CN116974027A - Control method and control mechanism for light source brightness and color wheel delay of projection device - Google Patents
Control method and control mechanism for light source brightness and color wheel delay of projection device Download PDFInfo
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- G—PHYSICS
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- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
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- G—PHYSICS
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- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/007—Optical devices or arrangements for the control of light using movable or deformable optical elements the movable or deformable optical element controlling the colour, i.e. a spectral characteristic, of the light
- G02B26/008—Optical devices or arrangements for the control of light using movable or deformable optical elements the movable or deformable optical element controlling the colour, i.e. a spectral characteristic, of the light in the form of devices for effecting sequential colour changes, e.g. colour wheels
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- 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
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- G03B21/142—Adjusting of projection optics
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- H04N9/00—Details of colour television systems
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Abstract
The application discloses a control method and a control mechanism for light source brightness and color wheel delay of a projection device, and relates to the technical field of projection. The control method comprises the following steps: respectively acquiring a color wheel delay reference value, a target brightness mode, a video source field synchronous signal corresponding to the target brightness mode and a color wheel delay calibration value corresponding to the target brightness mode; calculating the sum of the color wheel delay reference value and the color wheel delay calibration value as a color wheel target delay value; the color wheel is controlled to rotate based on the color wheel target delay value, and the brightness mode of the projection device is adjusted to be a target brightness mode based on the video source field synchronous signal. Through the mode, the color wheel delay of the projection device can be matched with the brightness mode, the influence of the color wheel delay of the brightness of the light source can be eliminated, and the display effect is improved.
Description
Technical Field
The present application relates to the field of projection technologies, and in particular, to a method and a mechanism for controlling brightness of a light source and delay of a color wheel of a projection device.
Background
As projection technology of projection devices is developed, the projection devices are used in various applications, and it is known that color wheel retardation is inevitably generated during the operation of color wheels of the projection devices, and thus correction of the color wheel retardation is required. In the color wheel driving scheme, the core is to perform closed-loop control by detecting the phase difference between a video source field synchronous signal and a sensor position feedback signal to obtain a stable phase difference value, namely a color wheel delay value, so as to realize closed-loop control.
For a typical projection device, the color wheel delay value, once validated, need not be modified. However, as the miniature projection device is increasingly miniaturized and the brightness is continuously improved, the sensor selectivity is reduced and the sensor is easily affected by the brightness, so that the brightness mode of the projection device is not matched with the delay value of the color wheel during the closed-loop control of the color wheel, and the influence of the delay of the color wheel of the brightness of the light source cannot be completely eliminated.
Disclosure of Invention
The application mainly solves the technical problem of providing a control method and a control mechanism for the light source brightness and the color wheel delay of the projection device, so that the color wheel delay of the projection device is matched with a brightness mode, the influence of the light source brightness color wheel delay can be eliminated, and the display effect is improved.
In order to solve the technical problems, the application adopts a technical scheme that: there is provided a control method of light source brightness and color wheel delay of a projection apparatus, the control method comprising: respectively acquiring a color wheel delay reference value, a target brightness mode, a video source field synchronous signal corresponding to the target brightness mode and a color wheel delay calibration value corresponding to the target brightness mode; calculating the sum of the color wheel delay reference value and the color wheel delay calibration value as a color wheel target delay value; the color wheel is controlled to rotate based on the color wheel target delay value, and the brightness mode of the projection device is adjusted to be a target brightness mode based on the video source field synchronous signal.
In order to solve the technical problems, the application adopts a technical scheme that: there is provided a control mechanism for controlling light source brightness and color wheel delay of a projection apparatus, the control mechanism comprising: and the controller is respectively connected with the front end mechanism, the light source and the color wheel of the projection device and is used for controlling the front end mechanism, the light source and the color wheel to work based on the position feedback signal and by adopting the control method.
