CN115981088A

CN115981088A - Laser projection apparatus and method of driving light source thereof

Info

Publication number: CN115981088A
Application number: CN202310127193.6A
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 switching signal to a first switching circuit and output an enable signal and a brightness control signal to a light source driving circuit so as to drive the light source driving circuit to output a driving current. The first switch circuit can transmit the second switch signal to the second switch circuit under the control of the first switch signal, so that the second switch circuit can sequentially conduct the grounding end and the plurality of laser light sources, and further the plurality of laser light sources can sequentially emit light under the drive of the drive current. Therefore, the driving current output by the light source driving circuit can drive the plurality of laser light sources to emit light sequentially. Because the laser projection equipment can realize the light-emitting drive of a plurality of laser light sources with different colors only by one light source drive circuit, the structure of the 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 comprising: the laser display device comprises a display control circuit, a light source driving circuit, a first switch circuit, a second switch circuit and a plurality of laser light sources with different colors;

the display control circuit is respectively connected with the control end of the first switch circuit and the input end of the light source driving circuit, and is used for outputting a first switch signal to the first switch circuit based on the light emitting time sequence of the laser light sources and outputting an enable signal and a brightness control signal to the light source driving circuit;

the output end of the light source driving circuit is respectively connected with one end of each of the plurality of laser light sources and the first end of the first switch circuit, and the light source driving circuit is used for outputting driving current to one end of each of the plurality of laser light sources and outputting a second switch signal to the first switch circuit under the driving of the enabling signal and the brightness control 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 laser light sources respectively, the second end of the second switch circuit is connected with the grounding end, the second switch circuit is used for controlling the laser light sources to sequentially emit light under the driving of the driving current under the control of the second switch signal, so that the laser projection equipment displays a projection image, wherein the light emitting time periods of any two laser light sources are not overlapped with each other.

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

the display control circuit outputs a first switching signal to the first switching circuit based on the light emitting time sequence of the plurality of laser light sources, and outputs an enable signal and a brightness control signal to the light source driving circuit;

the light source driving circuit outputs driving current to one end of the plurality of laser light sources under the driving of the enabling signal and the brightness control 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 the plurality of laser light sources to sequentially emit light under the driving of the driving current under the control of the second switch signal, so that the laser projection equipment displays a projection image, wherein the light emitting time periods of any two laser light sources are not overlapped with each other.

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 application provides a laser projection device and a driving method of a light source thereof, wherein a display control circuit of the laser projection device can output a first switching signal to a first switching circuit and output an enable signal and a brightness control signal to a light source driving circuit so as to drive the light source driving circuit to output a driving current. The first switch circuit can transmit the second switch signal to the second switch circuit under the control of the first switch signal, so that the second switch circuit sequentially conducts the grounding end and the plurality of laser light sources, and the plurality of laser light sources sequentially emit light under the drive of the drive current. Therefore, the driving current output by the light source driving circuit can drive the plurality of laser light sources to emit light sequentially. Because the laser projection equipment can realize the light-emitting drive of a plurality of laser light sources with different colors only by one light source drive circuit, the structure of the projection equipment is effectively simplified.

In addition, because the light emitting periods of the plurality of laser light sources are not overlapped, the light emitting purity of the plurality of laser light sources can be ensured, and the display effect of the projection image is effectively improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other 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 waveform diagram of output signals of various devices in a laser projection apparatus according to an embodiment of the present disclosure;

FIG. 4 is a schematic structural diagram of another laser projection apparatus provided in 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 according to an embodiment of the present disclosure.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, the following detailed description of the embodiments of the present application will be made 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 light source driving circuit 20, a first switching circuit 30, a second switching circuit 40, and a plurality of laser light sources 50 different in color from each other. The plurality of laser light sources 50 may also be referred to as lasers. For example, the plurality of laser light sources 50 may include a red laser light source, a green laser light source, and a blue laser light source.

Referring to fig. 1, the display control circuit 10 is connected to the control terminal C1 of the first switch circuit 30 and the input terminal of the light source driving circuit 20, respectively. The display control circuit 10 is configured to output a first switching signal DRVM _1 to the first switching circuit 30 based on the light emission timings of the plurality of laser light sources 50, and to output an enable signal EN and a luminance control signal dimimgn to the light source driving circuit 20.

