CN115981089A

CN115981089A - Laser projection apparatus and method of driving light source thereof

Info

Publication number: CN115981089A
Application number: CN202310127204.0A
Authority: CN
Inventors: 高力波; 张希刚
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2023-02-16
Filing date: 2023-02-16
Publication date: 2023-04-18

Abstract

The application discloses a laser projection device and a driving method of a light source thereof.A display control circuit of the laser projection device can output a first switch control signal to a first switch circuit, output a first driving signal to a first light source driving circuit, and output a second driving signal to a second light source driving circuit. The first driving signal is used for driving the first light source driving circuit to output a first driving current, and the second driving signal is used for driving the second light source driving circuit to output a second driving current and a second switching signal. The first switching circuit is capable of transmitting the second switching signal to the second switching circuit under control of the first switching control signal. The second switch circuit can control one of the second laser light sources to emit light under the drive of the second drive current under the control of the second switch signal. The second light source driving circuit can drive the plurality of second laser light sources to emit light, so that the structure of the laser projection equipment is effectively simplified.

Description

Laser projection apparatus and method of driving light source thereof

Technical Field

The present disclosure relates to projection display technologies, and in particular, to a laser projection apparatus and a driving method of a light source thereof.

Background

The laser projection apparatus generally includes three laser light sources of red, green, and blue, and three light source driving circuits corresponding to the three laser light sources one to one. Each light source driving circuit is used for driving one corresponding laser light source to emit light.

However, the structure of the laser projection apparatus in the related art is complicated.

Disclosure of Invention

The application provides a laser projection device and a driving method of a light source thereof, which can solve the problem that the structure of the laser projection device is complex in the related technology. The technical scheme is as follows:

in one aspect, a laser projection apparatus is provided, the laser projection apparatus including: the display control circuit comprises a display control circuit, a first light source driving circuit, a second light source driving circuit, a first switch circuit, a second switch circuit, a first laser light source and a plurality of second laser light sources;

the display control circuit is respectively connected with the control end of the first switch circuit, the input end of the first light source driving circuit and the input end of the second light source driving circuit, the display control circuit is used for outputting a first switch signal to the first switch circuit based on the light emitting time sequence of the plurality of second laser light sources, outputting a first driving signal to the first light source driving circuit and outputting a second driving signal to the second light source driving circuit, and the first driving signal and the second driving signal both comprise an enabling 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 so as to drive the first laser light source to emit light;

the output end of the second light source driving circuit is connected with one end of each of the plurality of second laser light sources and the first end of the first switch circuit, and the second light source driving circuit is used for outputting a second driving current to one end of each of the plurality of second laser light sources and outputting a second switch signal to the first switch circuit under the driving of the second driving signal;

a second end of the first switch circuit is connected with a control end of the second switch circuit, and the first switch circuit is used for transmitting the second switch signal to the second switch circuit under the control of the first switch signal;

the first end of the second switch circuit is respectively connected with the other ends of the plurality of second laser light sources, the second end of the second switch circuit is connected with the grounding end, the second switch circuit is used for controlling one of the plurality of second laser light sources to emit light under the control of the second switch signal.

In another aspect, there is provided a driving method of a light source of a laser projection apparatus including: the display control circuit comprises a display control circuit, a first light source driving circuit, a second light source driving circuit, a first switch circuit, a second switch circuit, a first laser light source and a plurality of second laser light sources; the method comprises the following steps:

the display control circuit outputs a first switching signal to the first switching circuit, outputs a first driving signal to the first light source driving circuit, and outputs a second driving signal to the second light source driving circuit based on the light emitting time sequence of the plurality of second laser light sources, wherein the first driving signal and the second driving signal both 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 so as to drive the first laser light source to emit light;

the second light source driving circuit outputs a second driving current to one end of the plurality of second laser light sources under the driving of the second driving signal, and outputs a second switching signal to the first switching circuit;

the first switching circuit transmits the second switching signal to the second switching circuit under the control of the first switching signal;

the second switch circuit controls one of the plurality of second laser light sources to emit light under the control of the second switch signal.

In yet another aspect, there is provided a laser projection apparatus including: a memory, a processor and a computer program stored on the memory, the processor implementing the method of driving a light source as described above when executing the computer program.

In yet another aspect, a computer-readable storage medium is provided, in which instructions are stored, the instructions being loaded and executed by a processor to implement the driving method of the light source as described in the above aspect.

In a further aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of driving a light source as described in the preceding aspect.

The beneficial effect that technical scheme that this application provided brought includes at least:

the display control circuit of the laser projection device can output a first switch control signal to a first switch circuit, output a first drive signal to a first light source drive circuit, and output a second drive signal to a second light source drive circuit. The first driving signal is used for driving the first light source driving circuit to output a first driving current, and the second driving signal is used for driving the second light source driving circuit to output a second driving current and a second switching signal. The first switching circuit is capable of transmitting the second switching signal to the second switching circuit under control of the first switching control signal. The second switch circuit can control one of the second laser light sources to emit light under the drive of the second drive current under the control of the second switch signal. The second light source driving circuit can drive the plurality of second laser light sources to emit light, so that the structure of the laser projection equipment is effectively simplified.

In addition, the display control circuit can respectively output driving signals to the first light source driving circuit and the second light source driving circuit, so that the flexibility of the light source driving of the laser projection equipment is effectively improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a laser projection apparatus provided in an embodiment of the present application;

FIG. 2 is a schematic structural diagram of another laser projection apparatus provided in an embodiment of the present application;

FIG. 3 is a schematic structural diagram of another laser projection apparatus provided in an embodiment of the present application;

FIG. 4 is a waveform diagram of output signals of various devices in a laser projection apparatus according to an embodiment of the present application;

FIG. 5 is a schematic structural diagram of another laser projection apparatus provided in an embodiment of the present application;

FIG. 6 is a schematic structural diagram of another laser projection apparatus provided in an embodiment of the present application;

fig. 7 is a schematic flowchart of a driving method of a light source of a laser projection apparatus according to an embodiment of the present disclosure;

fig. 8 is a schematic flowchart of a driving method of a light source of another laser projection apparatus provided in an embodiment of the present application;

fig. 9 is a schematic flowchart of a driving method of a light source of another laser projection apparatus according to an embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a laser projection apparatus provided in an embodiment of the present application, and with reference to fig. 1, the laser projection apparatus includes: a display control circuit 10, a first light source driving circuit 20, a second light source driving circuit 30, a first switching circuit 40, a second switching circuit 50, a first laser light source 60, and a plurality of second laser light sources 70. The first laser light source 60 and the plurality of second laser light sources 70 are different in color from each other. For example, the first laser light source 60 may be a red laser light source, and the plurality of second laser light sources 70 may include a green laser light source and a blue laser light source. Alternatively, the first laser light source 60 may be a green laser light source, and the plurality of second laser light sources 70 may include a red laser light source and a blue laser light source. Still alternatively, the first laser light source 60 may be a blue laser light source, and the plurality of second laser light sources 70 may include a red laser light source and a green laser light source.

Referring to fig. 1, the display control circuit 10 is respectively connected to the control terminal C1 of the first switch 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. The display control circuit 10 is configured to output a first switching signal to the first switching circuit 40, 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 based on the light emission timings of the plurality of second laser light sources 70. Wherein the first driving signal comprises: an enable signal EN _1 and a brightness control signal DIMMIGN _1, and the second driving signals include an enable signal EN _2 and a brightness control signal DIMMIGN _2.

The output terminal of the first light source driving circuit 20 is connected to the first laser light source 60. The first light source driving circuit 20 is configured to output a first driving current to the first laser light source 60 under the driving of the first driving signal, so as to drive the first laser light source 60 to emit light.

The output end of the second light source driving circuit 30 is connected to one end of the plurality of second laser light sources 70 and the first end 1 of the first switching circuit 40, respectively. The second light source driving circuit 30 is configured to output a second driving current to one end of the plurality of second laser light sources 70 and output a second switching signal to the first switching circuit 40 under the driving of the second driving signal.

The second terminal 2 of the first switch circuit 40 is connected to the control terminal C2 of the second switch circuit 50. The first switching circuit 40 is configured to transmit the second switching signal to the second switching circuit 50 under the control of the first switching signal. The first terminal 1 of the second switch circuit 50 is connected to the other terminals of the plurality of second laser light sources 70, respectively, and the second terminal 2 of the second switch circuit 50 is connected to the ground GND. The second switching circuit 50 is configured to control one of the plurality of second laser light sources 70 to emit light under the control of the second switching signal.