The beneficial effects of the application are as follows: compared with the prior art, before the color wheel driving and brightness mode switching of the projection device, the application firstly acquires the reference value of the color wheel delay, the target brightness mode, the video source field synchronous signal corresponding to the target brightness mode and the color wheel delay calibration value corresponding to the target brightness mode, and calculates the sum of the color wheel delay reference value and the color wheel delay calibration value as the color wheel target delay value; when the color wheel closed-loop control is carried out, the color wheel is controlled to rotate based on the color wheel target delay value corresponding to the target brightness mode, and the brightness mode of the projection device is adjusted to the target brightness mode based on the video source field synchronous signal corresponding to the target brightness mode, so that the color wheel delay of the projection device is matched with the brightness mode, the influence of the light source brightness color wheel delay is completely eliminated, and the display effect is improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art. Wherein:
FIG. 1 is a schematic diagram of a fixed threshold timing circuit of the present application;
fig. 2 is a schematic diagram of the relationship between the physical delay of the color wheel and the magnitude of the color wheel position feedback signal according to the present application;
FIG. 3 is a flow chart illustrating a control method of the brightness of a light source and the delay of a color wheel of a projection apparatus according to an embodiment of the application;
FIG. 4 is a flowchart of step S101 in FIG. 3;
fig. 5 is a schematic flow chart of a portion of step S103 in fig. 3;
FIG. 6 is a flowchart illustrating another embodiment of a method for controlling the brightness of a light source and the delay of a color wheel of a projection apparatus according to the present application;
FIG. 7 is a flowchart of a first embodiment of generating color wheel delay calibration values for a projection apparatus according to the present application;
FIG. 8 is a flowchart of a second embodiment of generating color wheel delay calibration values for a projection apparatus according to the present application;
fig. 9 is a flowchart illustrating a third embodiment of a method for generating a color wheel delay calibration value according to the present application;
FIG. 10 is a flowchart illustrating an embodiment of generating color wheel delay calibration values for a projection apparatus according to the present application;
FIG. 11 is a schematic block diagram illustrating an embodiment of a control mechanism for controlling the brightness of a light source and the color wheel delay of a projection apparatus according to the present application;
fig. 12 is a schematic structural diagram of an embodiment of a control mechanism for controlling the brightness of a light source and the delay of a color wheel of the projection device of the present application.
Detailed Description
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
With the development of projection technology of projection devices, miniature projection devices are increasingly miniaturized, and optional light shielding interrupt (Photo Interrupter Sensor, PIS) sensors are reduced in size, limited in general model parameter characteristics and reduced in selectivity. Meanwhile, the brightness of the miniature projection device is also continuously improved. The above factors make the PIS sensor output signal more and more affected by the brightness of the light source. The peak wavelength of the PIS sensor response is usually 960nm, the lower limit can reach 700nm, the wavelength of visible red light is 680 nm-740 nm, and the PIS sensor response comprises a part of wavelengths. With the improvement of brightness, the light intensity of the stray light in the optical machine reaching the PIS sensor is increased, so that the equivalent dark current of the PIS sensor is increased, and the high-level output amplitude is reduced. In addition, the increase in brightness can cause the temperature of the opto-mechanical cavity to change, and can also affect the output waveform of the PIS sensor.
The variation of the PIS sensor output signal may cause deviation of the phase difference between the video source field synchronization signal and the PIS sensor output signal, that is, deviation of the color wheel delay, and further result in degradation of the display effect.
Typically, the color wheel phase detection method is based on the PIS sensor output signal to obtain the position signal through a comparator with a fixed threshold, i.e. a fixed threshold timing circuit. As shown in fig. 1, vth is a threshold center voltage, and the hysteresis value of the comparator is set by adjusting the resistor R1 and the resistor R2, and the output signal of the PIS sensor is input at the inverting terminal input of the comparator. The fixed threshold timing circuit has the advantage of simple circuitry, which is appropriate when solving for the better digital signal corresponding to the PIS sensor output signal.
Second, when the output signal amplitude of the PIS sensor changes, as shown in fig. 2, the color wheel delay will deviate from the value before the change based on the above-mentioned fixed threshold timing method. In fig. 2, VSYNC is a video source field sync signal, typically 60-240 Hz, substantially in the range of 120-240 Hz for projection schemes using color wheels. Low current represents a Low current value of the light source current, and High current represents a High current value of the light source current. Cw_index is the position feedback signal output by the comparator of fig. 1. In fig. 2, physical_delay is a real color wheel delay signal. It can be seen that if the reference value delay_set of the color wheel delay is not modified, for a timing circuit with a fixed threshold, the color wheel delay will be offset δpdelay, which will cause the color wheel delay to be mismatched with the brightness, thereby causing the display effect to be reduced, and the gray-scale test picture will have obvious flaws, affecting the customer experience, and further reducing the product competitiveness.
In order to solve the above-mentioned problems, the present application first proposes a method for controlling the brightness of a light source and the color wheel delay of a projection device. As shown in fig. 3, fig. 3 is a flowchart illustrating a control method of light source brightness and color wheel delay of a projection apparatus according to an embodiment of the application, where the control method specifically includes steps S101 to S103:
step S101: the color wheel delay reference value, the target luminance pattern, the video source field synchronization signal corresponding to the target luminance pattern, and the color wheel delay calibration value corresponding to the target luminance pattern are acquired, respectively.
