Projection device and driving method for its light source

Abstract

The present application discloses a projection device and a driving method for its light source, relating to the field of projection technology. This method can recognize the gestures of a target object through a radar, and after recognizing that the gesture is a first gesture for indicating entering the shooting mode, drive the light source with a first driving current in the shooting mode. Since this first driving current is the driving current of the light source when the picture captured by the shooting device has no color cast, driving the light source with the first driving current can ensure that the picture captured by the shooting device has no color cast phenomenon. Moreover, since this method can control the working mode of the projection device based on the gestures of the hand of the target object, the flexibility of controlling the projection device is improved.

Description

Technical Field

[0001] This application relates to the field of projection technology, and particularly to a projection device and a driving method for its light source. Background Art

[0002] Laser projection devices (such as laser TVs and laser projectors) can project images. During the process of a laser projection device projecting an image, if a user needs to record the image, the user can use a shooting device such as a mobile phone to shoot the image to record it.

[0003] However, there will be a large difference between the color of the image obtained by the shooting device and the color of the image projected by the laser projection device, that is, the obtained image will have a color cast phenomenon. Summary of the Invention

[0004] This application provides a projection device and a driving method for its light source, which can solve the problem that the image obtained by shooting the image projected by the projection device with a shooting device in the related art has a color cast phenomenon. The technical solutions are as follows:

[0005] On the one hand, a driving method for a light source is provided, which is applied to a projection device. The projection device includes: a light source and a radar; the method includes:

[0006] Controlling the radar to emit a detection signal and collecting the echo signal reflected by the target object through the radar;

[0007] Identifying the gesture of the hand of the target object based on the echo signal;

[0008] If the gesture of the hand is a first gesture for indicating entering the shooting mode, driving the light source to emit light with a first driving current in the shooting mode, so that the projection device operates in the shooting mode.

[0009] On the other hand, a driving method for a light source is provided, which is applied to a projection device. The projection device includes: a light source; the method includes:

[0010] If the received first voice command includes a wake-up keyword, performing voice recognition on the second voice command received after the first voice command;

[0011] If it is recognized that the second voice command is a voice command for indicating entering the shooting mode, driving the light source to emit light with a first driving current in the shooting mode, so that the projection device operates in the shooting mode.

[0012] On yet another hand, a projection device is provided. The projection device includes: a light source and a radar; the projection device is used for:

[0013] Control the radar to transmit detection signals, and collect echo signals reflected by the target object through the radar;

[0014] Identify the gesture of the hand of the target object based on the echo signal;

[0015] If the gesture of the hand is a first gesture for indicating entering the shooting mode, drive the light source to emit light with a first driving current in the shooting mode, so that the projection device operates in the shooting mode.

[0016] On the other hand, a projection device is provided, and the projection device includes: a light source; the projection device is configured to:

[0017] If the received first voice command includes a wake-up keyword, perform voice recognition on the second voice command received after the first voice command;

[0018] If it is recognized that the second voice command is a voice command for indicating entering the shooting mode, drive the light source to emit light with a first driving current in the shooting mode, so that the projection device operates in the shooting mode.

[0019] On the other hand, a projection device is provided, and the projection device includes: a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the driving method of the light source as described in the above aspect is implemented.

[0020] On the other hand, a computer-readable storage medium is provided, and a computer program is stored in the computer-readable storage medium. The computer program is loaded and executed by a processor to implement the driving method of the light source as described in the above aspect.

[0021] On the other hand, a computer program product containing instructions is provided. When the computer program product runs on the computer, the computer is made to execute the driving method of the light source as described in the above aspect.

[0022] The beneficial effects brought by the technical solution provided in this application at least include:

[0023] The present application provides a projection device and a driving method for its light source. This method can identify the gestures of a target object through a radar, and after identifying that the gesture is the first gesture for indicating entering the shooting mode, drive the light source with the first driving current in the shooting mode. Since the first driving current is the driving current of the light source when the image captured by the shooting device has no color cast, driving the light source with the first driving current can ensure that the image captured by the shooting device has no color cast phenomenon. Moreover, since this method can control the working mode of the projection device based on the gestures of the target object's hand, the flexibility of controlling the projection device is improved. Description of the Drawings

[0024] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 It is a schematic structural diagram of a projection device provided by an embodiment of the present application;

[0026] Figure 2 It is a schematic structural diagram of another projection device provided by an embodiment of the present application;

[0027] Figure 3 It is a flowchart of a driving method for a light source provided by an embodiment of the present application;

[0028] Figure 4 It is a flowchart of another driving method for a light source provided by an embodiment of the present application;

[0029] Figure 5 It is a schematic structural diagram of a radar provided by an embodiment of the present application;

[0030] Figure 6 It is a schematic diagram showing the change of the amplitude of a detection signal with time provided by an embodiment of the present application;

[0031] Figure 7 It is a schematic diagram showing the change of the frequency of a detection signal with time provided by an embodiment of the present application;

[0032] Figure 8 It is a schematic diagram of an intermediate frequency signal obtained after mixing a detection signal and an echo signal provided by an embodiment of the present application;

[0033] Figure 9 It is a schematic diagram of two consecutive echo signals provided by an embodiment of the present application;

[0034] Figure 10It is a comparison schematic diagram of two consecutive echo signals provided by an embodiment of the present application;

[0035] Figure 11 It is a schematic diagram of the arrival angle of an echo signal provided by an embodiment of the present application;

[0036] Figure 12 It is a schematic diagram of the arrangement of multiple receiving antennas provided by an embodiment of the present application;

[0037] Figure 13 It is another schematic diagram of the structure of a projection device provided by an embodiment of the present application;

[0038] Figure 14 It is a flowchart of a driving method for a light source provided by an embodiment of the present application;

[0039] Figure 15 It is a flowchart of another driving method for a light source provided by an embodiment of the present application. Detailed implementation manners

[0040] To make the objectives, technical solutions, and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the accompanying drawings.