In the embodiment of the present application, after the laser projection apparatus is powered on, the display control circuit 10 of the laser projection apparatus can output the first switching signal to the first switching circuit 40 based on the light emitting information of the plurality of laser light sources to control the switching state of the first switching circuit 40. The first switch circuit 40 may have a plurality of second terminals 2 (not shown in fig. 1), and the number of the plurality of second terminals 2 is the same as the number of the plurality of second laser light sources 70. Therefore, the switching state of the first switching circuit 40 may refer to the on/off state of any one second terminal 2 between the first terminal 1 and the plurality of second terminals 2.

The display control circuit 10 may also output a first drive signal to the first light source drive circuit 20 and a second drive signal to the second light source drive circuit 30 based on the emission information of the plurality of laser light sources. The enable signal of the two driving signals is used to control the operating states of the first light source driving circuit 20 and the second light source driving circuit 30, i.e., to control whether the two light source driving circuits output the driving current. The brightness control signal of the two driving signals is used for controlling the magnitude of the driving current output by the two light source driving circuits.

The light emission information of the plurality of laser light sources may include duty time and current information of the plurality of laser light sources. The duty time of the plurality of laser light sources may indicate a light emission timing and a light emission period of the plurality of laser light sources within a unit time period (e.g., 1 second). The current information of the plurality of laser light sources is a rated driving current required when the plurality of laser light sources emit light. The rated driving current of the laser light source is the driving current capable of driving the laser light source to normally emit light.

The first light source driving circuit 20 and the second light source driving circuit 30 can output a driving current after receiving the enable signal and the luminance control signal. The brightness control signal may be a Pulse Width Modulation (PWM) signal. The magnitude of the driving current is positively correlated with the duty ratio of the luminance control signal, that is, the larger the duty ratio of the luminance control signal is, the higher the signal value of the driving current is. Accordingly, the higher the light emission luminance of the laser light source driven by the driving current.

The second light source driving circuit 30 may also output a second switching signal to the first terminal 1 of the first switching circuit 40 after receiving the second driving signal. The first switch circuit 40 is capable of turning on the first terminal 1 and one of the second terminals 2 under the control of the first switch control signal. Thus, the first switch circuit 40 can transmit the received second switch signal from the first terminal 1 to the one conducting second terminal 2, and further transmit the second switch signal to the control terminal C2 of the second switch circuit 50 connected to the second terminal 2.

When the control terminal C2 of the second switch circuit 50 receives the second switch signal, one of the second laser light sources 70 in the plurality of second laser light sources 70 can be conducted to the ground terminal GND. Thus, the second driving current outputted from the second light source driving circuit 30 can flow through the one conducting second laser light source 70, and flows to the ground GND to drive the one conducting second laser source 70 to emit light.

The second switch circuit 40 may have a control terminal C2 corresponding to the plurality of second laser light sources 70, and a plurality of first terminals 1 (not shown in fig. 1) connected to the plurality of second laser light sources 70, and the control terminals C2 correspond to the first terminals 1. When the target control terminal C2 of the plurality of control terminals C2 in the second switch circuit 50 receives the second switch signal, it can turn on the corresponding one of the first terminal 1 and the second terminal 2. This allows the target second laser light source 70 among the plurality of second laser light sources 70 to be electrically connected to the ground GND. The target second laser light source 70 may be the second laser light source 70 that the display control circuit 10 determines based on the light emission timing of the plurality of second laser light sources 70 that the laser projection apparatus currently needs to be lit.

Based on the above analysis, the first light source driving circuit 20 can directly drive the first laser light source 60 to emit light. The second driving current outputted by the second light source driving circuit 30 needs to be transmitted to one of the second laser light sources 70 connected to the ground GND under the control of the first switch circuit 40 and the second switch circuit 50.

As a possible implementation manner, the display control circuit 10 may control the first laser light source 60 and the plurality of second laser light sources 70 to sequentially emit light through the first light source driving circuit 20 and the second light source driving circuit 30. That is, the light emitting periods of the first laser light source 60 and the plurality of second laser light sources 70 are not overlapped. For example, the display control circuit 10 may output the first luminance control signal DIMMING _1 and the first enable signal EN _1 to the first light source driving circuit 20 first, so that the first light source driving circuit 20 drives the first laser light source 60 to emit light. After the light emitting duration of the first laser source 60 reaches the duty time of the first laser source 60, 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 first switch control signal to the first switch circuit 40, so that the second light source driving circuit 30 drives the plurality of second laser sources 70 to sequentially emit light.

As another possible implementation, the display control circuit 10 may also output the second luminance control signal DIMMING _2 and the second enable signal EN _2 to the second light source driving circuit 30 and output the switching control signal to the first switching circuit 40 while outputting the first luminance 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 60 may emit light simultaneously with one of the plurality of second laser light sources 70 that is turned on. Thus, the light beam emitted from the first laser light source 60 and the light beam emitted from the one second laser light source 70 that is turned on can be mixed into a light beam of a new color. For example, the light beams emitted by the green laser light source and the red laser light source may be mixed into a yellow light beam, and the light beams emitted by the green laser light source and the blue laser light source may be mixed into a cyan light beam.

It will be appreciated that the brightness of the mixed beam of light from the two differently colored laser light sources is higher than the brightness of the beam of light from the single laser light source. Therefore, in the process of displaying the projection image by the laser projection device, the display control circuit 10 drives the first laser light source 60 and the second laser light source 70 to emit light simultaneously through the first light source driving circuit 20 and the second light source driving circuit 30, so that the brightness of the projection image projected by the laser projection device is high, and the display effect of the projection image is good.

It can be further understood that, since the first switch circuit 40 can control the on-off states of the first end 1 and the second end 2 of the second switch circuit 50 under the control of the first switch control signal, and further realize the control of the on-off state between any one of the second laser light sources 70 in the plurality of second laser light sources 70 and the contact end GND, the laser projection apparatus can realize the light emitting driving of the plurality of laser light sources with different colors only by using two light source driving circuits. Therefore, the structure of the laser projection equipment is effectively simplified, and the manufacturing cost of the laser projection equipment is reduced.

In summary, the present application provides a laser projection apparatus, where a display control circuit of the laser projection apparatus is capable of outputting a first switch control signal to a first switch circuit, outputting a first driving signal to a first light source driving circuit, and outputting a second driving signal to a second light source driving circuit. The first driving signal is used for driving the first light source driving circuit to output a first driving current, and the second driving signal is used for driving the second light source driving circuit to output a second driving current and a second switching signal. The first switching circuit is capable of transmitting the second switching signal to the second switching circuit under control of the first switching control signal. The second switch circuit can control one of the second laser light sources to emit light under the drive of the second drive current under the control of the second switch signal. The second light source driving circuit can drive the plurality of second laser light sources to emit light, so that the structure of the laser projection equipment is effectively simplified.

Alternatively, the display control circuit 10 may include a Digital Light Processing (DLP) chip. Alternatively, the display control circuit 10 may include a Micro Controller Unit (MCU), which may also be referred to as a single chip. Still alternatively, the display control circuit 10 may include a system on chip (SoC). The first light source driving circuit 20 and the second light source driving circuit 30 may each include a constant current driving Integrated Circuit (IC), which may also be referred to as a constant current driving chip.

Fig. 2 is a schematic structural diagram of another laser projection apparatus provided in an embodiment of the present application, and with reference to fig. 2, the laser projection apparatus may further include: a power supply circuit 80. The output terminal of the power supply circuit 80 is connected to the input terminals of the first light source driving circuit 20 and the second light source driving circuit 30, respectively. The power supply circuit 80 is used for providing a first driving voltage VCC _1 to the first light source driving circuit 20 and providing a second driving voltage VCC _2 to the second light source driving circuit 30. Thus, the first light source driving circuit 20 can be driven by the first driving voltage VCC _1 to output a first driving current, and the second light source driving circuit 30 can be driven by the second driving voltage VCC _2 to output a second driving current. The voltage value of the first driving voltage VCC _1 and the voltage value of the second driving voltage VCC _2 may be the same.

Alternatively, the power circuit 80 may include an alternating current-direct current (AD-DC) converter.

Alternatively, referring to fig. 3, the first switching circuit 40 may include: single pole, multiple throw switch N1. The second switch circuit 40 has a plurality of control terminals C2 corresponding to the plurality of second laser light sources 70 one to one.