The controller respectively acquires a color wheel delay reference value of color wheel synchronous control, a target brightness mode of the projection device, a video source field synchronous signal corresponding to the target brightness mode and a color wheel delay calibration value corresponding to the target brightness mode before the color wheel closed-loop control.
The color wheel delay reference value is a color wheel delay value in a default brightness mode of a threshold value, and is matched with the default brightness mode, so that the projection device can normally work in the default brightness mode without a brightness switching instruction, and the display effect is ensured.
The method for obtaining the color wheel delay calibration value may be referred to as follows.
Step S102: and calculating the sum of the color wheel delay reference value and the color wheel delay calibration value as a color wheel target delay value.
The controller calculates the sum of the color wheel delay reference value and the color wheel delay calibration value as a color wheel target delay value before performing light source brightness mode adjustment and color wheel closed-loop control.
Step S103: the color wheel is controlled to rotate based on the color wheel target delay value, and the brightness mode of the projection device is adjusted to be a target brightness mode based on the video source field synchronous signal.
And when the color wheel is in closed-loop control, the controller controls the color wheel to rotate based on the target delay value of the color wheel, the controller synchronously adjusts the brightness mode of the light source, and the brightness mode of the projection device is adjusted to be the target brightness mode based on the video source field synchronous signal.
When a user sends out a brightness adjustment instruction, the controller sends out a brightness adjustment instruction, waits for a video source field synchronous signal, acquires a color wheel target delay value corresponding to a target brightness mode after capturing the video source field synchronous signal, and controls the color wheel to rotate based on the color wheel target delay value; the controller obtains a light source current value corresponding to the color wheel target delay value based on the video source field synchronous signal, and adjusts the light source current to the light source current value so as to switch the brightness mode to the target brightness mode, thereby realizing the matching of the brightness mode and the color wheel delay.
Compared with the prior art, before the color wheel driving and brightness mode switching of the projection device, the application firstly acquires the reference value of the color wheel delay, the target brightness mode, the video source field synchronous signal corresponding to the target brightness mode and the color wheel delay calibration value corresponding to the target brightness mode, and calculates the sum of the color wheel delay reference value and the color wheel delay calibration value as the color wheel target delay value; when the color wheel closed-loop control is carried out, the color wheel is controlled to rotate based on the color wheel target delay value corresponding to the target brightness mode, and the brightness mode of the projection device is adjusted to the target brightness mode based on the video source field synchronous signal corresponding to the target brightness mode, so that the color wheel delay of the projection device is matched with the brightness mode, the influence of the light source brightness color wheel delay is completely eliminated, and the display effect is improved.
Alternatively, the present embodiment may implement step S101 by a method as shown in fig. 4, fig. 4 is a schematic flowchart of step S101 in fig. 3, and the step of acquiring the target luminance pattern and the video source field synchronization signal corresponding to the target luminance pattern in step S101 is implemented, where the specific implementation steps include steps S201 to S201:
step S201: a luminance pattern switching signal is acquired, and a target luminance pattern is acquired based on the luminance pattern switching signal.
When the controller acquires the switching signal of the luminance mode, the controller acquires the target luminance mode from the luminance mode switching signal.
In an application scene, the controller acquires a gear switching action of brightness adjustment of the projection device and a gear after switching, and takes the gear after switching as a target brightness mode.
Step S202: and acquiring a video source field synchronous signal corresponding to the target brightness mode.
The controller acquires a video source field synchronization signal corresponding to the target luminance pattern based on the target luminance pattern.
In an application scene, the controller obtains the gear before the gear switching action of the brightness adjusting piece as the current brightness mode, and judges whether the gear of the current brightness mode is the gear of the target brightness mode. If not, acquiring a video source field synchronous signal. If the current brightness mode of the projection device is not the target brightness mode, the light source brightness of the projection device is determined to be changed, the problem of mismatch between the color wheel delay and the brightness is caused, and the color wheel delay and the light source brightness are required to be adjusted to enable the color wheel delay to be matched with the light source brightness. At this time, a video source field synchronizing signal corresponding to the target luminance pattern is acquired.
