Laser projection device and driving method of light source thereof

Abstract

The application discloses a laser projection device and a driving method of a light source thereof. A display control circuit in the laser projection device can output a switching control signal to a switching circuit based on a light-emitting timing sequence of a plurality of second laser light sources, and output a first driving signal to a first light source driving circuit and a second driving signal to a second light source driving circuit. The first driving signal is used to drive the first light source driving circuit to output a first driving current to the first laser light source, and the second driving signal is used to drive the second light source driving circuit to output a second driving current. The switching circuit can be controlled by the switching control signal to turn on the second light source driving circuit and one of the plurality of second laser light sources, so as to drive the second laser light source to emit light. Since the second light source driving circuit can drive the plurality of second laser light sources to emit light, the structure of the laser projection device is effectively simplified.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of projection display, in particular to a laser projection device and a driving method of a light source thereof. BACKGROUND

[0002] The laser projection device generally comprises laser light sources of red, green and blue colors, and three light source driving circuits corresponding to the laser light sources of the three colors. Each light source driving circuit is used to drive the corresponding laser light source to emit light.

[0003] However, the structure of the laser projection device in the related art is relatively complex. SUMMARY

[0004] The present application provides a laser projection device and a driving method of a light source thereof, which can solve the problem of complex structure of the laser projection device in the related art. The technical solution is as follows:

[0005] In one aspect, a laser projection device is provided, comprising a display control circuit, a first light source driving circuit, a second light source driving circuit, a switch circuit, a first laser light source, and a plurality of second laser light sources.

[0006] The display control circuit is connected with the control end of the switch circuit, the input end of the first light source driving circuit, and the input end of the second light source driving circuit, respectively. The display control circuit is used to output a switch control signal to the switch circuit based on the light emission timing of the plurality of second laser light sources, and output a first driving signal to the first light source driving circuit and a second driving signal to the second light source driving circuit. The first driving signal and the second driving signal comprise an enable signal and a brightness control signal.

[0007] The output end of the first light source driving circuit is connected with the first laser light source. The first light source driving circuit is used to output a first driving current to the first laser light source under the driving of the first driving signal, so as to drive the first laser light source to emit light.

[0008] The output end of the second light source driving circuit is connected with the first end of the switch circuit. The second light source driving circuit is used to output a second driving current under the driving of the second driving signal.

[0009] The second end of the switch circuit is connected with the plurality of second laser light sources. The switch circuit is used to turn on the second light source driving circuit and one of the plurality of second laser light sources under the control of the switch control signal, so as to drive the second laser light source to emit light.

[0010] In another aspect, a light source driving method of a laser projection device is provided, the laser projection device comprising a display control circuit, a first light source driving circuit, a second light source driving circuit, a switch circuit, a first laser light source, and a plurality of second laser light sources; the method comprising:

[0011] The display control circuit outputs a switch control signal to the switch circuit and outputs a first driving signal to the first light source driving circuit and a second driving signal to the second light source driving circuit based on the light emission timing of the plurality of second laser light sources, the first driving signal and the second driving signal comprising an enable signal and a brightness control signal;

[0012] The first light source driving circuit outputs a first driving current to the first laser light source under the driving of the first driving signal to drive the first laser light source to emit light;

[0013] The second light source driving circuit outputs a second driving current under the driving of the second driving signal;

[0014] The switch circuit turns on the second light source driving circuit and one of the plurality of second laser light sources under the control of the switch control signal to drive the second laser light source to emit light.

[0015] In yet another aspect, a laser projection device is provided, the laser projection device comprising a memory, a processor, and a computer program stored in the memory, the processor implementing the light source driving method of the above aspect when executing the computer program.

[0016] In still another aspect, a computer readable storage medium is provided, the computer readable storage medium storing instructions, the instructions being loaded and executed by a processor to implement the light source driving method of the above aspect.

[0017] In still another aspect, a computer program product comprising instructions which, when the computer program product is run on a computer, cause the computer to carry out the light source driving method of the above aspect.

[0018] The technical solutions provided in the present application have at least the following beneficial effects:

[0019] The application provides a laser projection device and a driving method of a light source thereof. A display control circuit in the laser projection device is capable of outputting a switching control signal to a switching circuit based on a light-emitting timing sequence of a plurality of second laser light sources, and outputting a first driving signal to a first light source driving circuit and a second driving signal to a second light source driving circuit. The first driving signal is used to drive the first light source driving circuit to output a first driving current to the first laser light source, and the second driving signal is used to drive the second light source driving circuit to output a second driving current. The switching circuit is capable of turning on the second light source driving circuit and one of the plurality of second laser light sources under the control of the switching control signal, so as to drive the second laser light source to emit light. Since the second light source driving circuit is capable of driving the plurality of second laser light sources to emit light, the structure of the laser projection device is effectively simplified. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0021] Figure 1 is a structural schematic diagram of a laser projection device provided by an embodiment of the present application;

[0022] Figure 2 is a structural schematic diagram of another laser projection device provided by an embodiment of the present application;

[0023] Figure 3 is a structural schematic diagram of still another laser projection device provided by an embodiment of the present application;

[0024] Figure 4 is a waveform diagram of output signals of various devices in a laser projection device provided by an embodiment of the present application;

[0025] Figure 5 is a structural schematic diagram of still another laser projection device provided by an embodiment of the present application;

[0026] Figure 6 is a structural schematic diagram of still another laser projection device provided by an embodiment of the present application;

[0027] Figure 7 is a flowchart of a light source driving method of a laser projection device provided by an embodiment of the present application;

[0028] Figure 8 is a flowchart of another light source driving method of a laser projection device provided by an embodiment of the present application;

[0029] Figure 9 This is a schematic flowchart of another light source driving method for a laser projection device provided in an embodiment of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0031] Figure 1 This is a schematic diagram of the structure of a laser projection device provided in an embodiment of this application, with reference to... Figure 1 The laser projection device includes: a display control circuit 10, a first light source driving circuit 20, a second light source driving circuit 30, a switching circuit 40, a first laser light source 50, and a plurality of second laser light sources 60. The first laser light source 50 and the plurality of second laser light sources 60 are of different colors. For example, the first laser light source 50 can be a red laser light source, and the plurality of second laser light sources 60 can include green and blue laser light sources. Alternatively, the first laser light source 50 can be a green laser light source, and the plurality of second laser light sources 60 can include red and blue laser light sources. Or, the first laser light source 50 can be a blue laser light source, and the plurality of second laser light sources 60 can include red and green laser light sources.

[0032] like Figure 1 As shown, the display control circuit 10 is connected to the control terminal C of the switching circuit 40, the input terminal of the first light source driving circuit 20, and the input terminal of the second light source driving circuit 30, respectively. The display control circuit 10 is used to output a switching control signal to the switching circuit 40 based on the emission timing of the multiple second laser light sources 60, and to output a first driving signal to the first light source driving circuit 20 and a second driving signal to the second light source driving circuit 30. The first driving signal includes an enable signal EN_1 and a brightness control signal DIMMING_1, and the second driving signal includes an enable signal EN_2 and a brightness control signal DIMMING_2.

[0033] The output end of the first light source driving circuit 20 is connected with the first laser light source 50. The first light source driving circuit 20 is configured to output a first driving current to the first laser light source 50 under the driving of a first driving signal, so as to drive the first laser light source 50 to emit light. The output end of the second light source driving circuit 30 is connected with the first end 1 of the switch circuit 40. The second light source driving circuit 30 is configured to output a second driving current under the driving of a second driving signal. The second end 2 of the switch circuit 40 is connected with a plurality of second laser light sources 60. The switch circuit 40 is configured to, under the control of a switch control signal, turn on the second light source driving circuit 30 and one of the plurality of second laser light sources 60, so as to drive the second laser light source 60 to emit light.