As shown in fig. 3, the control terminal C3 of the single-pole multi-throw switch N1 is connected to the display control circuit 10 as the control terminal C1 of the first switch circuit 40, the moving terminal P1 of the single-pole multi-throw switch N1 is connected to the output terminal of the second light source driving circuit 30 as the first terminal 1 of the first switch circuit 40, and the plurality of stationary terminals of the single-pole multi-throw switch N1 are connected to the plurality of control terminals C2 of the second switch circuit 50 as the second terminal 2 of the first switch circuit 40 in a one-to-one correspondence manner. The second switch circuit 50 is configured to control the second laser source 70 corresponding to any one of the control terminals C2 to emit light when the control terminal C2 receives a second switch signal.

As shown in fig. 3, the plurality of second laser light sources 70 may include two second laser light sources 70, and the single-pole-multiple-throw switch N1 may be a single-pole-double-throw switch N1. The single-pole double-throw switch N1 is configured to transmit a second switching signal to the control terminal C2 of the second switching circuit 50 corresponding to one second laser light source 70 when receiving a first switching signal of a first level, and transmit the second switching signal to the control terminal C2 of the second switching circuit 50 corresponding to another second laser light source 70 when receiving a first switching signal of a second level. The first level may be a low level relative to the second level.

In the embodiment of the present application, when the control terminal C2 of the second switch circuit 50 corresponding to one second laser light source 70 receives the second switch signal, the second switch circuit 50 can connect the one second laser light source 70 with the ground terminal, so that the one second laser light source 70 emits light under the driving of the second driving current. At this time, the other second laser light source 70 of the two second laser light sources 70 does not emit light. When the control terminal C2 of the second switch circuit 50 corresponding to the other second laser light source 70 receives the second switch signal, the second switch circuit 50 can connect the other second laser light source 70 with the ground terminal GND, so that the other second laser light source 70 emits light under the driving of the second driving current.

With continued reference to fig. 3, the second switching circuit 50 may include: and a plurality of first transistors M1 in one-to-one correspondence with the plurality of second laser light sources 70. A gate (gate, G) of each first transistor M1 is connected to the second terminal 2 of the first switch circuit 40 as a control terminal C2 of the second switch circuit 50, a first pole of each first transistor M1 is connected to the other end of a corresponding one of the second laser light sources 70 as a first terminal 1 of the second switch circuit 50, and a second pole of each first transistor M1 is connected to the ground terminal GND as a second terminal 2 of the second switch circuit 50.

Alternatively, referring to fig. 3, the plurality of first transistors M1 may be all Metal Oxide Semiconductor (MOS) transistors. Also, the first poles of the plurality of first transistors M1 may be sources (S), and the second poles of the plurality of first transistors M1 may be drains (D).

Alternatively, the display control circuit 10 may be configured to output the switching control to the gates G of the plurality of first transistors M1 in a one-to-one correspondence, and may also sequentially output the plurality of luminance control signals DIMMING in a one-to-one correspondence with the plurality of laser light sources 30 to the light source driving circuit 20. Here, in the output period of the luminance control signal DIMMING corresponding to each laser light source 30, the level of the switching control signal received by the first transistor M1 corresponding to the laser light source 30 is the active level.

In the embodiment of the present application, after the display control circuit 10 is powered on and started (which may also be referred to as initialization), the light emitting information of the plurality of laser light sources during the projection process of the laser projection apparatus can be acquired. Wherein the luminescence information may include duty time and current information of the plurality of laser light sources. The duty time of the plurality of laser light sources may indicate a light emission timing and a light emission time period of the plurality of laser light sources. The light emission information of the plurality of laser light sources may be stored in the display control circuit 10 in advance. Alternatively, the laser projection device may further include a memory. The light emission information of the plurality of laser light sources may be acquired from the memory after the display control circuit 10 is powered on.

The display control circuit 10 may output the second drive signal from the second light source drive circuit 30 and output the first switch signal DRVM _1 to the single-pole-multi-throw switch N1 when it is determined that one of the plurality of second laser light sources 70 needs to be turned on based on the light emission information of the plurality of laser light sources.

Alternatively, the display control circuit 10 may sequentially output the plurality of luminance control signals DIMMING _2 corresponding one-to-one to the plurality of second laser light sources 70 to the second light source driving circuit 30. In the output period of the brightness control signal DIMMING _2 corresponding to each second laser source 70, the first transistor M1 corresponding to the second laser source 70 is in a conducting state.

The single-pole multi-throw switch N1, upon receiving the first on signal DRVM _1 transmitted from the display control circuit 10, can, under the control of the first switch signal DRVM _1, the on-off state of the movable end P1 and any one of the plurality of stationary ends is controlled, so as to control the on-off of any one of the first transistors M1 in the second light source driving circuit 40 and the second switch circuit 50. Thus, the second switch signal DRVM _2 received by the moving terminal P1 of the single-pole-multi-throw switch N1 can be transmitted to the gate G of the turned-on first transistor M1.

Alternatively, the first switching signal DRVM _1 may be a level signal. For example, referring to fig. 3, the single-pole, multi-throw switch N1 may be a single-pole, double-throw switch. When the level of the first switch signal DRVM _1 is the first level, the single-pole-multi-throw switch N1 can conduct the active terminal P1 and the inactive terminal P2_1 thereof, and further transmit the second switch signal DRVM _2 to the first transistor M1 connected to the inactive terminal P2_ 1. When the level of the first switch signal DRVM _1 is the second level, the single-pole multi-throw switch N1 can conduct the active terminal P1 and the inactive terminal P2_2 thereof, and further transmit the second switch signal DRVM _2 to the first transistor M1 connected to the inactive terminal P2_ 2. The first level may be a low level relative to the second level.

When a first transistor M1 in the second switch circuit 40 receives the second switch signal DRVM _ then the first transistor M1 can conduct its source S and drain D under the control of the second switch signal DRVM _2, so that the second laser source 70 connected to the first transistor M1 can be conducted with the ground GND. Therefore, the second driving current output by the second light source driving circuit 30 can flow through the one of the second laser light sources 70 and flow to the ground GND, so as to realize the light emitting driving of the one of the second laser light sources 70. In the second switch circuit 40, the source S and the drain D of the first transistor M1 that do not receive the second switch signal DRVM _2 are in an off state, and the second laser light source 70 to which the first transistor M1 is connected does not emit light.

The on time of the first transistor M1 corresponding to the target second laser light source 70 in the plurality of second laser light sources 70 may be a duty time of the target second laser light source 60. The target second laser light source 70 is the second laser light source 70 that the laser projection device needs to light currently. After determining that the on-time of the first transistor M1 corresponding to the target second laser light source 70 reaches the duty time of the target second laser light source 70, the display control circuit 10 may turn off the first transistor M1 corresponding to the target second laser light source 70 by controlling the on-off state of the single-pole multi-throw switch N1, so as to stop the target second laser light source 70 from emitting light. In addition, the display control circuit 10 may further turn on the first transistor M1 corresponding to the second light source driving circuit 30 and another second laser light source 70 (i.e., a new target second laser light source 70) by controlling the on/off state of the single-pole multi-throw switch N1, so that the another second laser light source 70 emits light under the driving of the second driving current.

Optionally, the display control circuit 10 may turn on the second light source driving circuit 30 and the first transistor M1 corresponding to another second laser light source 70 through the single-pole multi-throw switch N1 after the time length that the first transistor M1 corresponding to the target second laser light source 70 does not receive the second switch signal DRVM _2 reaches the target time length t. The target time duration may be determined based on the off time duration of the first transistor M1 corresponding to the target second laser light source 70, for example, the target time duration may be greater than or equal to the off time duration. Also, the turn-off time periods of the first transistors M1 corresponding to the plurality of second laser light sources 70 may be the same.

Alternatively, referring to fig. 3, the first laser light source 60 may be a red laser light source 60 \ u r, and the plurality of second laser light sources 70 may include a green laser light source 70 \ u g and a blue laser light source 70 \ u b. Referring to fig. 4, after the display control circuit 10 is powered on, the active level enable signal EN _1 and the luminance control signal DIMMING _1 corresponding to the red laser source 60_rmay be output to the first light source driving circuit 20. The first light source driving circuit 20 is further capable of outputting a first driving current DC _1 to the red laser light source 60\ r to drive the red laser light source 60 _rto emit light. At this time, the green laser light source 70 g and the blue laser light source 70 u b do not emit light. As shown in fig. 4, the active level of the enable signal EN _1 may be a high level relative to the inactive level.