Alternatively, the present embodiment may implement step S103 by a method as shown in fig. 5, and fig. 5 is a schematic flow chart of a portion of step S103 in fig. 3, and specifically implement a step of adjusting the brightness mode of the projection apparatus to the target brightness mode based on the video source field synchronization signal in step S103, where the specific implementation steps include steps S301 to S302:
step S301: a light source drive current signal is obtained based on the video source field sync signal.
The controller analyzes the video source field synchronization signal after acquiring the video source field synchronization signal corresponding to the target luminance pattern, thereby acquiring a light source driving current signal corresponding to the target luminance pattern.
Step S302: controlling the light source current of the projection device according to the light source driving current signal so as to adjust the brightness mode of the projection device to be a target brightness mode.
The controller controls the light source current of the projection device according to the light source driving current signal corresponding to the target brightness mode, and adjusts the light source current. The light source current of the projection device corresponds to the brightness mode, and the projection device can be adjusted to the target brightness mode by adjusting the light source current.
In other embodiments, as shown in fig. 6, fig. 6 is a flowchart illustrating another embodiment of a method for controlling the brightness of a light source and the delay of a color wheel of the projection device according to the present application; the method for controlling the brightness of the light source and the color wheel delay of the projection device in this embodiment specifically includes steps S401 to S405:
step S401: the color wheel delay reference value, the target luminance pattern, the video source field synchronization signal corresponding to the target luminance pattern, and the color wheel delay calibration value corresponding to the target luminance pattern are acquired, respectively.
Step S401 corresponds to step S101, and will not be described again.
Step S402: and calculating the sum of the color wheel delay reference value and the color wheel delay calibration value as a color wheel target delay value.
Step S402 corresponds to step S102, and will not be described again.
Step S403: and acquiring a starting instruction of the projection device, and setting the light source current of the projection device as a current reference value.
After the controller obtains the starting instruction of the projection device, the current value of the light source of the projection device is set as a current reference value.
The current reference value may be a light source current corresponding to a preset default brightness mode, so that the projection device works in the default brightness mode when the brightness-free mode is switched.
Step S404: the color wheel delay of the projection device is set to a color wheel delay reference value.
After the controller obtains the starting instruction of the projection device, the color wheel delay of the current projection device is set as a color wheel delay reference value.
The color wheel delay reference value is a color wheel delay value under a default brightness mode corresponding to the current reference value, and the color wheel delay reference value is matched with the default brightness mode, so that the projection device can normally work under the default brightness mode without a brightness switching instruction, and the display effect is ensured.
Step S405: the color wheel is controlled to rotate based on the color wheel target delay value, and the brightness mode of the projection device is adjusted to be a target brightness mode based on the video source field synchronous signal.
Step S405 corresponds to step S103, and will not be described again.
Alternatively, the color wheel delay calibration value may be generated by the method shown in fig. 7, and fig. 7 is a flowchart of a first embodiment of generating the color wheel delay calibration value of the projection apparatus according to the present application, and the specific implementation steps include steps S501 to S505:
step S501: the light source current of the projection device is set to a current reference value.
After the controller obtains the starting instruction of the projection device, the projection device is started, and the current of the light source of the projection device is set as a current reference value.
Step S502: and acquiring a video source field synchronous signal corresponding to the preset brightness mode.
The projection device is provided with a plurality of preset brightness modes, and before generating the color wheel delay calibration value, a video source field synchronous signal corresponding to the preset brightness modes is firstly obtained.
Step S503: and adjusting the light source current of the projection device to a current preset value based on a video source field synchronous signal corresponding to the preset brightness mode so as to adjust the brightness mode of the projection device to the preset brightness mode.
After the projection device acquires the video source field synchronous signal corresponding to the preset brightness mode, the controller analyzes the video source field synchronous signal corresponding to the preset brightness mode, acquires the current preset value corresponding to the preset brightness mode, and adjusts the brightness mode of the projection device to be the preset brightness mode.
Step S504: the current color wheel delay value of the projection device in a preset brightness mode is measured.
The brightness mode of the projection device is switched to a preset brightness mode, so that the brightness of a light source of the projection device is changed, the PIS sensor is affected by the brightness, and the color wheel delay value of the projection device in the preset brightness mode is not matched with that of the color wheel, so that the display effect of the display projection device is reduced, and the current color wheel delay value of the projection device in the preset brightness mode is required to be measured.
Step S505: and calculating the difference value between the current color wheel delay value and the color wheel delay reference value as a color wheel delay calibration value corresponding to the preset brightness mode.