[0034] In the embodiment of the present application, after the laser projection device is powered on, the display control circuit 10 of the laser projection device can output a switch control signal to the switch circuit 40 based on the light emission information of the plurality of laser light sources, so as to control the switching state (i.e. the on-off state of the first end 1 and the plurality of second laser light sources 60) of the switch circuit 40. The switch control signal can be a level signal. In addition, the display driving circuit 10 can also provide a first driving signal to the first light source driving circuit 20 and a second driving signal to the second light source driving circuit 30 based on the light emission information. The enable signals in the two driving signals are used to control the working state of the first light source driving circuit 20 and the second light source driving circuit 30, i.e. whether the two light source driving circuits output driving current. The brightness control signals in the two driving signals are used to control the size of the driving current output by the two light source driving circuits.

[0035] The light emission information of the plurality of laser light sources can include duty time and current information of the plurality of laser light sources. The duty time of the plurality of laser light sources can indicate the light emission timing and light emission time length of the plurality of laser light sources in a unit time length (e.g. 1 second). The current information of the plurality of laser light sources refers to the rated driving current required by the plurality of laser light sources when emitting light. The rated driving current of the laser light source refers to the driving current that can drive the laser light source to emit light normally.

[0036] The first light source driving circuit 20 and the second light source driving circuit 30 can output driving current after receiving the enable signal and the brightness control signal. The brightness control signal can be a pulse width modulation (PWM) signal. The size of the driving current is positively correlated with the duty ratio of the brightness control signal, i.e. the greater the duty ratio of the brightness control signal, the higher the signal value of the driving current. Correspondingly, the higher the light emission brightness of the laser light source driven by the driving current.

[0037] The switch circuit 40 connected with the second light source driving circuit 30 can, after receiving the switch control signal, conduct the second light source driving circuit 30 with one of the second laser light sources 60 under the control of the switch control signal. Thus, the driving current output by the second light source driving circuit 30 can drive the conducted one of the second laser light sources 60 to emit light.

[0038] That is, the first driving current output by the first light source driving circuit 20 can be directly transmitted to the first laser light source 50 to drive the first laser light source 50 to emit light. The second driving current output by the second light source driving circuit 30 needs to be transmitted to one of the second laser light sources 60 conducted by the second light source driving circuit 30 under the control of the switch circuit 40.

[0039] As a possible implementation, the display control circuit 10 can control the first laser light source 50 and the plurality of second laser light sources 60 to emit light in sequence through the first light source driving circuit 20 and the second light source driving circuit 30. That is, the light emitting period of the first laser light source 50 and the plurality of second laser light sources 60 is not overlapped. For example, the display control circuit 10 can first output the first brightness control signal DIMMING_1 and the first enable signal EN_1 to the first light source driving circuit 20 to make the first light source driving circuit 20 drive the first laser light source 50 to emit light. After the light emitting time of the first laser light source 50 reaches the duty time of the first laser light source 50, the display control circuit 10 outputs the second brightness control signal DIMMING_2 and the second enable signal EN_2 to the second light source driving circuit 30, and outputs the switch control signal to the switch circuit 40, so that the second light source driving circuit 30 drives the plurality of second laser light sources 60 to emit light in sequence.

[0040] As another possible implementation, the display control circuit 10 can output the second brightness control signal DIMMING_2 and the second enable signal EN_2 to the second light source driving circuit 30, and output the switch control signal to the switch circuit 40 when outputting the first brightness control signal DIMMING_1 and the first enable signal EN_1 to the first light source driving circuit 20. At this time, the first laser light source 50 can emit light at the same time as one of the second laser light sources 60 being conducted. Thus, the light beams emitted by the first laser light source 50 and the conducted one of the second laser light sources 60 can be mixed into a new color light beam. For example, the light beams emitted by the green laser light source and the red laser light source can be mixed into a yellow light beam, and the light beams emitted by the green laser light source and the blue laser light source can be mixed into a cyan light beam.

[0041] It can be understood that the brightness of the mixed light beams emitted by two laser light sources of different colors is higher than the brightness of the light beams emitted by a single laser light source. Therefore, in the process of displaying and projecting the projection image by the laser projection device, the display control circuit 10 drives the first laser light source 50 and the second laser light source 60 to emit light at the same time through the first light source driving circuit 20 and the second light source driving circuit 30, so that the laser projection device can project a projection image with high brightness, thereby ensuring that the display effect of the projection image is good.

[0042] It can also be understood that, since the switch circuit 40 can control the on-off state of the second light source driving circuit 30 and any one of the plurality of second laser light sources 60 under the control of the switch control signal, the laser projection device only needs to drive the light emission of a plurality of laser light sources with different colors through two light source driving circuits. Therefore, the structure of the laser projection device is effectively simplified, and the manufacturing cost of the laser projection device is reduced.

[0043] In summary, the embodiment of the present application provides a laser projection device. The display control circuit in the laser projection device can output a switch control signal to a switch circuit based on the light emission timing of a plurality of second laser light sources, and be configured to output a first driving signal to a first light source driving circuit and a second driving signal to a second light source driving circuit. The first driving signal is used to drive the first light source driving circuit to output a first driving current to the first laser light source, and the second driving signal is used to drive the second light source driving circuit to output a second driving current. The switch circuit can turn on the second light source driving circuit and one of the plurality of second laser light sources under the control of the switch control signal, so as to drive the second laser light source to emit light. Since the second light source driving circuit can drive a plurality of second laser light sources to emit light, the structure of the laser projection device is effectively simplified.

[0044] Moreover, since the display control circuit can output driving signals to the first light source driving circuit and the second light source driving circuit respectively, the flexibility of light source driving of the laser projection device is effectively improved.

[0045] Alternatively, the display control circuit 10 can include a digital light processing (DLP) chip. Or, the display control circuit 10 can include a microcontroller unit (MCU), which can also be referred to as a single-chip microcomputer. Alternatively, the display control circuit 10 can include a system on chip (SoC). The first light source driving circuit 20 and the second light source driving circuit 30 can each include a constant current driving integrated circuit (IC), which can also be referred to as a constant current driving chip.

[0046] Figure 2 is another structural schematic diagram of a laser projection device provided by an embodiment of the present application, referring to Figure 2 The laser projection device can further include a power supply circuit 70. An output end of the power supply circuit 70 is connected with input ends of the first light source driving circuit 20 and the second light source driving circuit 30 respectively. The power supply circuit 70 is configured to provide a first driving voltage VCC_1 to the first light source driving circuit 20 and a second driving voltage VCC_2 to the second light source driving circuit 30. Thus, the first light source driving circuit 20 can output a first driving current under the driving of the first driving voltage VCC_1, and the second light source driving circuit 30 can output a second driving current under the driving of the second driving voltage VCC_2. The voltage value of the first driving voltage VCC_1 and the voltage value of the second driving voltage VCC_2 can be the same.

[0047] Optionally, the power supply circuit 70 can include an alternating current-direct current (AD-DC) converter.

[0048] Optionally, referring to Figure 3 The switch circuit 40 can include a plurality of first transistors M1 corresponding to the plurality of second laser light sources 60 one by one.

[0049] As shown in Figure 3 the gate (G) of each first transistor M1 is connected with the control end C of the switch circuit 40, the first pole of each first transistor M1 is connected with the output end of the second light source driving circuit 30 as the first end 1 of the switch circuit 40, and the second pole of each first transistor M1 is connected with the corresponding second laser light source 60 as the second end 2 of the switch circuit 40.

[0050] Optionally, referring to Figure 3 The plurality of first transistors M1 can all be P-type metal oxide semiconductor (MOS) tubes. The first pole of the plurality of first transistors M1 can be a source (S), and the second pole of the plurality of first transistors M1 can be a drain (D).