After the light emitting duration of the red laser source 60\ u R reaches the duty time duty1 corresponding to the red laser source 60_R, the display control circuit 10 can output the enable signal EN _1 of the inactive level to the first light source driving circuit 20, and stop outputting the luminance control signal DIMMING _1 corresponding to the red laser source 60_R to the first light source driving circuit 20. At this time, the red laser light source 60\ u r stops emitting light.

After determining that the duration of the red laser light source 60\ u R stopping emitting light reaches the target duration t, the display control circuit 10 may output an enable signal EN _2 of an active level and a brightness control signal dim _2 corresponding to the green laser light source 70 _gto the second light source driving circuit 30, so as to drive the second light source driving circuit 30 to output the second driving current DC _2 and the second switching signal DRVM _2. The display control circuit 10 can also output the first switch signal DRVM _1 of the first level to the single-pole-multiple-throw switch N1. The single-pole multi-throw switch N1 can conduct the active terminal P1 and the inactive terminal P2_1 thereof under the control of the first switch signal DRVM _1 of the first level, and further transmit the second switch control signal DRVM _2 to the first transistor M1 corresponding to the green laser source 70 _g. The first transistor M1 can further conduct the green laser source 70\ g to the ground GND under the control of the second switching signal DRVM _2. The second driving current DC _2 can further drive the green laser source 70\ g to emit light. At this time, the red laser light source 60\ u R and the blue laser light source 70 \_B do not emit light.

After the light emitting duration of the green laser source 70\ u G reaches the duty time duty2 corresponding to the green laser source 70 \, the display control circuit 10 can output the enable signal EN _2 of the inactive level to the second light source driving circuit 30, and stop outputting the luminance control signal DIMMING _2 corresponding to the green laser source 70 \G to the second light source driving circuit 20. At this time, the green laser light source 70 g stops emitting light.

After determining that the duration of the green laser light source 70\ g stopping emitting light reaches the target duration t, the display control circuit 10 may output an enable signal EN _2 of an active level and a luminance control signal dim _3 corresponding to the blue laser light source 70 _bto the second light source driving circuit 30, so as to drive the second light source driving circuit 30 to output a second driving current DC _3 and a second switching signal DRVM _2. The display control circuit 10 can also output the first switch signal DRVM _1 of the second level to the single-pole-multiple-throw switch N1. The single-pole multi-throw switch N1 can conduct the movable terminal P1 and the fixed terminal P2_2 thereof under the control of the first switch signal DRVM _1 of the second level, and further transmit the second switch control signal DRVM _2 to the first transistor M1 corresponding to the blue laser source 70_b. The first transistor M1 can further conduct the blue laser source 70_b to the ground GND under the control of the second switch signal DRVM _2. The second driving current DC _3 can further drive the blue laser source 70_b to emit light. At this time, the red laser light source 60\ u R and the green laser light source 70 \ u G do not emit light.

After the light emitting duration of the blue laser source 70\uB reaches the duty time duty3 corresponding to the blue laser source 70_B, the display control circuit 10 can output the enable signal EN _2 of the inactive level to the second light source driving circuit 30, and stop outputting the luminance control signal DIMMING _3 corresponding to the blue laser source 70 _Bto the second light source driving circuit 20. At this time, the blue laser light source 70\ u b stops emitting light.

In the embodiment of the present application, if the laser projection apparatus needs to increase the brightness of the projected image, the first laser light source 60 and one of the second laser light sources 70 of the plurality of second laser light sources 70 can simultaneously output the driving current through the first light source driving circuit 20 and the second light source driving circuit 30.

With continued reference to fig. 4, after determining that the duration of the blue laser light source 70_b stopping emitting light reaches the target duration t, the display control circuit 10 may output the enable signal EN _1 of the active level and the luminance control signal dim _1 corresponding to the red laser light source 60 _rto the first light source driving circuit 20, output the enable signal EN _2 of the active level and the luminance control signal dim _2 corresponding to the green laser light source 70 _gto the second light source driving circuit 30, and output the first switching signal DRVM _1 of the first level to the first switching circuit 40. At this time, the red laser light source 60 and the green laser light source 70\\ u g can emit light simultaneously. For example, the color of the mixed light beam emitted by the red laser light source 60 u r and the green laser light source 70 u g may be yellow.

After the light emitting time periods of the red and green laser light sources 60 \ u r and 70 \ u g reach the preset duty time duty4, the display control circuit 10 may stop outputting the enable signals of the active levels to the first and second light

source driving circuits

20 and 20. At this time, the red laser light source 60\ u r and the green laser light source 70 \ u g stop emitting light.

After determining that the light emitting periods of the red and green laser light sources 60 \ r and 70 \ g stop reaching the target period t, the display control circuit 10 may output the enable signal EN _1 at an active level and the brightness control signal dim _1 corresponding to the red laser light source 60 \ r to the first light source driving circuit 20, output the enable signal EN _2 at an active level and the brightness control signal dim _3 corresponding to the blue laser light source 60 \ b to the second light source driving circuit 30, and output the first switching signal DRVM _2 at a second level to the first switching circuit 40. At this time, the red laser light source 60 and the blue laser light source 70\\ u b can emit light simultaneously. For example, the color of the mixed beam emitted by the red laser source 60 u r and the blue laser source 70 u b may be purple.

After the light emitting periods of the red and blue laser light sources 60 \ u r and 70 \ u b reach the preset duty time duty5, the display control circuit 10 may stop outputting the enable signals of the active level to the first and second light source driving circuits 20 and 30. At this time, the red laser light source 60\ u r and the blue laser light source 70 \_b stop emitting light.

Optionally, as shown in fig. 5, the laser projection apparatus may further include: a first current adjusting circuit 90 corresponding to the first light source driving circuit 20, and a second current adjusting circuit 00 corresponding to the second light source driving circuit 30. Referring to fig. 5, the first current adjusting circuit 90 is connected to the output terminal of the first light source driving circuit 20 and the first laser light source 60, respectively. The first current adjusting circuit 90 is used for adjusting the first driving current DC _1 output by the first light source driving circuit 20.

The second current adjusting circuit 00 is connected to the output terminal of the second light source driving circuit 30 and one end of the plurality of second laser light sources 70. The second current adjusting circuit 00 is used for adjusting the second driving current DC _2 output by the second light source driving circuit 30.

It is understood that the driving currents output by the first light source driving circuit 20 and the second light source driving circuit 30 may differ from the driving current flowing through the laser light source, i.e. the driving current received by the laser light source does not coincide with the rated driving current required by the laser light source when emitting light. Therefore, the first current adjusting circuit 90 in the laser projection apparatus can adjust the magnitude of the first driving current DC _1 output by the first light source driving circuit 20, so that the first driving current DC _1 actually flowing through the first laser light source 60 is more consistent with the rated driving current required by the first laser light source 60. The second current adjusting circuit 00 can adjust the magnitude of the second driving current DC _2 output by the second light source driving circuit 30, so that the second driving current DC _2 actually flowing through the second laser light source 70 is relatively consistent with the rated driving current required by the second laser light source 70. Therefore, the plurality of laser light sources can be ensured to emit light normally, and the display effect of the projected images projected by the laser projection equipment is better.

Alternatively, as shown in fig. 5, the first current regulating circuit 90 may include: a first inductor L1, a first diode D1 and a second transistor M2.

One end of the first inductor L1 is connected to the output end 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 60. The second terminal of the first diode D1 is connected to the other terminal of the first laser source 60 and the first terminal of the second transistor M2. The gate G of the second transistor M2 is connected to the output terminal of the first light source driving circuit 20, and the second pole of the second transistor M2 is connected to the ground GND.

Alternatively, the plurality of second laser light sources 70 may include two second laser light sources 70. For example, referring to fig. 5, the plurality of second laser light sources 70 may include a green laser light source 70_g and a blue laser light source 70_b. With continued reference to fig. 5, the second current regulating circuit 90 may include: a second inductor L2, a third inductor L3, a second diode D2 and a third diode D3.