The output terminals of the light source driving circuit 20 are connected to the plurality of laser light sources 50, respectively. The light source driving circuit 20 is configured to output a driving current to one end of the plurality of laser light sources 50 and output a second switching signal DRVM _2 to the first switching circuit 30 under the driving of the enable signal EN and the luminance control signal dimimgn.

The second terminal 2 of the first switch circuit 30 is connected to the control terminal C2 of the second switch circuit 40. The first switch circuit 30 is used to transmit the second switch signal DRVM _2 to the second switch circuit 40 under the control of the first switch signal DRVM _1. The first terminal 1 of the second switch circuit 40 is connected to the other terminals of the plurality of laser light sources 50, respectively, and the second terminal 2 of the second switch circuit 40 is connected to the ground GND. The second switch circuit 40 is configured to control the plurality of laser light sources 50 to sequentially emit light under the driving of the driving current under the control of the second switch signal DRVM _2, so that the laser projection apparatus displays a projection image. Wherein the light emitting periods of any two laser light sources 50 do not overlap each other.

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 switch signal DRVM _1 to the first switch circuit 30 based on the light emitting information of the plurality of laser light sources 50 to control the switch state of the first switch circuit 30. The first switch circuit 30 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 laser light sources 50. Therefore, the switching state of the first switch circuit 30 may refer to the on/off state of the first terminal 1 and any one of the plurality of second terminals 2.

The display control circuit 10 can also output the enable signal EN and the luminance control signal dimimgn to the light source driving circuit 20 based on the light emission information of the plurality of laser light sources 50. The enable signal EN is used to control the operating state of the light source driving circuit 20, that is, to control whether the light source driving circuit 20 outputs the driving current. The luminance control signal dimimgn is used to control the magnitude of the driving current output by the light source driving circuit 20.

The light emission information of the plurality of laser light sources 50 may include duty time and current information of the plurality of laser light sources 50. The duty time of the plurality of laser light sources 50 may indicate the light emission timing and the light emission time period of the plurality of laser light sources 50 within a unit time period (e.g., 1 second). The current information of the plurality of laser light sources 50 is a rated driving current required for the plurality of laser light sources 50 to emit light. The rated driving current of the laser light source 50 is a driving current capable of driving the laser light source 50 to emit light normally.

The light source driving circuit 20 can output a driving current after receiving the enable signal EN and the luminance control signal dimimgn. The luminance control signal dimimgn may be a Pulse Width Modulation (PWM) signal. The magnitude of the driving current is positively correlated with the duty cycle of the luminance control signal DIMMIGN, i.e., the larger the duty cycle of the luminance control signal DIMMIGN, the higher the signal value of the driving current. Accordingly, the higher the light emission luminance of the laser light source 50 driven by the driving current.

The light source driving circuit 20 may also output the second switching signal DRVM _2 to the first terminal 1 of the first switching circuit 30 after receiving the enable signal EN and the luminance control signal dimimgn. The first switch circuit 30 is capable of conducting the first terminal 1 thereof with one of the second terminals 2 under the control of the first switch signal DRVM _1. Thus, the first switch circuit 30 can transmit the received second switch signal DRVM _2 from the first terminal 1 to the conducting second terminal 2, and further transmit the second switch signal DRVM _2 to the control terminal C2 of the second switch circuit 40 connected to the second terminal 2.

In the embodiment of the present application, after the control terminal C2 of the second switch circuit 40 receives the second switch signal DRVM _2, it can conduct one of the laser sources 50 with the ground terminal GND. Thus, the driving current outputted by the light source driving circuit 20 can flow through the one conducting laser light source 50 and flow to the ground GND to drive the one conducting laser light source 50 to emit light.