[0051] In the embodiment of the present application, the display control circuit 10 can obtain the light emission information of the plurality of laser light sources in the laser projection device during projection after power-on start (which can also be referred to as initialization). The light emission information can include the duty time and current information of the plurality of laser light sources. The duty time of the plurality of laser light sources can indicate the light emission timing and light emission duration of the plurality of laser light sources. The light emission information of the plurality of laser light sources can be pre-stored in the display control circuit 10. Alternatively, the laser projection device can further include a memory. The light emission information of the plurality of laser light sources can be obtained by the display control circuit 10 from the memory after power-on start.

[0052] The display control circuit 10 can output, to the gate G of the first transistor M1 corresponding to the target second laser light source 60 in the switch circuit 40, a switch control signal of an active level, output, to the gate G of the first transistor M1 corresponding to the second laser light source 60 other than the target second laser light source 60 in the plurality of second laser light sources 60, a switch control signal of an inactive level, and output, to the second light source driving circuit 30, a brightness control signal corresponding to the target second laser light source 60, based on the light emission information of the plurality of laser light sources. The active level of the switch control signal can be a low level relative to the inactive level. The target second laser light source 60 can be the second laser light source 60 currently required to be turned on by the display control circuit 10 based on the light emission timing of the plurality of laser light sources.

[0053] In the embodiment of the present application, the second light source driving circuit 30 can transmit a second driving current to the source S of the plurality of first transistors M1 based on the brightness control signal corresponding to the target second laser light source 60. The gate G of the first transistor M1 corresponding to the target second laser light source 60 can turn on the source S and the drain D thereof after receiving the switch control signal of the active level. Thus, the second driving current output by the second light source driving circuit 30 can drive the target second laser light source 60 to emit light. At this time, the second laser light source 60 other than the target second laser light source 60 in the plurality of second laser light sources 60 does not emit light.

[0054] When the target second laser light source 60 needs to be turned off, the display control circuit 10 can output a switch control signal of an inactive level to the gate G of the first transistor M1 corresponding to the target second laser light source 60, so that the first transistor M1 turns off the source S and the drain D thereof. Thus, the second driving current output by the second light source driving circuit 30 can stop driving the target second laser light source 60 to emit light.

[0055] The on duration of the first transistor M1 corresponding to the target second laser light source 60 can be the duty time of the target second laser light source 60. After determining that the on duration of the first transistor M1 corresponding to the target second laser light source 60 reaches the duty time of the target second laser light source 60, the display control circuit 10 can output an invalid level of the switch control signal to the gate G of the first transistor M1. In addition, the display control circuit 10 can output a valid level of the switch control signal to the gate G of the first transistor M1 corresponding to another second laser light source 60 (i.e., a new target second laser light source 60) in the plurality of second laser light sources 60, and output the brightness control signal corresponding to the another second laser light source 60 to the light source driving circuit 20.

[0056] Optionally, the display control circuit 10 can output a valid level of the switch control signal to the gate G of the first transistor M1 corresponding to another second laser light source 60 in the plurality of second laser light sources 60 after the duration of outputting an invalid level of the switch control signal to the gate G of the first transistor M1 corresponding to the target second laser light source 60 reaches a target duration t. The target duration can be determined based on the off duration of the first transistor M1 corresponding to the target second laser light source 60, for example, the target duration can be greater than or equal to the off duration. In addition, the off durations of the first transistors M1 corresponding to the plurality of second laser light sources 60 can be the same.

[0057] Optionally, referring to Figure 3 , the first laser light source 50 can be a green laser light source 50_G, and the plurality of second laser light sources 60 can include a red laser light source 60_R and a blue laser light source 60_B. Referring to Figure 4 , after power-on, the display control circuit 10 can first output a valid level of the enable signal EN_1 and the brightness control signal DIMMING_1 corresponding to the green laser light source 50_G to the first light source driving circuit 20. The first light source driving circuit 20 can in turn output a first driving current DC_1 to the green laser light source 50_G to drive the green laser light source 50_G to emit light. At this time, the red laser light source 60_R and the blue laser light source 60_B do not emit light. As shown in Figure 4 , the valid level of the enable signal EN_1 can be a high level relative to an invalid level.

[0058] After the emission duration of the green laser light source 50_G reaches the duty time Duty1 corresponding to the green laser light source 50_G, the display control circuit 10 can output the enable signal EN_1 of the invalid level to the first light source driving circuit 20, and stop outputting the brightness control signal DIMMING_1 corresponding to the green laser light source 50_G to the first light source driving circuit 20. At this time, the green laser light source 50_G stops emitting light. After determining that the duration of the green laser light source 50_G stopping emitting light reaches the target duration t, the display control circuit 10 can output the enable signal EN_2 of the valid level and the brightness control signal DIMMING_2 corresponding to the red laser light source 60_R to the second light source driving circuit 30, and output the switch control signal DRVM_1 of the valid level to the gate G of the first transistor M1 corresponding to the red laser light source 60_R. At this time, the first transistor M1 can turn on the second light source driving circuit 30 and the red laser light source 60_R. The second driving current DC_2 output by the second light source driving circuit 30 can drive the red laser light source 60_R to emit light.

[0059] After the emission duration of the red laser light source 60_R reaches the duty time Duty2 corresponding to the red laser light source 60_R, the display control circuit 10 can output the switch control signal DRVM_1 of the invalid level to the gate G of the first transistor M1 corresponding to the red laser light source 60_R. At this time, the red laser light source 60_R stops emitting light. After determining that the duration of the red laser light source 60_R stopping emitting light reaches the target duration, the display control circuit 10 can output the switch control signal DRVM_2 of the valid level to the gate G of the first transistor M1 corresponding to the blue laser light source 60_B, and output the brightness control signal DIMMING_2 corresponding to the blue laser light source 60_B to the second light source driving circuit 30. At this time, the first transistor M1 corresponding to the blue laser light source 60_B can turn on the second light source driving circuit 30 and the blue laser light source 60_B under the control of the switch control signal DRVM_2. The second driving current DC_3 output by the second light source driving circuit 30 can drive the blue laser light source 60_B to emit light.

[0060] After the emission duration of the blue laser light source 60_B reaches the duty time Duty3 corresponding to the blue laser light source 60_B, the display control circuit 10 can output the switch control signal DRVM_2 of the invalid level to the gate G of the first transistor M1 corresponding to the blue laser light source 60_B. At this time, the blue laser light source 60_B stops emitting light.

[0061] In the embodiments of the present application, if the laser projection device needs to increase the brightness of the projected projection image, the first light source driving circuit 20 and the second light source driving circuit 30 can simultaneously output driving currents to make the first laser light source 50 and one of the plurality of second laser light sources 60 emit light at the same time. With continued reference to Figure 4 When the display control circuit 10 determines that the duration for which the blue laser light source 60_B stops emitting light reaches the target duration, the display control circuit 10 can output the enable signal EN_1 at the active level and the brightness control signal DIMMING_1 corresponding to the green laser light source 50_G to the first light source driving circuit 20, output the enable signal EN_2 at the active level and the brightness control signal DIMMING_2 corresponding to the red laser light source 60_R to the second light source driving circuit 30, and output the switch control signal DRVM_1 at the active level to the gate G of the first transistor M1 corresponding to the red laser light source 60_R in the switch circuit 40. At this time, the green laser light source 50_G and the red laser light source 60_R can emit light at the same time. For example, the color of the mixed light beams emitted by the green laser light source 50_G and the red laser light source 60_R can be yellow.

[0062] When the durations for which the green laser light source 50_G and the red laser light source 60_R emit light reach the pre-set duty time Duty4, the display control circuit 10 can output the switch control signal DRVM_1 at the inactive level to the gate G of the first transistor M1 corresponding to the red laser light source 60_R, and stop outputting the enable signal EN_1 at the active level to the first light source driving circuit 20. At this time, the red laser light source 60_R and the green laser light source 50_G stop emitting light.