[0041] Figure 1 It is a schematic diagram of the structure of a projection device provided by an embodiment of the present application. Refer to Figure 1 , the projection device includes: a projection host 10, and a radar 20 connected to the projection host 10.

[0042] Among them, the radar 20 can transmit a detection signal under the drive of the operating voltage provided by the projection host 10, receive the echo signal emitted by the target object, and recognize the gesture of the hand of the target object based on the echo signal. Then, the radar 20 can send the recognized gesture to the projection host 10 for the projection host 10 to control the projection device to enter the shooting mode or exit the shooting mode based on the recognized gesture.

[0043] Optionally, the target object can be a human body. The radar 20 can be a millimeter-wave radar or an ultrasonic radar. If the radar 20 is a millimeter-wave radar, the detection signal can be a millimeter-wave signal, for example, it can be a frequency-modulated continuous wave (FMCW). If the radar 20 is an ultrasonic radar, the detection signal can be an ultrasonic signal.

[0044] Figure 2 It is a schematic diagram of the structure of a projection host provided by an embodiment of the present application. Refer to Figure 2, the projection host 10 includes: a multimedia processing circuit 110, a display control circuit 120, a light source drive circuit 130, an optical engine assembly 140, a light source 150, and a lens 160.

[0045] See Figure 2 , the multimedia processing circuit 110 is respectively connected to the radar 20 and the display control circuit 120. The multimedia processing circuit 110 is used to receive the encoded video signal through various communication interfaces, such as a universal serial bus (USB) interface. After that, the multimedia processing circuit 110 can transmit the encoded video signal picture to the display control circuit 120. Among them, the multimedia processing circuit 110 may include a system on chip (SoC).

[0046] The display control circuit 120 is also respectively connected to the light source drive circuit 130 and the optical engine assembly 140. The display control circuit 120 is used to decode the encoded video signal and send an optical engine control signal to the optical engine assembly 140 based on the decoded video signal. And the display control circuit 120 is also used to determine the drive current of the light source 150 based on the decoded video signal, and output an enable signal and an analog dimming (ADIM) signal to the light source drive circuit 130 connected to the light source 150 based on the drive current. Among them, the enable signal may be a pulse width modulation (PWM) signal.

[0047] The light source drive circuit 130 is used to receive the enable signal and the ADIM signal, and output a drive current to the corresponding light source 150 based on the enable signal and the ADIM signal to drive the light source 150 to emit light. Among them, the enable signal is used to control the presence or absence of the drive current transmitted to the light source 150, and the ADIM signal is used to control the magnitude of the drive current.

[0048] The optical engine assembly 140 integrates digital micromirror devices (DMD) and a DMD drive circuit. The DMD drive circuit is used to receive the optical engine control signal and drive the DMD to work based on the optical engine control signal. The DMD is used to modulate the light emitted by the light source 150 into an image beam under the control of the DMD drive circuit, and project the image beam onto the lens 160. The lens 160 can then project the image beam onto the projection plane to enable the projection device to project a picture.

[0049] The image to be projected drives the DMD to work. The DMD is used to modulate the light emitted by at least one light source 150 under the control of a DMD driving circuit to form the image to be projected. The lens 160 can magnify the image to be projected and project the image to be projected onto a target object in the form of a light beam. Among them, the target object can be a projection screen or a wall, etc.

[0050] In the embodiment of the present application, the projection device may include at least one light source 150 and a light source driving circuit 130 corresponding to each of the at least one light source. The at least one light source 150 includes at least a blue light source. For example, the at least one light source 150 includes: a red light source, a green light source, and a blue light source. Correspondingly, the at least one light source driving circuit 130 includes: a red light driving circuit, a green light driving circuit, and a blue light driving circuit.

[0051] Optionally, each light source 150 in the at least one light source 150 may be a laser light source. Correspondingly, the projection device may be a laser projection device (such as a laser projection TV). Or, each light source 150 may be other types of light sources such as a light-emitting diode (LED).

[0052] The embodiment of the present application provides a method for driving a light source, and this method is applied to a projection device. The projection device includes: a light source and a radar. For example Figure 1 and Figure 2 the projection device shown. See Figure 3 , this method includes:

[0053] Step 101, control the radar to emit a detection signal, and collect the echo signal reflected by the target object through the radar.

[0054] In the embodiment of the present application, after the projection device is started, the radar in the projection device can emit a detection signal. When the target object enters the detection area of the radar, the detection signal can be reflected by the target object to generate an echo signal. The radar can then receive the echo signal.

[0055] Step 102, identify the gesture of the hand of the target object based on the echo signal.

[0056] In the embodiment of the present application, the radar in the projection device can determine the point cloud data of the hand of the target object based on the received echo signal, and then determine the gesture of the hand based on the point cloud data.

[0057] The gesture can be one of the following gestures: a first gesture for instructing the projection device to enter the shooting mode, and a second gesture for instructing the projection device to exit the shooting mode. The shooting mode refers to a working mode of the projection device when the shooting device shoots the image projected by the projection device to obtain an image without color cast.

[0058] Step 103: If the gesture of the hand is the first gesture for instructing to enter the shooting mode, drive the light source to emit light with the first driving current in the shooting mode, so that the projection device operates in the shooting mode.

[0059] After the projection device recognizes the gesture of the hand of the target object, it can detect whether the gesture is the first gesture for instructing the projection device to enter the shooting mode. If the projection device determines that the gesture is the first gesture, it can read the first driving current in the shooting mode stored in advance, and can drive the light source to emit light with the first driving current, so that the projection device operates in the shooting mode.