As shown in fig. 5, one end of the second inductor L2 is connected to the output end 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 one end of one of the two second laser light sources 70, which is one of the two second laser light sources 70. The second end of the second diode D2 is connected to the other end of a second laser source 70 and the first end 1 of the second switch circuit 50. One end of the third inductor L3 is connected to the output end of the second light source driving circuit 30 and the first end of the third diode D3, respectively, and the other end of the third inductor L3 is connected to one end of the other second laser light source 70 of the two second laser light sources 70. The second end of the third diode D3 is connected to the other end of the second laser source 70 and the first end 1 of the second switch circuit 50.

Alternatively, referring to fig. 5, the first ends of the first diode D1, the second diode D2 and the second diode D3 may be cathodes, and the second ends of the first diode D1, the second diode D2 and the second diode D3 may be anodes. The second transistor M2 may also be a P-type MOS transistor. The first poles of the second transistors M2 may be both source electrodes S, and the second poles of the second transistors M2 may be both drain electrodes D.

In the present embodiment, the first light source driving circuit 20 may further output the third switching signal DRVM _3 to the gate G of the second transistor M2 when outputting the first driving current DC _1 to the first laser light source 60. The third switching signal DRVM _3 may be a PWM signal. Based ON the principle of PWM, the PWM signal is output in the form of a periodic pulse train in an ON (ON) state or an OFF (OFF) state. Wherein, the pulse in the on state is high level, and the off state is equivalent to no pulse output.

When the third switching signal DRVM _3 output from the first light source driving circuit 20 is output to the gate G of the second transistor M2 in a pulse-free form, the source S and the drain D of the second transistor M2 can be turned on. At this time, the first diode D1 is in a cutoff state. Thus, the first light source driving circuit 20 can be turned on to the ground GND, so that the first laser light source 60 is in a light emitting state.

It can be understood that when the output terminal of the first light source driving circuit 20 is conducted to the ground terminal GND, the first inductor L1 can store a part of the first driving current DC _1 output by the first light source driving circuit 20 in the form of electric energy. That is, when the second transistor M2 is in the on state, the first inductor L1 is in the charging state.

When the third switching signal DRVM _3 output from the first light source driving circuit 20 is pulsed to the gate G of the second transistor M2, the source S and the drain D of the second transistor M2 are turned off. At this time, the first diode D1 is in a conducting state, and the first inductor L1 is in a discharging state. Therefore, when the second transistor M2 is in the off state, the first inductor L1 can continue to drive the first laser source 50 to emit light. This ensures the stability of the light emission of the first laser light source 50.

It is understood that the first light source driving circuit 20 can change the on-time of the second transistor M2 by adjusting the duty ratio of the third switching signal DRVM _3 outputted therefrom. When the duty ratio of the third switching signal DRVM _3 in a unit time (e.g., 1 second) is small, the on-time 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 60 is also large. When the duty ratio of the third switching signal DRVM _3 in a unit time is larger, the off duration of the second transistor M2 in the unit time is longer (i.e., the on duration is shorter), and the first driving current DC _1 flowing through the first laser light source 60 is also smaller. Therefore, the first driving current DC _1 flowing through the first laser light source 60 can be adjusted, so that the difference between the first driving current DC _1 flowing through the first laser light source 60 and the rated driving current of the first laser light source 60 is small, and the light emitting effect of the first laser light source 60 is further ensured.

In the embodiment of the present application, when the second current regulating circuit 00 realizes the current regulating function thereof, it is further required to control the plurality of first transistors M1 to realize the regulation of the second driving current. The first transistor M1 to which the second inductor L2, the second diode D2 and the second diode D2 are connected can form a current regulation sub-circuit. The third inductor L3, the third diode D3 and a first transistor M1 to which the third diode is connected can form a current regulation sub-circuit. The two current adjusting sub-circuits are in one-to-one correspondence with the two second laser light sources 70, and are configured to adjust the second driving current flowing through the corresponding second laser light source 70. The working principle of the two current regulation sub-circuits can refer to the description of the working principle of the first current regulation circuit 90, and the working principle of the embodiment of the present application is not described herein again.

Based on the above analysis, the plurality of first transistors M1 in the second switch circuit 50 not only can implement the driving switching of the plurality of second laser light sources 70, but also can implement the adjustment of the second driving current flowing through the plurality of second laser light sources 70, thereby effectively improving the utilization rate of the plurality of first transistors M1. In addition, since the laser projection apparatus only needs the single-pole multi-throw switch N1 and the two first transistors M1, the driving switching of the plurality of second laser light sources 70 can be realized. Therefore, the structure of the laser projection equipment is effectively simplified.

Optionally, as shown in fig. 5, the laser projection apparatus may 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 first laser source 60 and the feedback end of the first light source driving circuit 20, respectively, and the other end of the first sampling resistor R1 is connected to the ground GND. One end of the second sampling resistor R2 is connected to the second end 2 of the second switch circuit 50 and the feedback end of the second light source driving circuit 30, and the other end of the second sampling resistor R2 is connected to the ground GND.

In the embodiment of the present application, when the output terminal of the first light source driving circuit 20 (i.e. the terminal outputting the first driving current DC _ 1) is connected to the ground terminal GND, the first sampling resistor R1 can sample the driving first driving current DC _1 flowing through the first laser light source 60. The first light source driving circuit 20 can receive the driving current sampled by the first sampling resistor R1 through its feedback terminal. The rated driving current of the first laser light source 60 may be stored in the first light source driving circuit 20 in advance. The first light source driving circuit 20 is capable of adjusting the duty ratio of the third switching signal DRVM _3 outputted therefrom based on the sampled driving current and the rated driving current stored in advance.

For example, when the first light source driving circuit 20 determines that the sampled driving current is smaller than the rated driving current, the duty ratio of the third switching signal DRVM _3 output by the first light source driving circuit may be decreased, so that the on-time of the second transistor M2 may be increased, and the current value of the first driving current DC _1 flowing through the first laser light source 60 may be increased. When the first light source driving circuit 20 determines that the sampled driving current is greater than the rated driving current, the duty ratio of the third switching signal DRVM _3 output by the first light source driving circuit may be increased, so that the on-time of the second transistor M2 may be reduced, and the current value of the first driving current DC _1 flowing through the first laser light source 60 may be further reduced.

The second light source driving circuit 30 may also adjust the duty ratio of the second switching signal DRVM _2 output by the second sampling resistor R2 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.

Fig. 6 is a schematic structural diagram of a projection apparatus in the related art. Referring to fig. 6, the projection apparatus includes: the display control circuit 01 includes a plurality of light sources having different colors, a light source drive circuit 03 corresponding to the plurality of light sources one by one, and a current adjustment circuit 04 corresponding to the plurality of light sources one by one. Wherein. Each current regulating circuit 04 includes: a fourth inductor L4, a fourth diode D4, and a third transistor M3. Alternatively, as shown in fig. 6, the plurality of light sources may include: a red light source 02 \ u R, a green light source 02 \ u G, and a blue light source 02 \ u B.

A circuit formed by each light source, and the light source driving circuit 03 and the current adjusting circuit 04 corresponding to the light source may be referred to as a BUCK (BUCK) topology circuit. And, the BUCK topology circuit can be integrated on a light source driving board of the projection device.

As shown in fig. 6, the projection apparatus may further include a third sampling resistor R3 connected to the plurality of current adjusting circuits 04 in one-to-one correspondence. The light source driving circuit 03 may adjust the driving current flowing through the light source by the driving current sampled by the third sampling resistor R3.

When the display control circuit 01 outputs the luminance control signal DIMMING and the enable signal EN of the active level to the light source driving circuit 03 corresponding to the red light source 02\ r, the light source driving circuit 02 can output a driving current to the red light source 02_r through the third inductor L3 and output a driving control signal DRVM _3 to the gate G of the fourth transistor M4. The third transistor M3 can be switched in an on/off state under the control of the driving control signal DRVM _3, so that the light source driving circuit 03 can drive the red light source 02 \ u r to emit light. The light emission principle of the green light source 02 _Gand the blue light source 02 _Bis the same as the light emission principle of the red light source 02_R, and the description thereof is omitted.

It is understood that, in the related art, the projection apparatus needs to be provided with three light source driving circuits to realize the light emission driving of the plurality of light sources. Therefore, the structure of the projection equipment is complex, and the manufacturing cost is high. In addition, when the projection apparatus in the related art implements the light emitting driving of the plurality of light sources, the display control circuit 01 needs to output the luminance adjusting signal dim and the enable signal EN to the plurality of light source driving circuits 03 corresponding to the plurality of light sources one by one, respectively. For example, if the projection apparatus includes 3 light sources, the display control circuit 01 needs to output 3 enable signals EN and 3 DIMMING signals simultaneously. This increases the complexity of the output signal of the display control circuit 01.