[0063] When the display control circuit 10 determines that the durations for which the red laser light source 60_R and the green laser light source 50_G stop emitting light reach the target duration, the display control circuit 10 can output the enable signal EN_1 at the active level and the brightness control signal DIMMING_1 corresponding to the green laser light source 50_G to the first light source driving circuit 20, output the enable signal EN_2 at the active level and the brightness control signal DIMMING_2 corresponding to the blue laser light source 60_B to the second light source driving circuit 30, and output the switch control signal DRVM_2 at the active level to the gate G of the first transistor M1 corresponding to the blue laser light source 60_B in the switch circuit 40. At this time, the green laser light source 50_G and the blue laser light source 60_B can emit light at the same time. For example, the color of the mixed light beams emitted by the green laser light source 50_G and the blue laser light source 60_B can be cyan.

[0064] After the light-emitting duration of the green laser light source 50_G and the blue laser light source 60_B reaches the preset duty time Duty5, the display control circuit 10 can output an invalid level switch control signal DRVM_2 to the gate G of the first transistor M1 corresponding to the blue laser light source 60_B, and stop outputting an effective level enable signal EN_1 to the first light source driving circuit 20. At this time, the blue laser light source 60_B and the green laser light source 50_G stop emitting light.

[0065] Optionally, as shown in Figure 5 , the laser projection device can further include: a first current adjusting circuit 80 corresponding to the first light source driving circuit 20, and a second current adjusting circuit 90 corresponding to the second light source driving circuit 30. Referring to Figure 5 , the first current adjusting circuit 80 is connected with the output end of the first light source driving circuit 20 and the first laser light source 50 respectively. The first current adjusting circuit 80 is used to adjust the first driving current DC_1 output by the first light source driving circuit 20.

[0066] The second current adjusting circuit 90 is connected with the output end of the second light source driving circuit 30, the first end 1 of the switch circuit 40, and the plurality of second laser light sources 60 respectively. The second current adjusting circuit 90 is used to adjust the second driving current DC_2 output by the second light source driving circuit 30.

[0067] It can be understood that the driving currents output by the first light source driving circuit 20 and the second light source driving circuit 30 may be different from the driving current flowing through the laser light source, that is, the driving current received by the laser light source is not consistent with the rated driving current required by the laser light source when emitting light. Therefore, the first current adjusting circuit 80 in the laser projection device can adjust the size of the first driving current DC_1 output by the first light source driving circuit 20, so that the actual first driving current DC_1 flowing through the first laser light source 50 is consistent with the rated driving current required by the first laser light source 60. The second current adjusting circuit 90 can adjust the size of the second driving current DC_2 output by the second light source driving circuit 30, so that the actual second driving current DC_2 flowing through the second laser light source 60 is consistent with the rated driving current required by the second laser light source 60. In this way, it can be ensured that the plurality of laser light sources can emit light normally, and in turn ensure that the display effect of the projection image projected by the laser projection device is better.

[0068] Optionally, as shown in Figure 5 , the first current adjusting circuit 80 can include: a first inductor L1, a first diode D1 and a second transistor M2.

[0069] One end of the first inductor L1 is connected to the output terminal of the first light source driving circuit 20 and the first end of the first diode D1 respectively, and the other end of the first inductor L1 is connected to one end of the first laser light source 50. The second end of the first diode D1 is connected to the other end of the first laser light source 50 and the first electrode of the second transistor M2 respectively. The gate electrode G of the second transistor M2 is connected to the output terminal of the first light source driving circuit 20, and the second electrode of the second transistor M2 is connected to the ground terminal GND.

[0070] With reference to the foregoing Figure 5 , the second current regulating circuit 90 can comprise a second inductor L2, a second diode D2 and a third transistor M3. One end of the second inductor L2 is connected to the output terminal of the second light source driving circuit 30 and the first end of the second diode D2 respectively, and the other end of the second inductor L2 is connected to the first end of the switching circuit 40. The second end of the second diode D2 is connected to the plurality of second laser light sources 60 and the first electrode of the third transistor M3 respectively. The gate electrode G of the third transistor M3 is connected to the output terminal of the second light source driving circuit 30, and the second electrode of the third transistor M3 is connected to the ground terminal GND.

[0071] Optionally, with reference to the foregoing Figure 5 , the first ends of the first diode D1 and the second diode D2 can be cathodes, and the second ends of the first diode D1 and the second diode D2 can be anodes. The second transistor M2 and the third transistor M3 can also be P-type MOS transistors. The first electrodes of the second transistor M2 and the third transistor M3 can both be source electrodes S, and the second electrodes of the second transistor M2 and the third transistor M3 can both be drain electrodes D.

[0072] Since the first current regulating circuit 80 and the second current regulating circuit 90 have the same structure, the working principles of the two current regulating circuits will be described below taking the first current regulating circuit 80 as an example.

[0073] In the present application, when the first light source driving circuit 20 outputs the first driving current DC_1 to the first laser light source 50, it can also output a driving control signal DRV_1 to the gate electrode G of the second transistor M2. The driving control signal DRV_1 can also be a PWM signal. Based on the principle of PWM, a PWM signal is output in the form of a periodic pulse sequence in an ON state or an OFF state. The pulse in the ON state is high, and the OFF state is equivalent to no pulse output.

[0074] When the driving control signal DRV_1 outputted by the first light source driving circuit 20 is outputted to the gate G of the second transistor M2 in the form of pulse, the source S and the drain D of the second transistor M2 are turned off. At this time, the first diode D1 is turned on, and the first inductor L1 is discharged. Therefore, the electric energy discharged by the first inductor L1 can continue to drive the first laser light source 50 to emit light when the second transistor M2 is turned off. Thus, the stability of the light emission of the first laser light source 50 can be ensured.

[0075] It can be understood that when the output end of the first light source driving circuit 20 is connected to the ground GND, the first inductor L1 can store part of the first driving current DC_1 outputted by the first light source driving circuit 20 in the form of electric energy. That is, when the second transistor M2 is turned on, the first inductor L1 is in the charging state.

[0076] It can be understood that when the outputted driving control signal DRV_1 of the first light source driving circuit 20 is outputted to the gate G of the second transistor M2 in the form of pulse, the source S and the drain D of the second transistor M2 are turned off. At this time, the first diode D1 is turned on, and the first inductor L1 is discharged. Therefore, the electric energy discharged by the first inductor L1 can continue to drive the first laser light source 50 to emit light when the second transistor M2 is turned off. Thus, the stability of the light emission of the first laser light source 50 can be ensured.

[0077] It can be understood that the first light source driving circuit 20 can change the on duration of the second transistor M2 by adjusting the duty cycle of the driving control signal DRV_1 outputted by the first light source driving circuit 20. When the duty cycle of the driving control signal DRV_1 in a unit time (for example, 1 second) is small, the on duration of the second transistor M2 in the unit time is long, and the first driving current DC_1 flowing through the first laser light source 50 is also large. When the duty cycle of the driving control signal DRV_1 in the unit time is large, the off duration of the second transistor M2 in the unit time is long (i.e., the on duration is short), and the first driving current DC_1 flowing through the first laser light source 50 is also small. Thus, the adjustment of the first driving current DC_1 flowing through the first laser light source 50 can be realized, so that the difference between the first driving current DC_1 flowing through the first laser light source 50 and the rated driving current of the first laser light source 50 is small, and the light emission effect of the first laser light source 50 is ensured.

[0078] Optionally, as Figure 5As shown, the laser projection device can further include a first sampling resistor R1 and a second sampling resistor R2. One end of the first sampling resistor R1 is connected to the output end and the feedback end of the first light source driving circuit 20 respectively. The other end of the first sampling resistor R1 is connected to the ground end GND. One end of the second sampling resistor R2 is connected to the output end and the feedback end of the second light source driving circuit 30 respectively, and the other end of the second sampling resistor R2 is connected to the ground end GND.