[0060] Wherein, the first driving current refers to the driving current of the light source when the shooting device shoots the image projected by the projection device to obtain an image without color cast phenomenon.

[0061] In summary, the embodiment of the present application provides a method for driving a light source. This method can recognize the gesture of the target object through the radar, and after recognizing that the gesture is the first gesture for instructing to enter the shooting mode, drive the light source with the first driving current in the shooting mode. Since the first driving current is the driving current of the light source when the shooting device shoots an image without color cast, driving the light source with the first driving current can ensure that the shooting device shoots an image without color cast phenomenon. And because this method can control the working mode of the projection device based on the gesture of the hand of the target object, the flexibility of controlling the projection device is improved.

[0062] In the embodiment of the present application, taking the radar as a millimeter-wave radar as an example, the method for driving the light source provided by the embodiment of the present application is exemplarily described. This method can be applied to a projection device. The projection device may include: a light source and a radar. See Figure 4 , this method may include:

[0063] Step 201: Control the radar to emit a detection signal, and collect the echo signal reflected by the target object through the radar.

[0064] In the embodiment of the present application, after the projection device is started, the radar can emit a detection signal. When the target object enters the detection area of the radar, the detection signal can be reflected by the target object to generate an echo signal. The radar can then receive the echo signal.

[0065] Optionally, after the projection device is started, the radar can transmit detection signals under the drive of the operating voltage provided by the multimedia processing circuit of the projection device. Alternatively, the projection device may further include: a voice detection component. The voice detection component can collect voice commands and, after determining that the voice command includes a wake-up keyword, send a wake-up signal to the multimedia processing circuit. The multimedia processing circuit is further configured to, after receiving the wake-up signal, provide a power supply voltage for the radar so that the radar transmits detection signals. That is, the method provided in the embodiments of the present application can wake up the radar by means of far-field voice, and then recognize the gestures of the hand of the target object. In this way, electric energy can be saved. Among them, the wake-up keyword can be pre-stored in the voice detection component.

[0066] See Figure 5 , the radar may include: a signal synthesizer 01, at least one transmit antenna 02 (which may also be referred to as TX antenna 02), and a plurality of receive antennas 03 (which may also be referred to as RX antennas 03). The signal synthesizer 01 can be connected to the multimedia processing circuit 110 of the projection device, and the signal synthesizer 01 is configured to generate a detection signal (such as FMCW) under the drive of the operating voltage provided by the multimedia processing circuit 110, and transmit the detection signal through the at least one transmit antenna 02. After the transmitted detection signal is transmitted to the target object A, it can be reflected by the target object A to generate an echo signal. Then, the radar can receive the echo signal through the plurality of receive antennas 03.

[0067] Figure 6 is a schematic diagram showing the change of the amplitude of a detection signal over time provided by an embodiment of the present application, Figure 7 is a schematic diagram showing the change of the frequency of a detection signal over time provided by an embodiment of the present application. Figure 7 In, fs is the initial frequency of the detection signal, fe is the termination frequency of the detection signal, and S is the change rate of the frequency of the detection signal within the duration Tc, that is, the slope.

[0068] From Figure 6 it can be seen that the detection signal can be a signal whose frequency increases with time, that is, a chirp signal. A chirp signal is an electromagnetic wave signal whose frequency changes with time. From Figure 7 it can be seen that the frequency of the chirp signal can increase linearly with time. Thus, the detection signal is a linear FMCW. In addition, from Figure 7 it can also be seen that the bandwidth B of the detection signal satisfies: B = fe - fs. Correspondingly, the slope S satisfies: S = B / Tc.

[0069] Step 202: Determine the point cloud data of the hand of the target object based on the echo signal.

[0070] In the embodiments of the present application, please continue to refer to Figure 5 , the radar further includes: a mixer 04, a signal processing circuit 05, and a main control circuit 06. The mixer 04 can mix the detection signal generated by the signal synthesizer 01 and the echo signals received by each of the multiple receiving antennas 03 to obtain an intermediate frequency (IF) signal corresponding to each of the multiple receiving antennas 03, and transmit the intermediate frequency signals corresponding to the multiple receiving antennas 03 to the signal processing circuit 04. Wherein, the frequency of the intermediate frequency signal corresponding to each receiving antenna 03 is equal to the difference between the instantaneous frequency of the detection signal at any moment and the instantaneous frequency of the echo signal received by the receiving antenna.

[0071] The signal processing circuit 05 can filter the intermediate frequency signals corresponding to the multiple receiving antennas 03 to filter out the clutter in the multiple intermediate frequency signals, and then perform analog-to-digital conversion processing on the filtered intermediate frequency signals to obtain digitized intermediate frequency signals, and transmit the digitized intermediate frequency signals to the main control circuit 06.

[0072] For each of the multiple receiving antennas, the main control circuit 06 can perform digital-to-analog conversion processing on the digitized intermediate frequency signal of the receiving antenna 03, and perform fast Fourier transform (FFT) on the processed intermediate frequency signal to obtain a two-dimensional grid data table of the range dimension and Doppler dimension corresponding to the receiving antenna (which can also be called a range-Doppler matrix). Wherein, the Doppler dimension in the range-Doppler matrix represents the moving speed of the hand of the target relative to the radar, the range dimension represents the distance of the hand relative to the radar, and the elements in the range-Doppler matrix represent the signal strength of the intermediate frequency signal determined based on the echo signal reflected by the hand of the target at the corresponding distance and moving speed. And the peak value in the range-Doppler matrix is used to indicate the existence of a target at the corresponding distance. That is, the main control circuit can determine the distance from the hand of the target to the radar based on the peak value in the range-Doppler matrix. For example, if the value of the range dimension corresponding to a peak value in the range-Doppler matrix is 2 meters (m), the main control circuit can determine that the distance from the hand of the target to the radar is 2m.