In the laser projection device provided by the application, the light emitting drive of the plurality of second laser light sources can be realized only by one light source drive circuit and two switch circuits. Therefore, the structure of the light source driving board in the laser projection equipment is effectively simplified, and the cost of the laser projection equipment is reduced. In addition, the display control circuit 10 only needs to output one path of enable signal EN _1 and one path of brightness adjusting signal DIMMING _1 to the first light source driving circuit 20, output one path of enable signal EN _2 and one path of brightness adjusting signal DIMMING _2 to the first light source driving circuit 20, and output the first switch signal to the first switch circuit 40 at the same time. Therefore, the complexity of the output signal of the display control circuit is effectively reduced. In addition, the light source driving board of the laser projection equipment is simple in structure and small in area, so that the light source driving board and the light source board (such as a laser) can be conveniently integrated, and the miniaturization of the laser projection equipment is further realized.

In summary, the present application provides a laser projection device, where a display control circuit of the laser projection device is capable of outputting a first switch control signal to a first switch circuit, outputting a first driving signal to a first light source driving circuit, and outputting a second driving signal to a second light source driving circuit. The first driving signal is used for driving the first light source driving circuit to output a first driving current, and the second driving signal is used for driving the second light source driving circuit to output a second driving current and a second switching signal. The first switching circuit is capable of transmitting a second switching signal to the second switching circuit under control of the first switching control signal. The second switch circuit can control one of the second laser light sources to emit light under the drive of the second drive current under the control of the second switch signal. The second light source driving circuit can drive the plurality of second laser light sources to emit light, so that the structure of the laser projection equipment is effectively simplified.

Fig. 7 is a schematic flowchart of a method for driving a light source of a laser projection apparatus according to an embodiment of the present disclosure. The method may be applied to a laser projection device, such as the laser projection device shown in fig. 1, which, with reference to fig. 1, comprises: the display control circuit 10, the first light source driving circuit 20, the second light source driving circuit 30, the first switching circuit 40, the second switching circuit 50, the first laser light source 50, and the plurality of second laser light sources 60. Referring to fig. 7, the method includes:

step 101, the display control circuit outputs a first switch signal to the first switch circuit, outputs a first driving signal to the first light source driving circuit, and outputs a second driving signal to the second light source driving circuit based on the light emitting timing sequence of the plurality of second laser light sources.

Wherein the first and second driving signals include an enable signal and a brightness control signal. After the laser projection apparatus is powered on, the display control circuit 10 of the laser projection apparatus can output a first switching signal to the first switching circuit 40 based on the light emitting information of the plurality of laser light sources to control the switching state of the first switching circuit 40. The first switch circuit 40 may have a plurality of second terminals 2, and the number of the second terminals 2 is the same as the number of the second laser light sources 70. Therefore, the switching state of the first switch circuit 40 may refer to the on/off state of any one second terminal 2 between the first terminal 1 and the plurality of second terminals 2.

And 102, outputting a first driving current to the first laser light source by the first light source driving circuit under the driving of the first driving signal so as to drive the first laser light source to emit light.

The brightness control signal received by the first light source driving circuit 20 may be a PWM signal. The magnitude of the first driving current may be positively correlated with the duty ratio of the brightness control signal, i.e., the larger the duty ratio of the brightness control signal is, the higher the signal value of the first driving current is. Accordingly, the higher the light emission luminance of the first laser light source 60 driven by the first driving current.

And 103, outputting a second driving current to one end of the plurality of second laser light sources by the second light source driving circuit under the driving of the second driving signal, and outputting a second switching signal to the first switching circuit.

The magnitude of the second driving current may be positively correlated to the duty ratio of the brightness control signal in the second driving signal. The second switch signal is used to control the on/off states of the first terminal 1 and the second terminal 2 of the second switch circuit 50.

And 104, the first switch circuit transmits the second switch signal to the second switch circuit under the control of the first switch signal.

When the first switch circuit 40 receives the first switch signal and is controlled by the first switch control signal to turn on the first terminal 1 and one second terminal 2 of the plurality of second terminals 2, the first switch circuit 40 is capable of transmitting the received second switch signal from the first terminal 1 to the conducting second terminal 2, and further transmitting the second switch signal to the control terminal C2 of the second switch circuit 50 connected to the second terminal 2.

And 105, the second switch circuit controls one of the second laser light sources to emit light under the control of the second switch signal.

In the embodiment of the present application, when the control terminal C2 of the second switch circuit 50 receives the second switch signal, one of the second laser light sources 70 in the plurality of second laser light sources 70 can be conducted to the ground terminal GND. Thus, the second driving current outputted by the second light source driving circuit 30 can flow through the one conducting second laser light source 70 and flow to the ground GND, so as to drive the one conducting second laser light source 70 to emit light.

The second switch circuit 40 may have a control terminal C2 corresponding to the plurality of second laser light sources 70, and a plurality of first terminals 1 (not shown in fig. 1) connected to the plurality of second laser light sources 70, and the control terminals C2 correspond to the first terminals 1. When the target control terminal C2 of the plurality of control terminals C2 in the second switch circuit 50 receives the second switch signal, it can turn on the corresponding one of the first terminal 1 and the second terminal 2. Thereby, the target second laser light source 70 among the plurality of second laser light sources 70 can be electrically connected to the ground GND. The target second laser light source 70 may be the second laser light source 70 that the display control circuit 10 determines based on the light emission timing of the plurality of second laser light sources 70 that the laser projection device currently needs to be lit.

Based on the above analysis, the first light source driving circuit 20 can directly drive the first laser light source 60 to emit light. The second driving current outputted by the second light source driving circuit 30 needs to be transmitted to one of the second laser light sources 70 that is conducted with the second light source driving circuit 30, under the control of the first switching circuit 40 and the second switching circuit 50.

Wherein the light emitting periods of two adjacent second laser light sources 70 may be spaced by a target time length. The target time period may be determined based on the switching time periods of the first and

second switching circuits

40 and 50. That is, the second light source driving circuit 30 may drive only one second laser light source 60 of the plurality of second laser light sources 60 to emit light in the same period, that is, the light emitting periods of the plurality of second laser light sources 70 are not overlapped. The lengths of the light emitting periods of the plurality of second laser light sources 70 may be the same or different.

It is understood that the first switch circuit 40 and the second switch circuit 50 require a certain period of time when switching the paths between the second light source driving circuit 30 and the plurality of second laser light sources 70. By spacing the conduction periods of the two adjacent second laser light sources 70 and the second light source driving circuit 30 by the target duration, the second light source driving circuit 30 can be prevented from driving the two second laser light sources 70 to emit light at the same time. This can effectively ensure the emission purity of the plurality of second laser light sources 70.

As a first possible implementation manner, the light emitting periods of the first laser light source 60 and the plurality of second laser light sources 70 do not overlap with each other. In this implementation, the display control circuit 10 may control the first laser light source 60 and the plurality of second laser light sources 70 to sequentially emit light through the first light source driving circuit 20 and the second light source driving circuit 30. For example, the display control circuit 10 may first drive the first laser light source 60 to emit light by the first light source driving circuit 20. After the light emitting duration of the first laser light source 50 reaches the duty time corresponding to the first laser light source 60, the display control circuit 10 may drive the plurality of second laser light sources 70 to sequentially emit light through the second light source driving circuit 30.

As a second possible implementation manner, the light emitting periods of the first laser light source 60 and one second laser light source 70 of the plurality of second laser light sources 70 overlap, and the light emitting periods of the plurality of second laser light sources 70 do not overlap. In this implementation, the display control circuit 10 may control the first laser light source 60 to emit light through the first light source driving circuit 20, and may drive the plurality of second laser light sources 70 to sequentially emit light through the second light source driving circuit 30, the first switching circuit 40, and the second switching circuit 50. Thus, the light beam emitted from the first laser light source 60 and the light beam emitted from one of the second laser light sources 70 among the plurality of second laser light sources 70 can be mixed into a light beam of a new color.