[0079] In the embodiment of the present application, when the output end of the first light source driving circuit 20 (i.e. one end of the output first driving current DC_1) is connected to the ground end GND, the first sampling resistor R1 can sample the driving first driving current DC_1 flowing through the first laser light source 50. The first light source driving circuit 20 can receive the driving current sampled by the first sampling resistor R1 through the feedback end thereof. The first light source driving circuit 20 can pre-store the rated driving current of the first laser light source 50. The first light source driving circuit 20 can adjust the duty cycle of the driving control signal DRV_1 outputted thereby based on the sampled driving current and the pre-stored rated driving current.

[0080] For example, when the first light source driving circuit 20 determines that the sampled driving current is less than the rated driving current, the duty cycle of the driving control signal DRV_1 outputted thereby can be reduced, so as to increase the on duration of the second transistor M2, and further increase the current value of the first driving current DC_1 flowing through the first laser light source 50. When the first light source driving circuit 20 determines that the sampled driving current is greater than the rated driving current, the duty cycle of the driving control signal DRV_1 outputted thereby can be increased, so as to reduce the on duration of the second transistor M2, and further reduce the current value of the first driving current DC_1 flowing through the first laser light source 50.

[0081] The second light source driving circuit 30 can also adjust the duty cycle of the driving control signal DRV_2 outputted thereby based on the driving current sampled by the second sampling resistor R2, and further adjust the current value of the second driving current DC_2 flowing through the second laser light source 60.

[0082] Figure 6 is a structural schematic diagram of a projection device in the related art. Referring to Figure 6 The projection device includes a display control circuit 01, a plurality of light sources with different colors, a light source driving circuit 03 corresponding to each of the plurality of light sources, and a current adjusting circuit 04 corresponding to each of the plurality of light sources. Each current adjusting circuit 04 includes a third inductor L3, a third diode D3, and a fourth transistor M4. Optionally, as Figure 5 As shown, the plurality of light sources can include a red light source 02_R, a green light source 02_G, and a blue light source 02_B.

[0083] Each light source, along with its corresponding light source driver circuit 03 and current regulation circuit 04, can be referred to as a buck topology circuit. Furthermore, this buck topology circuit can be integrated onto the light source driver board of the projection device.

[0084] like Figure 6 As shown, the projection device may also include sampling resistors R3 connected one-to-one with multiple current adjustment circuits 04. The light source driving circuit 03 can adjust the driving current flowing through the light source by sampling the driving current obtained by the sampling resistors R3.

[0085] When the display control circuit 01 outputs a brightness control signal DIMMING and an enable signal EN at an effective level to the light source driver circuit 03 corresponding to the red light source 02_R, the light source driver circuit 02 can output a drive current to the red light source 02_R through the third inductor L3, and output a drive control signal DRVM_3 to the gate G of the fourth transistor M4. The third transistor M3 can switch between on and off states under the control of the drive control signal DRVM_3, so that the light source driver circuit 03 can drive the red light source 02_R to emit light. The light emission principles of the green light source 02_G and the blue light source 02_B are the same as those of the red light source 02_R, and will not be described further.

[0086] Understandably, when multiple light sources emit light, the multiple fourth transistors M4 in the current regulation circuit 04 corresponding to these light sources are in a high-speed switching state. When these multiple fourth transistors M4 frequently switch between states, they generate a large amount of electromagnetic radiation, leading to electromagnetic compatibility (EMC) problems. Projection devices need to incorporate magnetic rings or other devices capable of shielding electromagnetic radiation to reduce EMC issues. Furthermore, these multiple fourth transistors M4 generate significant heat during switching and conduction. Projection devices require heat sinks for cooling. Therefore, it is evident that the structure of projection devices in related technologies is relatively complex and costly.

[0087] refer to Figure 5 It is known that projection devices in related technologies require multiple light source driving circuits 03 and energy storage inductors L3. These multiple light source driving circuits 03 and the third inductor L3 not only increase the cost of the projection device, but also increase the area and structural complexity of the light source driving board of the projection device.

[0088] In the laser projection device provided in the present application, only two light source driving circuits and one switch circuit 40 are needed to realize the light emission driving of the plurality of laser light sources. Moreover, only two current adjusting circuits are needed to be arranged in the laser projection device to realize the adjustment of the driving current output by the two light source driving circuits. Thus, the structure of the light source driving board in the laser projection device is effectively simplified, and the cost of the laser projection device is reduced. Moreover, since the structure of the light source driving board in the laser projection device is relatively simple and the area is small, the integrated arrangement of the light source driving board and the light source board (e.g. laser) can be facilitated, and the miniaturization of the laser projection device is further realized.

[0089] It can also be understood that, in the laser projection device provided in the present application, only the second transistor M2 and the third transistor M3 are in the high-speed switching state. Thus, the heat and electromagnetic radiation generated in the process of adjusting the driving current output by the light source driving circuit by the current adjusting circuit can be effectively reduced. Therefore, the laser projection device also does not need to be provided with a heat sink and a device for shielding electromagnetic radiation, and the structure of the laser projection device is further simplified, and the cost of the laser projection device is further reduced.

[0090] In summary, the embodiment of the present application provides a laser projection device. The display control circuit in the laser projection device can output a switch control signal to the switch circuit based on the light emission timing of the plurality of second laser light sources, and be used to output a first driving signal to the first light source driving circuit and a second driving signal to the second light source driving circuit. The first driving signal is used to drive the first light source driving circuit to output a first driving current to the first laser light source, and the second driving signal is used to drive the second light source driving circuit to output a second driving current. The switch circuit can turn on the second light source driving circuit and one of the plurality of second laser light sources under the control of the switch control signal, to drive the second laser light source to emit light. Since the second light source driving circuit can drive the plurality of second laser light sources to emit light, the structure of the laser projection device is effectively simplified.

[0091] Moreover, since the display control circuit can output driving signals to the first light source driving circuit and the second light source driving circuit respectively, the flexibility of the light source driving of the laser projection device is effectively improved.

[0092] Figure 7 is a flowchart of a light source driving method of a laser projection device provided in the present application. The method can be applied to a laser projection device, for example Figure 1 as shown in the laser projection device, with reference to Figure 1 The laser projection device includes a display control circuit 10, a first light source driving circuit 20, a second light source driving circuit 30, a switch circuit 40, a first laser light source 50, and a plurality of second laser light sources 60. With reference toFigure 7 The method comprises:

[0093] In step 101, the display control circuit outputs a switch control signal to the switch circuit and outputs a first driving signal to the first light source driving circuit and a second driving signal to the second light source driving circuit based on the light emission timing of the plurality of second laser light sources.

[0094] The first driving signal and the second driving signal comprise an enable signal and a brightness control signal. After the laser projection device is powered on, the display control circuit 10 of the laser projection device can output a switch control signal to the switch circuit 40 based on the light emission information of the plurality of laser light sources to control the switch state (i.e. the on-off state of the first end 1 and the plurality of second laser light sources 60) of the switch circuit 40. The switch control signal can be a level signal. In addition, the display driving circuit 10 can also provide a first driving signal to the first light source driving circuit 20 and a second driving signal to the second light source driving circuit 30 based on the light emission information. The enable signal in the first driving signal and the second driving signal is used to control the working state of the first light source driving circuit 20 and the second light source driving circuit 30, i.e. whether the light source driving circuit outputs a driving current. The brightness control signal in the first driving signal and the second driving signal is used to control the size of the driving current output by the light source driving circuit.