And obtaining a corresponding current color wheel delay value under a preset brightness mode, then calculating a difference value between the current color wheel delay value and a color wheel delay reference value, and obtaining a color wheel delay calibration value corresponding to the preset brightness mode one by one.
In an application scenario, the projection device is provided with a plurality of preset brightness modes such as a brightness mode 1, a brightness mode 2 and a brightness mode 3, each brightness mode has different brightness, and after the brightness modes are switched, the PIS sensor is influenced by brightness, so that the brightness mode 1 of the preset brightness mode is not matched with a color wheel delay reference value after the projection device is started, the display effect is reduced, the current color wheel delay value corresponding to different preset brightness modes is required to be obtained, and the color wheel delay calibration value corresponding to different preset brightness modes is calculated based on the current color wheel delay value corresponding to different preset brightness modes and the color wheel delay reference value.
Alternatively, the color wheel delay calibration value may be generated by the method shown in fig. 8, and fig. 8 is a flowchart of a second embodiment of generating the color wheel delay calibration value of the projection apparatus according to the present application, and the specific implementation steps include steps S601 to S608:
step S601: the light source current of the projection device is set to a current reference value.
Step S601 corresponds to step S501, and will not be described again.
Step S602: the color wheel delay of the projection device is set to a color wheel reference value.
Specifically, when the projection device is started, the current value of the light source in the default brightness mode is set as a current reference value, and then the color wheel delay is adjusted according to the gray scale graph, so that the display effect is optimal, and the color wheel delay at the moment is the color wheel delay reference value. In this way, the projection device can be matched with the delay reference value in the brightness mode, and the display effect is ensured.
Step S603: and starting the color wheel synchronous closed-loop control of the projection device.
After the projector is started, setting the current value of the light source as a current reference value and the color wheel delay corresponding to the best display effect in the current brightness mode as a color wheel delay reference value, and starting the color wheel synchronous control of the projector.
Step S604: and acquiring a video source field synchronous signal corresponding to the preset brightness mode.
Step S604 corresponds to step S502, and will not be described again.
Step S605: and closing the color wheel synchronous closed-loop control of the projection device.
When the video source field synchronous signal corresponding to the preset brightness mode is obtained, the color wheel synchronous control is closed, and the projection device does not perform the color wheel synchronous control, but the color wheel has higher rotational inertia, and the phase change in one period is very tiny, so the color wheel delay value of the projection device in the preset brightness mode is the current color wheel delay value corresponding to the preset brightness mode.
Step S606: and adjusting the light source current of the projection device to a current preset value based on a video source field synchronous signal corresponding to the preset brightness mode so as to adjust the brightness mode of the projection device to the preset brightness mode.
Step S606 corresponds to step S503, and will not be described again.
Step S607: the current color wheel delay value of the projection device in a preset brightness mode is measured.
Step S607 corresponds to step S504, and will not be described again.
Step S608: and calculating the difference value between the current color wheel delay value and the color wheel delay reference value as a color wheel delay calibration value corresponding to the preset brightness mode.
Step S608 corresponds to step S505, and will not be described again.
Optionally, in other embodiments, the projection apparatus is provided with a plurality of different preset brightness modes, where each preset brightness mode corresponds to a different current preset value, as shown in fig. 9, and fig. 9 is a flowchart of a third embodiment of the method for generating a color wheel delay calibration value according to the present application. The method for generating the color wheel delay calibration value further includes steps S701 to S702:
step S701: the number of preset luminance patterns for which the color wheel delay calibration value has been calculated is counted.
The controller counts the number of preset luminance patterns for which the color wheel delay calibration value has been calculated.
Step S702: if the number of the preset brightness modes of the calculated color wheel delay calibration value is smaller than the total number of the preset brightness modes, the step of adjusting the light source current of the projection device to the current preset value based on the video source field synchronous signal corresponding to the preset brightness modes to adjust the brightness mode of the projection device to the preset brightness mode, the step of measuring the current color wheel delay value of the projection device in the preset brightness mode, and the step of calculating the difference value between the current color wheel delay value and the color wheel delay reference value as the color wheel delay calibration value corresponding to the preset brightness mode are executed.
When the number of the preset brightness modes of which the color wheel delay calibration values are calculated is smaller than the total number of the preset brightness modes, the color wheel delay calibration values corresponding to the preset brightness modes are not obtained, the controller continues to execute the steps of adjusting the light source current of the projection device to the current preset value based on the video source field synchronous signals corresponding to the preset brightness modes so as to adjust the brightness modes of the projection device to the preset brightness modes, measuring the current color wheel delay value of the projection device in the preset brightness modes, and calculating the difference value between the current color wheel delay value and the color wheel delay reference value to be the color wheel delay calibration value corresponding to the preset brightness modes.