[0073] Then, the main control circuit can obtain two-dimensional network data tables of multiple azimuth dimensions and Doppler dimensions based on the range-Doppler matrices of the multiple receiving antennas. After that, the main control circuit can perform non-coherent accumulation processing on the two-dimensional grid data tables of the multiple receiving range dimensions and Doppler dimensions, and the two-dimensional network data tables of the azimuth dimension and Doppler dimension to obtain three-dimensional point cloud data of the range dimension - azimuth dimension - Doppler dimension of the hand of the target. Each point in the point cloud data has characteristic information such as distance, moving speed, and azimuth.

[0074] Exemplarily, refer to Figure 8 , Figure 8 which shows a schematic diagram of an intermediate frequency signal obtained after mixing a detection signal and an echo signal. As Figure 8 shown, after the transmitting antenna transmits a detection signal (i.e., the TX signal shown in Figure 8 ), after a time duration τ, the receiving antenna receives an echo signal (i.e., the RX signal shown in Figure 8 ). Thus, it can be known that the transmission time duration of the detection signal emitted by the transmitting antenna between the projection device and the target is τ (which can also be referred to as the delay time duration).

[0075] And it can be seen from Figure 8 that the frequency f0 of the intermediate frequency signal obtained by mixing the transmitting antenna and the receiving antenna can be equal to the difference between the instantaneous frequency of the detection signal and the instantaneous frequency of the echo signal. That is, the frequency f0 can satisfy the following formula:

[0076] f0 = S * τ Formula (1)

[0077] Step 203: Determine the gesture of the hand of the target based on the point cloud data.

[0078] In the embodiments of the present application, the projection device can extract features from the point cloud data through a radar to obtain the feature information of the hand of the target. The feature information includes: the distance of the hand relative to the radar, the azimuth angle of the hand relative to the radar, and the moving speed of the hand relative to the radar. Then, the radar can determine the gesture of the hand based on the feature information.

[0079] In an alternative implementation, a gesture recognition model is pre-stored in the radar. The radar can input the feature information into the gesture recognition model to obtain the gesture of the hand output by the gesture recognition model. Among them, the gesture recognition model can be trained based on multiple sample information, and each sample information includes: a sample gesture, and the distance, azimuth angle, and moving speed of the hand to which the sample gesture belongs relative to the radar.

[0080] In the embodiments of the present application, the gesture recognition model can generate a time series corresponding to each feature (i.e., distance, azimuth angle, and moving speed) in the feature information based on the feature information of the hand of the target. Then, the gesture recognition model can decompose the time series corresponding to each feature in chronological order to determine the action of the hand of the target at each moment within the target time period (i.e., the transmission period of the detection signal). Then, the gesture recognition model can obtain the gesture of the hand of the target based on the actions arranged in chronological order.

[0081] For example, based on the feature information of the point cloud data, the gesture recognition model obtains three actions: "the palm is naturally unfolded, moved horizontally left and right, and the tiger's mouth is kept open during the movement". After that, the gesture recognition model can determine that the gesture of the hand of the target object is "the palm moves horizontally back and forth" based on these three actions.

[0082] In another alternative implementation, a plurality of alternative feature information corresponding to a plurality of alternative gestures are pre-stored in the radar. The plurality of alternative gestures include: a first gesture for instructing the projection device to enter the shooting mode, and a second gesture for instructing the projection device to exit the shooting mode. The radar can determine the similarity between each piece of alternative feature information in the plurality of alternative feature information and the feature information of the hand of the target object, and can determine the alternative gesture corresponding to the piece of alternative feature information with the highest similarity in the plurality of alternative feature information as the gesture of the hand of the target object.

[0083] In the embodiments of the present application, based on the ranging principle of the radar, it can be known that the radar can determine the distance of the hand of the target object relative to the radar based on the frequency f0 of the intermediate frequency signal corresponding to the receiving antenna. Based on the speed measurement principle of the radar, it can be known that the radar can determine the moving speed of the hand of the target object relative to the radar based on the phase difference between two consecutive intermediate frequency signals corresponding to the receiving antenna. Based on the angle measurement principle of the radar, it can be known that the radar can determine the azimuth angle of the hand of the target object relative to the radar based on the phase difference between the intermediate frequency signals corresponding to at least two receiving antennas among a plurality of receiving antennas, and the difference in the distances from the hand of the target object to the at least two receiving antennas.

[0084] Among them, the ranging principle of the radar is as follows: The transmission duration of the detection signal emitted by the transmitting antenna between the projection device and the target object is τ, and the τ satisfies the following formula:

[0085]

[0086] In formula (2), d is the distance of the hand of the target object relative to the radar, and c is the speed of light.

[0087] Since the frequency of the intermediate frequency signal can be obtained from the point cloud data, the distance d of the hand of the target object relative to the radar can be determined through the above formulas (1) and (2), and the distance d can satisfy the following formula:

[0088]

[0089] In formula (3), S is the change rate of the frequency of the detection signal within the duration Tc. And S is equal to the quotient of the bandwidth of the detection signal and the duration.

[0090] The speed measurement principle of the radar is derived based on the Doppler frequency shift. This Doppler frequency shift means that when the target moves at a constant speed along a certain direction, due to the difference in the propagation path of the wave, it will cause changes in the phase and frequency of the intermediate frequency signal synthesized by the mixer of the radar.