The second switch circuit 40 may have a control terminal C2 corresponding to the plurality of laser light sources 50 one to one, and a plurality of first terminals 1 (not shown in fig. 1) connected to the plurality of laser light sources 50 one to one, and the plurality of control terminals C2 correspond to the plurality of first terminals 1 one to one. When the target control terminal C2 of the plurality of control terminals C2 in the second switch circuit 40 receives the second switch signal DRVM _2, it can conduct a corresponding one of the first terminal 1 and the second terminal 2. This allows the target laser light source 50 among the plurality of laser light sources 50 to be electrically connected to the ground GND. The target laser light source 50 may be a laser light source 50 that the display control circuit 10 determines based on the light emission timing of the plurality of laser light sources 50 that the laser projection apparatus currently needs to be lit.

It can be understood that, after receiving the first switching signal, the first switching circuit 30 can control the second switching circuit 40 to sequentially turn on the ground GND and the plurality of laser light sources 50 under the control of the first switching signal DRVM _1, so that the plurality of laser light sources 50 sequentially emit light under the driving of the driving current output by the light source driving circuit 20. This enables display of a projected image. Also, the light source driving circuit 20 may drive only one laser light source 50 of the plurality of laser light sources 50 to emit light at the same time period, that is, the light emitting time periods of the plurality of laser light sources 50 are not overlapped. Therefore, the laser light sources 50 with two different colors can be prevented from emitting light at the same time, the color mixing problem of the laser light sources 50 in the light emitting process is avoided, and the display effect of the projected image is effectively ensured.

It can also be understood that, since the first switch circuit 30 and the second switch circuit 40 can control the on/off states of the ground GND and any one of the plurality of laser light sources 50, the laser projection apparatus can realize the light-emitting driving of the plurality of laser light sources 50 with different colors by only one light source driving circuit 20. 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 embodiment of the present application provides a laser projection apparatus, where a display control circuit of the laser projection apparatus is capable of outputting a first switching signal to a first switching circuit, and outputting an enable signal and a brightness control signal to a light source driving circuit to drive the light source driving circuit to output a driving current. The first switch circuit can transmit the second switch signal to the second switch circuit under the control of the first switch signal, so that the second switch circuit sequentially conducts the grounding end and the plurality of laser light sources, and the plurality of laser light sources sequentially emit light under the drive of the drive current. Therefore, the driving current output by the light source driving circuit can drive the plurality of laser light sources to emit light sequentially. Because the laser projection equipment can realize the light-emitting drive of a plurality of laser light sources with different colors only by one light source drive circuit, the structure of the 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 referring to fig. 2, the first switching circuit 30 may include: a single pole, multiple throw switch N1. The second switch circuit 40 has a plurality of control terminals C2 corresponding to the plurality of laser light sources 50 one to one.

As shown in fig. 2, 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 30, the moving terminal P1 of the single-pole multi-throw switch N1 is connected to the output terminal of the light source driving circuit 20 as the first terminal 1 of the first switch circuit 30, 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 40 as the second terminal 2 of the first switch circuit 30 in a one-to-one correspondence manner. The second switch circuit 40 is configured to control the laser light source 50 corresponding to any one of the control terminals C2 to emit light when the control terminal C2 receives the second switch signal.

In the embodiment of the present application, after the display control circuit 10 is powered on (may also be referred to as initialization), the light emitting information of the plurality of laser light sources 50 during the projection process of the laser projection apparatus can be acquired. Wherein the light emission information may include duty time and current information of the plurality of laser light sources 50. The duty time of the plurality of laser light sources 50 may indicate the light emitting timing and the light emitting duration of the plurality of laser light sources 50. The light emission information of the plurality of laser light sources 50 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 50 may be acquired from the memory after the display control circuit 10 is powered on.

The display control circuit 10 can output the enable signal EN of the active level and the luminance control signal dim of the laser light source 50 to be turned on to the light source driving circuit 20 and output the first switch signal DRVM _1 to the single-pole multi-throw switch N1 when it is determined that one laser light source 50 of the plurality of laser light sources 50 needs to be turned on based on the light emission information of the plurality of laser light sources 50.

After receiving the first on signal DRVM _1 transmitted by the display control circuit 10, the single-pole multi-throw switch N1 can control the on/off states of the movable terminal P1 and any one of the plurality of stationary terminals under the control of the first on/off signal DRVM _1, thereby implementing the on/off control of any one of the control terminals C2 in the light source driving circuit 30 and the second on/off circuit 40. Therefore, 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 conducting one of the control terminals C2.