If the number of preset brightness modes for which the color wheel delay calibration value has been calculated is equal to the total number of the plurality of preset brightness modes, the acquisition of the correction data is ended.
In a specific application scenario, the projection device works in n preset brightness modes, and n current gears are corresponding to the projection device. When the light source brightness pattern changes, as shown in fig. 2, the position feedback signal amplitude of the color wheel changes, and the rise time changes, thereby causing a timing error to be generated by the timing circuit based on a constant threshold value. The principle of the color wheel delay control is to adjust the delay (phase difference) between the field sync signal and the position feedback signal to the color wheel delay reference value delay_set. Obviously, if the color wheel delay calibration value is obtained by obtaining the calibration data, the influence of the brightness change can be eliminated by compensating before the brightness change.
As shown in fig. 10, fig. 10 is a flowchart illustrating an embodiment of generating a color wheel delay calibration value of the projection apparatus according to the present application, and the specific steps include steps S801 to S805:
step S801: the light source current is set to a current reference value x0.
The projector is started, and the light source current is set to a current reference value x0.
Step S802: the color wheel delay reference value y0 is set.
After setting the current reference value x0, adjusting the color wheel delay value according to the gray scale graph to optimize the display effect, and setting the color wheel delay value at the moment as the color wheel delay reference value y0.
Step S803: and starting the color wheel synchronous closed-loop control of the projection device.
Step S804: it is determined whether the number of preset luminance patterns for which the color wheel delay calibration value has been calculated is greater than the total number of preset luminance patterns.
The number of preset luminance patterns for which the color wheel delay calibration value has been calculated is n, which is initially set to 0.
Step S805: if not, capturing a video source field synchronous signal corresponding to a preset brightness mode, closing a color wheel synchronous closed-loop control, adjusting the light source current of the projection device to a current preset value, measuring the current color wheel delay value of the projection device in the preset brightness mode, calculating the difference value between the current color wheel delay value and a color wheel delay reference value to be a color wheel delay calibration value corresponding to the preset brightness mode, and recording.
If the number n of the preset brightness modes of the calculated color wheel delay calibration value is smaller than or equal to the total number of the preset brightness modes, the controller waits for arrival of a primary video source field synchronous signal corresponding to the preset brightness modes, after detecting the pulse of the video source field synchronous signal, the controller turns off the color wheel synchronous closed-loop control of the period, then the controller changes the light source current into a current preset value x (1), and then the current color wheel delay value y (1) of the projection device in the preset brightness modes is measured. Because the color wheel is closed in the period and the color wheel is controlled in a synchronous closed loop, the color wheel is not controlled, and the color wheel has higher rotational inertia, so that the phase change in one period is very tiny. The difference d (1) between the current color wheel delay value y (1) and the color wheel delay reference value y0 is the color wheel delay calibration value required by the brightness level 1. The controller records the color wheel delay calibration value d (1), changes the number n=n+1 of preset brightness modes of the calculated color wheel delay calibration value after recording, and goes to step S801.
When a user changes a preset brightness mode, the color wheel delay calibration values corresponding to all preset brightness modes can be applied to enable the color wheel of the projection device to be in delay fit when the projection device acquires a preset brightness switching instruction. When a user sends out a brightness adjustment command, the controller sends out a brightness adjustment command, waits for the pulse of a video source field synchronous signal, obtains a light source driving current signal based on the video source field synchronous signal after the pulse of the video source field synchronous signal is obtained, controls the light source current of the projection device according to the light source driving current signal so as to adjust the brightness mode of the projection device into a target brightness mode, obtains a color wheel delay calibration value corresponding to a preset brightness mode, calculates to obtain a color wheel delay value y (n) corresponding to the current preset brightness mode, and then completes the modification of the color wheel delay to enable the preset brightness mode to be matched with the color wheel delay. And the above actions are completed between two video source field sync signals.
The present application further provides a control mechanism for controlling light source brightness and color wheel delay of a shadow mask, as shown in fig. 11, fig. 11 is a schematic block diagram of an embodiment of a control mechanism for controlling light source brightness and color wheel delay of a projection device according to the present application, where the control mechanism for controlling light source brightness and color wheel delay of a projection device according to the present embodiment includes:
the controller 120 is connected to the front-end mechanism 130, the light source 140 and the color wheel 150 of the projection device, and is used for controlling the front-end mechanism, the light source and the color wheel to operate based on the position feedback signal and the adjustment method.