[0091] For example, the radar emits detection signals through at least one transmitting antenna at fixed time intervals Tc, that is, the duration of each detection signal is Tc. See Figure 9 , assuming that the radar emits detection signal TX1 and detection signal TX2 through at least one transmitting antenna at fixed time intervals Tc. The detection signal TX1 is reflected by the hand of the target to obtain the echo signal RX1, and the detection signal TX2 is reflected by the hand of the target to obtain the echo signal RX2. If the frequencies of the echo signal RX1 and the echo signal RX2 are the same and the phases are also the same (i.e., the phase difference is 0), it indicates that the hand of the target is in a stationary state.

[0092] If the frequencies of the echo signal RX1 and the echo signal RX2 are the same but the phases are different, it indicates that the hand of the target is in a moving state. For the case where the hand of the target is in a moving state, the radar can determine the moving speed of the hand of the target based on the phase difference between the echo signals RX1 and RX2.

[0093] Assume that the moving speed of the hand of the target is v. Then the distance Δd moved by the hand of the target within the time duration Tc can satisfy the following formula:

[0094] Δd = v × Tc Formula (4)

[0095] Since the phase φ of the intermediate frequency signal corresponding to the receiving antenna satisfies the following formula (5), the phase difference Δφ1 between two consecutive intermediate frequency signals corresponding to this receiving antenna can satisfy the following formula (6):

[0096]

[0097]

[0098] In formula (5), d is the distance from the hand of the target to the radar, and λ is the wavelength of the detection signal when the frequency is the initial frequency.

[0099] Based on the above formula (4) and formula (6), the moving speed v of the hand of the target can be determined to satisfy:

[0100]

[0101] Exemplarily, see Figure 10 , Figure 10 shows a comparison schematic diagram of two consecutive echo signals. From Figure 10It can be seen that the frequencies and phases of the two echo signals are different. Thus, it can be known that the hand of the target object is in a moving state.

[0102] Taking the azimuth angle as the angle of arrival as an example, the angle measurement principle of the radar is exemplarily described: Assume that the transmission directions of the echo signals reaching multiple receiving antennas after being emitted by the target object are parallel, and as Figure 11 shown, define the angle between the transmission direction of the echo signal and the target direction as the angle of arrival θ of the echo signal. Among them, multiple receiving antennas (i.e., Figure 11 the RX antenna 0, RX antenna 1, and RX antenna 2 shown) are coaxial array antennas, and the target direction X can be perpendicular to the extension direction Y of the axis of the coaxial array antenna.

[0103] As Figure 12 shown, the distance between two adjacent receiving antennas is r. Therefore, based on the principle of similar triangles, it can be determined that the relative delay experienced by the echo signals reaching two adjacent receiving antennas satisfies:

[0104]

[0105] Then, according to formula (5) and formula (8), it can be determined that the phase difference of the intermediate frequency signals corresponding to the two adjacent receiving antennas satisfies:

[0106]

[0107] After that, based on the above formula (9), the angle of arrival θ can be determined to satisfy:

[0108]

[0109] Step 204: If the gesture of the hand is the first gesture for indicating entering the shooting mode, then drive the light source to emit light with the first drive current in the shooting mode, so that the projection device operates in the shooting mode.

[0110] Among them, the first drive current refers to: when the shooting device takes a picture of the picture projected by the projection device to obtain a picture without color cast, the drive current of the light source.

[0111] Optionally, if the projection device determines that the gesture of the hand of the target object is the first gesture, and the projection device is currently operating in a non-shooting mode, then the light source can be driven to emit light with the first drive current in the shooting mode.

[0112] In the embodiment of the present application, after the radar recognizes the gesture of the hand of the target object, the recognized gesture can be sent to the multimedia processing circuit. If the multimedia processing circuit determines that the gesture of the hand is the first gesture, it can detect whether the shooting device is operating in a non-shooting mode. If the multimedia processing circuit determines that the shooting device is operating in the shooting mode, the operation can be ended.

[0113] If the multimedia processing circuit determines that the shooting device is operating in a non-shooting mode, it can send a first control instruction to the display control circuit. This first control instruction is used to instruct the display control circuit to drive the light source to emit light using the driving current in the shooting mode. Correspondingly, when the display control circuit receives this first control instruction, it can read the first driving current in the shooting mode stored in advance, and then use this first driving current to drive the light source to emit light, so that the projection device operates in the shooting mode.

[0114] Optionally, the multimedia processing circuit can be connected to the display control circuit through an inter-integrated circuit (IIC).

[0115] Step 205: If the gesture of the hand is a second gesture for exiting the shooting mode and the projection device is operating in the shooting mode, then drive the light source to emit light using the second driving current in the non-shooting mode, so that the projection device exits the shooting mode.

[0116] Among them, the second driving current is the driving current of the light source determined based on the picture to be projected by the projection device.

[0117] In the embodiment of the present application, after the radar sends the recognized gesture to the multimedia processing circuit, if the multimedia processing circuit determines that the gesture is a second gesture, it can detect whether the shooting device is operating in the shooting mode. If the multimedia processing circuit determines that the shooting device is operating in the non-shooting mode, it can end the operation. If the multimedia processing circuit determines that the shooting device is operating in the shooting mode, it can send a second control instruction to the display control circuit. This second control instruction is used to instruct the display control circuit to drive the light source to emit light using the driving current in the non-shooting mode. Correspondingly, after the display control circuit receives this second control instruction, it can read the driving current determined based on the picture to be projected by the projection device, and then use this driving current to drive the light source to emit light, so that the projection device exits the shooting mode.

[0118] The above embodiment is an exemplary illustration taking the radar as a millimeter-wave radar as an example. It can be understood that this radar can also be an ultrasonic radar. When the radar is an ultrasonic radar, the detection signal emitted by this radar is an ultrasonic signal. Correspondingly, this radar can recognize the gesture of the hand based on the ultrasonic signal reflected by the hand of the target object.