[0095] The light emission information of the plurality of laser light sources can include the duty time and current information of the plurality of laser light sources. The duty time of the plurality of laser light sources can indicate the light emission timing and light emission duration of the plurality of laser light sources in a unit time (e.g. 1 second). The current information of the plurality of laser light sources refers to the rated driving current required by the plurality of laser light sources when emitting light. The rated driving current of the laser light source refers to the driving current that can drive the laser light source to emit light normally.

[0096] In step 102, the first light source driving circuit outputs a first driving current to the first laser light source under the driving of the first driving signal to drive the first laser light source to emit light.

[0097] The brightness control signal received by the first light source driving circuit 20 can be a PWM signal. The size of the first driving current can be positively correlated with the duty cycle of the brightness control signal, i.e. the larger the duty cycle of the brightness control signal, the higher the signal value of the first driving current. Correspondingly, the first laser light source 50 driven by the first driving current has a higher light emission brightness.

[0098] In step 103, the second light source driving circuit outputs a second driving current under the driving of the second driving signal.

[0099] In the embodiment of the present application, the second light source driving circuit 30 can output the second driving current based on the brightness control signal in the second driving signal after receiving the second driving signal.

[0100] In step 104, the switch circuit turns on the second light source driving circuit and one of the second laser light sources in the plurality of second laser light sources under the control of the switch control signal to drive the second laser light source to emit light.

[0101] In the embodiment of the present application, the switch circuit 40 connected with the second light source driving circuit 30 can turn on the second light source driving circuit 30 and one of the second laser light sources 60 in the plurality of second laser light sources 60 under the control of the switch control signal after receiving the switch control signal. Thus, the second driving current output by the second light source driving circuit 30 can drive the turned-on one of the second laser light sources 60 to emit light.

[0102] It can be understood that the first driving current output by the first light source driving circuit 20 can be directly transmitted to the first laser light source 50 to drive the first laser light source 50 to emit light. The second driving current output by the second light source driving circuit 30 needs to be transmitted to one of the second laser light sources 60 in the plurality of second laser light sources 60 which is turned on by the second light source driving circuit 30 under the control of the switch circuit 40.

[0103] The light emitting time periods of the adjacent two second laser light sources 60 can be separated by a target time length. The target time length can be determined based on the switch switching time length of the switch circuit 40. That is, the second light source driving circuit 30 can only drive one of the second laser light sources 60 in the plurality of second laser light sources 60 to emit light in the same time period, that is, the light emitting time periods of the plurality of second laser light sources 60 are not overlapped. The time lengths of the light emitting time periods of the plurality of second laser light sources can be the same or different.

[0104] It can be understood that the switch circuit 40 needs a certain time length when switching the path between the second light source driving circuit 30 and the plurality of second laser light sources 60. By separating the turn-on time periods of the adjacent two second laser light sources 60 and the second light source driving circuit 30 by the target time length, the second light source driving circuit 30 can be prevented from driving two second laser light sources 60 to emit light at the same time. Thus, the light emitting purity of the plurality of second laser light sources 60 can be effectively ensured.

[0105] As a first possible implementation, the light emitting period of the first laser light source 50 does not overlap with the light emitting period of the plurality of second laser light sources 60. In this implementation, the display control circuit 10 can control the first laser light source 50 and the plurality of second laser light sources 60 to emit light in sequence through the first light source driving circuit 20 and the second light source driving circuit 30. For example, the display control circuit 10 can first drive the first laser light source 50 to emit light through the first light source driving circuit 20. After the light emitting time of the first laser light source 50 reaches the duty time corresponding to the first laser light source 50, the display control circuit 10 can drive the plurality of second laser light sources 60 to emit light in sequence through the second light source driving circuit 30.

[0106] As a second possible implementation, the light emitting period of the first laser light source 50 overlaps with the light emitting period of one of the plurality of second laser light sources 60, and the light emitting periods of the plurality of second laser light sources 60 do not overlap with each other. In this implementation, the display control circuit 10 can drive the plurality of second laser light sources 60 to emit light in sequence through the second light source driving circuit 30 and the switch circuit 40 while controlling the first laser light source 50 to emit light through the first light source driving circuit 20. In this way, the light beams emitted by the first laser light source 50 and the one of the plurality of second laser light sources 60 can be mixed into a light beam of a new color.

[0107] It can be understood that the brightness of the mixed light beams emitted by two laser light sources of different colors is higher than the brightness of the light beams emitted by a single laser light source. Therefore, during the process of displaying and projecting an image by the laser projection device, the display control circuit 10 can drive the first laser light source 50 and the second laser light source 60 to emit light at the same time through the first light source driving circuit 20 and the second light source driving circuit 30, so as to make the brightness of the projected image projected by the laser projection device higher, and thus ensure that the display effect of the projected image is better.

[0108] It can also be understood that, since the switch circuit 40 can control the on-off state of the second light source driving circuit 30 and any one of the plurality of second laser light sources 60 under the control of the switch control signal, the laser projection device only needs to use two light source driving circuits to realize the light emitting driving of a plurality of laser light sources of different colors. In this way, the structure of the laser projection device is effectively simplified, and the manufacturing cost of the laser projection device is reduced.

[0109] Reference Figure 4The first laser light source 50 can be a green laser light source 50 G, and the plurality of second laser light sources 60 can include a red laser light source 60 R and a blue laser light source 60 B. The driving method of the three laser light sources is described below. For reference Figure 8 The driving method can include:

[0110] Step S1, the laser projection device is powered on, and the display control circuit is initialized.

[0111] The user can control the laser projection device to be powered on by means of remote control or by pressing the switch button of the laser projection device. After the laser projection device is powered on, the display control circuit 10 can be initialized. During the initialization process, the display control circuit 10 can obtain the light-emitting information of the plurality of laser light sources in the laser projection device.

[0112] Step S2, the display control circuit outputs a first driving signal to the first light source driving circuit.

[0113] The first driving signal includes an enable signal of an effective level and a brightness control signal corresponding to the green laser light source 50 G. The first light source driving circuit 20 can output a first driving current to the green laser light source 50 B under the driving of the driving signal, so as to drive the green laser light source 50 G to emit light. At this time, the level of the enable signal output by the display control circuit 10 to the second light source driving circuit 30 is invalid, and the red laser light source 60 R and the blue laser light source 60 B do not emit light.

[0114] Step S3, the display control circuit detects whether the light-emitting duration of the green laser light source reaches a first duration.

[0115] The first duration can be the duty time of the green laser light source 50 G. If the display control circuit 10 determines that the light-emitting duration of the green laser light source 50 G reaches the first duration, the display control circuit 10 can execute the following step S4. If the display control circuit 10 determines that the light-emitting duration of the green laser light source 50 G does not reach the first duration, the display control circuit 10 can continue to drive the green laser light source 50 G to emit light through the first light source driving circuit 20.

[0116] Step S4, the display control circuit outputs an invalid level enable signal to the first light source driving circuit.

[0117] After the display control circuit 10 determines that the light-emitting duration of the green laser light source 50 G reaches the first duration, the display control circuit 10 can output an invalid level enable signal to the first light source driving circuit 20, so as to stop the first light source driving circuit 20 from driving the green laser light source 50 G to emit light.

[0118] Step S5, the display control circuit outputs a second driving signal to the second light source driving circuit, and outputs an effective level switch control signal to the first transistor corresponding to the red laser light source.

[0119] The driving signal can include an effective level enable signal and a brightness control signal corresponding to the red laser light source 60_R. The second light source driving circuit 30 can output a second driving current after receiving the driving signal. The first transistor M1 corresponding to the red laser light source 60_R can be turned on under the control of the effective level switch control signal after receiving the effective level switch control signal, so as to turn on the second light source driving circuit 30 and the red laser light source 60_R. At this time, the red laser light source 60_R can emit light under the driving of the second driving current, and the green laser light source 50_G and the blue laser light source 60_B do not emit light.