Optionally, the control mechanism for the brightness of the light source and the delay of the color wheel of the projection device of the present embodiment further includes a position detection mechanism 110.
The position detecting mechanism 110 is connected to the controller 120, and is configured to detect a position of the color wheel 150 when measuring a current color wheel delay value of the projection apparatus in a preset brightness mode, and generate a position feedback signal, so that the controller 120 obtains the current color wheel delay value based on the feedback signal.
In an application scenario, as shown in fig. 12, fig. 12 is a schematic structural diagram of an embodiment of a control mechanism for controlling the brightness of a light source and the delay of a color wheel of the projection device according to the present application, which is an implementation circuit of a color wheel control scheme of an unofficial digital light processing (Digital Light Processing, DLP) display technology.
The front-end mechanism 130 is connected to the DLP display module 160, and is configured to transmit video data to the DLP display module 160; the front end mechanism 130 is connected to the controller 120, the controller 120 is connected to the color wheel drive 170, the position detection mechanism 110, and the light source 140, and the color wheel drive 170 is connected to the color wheel 150.
The controller 120 includes a main control module 121, a light source control module 122, and a color wheel synchronization control module 123. The main control module 121 is connected with the front end mechanism 130 and is used for transmitting control signals; the light source control module 122 is connected with the main control module 121 and the light source 140 and is used for controlling the light source 140; the color wheel synchronization control module 123 is connected to the front end mechanism 130, the main control module 121, the color wheel drive 170, and the position detection mechanism 110, and is configured to capture a video source field synchronization signal and a position feedback signal for comparison to control the color wheel drive 170. The position detecting mechanism 110 is used for detecting the position of a color wheel 150 of the projection device, and the color wheel drive 170 is connected to the color wheel 150 and is used for controlling the position change of the color wheel 150.
The light source brightness control information is given by the front-end mechanism 130, and the main control module 121 combines the control signal and the information of the color wheel synchronization control module 123 to comprehensively implement the above-mentioned color wheel delay adjustment method of the projection device. The color wheel synchronization control module 123 controls the color wheel 150 to synchronize based on a micro control unit (Micro Control Unit, MCU).
When the synchronization of the color wheel 150 is completed, the position feedback signal and the video source field synchronization signal are each 1 pulse per rotation of the color wheel 150, and both have a certain phase difference in the case of synchronization. The control period of the controller 120 is thus once performed for each field sync signal, and the time period between two field sync signals may be approximately 4ms for a 240Hz frame rate time, which is sufficient for implementation of the control method of the light source brightness and color wheel delay of the projection device described above.
Compared with the prior art, before the color wheel driving and brightness mode switching of the projection device, the application firstly acquires the reference value of the color wheel delay, the target brightness mode, the video source field synchronous signal corresponding to the target brightness mode and the color wheel delay calibration value corresponding to the target brightness mode, and calculates the sum of the color wheel delay reference value and the color wheel delay calibration value as the color wheel target delay value; when the color wheel closed-loop control is carried out, the color wheel is controlled to rotate based on the color wheel target delay value corresponding to the target brightness mode, and the brightness mode of the projection device is adjusted to the target brightness mode based on the video source field synchronous signal corresponding to the target brightness mode, so that the color wheel delay of the projection device is matched with the brightness mode, the influence of the light source brightness color wheel delay is completely eliminated, and the display effect is improved.
And secondly, the functions related to the color wheel delay adjusting method are all functions needed to be used for normal color wheel synchronous control, so that no additional functional module is introduced, the cost of matching the color wheel delay and the brightness mode of the projection device is reduced, and the color wheel delay adjusting method can be directly applied to the subsequent production of the projection device of the model by only acquiring a part of color wheel delay after the color wheel delay is calibrated if the consistency of the projection device is good.
The foregoing description is only illustrative of the present application and is not intended to limit the scope of the application, and all equivalent structures or equivalent processes or direct or indirect application in other related technical fields are included in the scope of the present application.
Claims (10)
1. A method for controlling light source brightness and color wheel delay of a projection device, comprising:
respectively acquiring a color wheel delay reference value, a target brightness mode, a video source field synchronous signal corresponding to the target brightness mode and a color wheel delay calibration value corresponding to the target brightness mode;
calculating the sum of the color wheel delay reference value and the color wheel delay calibration value as a color wheel target delay value;
and controlling the color wheel to rotate based on the color wheel target delay value, and adjusting the brightness mode of the projection device to the target brightness mode based on the video source field synchronous signal.