[0119] It can be understood that the sequence of steps of the light source driving method provided by the embodiment of the present application can be appropriately adjusted, and the steps can also be increased or decreased accordingly according to the situation. For example, step 205 can also be deleted according to the situation. Any method of change that can be easily thought of by any person skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application, so it will not be elaborated here.

[0120] In summary, the embodiment of the present application provides a driving method for a light source. This method can recognize the gesture of the target object through radar, and after recognizing that the gesture is the first gesture for indicating entering the shooting mode, drive the light source with the first driving current in the shooting mode. Since the first driving current is the driving current of the light source when the picture captured by the shooting device has no color cast, driving the light source with the first driving current can ensure that the picture captured by the shooting device has no color cast phenomenon. Moreover, since this method can control the working mode of the projection device based on the gesture of the hand of the target object, the flexibility of controlling the projection device is improved.

[0121] Figure 13 is a schematic structural diagram of another projection device provided by the embodiment of the present application. Refer to Figure 13 , this projection device includes: a projection host 10 and a voice detection component 30. The voice detection component 30 can, after receiving the first voice command including the wake-up keyword, perform voice recognition on the received second voice command, and trigger the projection device to enter (or exit) the shooting mode after recognizing that the second voice command is used to indicate entering (or exiting) the shooting mode. Among them, the connection relationship between the components of the projection host 10 is detailed in the description for Figure 2 , which will not be elaborated in the embodiment of the present application here.

[0122] The embodiment of the present application also provides a driving method for a light source, which is applied to a projection device. The projection device includes: a light source. For example, Figure 13 the projection device shown. Refer to Figure 14 , this method includes:

[0123] Step 301, if the received first voice command includes a wake-up keyword, perform voice recognition on the second voice command received after the first voice command.

[0124] In the embodiment of the present application, after the projection device is started, the voice detection component in the projection device can collect the first voice command and detect whether the first voice command includes a wake-up keyword. If the voice detection component determines that the first voice command includes a wake-up keyword, it can perform voice recognition on the second voice command received after the first voice command.

[0125] If the voice detection component determines that the first voice command does not include a wake-up keyword, it can continue to collect the first voice command and detect whether the collected first voice command includes a wake-up keyword. Among them, the wake-up keyword can be pre-stored in the voice detection component.

[0126] Step 302: If it is recognized that the second voice command is a voice command for instructing to enter the shooting mode, the light source is driven to emit light by using the first driving current in the shooting mode, so that the projection device operates in the shooting mode.

[0127] Wherein, the shooting mode refers to a working mode of the projection device when the shooting device shoots the image projected by the projection device to obtain an image without color cast. Correspondingly, the first driving current refers to the driving current of the light source when the shooting device shoots the image projected by the projection device to obtain an image without color cast phenomenon, that is, the driving current of the light source that can enable the shooting device to operate in the shooting mode.

[0128] In summary, the embodiment of the present application provides a method for driving a light source. This method can perform voice recognition on the collected second voice command after determining that the first voice command includes a wake-up keyword, and after recognizing that the second voice command is used to instruct to enter the shooting mode, drive the light source by using the first driving current in the shooting mode. Since the first driving current is the driving current of the light source when the shooting device shoots an image without color cast, driving the light source with the first driving current can ensure that the shooting device shoots an image without color cast phenomenon. And because this method can control the working mode of the projection device based on voice commands, the flexibility of controlling the projection device is improved.

[0129] Figure 15 This is another method for driving a light source provided by the embodiment of the present application, and this method can be applied to a projection device. Refer to Figure 15 This method may include:

[0130] Step 401: Detect whether the received first voice command includes a wake-up keyword.

[0131] In the embodiment of the present application, the projection device includes a voice detection component. After the projection device is started, the voice detection component in the projection device can collect the first voice command and detect whether the first voice command includes a wake-up keyword.

[0132] If the voice detection component determines that the first voice command includes a wake-up keyword, step 402 can be executed. If the voice detection component determines that the first voice command does not include a wake-up keyword, it can continue to collect the first voice command and continue to execute step 401. Among them, the wake-up keyword can be pre-stored in the voice detection component.

[0133] In the embodiment of the present application, the voice detection component may include a microphone and a voice recognition sub-component. The microphone can collect the first voice command and send the collected first voice command to the voice recognition sub-component for the voice recognition sub-component to detect whether the first voice command includes a wake-up keyword.

[0134] Step 402: Perform speech recognition on the second voice command received after the first voice command.

[0135] If the projection device determines that the received first voice command includes a wake-up keyword, it can perform speech recognition on the second voice command received after the first voice command.

[0136] In the embodiment of the present application, if the first voice command includes a wake-up keyword, the microphone can collect the second voice command and send the second voice command to the speech recognition sub-component. The speech recognition sub-component can then perform speech recognition on the second voice command.

[0137] Step 403: If it is recognized that the second voice command is a voice command for instructing to enter the shooting mode, drive the light source to emit light using the first drive current in the shooting mode, so that the projection device operates in the shooting mode.

[0138] Wherein, the first drive current refers to the drive current of the light source when the shooting device shoots the projected image of the projection device to obtain an image without color cast.

[0139] Optionally, if the projection device determines that the recognized second voice command is a voice command for instructing to enter the shooting mode, and the projection device is currently operating in a non-shooting mode, it can drive the light source to emit light using the first drive current in the shooting mode.