[0120] Optionally, the display control circuit 10 can output a second driving signal to the second light source driving circuit 30 after detecting that the duration of the effective level enable signal output by the display control circuit 10 to the first light source driving circuit 20 reaches a first target duration. The first target duration can be the duration during which the first light source driving circuit 20 completely stops outputting the first driving current after receiving the effective level enable signal. In this way, the light emitting purity of the red laser light source 60_R can be ensured.

[0121] Step S6, the display control circuit detects whether the light emitting duration of the red laser light source reaches a second duration.

[0122] The second duration can be the duty time of the red laser light source 60_R. If the display control circuit 10 determines that the light emitting duration of the red laser light source 60_R reaches the second duration, the display control circuit 10 can execute the following step S7. If the display control circuit 10 determines that the light emitting duration of the red laser light source 60_R does not reach the second duration, the display control circuit 10 can continue to drive the red laser light source 60_R to emit light through the second light source driving circuit 30.

[0123] Step S7, the display control circuit outputs an ineffective level switch control signal to the first transistor corresponding to the red laser light source.

[0124] After determining that the light emitting duration of the red laser light source 60_R reaches the second duration, the display control circuit 10 can output an ineffective level switch control signal to the first transistor M1 corresponding to the red laser light source 60_R. The first transistor M1 can be turned off under the control of the ineffective level switch control signal, so as to turn off the second light source driving circuit 30 and the red laser light source 60_R. After the first transistor M1 is completely turned off, the red laser light source 60_R stops emitting light.

[0125] Step S8, the display control circuit outputs a third driving signal to the second light source driving circuit, and outputs an effective level of the switching control signal to the first transistor corresponding to the blue laser light source.

[0126] The third driving signal includes an effective level of the enable signal and a luminance control signal corresponding to the blue laser light source 60_B. The second light source driving circuit 30 can output a second driving current after receiving the second driving signal. The current value of the second driving current output by the second light source driving circuit 30 based on the second driving signal can be the same as or different from the current value of the second driving current output based on the third driving signal. The first transistor M1 corresponding to the blue laser light source 60_B can be turned on under the control of the effective level of the switching control signal after receiving the effective level of the switching control signal. At this time, the blue laser light source 60_B can emit light under the driving of the second driving current, and the green laser light source 50_G and the red laser light source 60_R do not emit light.

[0127] Optionally, the display control circuit 10 can output the third driving signal to the second light source driving circuit 30 after detecting that the off duration of the second light source driving circuit 30 and the red laser light source 60_R reaches a second target duration. The second target duration can be determined based on the off duration of the first transistor M1. For example, the second target duration can be greater than or equal to the off duration of the first transistor M1.

[0128] Step S9, the display control circuit detects whether the light emitting duration of the blue laser light source reaches a third duration.

[0129] The third duration can be the duty time of the blue laser light source 60_B. If the display control circuit 10 determines that the light emitting duration of the blue laser light source 60_B reaches the third duration, it can execute the following step S10. If the display control circuit 10 determines that the light emitting duration of the blue laser light source 60_B does not reach the third duration, it can continue to drive the blue laser light source 60_B to emit light through the second light source driving circuit 30.

[0130] Step S10, the display control circuit outputs an invalid level of the switching control signal to the first transistor corresponding to the blue laser light source.

[0131] The display control circuit 10 can output an invalid level switch control signal to the first transistor M1 corresponding to the blue laser light source 60_B after determining that the light emitting duration of the blue laser light source 60_B reaches the third duration. The first transistor M1 can be controlled by the invalid level switch control signal to turn off the second light source driving circuit 30 and the blue laser light source 60_B. After the first transistor M1 is completely turned off, the blue laser light source 60_B stops emitting light.

[0132] Optionally, with reference to Figure 9 the driving method of the three laser light sources can further include:

[0133] In step S11, the display control circuit outputs a first driving signal to the first light source driving circuit, a second driving signal to the second light source driving circuit, and an effective level switch control signal to the first transistor corresponding to the red laser light source.

[0134] The first light source driving circuit 20 can directly drive the green laser light source 50_G to emit light under the driving of the first driving signal. The second light source driving circuit 30 can drive the red laser light source 60_R to emit light through the first transistor M1 corresponding to the red laser light source 60_R under the driving of the second driving signal. At this time, the green laser light source 50_G and the red laser light source 60_R can emit light at the same time. The light beams emitted by the two laser light sources are mixed light beams. For example, the color of the mixed light beams can be yellow.

[0135] In step S12, the display control circuit detects whether the light emitting duration of the green laser light source and the red laser light source reaches a fourth duration.

[0136] The fourth duration can be determined based on the duty time of the light beams mixed by the green laser light source 50_G and the red laser light source 60_R. If the display control circuit 10 detects that the light emitting duration of the green laser light source 50_G and the red laser light source 60_R reaches the fourth duration, the display control circuit 10 can execute the following step 213. If the display control circuit 10 detects that the light emitting duration of the green laser light source 50_G and the red laser light source 60_R does not reach the fourth duration, the display control circuit 10 can drive the green laser light source 50_G and the red laser light source 60_R to continue emitting light through the first light source driving circuit 20 and the second light source driving circuit 30.

[0137] In step S13, the display control circuit outputs an invalid level enable signal to the first light source driving circuit and the second light source driving circuit, and an invalid level switch control signal to the first transistor corresponding to the red laser light source.

[0138] The display control circuit 10 can control the first light source driving circuit 20 to stop driving the green laser light source 50_G to emit light and control the second light source driving circuit 30 to stop driving the red laser light source 60_R to emit light after determining that the light emitting duration of the green laser light source 50_G and the red laser light source 60_R reaches the fourth duration.

[0139] In step S14, the display control circuit outputs the first driving signal to the first light source driving circuit, outputs the third driving signal to the second light source driving circuit, and outputs the switch control signal of the effective level to the first transistor M1 corresponding to the blue laser light source 60_B.

[0140] At this time, the green laser light source 50_G and the blue laser light source 60_B can emit light at the same time. The light beams emitted by the two laser light sources are mixed light beams. For example, the color of the mixed light beams can be cyan.

[0141] In step S15, the display control circuit detects whether the light emitting duration of the green laser light source and the blue laser light source reaches the fifth duration.

[0142] The fifth duration can be determined based on the duty time of the light beams mixed by the green laser light source 50_G and the blue laser light source 60_B. If the display control circuit 10 detects that the light emitting duration of the green laser light source 50_G and the blue laser light source 60_B reaches the fifth duration, the display control circuit 10 can execute the following step 216. If the display control circuit 10 detects that the light emitting duration of the green laser light source 50_G and the blue laser light source 60_B does not reach the fifth duration, the display control circuit 10 can drive the green laser light source 50_G and the blue laser light source 60_B to continue emitting light through the first light source driving circuit 20 and the second light source driving circuit 30.

[0143] In step S16, the display control circuit outputs the enable signal of the invalid level to the first light source driving circuit and the second light source driving circuit, and outputs the switch control signal of the invalid level to the first transistor corresponding to the blue laser light source.

[0144] The display control circuit 10 can control the first light source driving circuit 20 to stop driving the green laser light source 50_G to emit light and control the second light source driving circuit 30 to stop driving the blue laser light source 60_B to emit light after determining that the light emitting duration of the green laser light source 50_G and the blue laser light source 60_B reaches the fifth duration.

[0145] In step S17, the display control circuit detects whether a shutdown signal is received.

[0146] The display control circuit 10 can detect whether a shutdown signal is received when the time length of the enable signal output by the display control circuit 10 to the first light source driving circuit 20 and the second light source driving circuit 30 reaches the second target time length (i.e., after it is determined that the first light source driving circuit 20 and the second light source driving circuit 30 completely stop working). If the display control circuit 10 does not detect the shutdown signal, the display control circuit 10 can perform step S2. If the display control circuit 10 detects the shutdown signal, the display control circuit 10 can end the light source driving process of the laser projection device.