2. The control method according to claim 1, wherein acquiring a target luminance pattern and a video source field synchronization signal corresponding to the target luminance pattern comprises:
acquiring a brightness mode switching signal, and acquiring a target brightness mode based on the brightness mode switching signal;
and acquiring a video source field synchronous signal corresponding to the target brightness mode.
3. The control method according to claim 1, wherein the adjusting the brightness mode of the projection device to the target brightness mode based on the video source field sync signal includes:
obtaining a light source driving current signal based on the video source field synchronization signal;
and controlling the light source current of the projection device according to the light source driving current signal so as to adjust the brightness mode of the projection device to the target brightness mode.
4. The control method according to claim 2, characterized by further comprising:
acquiring a starting signal of the projection device, and setting the light source current of the projection device as a current reference value;
setting the color wheel delay of the projection device as the color wheel delay reference value.
5. The control method of claim 1, wherein the method of generating the color wheel delay calibration value comprises:
setting a light source current of the projection device as a current reference value;
acquiring a video source field synchronous signal corresponding to a preset brightness mode;
adjusting the light source current of the projection device to a current preset value based on a video source field synchronous signal corresponding to the preset brightness mode so as to adjust the brightness mode of the projection device to the preset brightness mode;
measuring a current color wheel delay value of the projection device in the preset brightness mode;
and calculating the difference value between the current color wheel delay value and the color wheel delay reference value as a color wheel delay calibration value corresponding to the preset brightness mode.
6. The control method according to claim 5, wherein after the step of setting the light source current of the projection device to the current reference value, the step of acquiring the video source field synchronization signal corresponding to the preset luminance pattern is preceded by the step of further comprising:
setting a color wheel delay of the projection device to the color wheel reference value;
starting a color wheel synchronous closed-loop control of the projection device;
after the step of obtaining the video source field synchronization signal corresponding to the preset brightness mode, the step of adjusting the light source current of the projection device to a current preset value based on the video source field synchronization signal corresponding to the preset brightness mode to adjust the brightness mode of the projection device to the preset brightness mode further includes:
and closing the color wheel synchronous closed-loop control of the projection device.
7. The control method according to claim 5 or 6, wherein the projection device is provided with a plurality of different preset brightness modes, each of which corresponds to a different current preset value, the method of generating the color wheel delay calibration value further comprising:
counting the number of preset brightness modes for which the color wheel delay calibration value is calculated;
and if the number of the preset brightness modes of the calculated color wheel delay calibration value is smaller than the total number of the preset brightness modes, executing the step of adjusting the light source current of the projection device to a current preset value based on the video source field synchronous signal corresponding to the preset brightness modes so as to adjust the brightness mode of the projection device to the preset brightness mode, the step of measuring the current color wheel delay value of the projection device in the preset brightness mode, and the step of calculating the color wheel delay calibration value corresponding to the preset brightness mode as the difference value between the current color wheel delay value and the color wheel delay reference value.
8. A control mechanism for light source brightness and color wheel delay of a projection device, comprising:
the controller is respectively connected with the front end mechanism, the light source and the color wheel of the projection device and is used for controlling the front end mechanism, the light source and the color wheel to work by adopting the control method of any one of claims 1 to 7.
9. The control mechanism as recited in claim 8, further comprising:
the position detection mechanism is connected with the controller and is used for detecting the position of the color wheel when measuring the current color wheel delay value of the projection device in a preset brightness mode and generating a position feedback signal so that the controller can acquire the current color wheel delay value based on the position feedback signal.
10. The control mechanism of claim 9, further comprising a color wheel drive, wherein the controller comprises a main control module, a light source control module, and a color wheel synchronization control module, wherein the main control module is connected to the front end mechanism for transmitting control signals; the light source control module is connected with the main control module and the light source and used for controlling the light source; the color wheel synchronous control module is connected with the front end mechanism, the main control module, the position detection mechanism and the color wheel drive and is used for capturing video source field synchronous signals and comparing the position feedback signals to control the color wheel drive.
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| CN202210447256.1A CN116974027A (en) | 2022-04-24 | 2022-04-24 | Control method and control mechanism for light source brightness and color wheel delay of projection device |
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| CN202210447256.1A CN116974027A (en) | 2022-04-24 | 2022-04-24 | Control method and control mechanism for light source brightness and color wheel delay of projection device |
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