Referring to fig. 4, the first laser light source 60 may be a red laser light source 60\ u r, and the plurality of second laser light sources 60 may include a green laser light source 50 _gand a blue laser light source 60_b. The first switch circuit 40 may include a single-pole-multi-throw switch N1, and the second switch circuit 50 may include two first transistors M1 connected to the two second laser light sources 70 in a one-to-one correspondence. A method of driving the three laser light sources will be described below. Referring to fig. 8, the driving method may include:

and S1, powering on and starting up the laser projection equipment, and initializing a display control circuit.

The user can control the laser projection device to be powered on and started up in a remote control mode or a mode of pressing a switch key of the laser projection device. After the laser projection device is powered on and started, the display control circuit 10 may be initialized. During the initialization process, the display control circuit 10 may obtain light emission information of a plurality of laser light sources in the laser projection apparatus.

And S2, the display control circuit outputs a first driving signal to the first light source driving circuit.

Wherein the first driving signal includes an enable signal of an active level and a brightness control signal DIMMING _1 corresponding to the red laser light source 60_r. The first light source driving circuit 20 is capable of outputting a first driving current to the red laser light source 60 r to drive the red laser light source 60 r to emit light under the driving of the first driving signal. At this time, the level of the enable signal output from the display control circuit 10 to the second light source driving circuit 30 is at the inactive level, and the green laser light source 70 g and the blue laser light source 70 v u b do not emit light.

And S3, detecting whether the light-emitting duration of the red laser light source reaches a first duration by the display control circuit.

The first time period may be a duty time of the red laser source 60 r. If the display control circuit 10 determines that the light emission time period of the red laser light source 60 \ u r reaches the first time period, the following step S4 may be executed. If the display control circuit 10 determines that the light emission time of the red laser light source 60 'u r does not reach the first time, the display control circuit may continue to drive the red laser light source 60' u r to emit light through the first light source driving circuit 20.

And S4, the display control circuit outputs an enable signal of an invalid level to the first light source driving circuit.

After determining that the light emitting duration of the red laser source 60 'u r reaches the first duration, the display control circuit 10 outputs an enable signal of an invalid level to the first light source driving circuit 20, so that the first light source driving circuit 20 stops driving the red laser source 60' u r to emit light.

And S5, the display control circuit outputs a second driving signal to the second light source driving circuit and outputs a first switching signal of a first level to the first switching circuit.

The driving signal may include an active level enable signal and a brightness control signal dim _2 corresponding to the green laser light source 70 g. The second light source driving circuit 30 can output the second driving current after receiving the second driving signal. After receiving the first switch signal DRVM _1 with the first level, the single-pole-multi-throw switch N1 in the first switch circuit 40 can conduct the active terminal P1 and the inactive terminal P2_1 thereof under the control of the first switch signal DRVM _1 with the first level, and further transmit the first switch control signal DRVM _1 to the first transistor M1 corresponding to the green laser source 70 _g. The first transistor M1 can further turn on the green laser source 70_g to the ground terminal under the control of the second switching signal. The second driving current DC _2 can further drive the green laser source 70\ g to emit light. At this time, the red laser light source 60\ u R and the blue laser light source 70 \_B do not emit light.

And S6, detecting whether the light-emitting time of the green laser light source reaches a second time by the display control circuit.

Wherein the second duration may be a duty time of the green laser source 70 g. If the display control circuit 10 determines that the light emission time period of the green laser light source 70 _greaches the second time period, the following step S7 may be executed. If the display control circuit 10 determines that the emission time period of the green laser light source 70 u g does not reach the second time period, the display control circuit may continue to drive the green laser light source 70 u g to emit light through the second light source driving circuit 30.

And S7, the display control circuit outputs an enable signal of an invalid level to the second light source driving circuit and stops outputting a brightness control signal corresponding to the green laser light source to the second light source driving circuit.

After determining that the light emitting duration of the green laser light source 70 g reaches the second duration, the display control circuit 10 outputs an enable signal of an invalid level to the second light source driving circuit, and stops outputting the brightness control signal corresponding to the green laser light source to the second light source driving circuit. The second light source driving circuit 30 can stop the output of the second driving current DC _2 to the green laser light source 70_g upon receiving the enable signal EN _2 of the inactive level. At this time, the green laser light source 70\gstops emitting light.

And S8, the display control circuit outputs an enabling signal of an effective level and a brightness control signal corresponding to the blue laser light source to the second light source driving circuit, and outputs a first switching signal of a second level to the first switching circuit.

The second light source driving circuit 30 is capable of outputting the second driving current DC _3 to the plurality of second laser light sources 70 connected thereto after receiving the enable signal EN _2 of the active level and the luminance control signal DIMMING _3 corresponding to the blue laser light source. The single-pole multi-throw switch N1 in the first switch circuit 40 can conduct the moving terminal P1 and the fixed terminal P2_2 thereof under the control of the first switch signal DRVM _1 of the second level, and further transmit the second switch control signal DRVM _2 to the first transistor M1 corresponding to the blue laser source 70_b. The first transistor M1 can further conduct the blue laser source 70_b to the ground GND under the control of the second switch signal DRVM _2. The second driving current DC _3 can further drive the blue laser source 70_b to emit light. At this time, the red laser light source 60\ u R and the green laser light source 70 \ u G do not emit light.

And S9, detecting whether the light-emitting time of the blue laser light source reaches a third time by the display control circuit.

Wherein the third duration may be a duty time of the blue laser source 70 u b. If the display control circuit 10 determines that the light emission time period of the blue laser light source 70\uB reaches the third time period, the following step S10 may be executed. If the display control circuit 10 determines that the emission time period of the blue laser light source 70 u b does not reach the third time period, the display control circuit may continue to drive the blue laser light source 70 u b to emit light by the second light source driving circuit 30.

And step S10, the display control circuit outputs an enable signal of an invalid level to the second light source driving circuit and stops outputting a brightness control signal corresponding to the blue laser light source to the second light source driving circuit.

After determining that the light emitting duration of the blue laser light source 70\\ b reaches the third duration, the display control circuit 10 may output the enable signal EN _2 of the inactive level to the second light source driving circuit 30, and stop outputting the luminance control signal DIMMING _3 corresponding to the blue laser light source 70 \ u b to the second light source driving circuit 30. When the second light source driving circuit 30 receives the enable signal EN _2 of the inactive level, the second light source driving circuit 30 stops outputting the second driving current DC _3 to the blue laser light source 70_b. At this time, the blue laser light source 70\ u b stops emitting light.

Alternatively, referring to fig. 9, the driving method of the three laser light sources may further include:

step S11, the display control circuit outputs a first driving signal to the first light source driving circuit, outputs a second driving signal to the second light source driving circuit, and outputs a first switching signal of a first level to the first switching circuit.

The first light source driving circuit 20 can directly drive the red laser light source 60 urr to emit light by being driven by the first driving signal. The second light source driving circuit 30 can drive the green laser light source 70 ugg to emit light by the first switching circuit 40 and the second switching circuit 50 under the drive of the second drive signal. At this time, the red laser light source 60 and the green laser light source 70\\ u g can emit light simultaneously. The light beams emitted by the two laser light sources are mixed light beams. For example, the color of the mixed light beam may be yellow.

And S12, detecting whether the light emitting time of the red laser light source and the green laser light source reaches the fourth time by the display control circuit.

Wherein the fourth time period may be determined based on a duty time of a beam obtained by mixing the red laser light source 60 u r and the green laser light source 70 u g. If the display control circuit 10 detects that the light emission time periods of the green laser light source 70 _gand the red laser light source 60 _rreach the fourth time period, the following step S13 may be executed. If the display control circuit 10 detects that the emission time periods of the red laser light source 60 \ u r and the green laser light source 70 \ u g do not reach the fourth time period, the first light source drive circuit 20 and the second light source drive circuit 30 can drive the red laser light source 60 \ u r and the green laser light source 70 \ u g to continue emitting light.

Step S13 the display control circuit outputs an enable signal of an invalid level to the first light source driving circuit and the second light source driving circuit.

After determining that the light emitting time periods of the red laser light source 60 u r and the green laser light source 70 u g reach the fourth time period, the display control circuit 10 may control the first light source driving circuit 20 to stop driving the red laser light source 60 u r to emit light, and control the second light source driving circuit 30 to stop driving the green laser light source 70 u g to emit light.

Step S14, the display control circuit outputs a first driving signal to the first light source driving circuit, outputs a second driving signal to the second light source driving circuit, and outputs a first switching signal of a second level to the first switching circuit.

At this time, the red-fixed laser light source 60 and the blue laser light source 70\\ u B can emit light simultaneously. The light beams emitted by the two laser light sources are mixed light beams. For example, the color of the mixed light beam may be purple.