[0140] In the embodiment of the present application, after the voice detection component determines that the second voice command is recognized, it can also detect whether the recognized second voice command is a voice command for instructing to enter the shooting mode. If the voice detection component recognizes that the second voice command is a voice command for instructing to enter the shooting mode, it can send a first signal for instructing to enter the shooting mode to the multimedia processing circuit of the projection device. After receiving the first signal, if the multimedia processing circuit determines that the projection device is currently operating in a non-shooting mode, it can send a first control command to the display control circuit. Correspondingly, the display control circuit can respond to the first control command, read the first drive current in the shooting mode stored in advance, and drive the light source to emit light using the first drive current, so that the projection device operates in the shooting mode.

[0141] Step 404: If it is recognized that the second voice command is a voice command for instructing to exit the shooting mode, and the projection device is operating in the shooting mode, drive the light source to emit light using the second drive current in the non-shooting mode, so that the projection device exits the shooting mode.

[0142] Wherein, the second drive current is the drive current of the light source determined based on the image to be projected by the projection device.

[0143] In an embodiment of the present application, after the voice detection component determines that the second voice command is recognized, if it is determined that the recognized second voice command is a voice command for instructing to exit the shooting mode, a second signal for instructing to enter the exit shooting mode may be sent to the multimedia processing circuit of the projection device. After receiving the second signal, if it is determined that the projection device is currently in the shooting mode, the multimedia processing circuit may send a second control command to the display control circuit. Correspondingly, the display control circuit may respond to the second control command and drive the light source to emit light with a second drive current in the non-shooting mode, so that the projection device operates in the non-shooting mode.

[0144] According to the above description, it can be seen that the method provided by the embodiment of the present application can control the projection device to enter the shooting mode or exit the shooting mode through the far-field voice. In this way, the control flexibility of the projection device can be improved on the premise of ensuring that the captured image of the shooting device has no color deviation.

[0145] It can be understood that the order of the steps of the light source driving method provided by the embodiment of the present application can be appropriately adjusted, and the steps can also be increased or decreased accordingly according to the situation. For example, step 404 can also be deleted according to the situation. Any method of change that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application, so it will not be elaborated here.

[0146] In summary, the embodiment of the present application provides a method for driving a light source. The method can perform voice recognition on the collected second voice command after determining that the first voice command includes a wake-up keyword, and when it is recognized that the second voice command is used to instruct to enter the shooting mode, drive the light source with the first drive current in the shooting mode. Since the first drive current is the drive current of the light source when the captured image of the shooting device has no color deviation, driving the light source with the first drive current can ensure that the captured image of the shooting device has no color deviation. And since the method can control the working mode of the projection device based on the voice command, the control flexibility of the projection device is improved.

[0147] The embodiment of the present application also provides a projection device, which includes: a light source and a radar. The projection device is used for:

[0148] Controlling the radar to emit a detection signal and collecting the echo signal reflected by the target object through the radar;

[0149] Identifying the gesture of the hand of the target object based on the echo signal;

[0150] If the gesture of the hand is a first gesture for instructing to enter the shooting mode, driving the light source to emit light with the first drive current in the shooting mode, so that the projection device operates in the shooting mode.

[0151] Optionally, the projection device can be used for:

[0152] Determining point cloud data of the hand based on the echo signal;

[0153] Determining the gesture of the hand based on the point cloud data.

[0154] Optionally, the projection device can be used for:

[0155] Performing feature extraction on the point cloud data to obtain feature information of the hand, where the feature information includes: the distance of the hand relative to the radar, the azimuth angle of the hand relative to the radar, and the moving speed of the hand relative to the radar;

[0156] Determining the gesture of the hand based on the feature information.

[0157] Optionally, the projection device can be used for:

[0158] Inputting the feature information into a gesture recognition model to obtain the gesture of the hand output by the gesture recognition model.

[0159] Optionally, the projection device can also be used for:

[0160] If the gesture of the hand is a second gesture for exiting the shooting mode and the projection device is operating in the shooting mode, then the light source is driven to emit light by a second driving current in the non-shooting mode, so that the projection device exits the shooting mode.

[0161] Optionally, the radar is a millimeter-wave radar; the detection signal is a frequency-modulated continuous wave.

[0162] In summary, the embodiment of the present application provides a projection device. The projection device can perform speech recognition on the collected second speech instruction after determining that the first speech instruction includes a wake-up keyword, and after recognizing that the second speech instruction is used to indicate entering the shooting mode, drive the light source with a first driving current in the shooting mode. Since the first driving current is the driving current of the light source when the picture captured by the shooting device has no color cast, driving the light source with the first driving current can ensure that the picture captured by the shooting device has no color cast phenomenon. And because the working mode of the projection device can be controlled based on the speech instruction, the flexibility of controlling the projection device is improved.

[0163] The embodiment of the present application also provides a projection device, which includes: a light source. The projection device is used for:

[0164] If the received first speech instruction includes a wake-up keyword, then perform speech recognition on the second speech instruction received after the first speech instruction;

[0165] If it is recognized that the second voice command is a voice command for instructing to enter the shooting mode, the light source is driven to emit light by using the first driving current in the shooting mode, so that the projection device operates in the shooting mode.

[0166] Optionally, the projection device can also be used for:

[0167] If it is recognized that the second voice command is a voice command for instructing to exit the shooting mode, and the projection device is operating in the shooting mode, the light source is driven to emit light by using the second driving current in the non-shooting mode, so that the projection device exits the shooting mode.

[0168] In summary, the embodiment of the present application provides a projection device. The projection device can perform voice recognition on the collected second voice command after determining that the first voice command includes a wake-up keyword, and after recognizing that the second voice command is used to instruct to enter the shooting mode, drive the light source by using the first driving current in the shooting mode. Since the first driving current is the driving current of the light source when the image captured by the shooting device has no color cast, driving the light source by using the first driving current can ensure that the image captured by the shooting device has no color cast phenomenon. And, since the working mode of the projection device can be controlled based on the voice command, the flexibility of controlling the projection device is improved.