[0147] In summary, the embodiment of the present application provides a light source driving method of a laser projection device, which is applied to the laser projection device. The display control circuit in the laser projection device can output a switching control signal to a switching circuit based on the light emission timing sequence of a plurality of second laser light sources, and output a first driving signal to a first light source driving circuit and a second driving signal to a second light source driving circuit. The first driving signal is used to drive the first light source driving circuit to output a first driving current to a first laser light source, and the second driving signal is used to drive the second light source driving circuit to output a second driving current. The switching circuit can turn on the second light source driving circuit and one of the plurality of second laser light sources under the control of the switching control signal, so as to drive the second laser light source to emit light. Since the second light source driving circuit can drive a plurality of second laser light sources to emit light, the structure of the laser projection device is effectively simplified.

[0148] The embodiment of the present application provides a laser projection device, which comprises a memory, a processor and a computer program stored in the memory. When the processor executes the computer program, the driving method of the light source (for example, the method shown in Figure 7 、 Figure 8 or Figure 9 ) provided by the above method embodiment is implemented.

[0149] The embodiment of the present application provides a computer readable storage medium, which stores instructions. The instructions are loaded and executed by a processor to implement the driving method of the light source (for example, the method shown in Figure 7 、 Figure 8 or Figure 9 ) provided by the above method embodiment.

[0150] The embodiment of the present application provides a computer program product containing instructions. When the computer program product is run on a computer, the computer executes the driving method of the light source (for example, the method shown in Figure 7 、 Figure 8 or Figure 9 ) provided by the above method embodiment.

[0151] Those skilled in the art can understand that all or part of the steps of the above-mentioned embodiments can be completed by hardware, or by program instructing relevant hardware to complete, and the program can be stored in a computer readable storage medium. The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0152] It can be understood that the term "a plurality of" in the present application means two or more. The terms "first", "second" and the like in the present application are used to distinguish the same items or similar items with substantially the same function, and it should be understood that there is no logical or time sequence between "first", "second", "n", and there is no limitation on the number and execution order.

[0153] The above only describes exemplary embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A laser projection device, characterized by, The laser projection device comprises a display control circuit, a first light source driving circuit, a second light source driving circuit, a switch circuit, a first laser light source, and a plurality of second laser light sources; The display control circuit is connected with the control end of the switch circuit, the input end of the first light source driving circuit, and the input end of the second light source driving circuit respectively, and is used for outputting a switch control signal to the switch circuit and a first driving signal to the first light source driving circuit and a second driving signal to the second light source driving circuit based on the light-emitting timing of the plurality of second laser light sources, wherein the first driving signal and the second driving signal comprise an enable signal and a brightness control signal; The output end of the first light source driving circuit is connected with the first laser light source, and the first light source driving circuit is used for outputting a first driving current to the first laser light source under the driving of the first driving signal to drive the first laser light source to emit light; The output end of the second light source driving circuit is connected with the first end of the switch circuit, and the second light source driving circuit is used for outputting a second driving current under the driving of the second driving signal; The second end of the switch circuit is connected with the plurality of second laser light sources, and the switch circuit is used for turning on the second light source driving circuit and one of the plurality of second laser light sources under the control of the switch control signal to drive the second laser light source to emit light; The switch circuit comprises a plurality of first transistors corresponding to the plurality of second laser light sources one by one; The gate of each first transistor is connected with the display control circuit as the control end of the switch circuit, the first pole of each first transistor is connected with the output end of the second light source driving circuit as the first end of the switch circuit, and the second pole of each first transistor is connected with the corresponding second laser light source as the second end of the switch circuit.

2. The laser projection device of claim 1, wherein, The laser projection device further comprises a first current adjusting circuit corresponding to the first light source driving circuit and a second current adjusting circuit corresponding to the second light source driving circuit; The first current adjusting circuit is connected with the output end of the first light source driving circuit and the first laser light source respectively, and is used for adjusting the first driving current output by the first light source driving circuit; The second current adjusting circuit is connected with the output end of the second light source driving circuit, the first end of the switch circuit, and the plurality of second laser light sources respectively, and is used for adjusting the second driving current output by the second light source driving circuit.

3. The laser projection device of claim 2, wherein, The first current adjusting circuit comprises a first inductor, a first diode, and a second transistor; One end of the first inductor is connected with the output end of the first light source driving circuit and the first end of the first diode respectively, and the other end of the first inductor is connected with one end of the first laser light source; The second end of the first diode is connected with the other end of the first laser light source and the first pole of the second transistor respectively; The second end of the first diode is connected with the other end of the first laser light source and the first pole of the second transistor respectively; The gate of the second transistor is connected with the output end of the first light source driving circuit, and the second electrode of the second transistor is connected with the ground end.

4. The laser projection device of claim 2, wherein, The second current adjusting circuit comprises a second inductor, a second diode and a third transistor. One end of the second inductor is connected with the output end of the second light source driving circuit and the first end of the second diode respectively, and the other end of the second inductor is connected with the first end of the switch circuit. The second end of the second diode is connected with the plurality of second laser light sources and the first electrode of the third transistor respectively. The gate of the third transistor is connected with the output end of the second light source driving circuit, and the second electrode of the third transistor is connected with the ground end.

5. The laser projection device according to any one of claims 1 to 4, wherein The laser projection device further comprises a first sampling resistor and a second sampling resistor. One end of the first sampling resistor is connected with the output end and the feedback end of the first light source driving circuit respectively, and the other end of the first sampling resistor is connected with the ground end. One end of the second sampling resistor is connected with the output end and the feedback end of the second light source driving circuit respectively, and the other end of the second sampling resistor is connected with the ground end.

6. The laser projection device according to any one of claims 1 to 4, wherein The display control circuit comprises a digital light processing chip.

7. The laser projection device according to any one of claims 1 to 4, wherein The laser projection device further comprises a power supply circuit. The output end of the power supply circuit is connected with the input end of the first light source driving circuit and the second light source driving circuit respectively, and the power supply circuit is used for providing a driving voltage for the first light source driving circuit and a driving voltage for the second light source driving circuit.

8. A light source driving method of a laser projection device, characterized by, The laser projection device comprises a display control circuit, a first light source driving circuit, a second light source driving circuit, a switch circuit, a first laser light source and a plurality of second laser light sources. The display control circuit outputs a switch control signal to the switch circuit and outputs a first driving signal to the first light source driving circuit and a second driving signal to the second light source driving circuit based on the light-emitting timing of the plurality of second laser light sources, and the first driving signal and the second driving signal comprise an enable signal and a brightness control signal. The first light source driving circuit outputs a first driving current to the first laser light source under the driving of the first driving signal to drive the first laser light source to emit light. The second light source driving circuit outputs a second driving current under the driving of the second driving signal. The switch circuit turns on the second light source driving circuit and one of the plurality of second laser light sources under the control of the switch control signal to drive the second laser light source to emit light. The switch circuit comprises a plurality of first transistors corresponding to the plurality of second laser light sources one by one. The gate of each first transistor is connected with the display control circuit as the control end of the switch circuit, the first electrode of each first transistor is connected with the output end of the second light source driving circuit as the first end of the switch circuit, and the second electrode of each first transistor is connected with a corresponding second laser light source as the second end of the switch circuit.

9. The method of claim 8, wherein, The light emitting time periods of the first laser light source and the plurality of second laser light sources do not overlap with each other. Alternatively, the light emitting time period of the first laser light source overlaps with that of one of the plurality of second laser light sources, and the light emitting time periods of the plurality of second laser light sources do not overlap with each other.

Images