And S15, the display control circuit detects whether the light emitting time of the red laser light source and the light emitting time of the blue laser light source reach the fifth time.

Wherein the fifth time period may be determined based on a duty time of a beam resulting from mixing the red laser light source 60 u r and the blue laser light source 70 u b. The display control circuit 10 may execute the following step S16 if it detects that the light emission periods of the red laser light source 60_r and the blue laser light source 70 _breach the fifth period. When the display control circuit 10 detects that the emission time periods of the red laser light source 70 _rand the blue laser light source 60 _bdo not reach the fifth time period, the first light source drive circuit 20 and the second light source drive circuit 30 can drive the red laser light source 70 _rand the blue laser light source 60 _bto continue emitting light.

And S16, the display control circuit outputs an enable signal of an invalid level to the first light source driving circuit and the second light source driving circuit.

After determining that the light emitting time periods of the red laser light source 70\\ u R and the blue laser light source 60 _Breach the fifth time period, the display control circuit 10 may control the first light source driving circuit 20 to stop driving the red laser light source 70 _Rto emit light, and control the second light source driving circuit 30 to stop driving the blue laser light source 60 _Bto emit light.

Step S17, the display control circuit detects whether a shutdown signal is received.

The display control circuit 10 may detect whether the shutdown signal is received when a time period in which the enable signal of the inactive level is output to the first light source driving circuit 20 and the second light source driving circuit 30 reaches a second target time period (i.e., after it is determined that the first light source driving circuit 20 and the second light source driving circuit 30 completely stop operating). If the display control circuit 10 does not detect the shutdown signal, the step S2 may be executed. If the display control circuit 10 detects the shutdown signal, it may end the light source driving process of the laser projection apparatus.

In summary, the embodiment of the present application provides a method for driving a light source of a laser projection device, which is applied to the laser projection device. The display control circuit of the laser projection device can output a first switch control signal to the first switch circuit, output a first drive signal to the first light source drive circuit, and output a second drive signal to the second light source drive circuit. The first driving signal is used for driving the first light source driving circuit to output a first driving current, and the second driving signal is used for driving the second light source driving circuit to output a second driving current and a second switching signal. The first switching circuit is capable of transmitting the second switching signal to the second switching circuit under control of the first switching control signal. The second switch circuit can control one of the second laser light sources to emit light under the drive of the second drive current under the control of the second switch signal. The second light source driving circuit can drive the plurality of second laser light sources to emit light, so that the structure of the laser projection equipment is effectively simplified.

The embodiment of the application provides a laser projection device, and the laser projection device comprises: a memory, a processor and a computer program stored on the memory, the processor implementing the method for driving a light source (e.g. the method shown in fig. 7, 8 or 9) as provided in the above method embodiments when executing the computer program.

The present application provides a computer-readable storage medium, in which instructions are stored, and the instructions are loaded and executed by a processor to implement the driving method of the light source (for example, the method shown in fig. 7, fig. 8 or fig. 9) provided by the above method embodiments.

Embodiments of the present application provide a computer program product comprising instructions which, when run on a computer, cause the computer to perform a method of driving a light source as provided in the above method embodiments (e.g. the method shown in fig. 7, 8 or 9).

It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by hardware related to instructions of a program, and the program may be stored in a computer readable storage medium, where the above mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk.

It is to be understood that the term "plurality" in this application means two or more. The terms "first," "second," and the like, in this application, are used for distinguishing between similar items and items that have substantially the same function or similar functionality, and it should be understood that "first," "second," and "nth" do not have any logical or temporal dependency, nor do they define a quantity or order of execution.

The above description is only exemplary of the present application and should not be taken as limiting the present application, and any modifications, equivalents, improvements and the like that are made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A laser projection device, characterized in that the laser projection device comprises: the display control circuit comprises a display control circuit, a first light source driving circuit, a second light source driving circuit, a first switch circuit, a second switch circuit, a first laser light source and a plurality of second laser light sources;

the output end of the second light source driving circuit is connected with one end of each of the plurality of second laser light sources and the first end of the first switching circuit, and the second light source driving circuit is used for outputting a second driving current to one end of each of the plurality of second laser light sources and outputting a second switching signal to the first switching circuit under the driving of the second driving signal;

the second end of the first switch circuit is connected with the control end of the second switch circuit, and the first switch circuit is used for transmitting the second switch signal to the second switch circuit under the control of the first switch signal;

the first end of the second switch circuit is connected with the other ends of the plurality of second laser light sources respectively, the second end of the second switch circuit is connected with the grounding end, and the second switch circuit is used for controlling one of the plurality of second laser light sources to emit light under the control of the second switch signal.

2. The laser projection device of claim 1, wherein the first switching circuit comprises: the second switch circuit is provided with a plurality of control ends in one-to-one correspondence with the plurality of second laser light sources;

the control end of the single-pole multi-throw switch is used as the control end of the first switch circuit and is connected with the display control circuit, the moving end of the single-pole multi-throw switch is used as the first end of the first switch circuit and is connected with the output end of the second light source driving circuit, and a plurality of fixed ends of the single-pole multi-throw switch are used as the second end of the first switch circuit and are connected with a plurality of control ends of the second switch circuit in a one-to-one correspondence manner;

and the second switch circuit is used for controlling the second laser light source corresponding to the control end to emit light when any control end receives the second switch signal.

3. The laser projection device of claim 2, wherein the plurality of second laser light sources comprises two second laser light sources, and the single-pole-multiple-throw switch is a single-pole-double-throw switch;

the single-pole double-throw switch is used for transmitting the second switching signal to a control end, corresponding to one second laser light source, of the second switching circuit when receiving a first switching signal of a first level, and is used for transmitting the second switching signal to a control end, corresponding to the other second laser light source, of the second switching circuit when receiving a first switching signal of a second level.

4. The laser projection device of claim 1, wherein the second switching circuit comprises: a plurality of first transistors in one-to-one correspondence with the plurality of second laser light sources;

the grid electrode of each first transistor is used as the control end of the second switch circuit and connected with the second end of the first switch circuit, the first pole of each first transistor is used as the first end of the second switch circuit and connected with the other end of the corresponding second laser light source, and the second pole of each first transistor is used as the second end of the second switch circuit and connected with the grounding end.

5. The projection apparatus according to claim 4, wherein the display control circuit is configured to sequentially output a plurality of luminance control signals corresponding to the plurality of second laser light sources one to the second light source driving circuit;

and in the output period of the brightness control signal corresponding to each second laser light source, the first transistor corresponding to the second laser light source is in a conducting state.

6. The laser projection device of any of claims 1 to 5, further comprising: 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 regulating circuit is respectively connected with the output end of the first light source driving circuit and the first laser light source, and is used for regulating a first driving current output by the first light source driving circuit;

the second current adjusting circuit is respectively connected with the output end of the second light source driving circuit and one end of the plurality of second laser light sources, and is used for adjusting the second driving current output by the second light source driving circuit.

7. The laser projection device of claim 6, wherein the first current regulation 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 respectively connected with the other end of the first laser light source and the first pole of the third transistor;

the grid electrode of the second transistor is connected with the output end of the first light source driving circuit, and the second pole of the second transistor is connected with the grounding end.

8. The laser projection device of claim 6, wherein the plurality of second laser light sources comprises two second laser light sources; the second current regulating circuit includes: a second inductor, a third inductor, a second diode and a third diode;

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 one end of one of the two second laser light sources;

a second end of the second diode is connected with the other end of the second laser light source and a first end of the second switch circuit respectively;

one end of the third inductor is connected with the output end of the second light source driving circuit and the first end of the third diode respectively, and the other end of the third inductor is connected with one end of the other of the two second laser light sources;

and the second end of the third diode is respectively connected with the other end of the other second laser light source and the first end of the second switch circuit.

9. A method of driving a light source of a laser projection apparatus, the laser projection apparatus comprising: the display control circuit comprises a display control circuit, a first light source driving circuit, a second light source driving circuit, a first switch circuit, a second switch circuit, a first laser light source and a plurality of second laser light sources; the method comprises the following steps:

10. The method according to claim 9, wherein the light emission periods of the first laser light source and the plurality of second laser light sources do not overlap each other;

or the light emitting periods of the first laser light source and one of the plurality of second laser light sources overlap, and the light emitting periods of the plurality of second laser light sources do not overlap.