[0169] The embodiment of the present application provides a projection device. The projection device may include a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the driving method of the light source provided in the above embodiment, such as Figure 3 , Figure 4 , Figure 14 or Figure 15 the method shown.

[0170] The embodiment of the present application provides a computer-readable storage medium. A computer program is stored in the computer-readable storage medium. The computer program is loaded and executed by the processor to implement the driving method of the light source provided in the above embodiment, such as Figure 3 , Figure 4 , Figure 14 or Figure 15 the method shown.

[0171] The embodiment of the present application also provides a computer program product including instructions. When the computer program product runs on a computer, it causes the computer to execute the driving method of the light source provided in the above method embodiment, such as Figure 3 , Figure 4 , Figure 14 or Figure 15 the method shown.

[0172] Those of ordinary skill in the art can understand that all or part of the steps to implement the above embodiments can be completed by hardware or by a program instructing relevant hardware. The program can be stored in a computer-readable storage medium, and the above-mentioned storage medium can be a read-only memory, a magnetic disk, an optical disc, etc.

[0173] It should be understood that the "and / or" mentioned herein represents three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. Also, the meaning of the term "at least one" in this application is one or more, and the meaning of the term "a plurality" in this application is two or more.

[0174] The terms "first", "second", etc. in this application are used to distinguish identical or similar items with basically the same functions. It should be understood that there is no logical or temporal dependency between "first", "second", and "nth", nor are the quantity and execution order limited. For example, without departing from the scope of the various examples, the first drive current can be referred to as the second drive current, and similarly, the second drive current can be referred to as the first drive current.

[0175] The above are only exemplary embodiments of this application and are not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims

1. A driving method for a light source, characterized in that, Applied to a projection device, the method is applied when the user needs to record the screen through a shooting device during the process of the projection device projecting the screen. The projection device includes: a light source and a radar; the method includes: Controlling the radar to emit a detection signal, and collecting the echo signal reflected by the target through the radar; Identifying the gesture of the hand of the target based on the echo signal; If the gesture of the hand is a first gesture for indicating entering the shooting mode, then driving the light source to emit light with a first driving current in the shooting mode, so that the projection device operates in the shooting mode. The shooting mode refers to a working mode in which a shooting device shoots the screen projected by the projection device to obtain a non-color-biased screen. The shooting device and the projection device are two different devices.

2. The method according to claim 1, characterized in that, The identifying the gesture of the hand of the target based on the echo signal includes: Determining the point cloud data of the hand based on the echo signal; Determining the gesture of the hand based on the point cloud data.

3. The method according to claim 2, characterized in that, The determining the gesture of the hand based on the point cloud data includes: Performing feature extraction on the point cloud data to obtain the feature information of the hand. The feature information includes: the distance of the hand relative to the radar, the azimuth angle of the hand relative to the radar, and the moving speed of the hand relative to the radar; Determining the gesture of the hand based on the feature information.

4. The method according to claim 3, characterized in that, The determining the gesture of the hand based on the feature information includes: Inputting the feature information into a gesture recognition model to obtain the gesture of the hand output by the gesture recognition model.

5. The method according to any one of claims 1 to 4, characterized in that, The method further includes: If the gesture of the hand is a second gesture for indicating exiting the shooting mode, and the projection device is operating in the shooting mode, then driving the light source to emit light with a second driving current in the non-shooting mode, so that the projection device exits the shooting mode.

6. The method according to any one of claims 1 to 4, characterized in that, The radar is a millimeter-wave radar; The detection signal is a frequency-modulated continuous wave.

7. A driving method for a light source, characterized in that, Applied to a projection device, the method is applied when the user needs to record the screen through a shooting device during the process of the projection device projecting the screen. The projection device includes: a light source; the method includes: If the first voice command received includes a wake-up keyword, then performing voice recognition on the second voice command received after the first voice command; If it is recognized that the second voice command is a voice command for indicating entering the shooting mode, then driving the light source to emit light with a first driving current in the shooting mode, so that the projection device operates in the shooting mode. The shooting mode refers to a working mode in which a shooting device shoots the screen projected by the projection device to obtain a non-color-biased screen. The shooting device and the projection device are two different devices.

8. The method according to claim 7, characterized in that, The method further includes: If it is recognized that the second voice command is a voice command for indicating exiting the shooting mode, and the projection device is operating in the shooting mode, then driving the light source to emit light with a second driving current in the non-shooting mode, so that the projection device exits the shooting mode.

9. A projection device for implementing the method according to claim 1, characterized in that, The projection device includes: a light source and a radar; the projection device is configured to: Control the radar to emit a detection signal, and collect an echo signal reflected by a target object through the radar; Identify a gesture of the hand of the target object based on the echo signal; If the gesture of the hand is a first gesture for indicating entry into a shooting mode, drive the light source to emit light using a first drive current in the shooting mode, so that the projection device operates in the shooting mode. The shooting mode refers to a working mode in which a shooting device shoots the image projected by the projection device to obtain an image without color cast. The shooting device and the projection device are two different devices.

10. A projection device for implementing the method according to claim 7, characterized in that, The projection device includes: a light source; the projection device is configured to: If a first voice command received includes a wake-up keyword, perform voice recognition on a second voice command received after the first voice command; If it is recognized that the second voice command is a voice command for indicating entry into a shooting mode, drive the light source to emit light using a first drive current in the shooting mode, so that the projection device operates in the shooting mode. The shooting mode refers to a working mode in which a shooting device shoots the image projected by the projection device to obtain an image without color cast. The shooting device and the projection device are two different devices.

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