, characterized in that: The white balance control method comprises: Acquire first sensing data obtained by sensing a current sampling light source using a first photoelectric sensing device, wherein the current sampling light source is obtained by sampling a current laser light source by a sampling component, and the light emitted by the current laser light source is a single primary color light among three primary colors; Acquire second sensing data obtained by sensing the current sampling light source using a second photoelectric sensing device, wherein the second photoelectric sensing device and the first photoelectric sensing device are photoelectric detectors with different spectral response curves; Acquire the wavelength and power of the current sampling light source according to the first sensing data, the second sensing data and a calibration coefficient obtained in advance, wherein the calibration coefficient is generated according to the wavelength and response signal of the irradiated laser of the first photoelectric sensing device and the second photoelectric sensing device; The driving current of the three-primary-color laser light source is adjusted according to the wavelength and power of the three-primary-color laser light source to achieve white balance control.

5. The white balance control method according to claim 4, characterized in that: Before acquiring first sensing data obtained by sensing the current sampling light source using the first photoelectric sensing device, the method further includes: The sampling component is used to sample the current laser light source.

6. The white balance control method according to claim 4, characterized in that: Before acquiring the wavelength and power of the current sampling light source according to the first sensing data, the second sensing data and the calibration coefficient obtained in advance, the method further includes: A first photoelectric sensing device and a second photoelectric sensing device are respectively used to sense the wavelength-adjustable laser light source to obtain first calibration sensing data and second calibration sensing data; A spectral response curve and the calibration coefficient are generated according to the first calibration sensing data and the second calibration sensing data.

7. The white balance control method according to claim 4, characterized in that: The driving current of the three-primary-color laser light source is adjusted according to the wavelength and power of the three-primary-color laser light source, including: The power ratio of each primary color laser light source at the wavelength of the corresponding primary color laser light source is calculated according to the color mixing theorem, and the driving current is adjusted according to the power ratio.

8. The white balance control method according to claim 7, characterized in that: Adjusting the driving current according to the power ratio includes: Determine the color temperature and color coordinates of the laser light generated by the three-primary-color laser light source according to the wavelength and power of the three-primary-color laser light source; Determining standard color coordinates of a target color gamut according to the color temperature; According to the color coordinates and the standard color coordinates of the target color gamut, the driving current of the three-primary-color laser light source is adjusted so that the laser light generated by the three-primary-color laser light source forms the target white light.

9. A laser display device, characterized in that: It comprises a laser light source, an optical machine and a projection lens, and a white balance control device according to any one of claims 1 to 3; wherein the laser light generated by the laser light source partially enters the optical machine and the projection lens after being sampled by a sampling component.

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