Alternatively, the plurality of laser light sources 50 may include a first laser light source 50, a second laser light source 50, and a third laser light source 50. The single pole, multiple throw switch N1 may be a single pole, three throw switch N1. The display control circuit 10 has a first general-purpose input/output (GPIO) pin GPIO _1 and a second GPIO pin GPIO _2. The first switching signal DRVM _1 output by the display control circuit 10 includes: a first output signal S1 output by the first GPIO pin GPIO _1 and a second output signal S2 output by the second GPIO pin GPIO _2. The first output signal S1 and the second output signal S2 are both level signals.

The single-pole-three-throw switch N1 is configured to transmit the second switch signal DRVM _2 to the control terminal C2 of the second switch circuit 40 corresponding to the first laser source 50 if the first output signal S1 and the second output signal S2 are both at the first level. If the first output signal S1 is at the first level and the second output signal is at the second level, the second switching signal DRVM _2 is transmitted to the control terminal C2 of the second switching circuit 40 corresponding to the second laser source 50. If the first output signal S1 is at the second level and the second output signal S2 is at the first level, the second switching signal DRVM _2 is transmitted to the control terminal C2 of the second switching circuit 40 corresponding to the third laser source 50.

The first level may be a high level relative to the second level. The first level may be represented by a value of "0" and the second level may be represented by a value of "1". Accordingly, when both the first output signal S1 and the second output signal S2 are at the first level, the first switching signal DRVM _1 received by the first switching circuit 30 may be represented as "00". When the first output signal S1 is at the first level and the second output signal S2 is at the second level, the first switching signal DRVM _1 received by the first switching circuit 30 may be represented as "01". When the first output signal S1 is at the second level and the second output signal S2 is at the first level, the first switching signal DRVM _1 received by the first switching circuit 30 may be represented as "10".

For example, referring to fig. 2, the first laser light source 50 may be a red laser light source 50\ur, the second laser light source 50 may be a green laser light source 50_g, and the third laser light source 50 may be a blue laser light source 50_b. When the single-pole-three-throw switch N1 receives the first switch signal DRVM _1, and the first output signal S1 and the second output signal S2 are both at the first level, it can conduct the moving terminal P1 and the stationary terminal P2_1, and further transmit the second switch signal DRVM _2 to the control terminal C2 (i.e., the control terminal C2 corresponding to the first laser light source 50\\ u r) connected to the stationary terminal P2_ 1. When the first switch signal DRVM _1 received by the single-pole three-throw switch N1 has the first level and the second output signal S2 has the second level, the first output signal S1 can conduct the movable terminal P1 and the stationary terminal P2_2, and the second switch signal DRVM _2 is transmitted to the control terminal C2 (i.e., the control terminal C2 corresponding to the green laser light source 50_g) connected to the stationary terminal P2_ 2. When the single-pole-three-throw switch N1 receives the first switch signal DRVM _1 of the third signal value, the first output signal S1 is at the second level, and the second output signal S2 is at the first level, it can conduct the moving terminal P1 and the stationary terminal P2_3, and further transmit the second switch signal DRVM _2 to the control terminal C2 (i.e., the control terminal C2 corresponding to the blue laser source 50 v u b) connected to the stationary terminal P2_ 3.

When the control terminal C2 of the second switch circuit 50 corresponding to the red laser source 50\\ r receives the second switch signal DRVM _2, the second switch circuit 50 can turn on the red laser source 50 _rand the ground terminal GND, so that the red laser source 50 _remits light under the driving of the driving current. At this time, green laser light source 50_g and blue laser light source 50_b do not emit light. When the control terminal C2 of the second switch circuit 50 corresponding to the green laser light source 50_g receives the second switch signal DRVM _2, the second switch circuit 50 can connect the green laser light source 50 _gto the ground terminal GND, so that the green laser light source 50 _gemits light under the driving of the driving current. When the control terminal C2 of the second switch circuit 50 corresponding to the blue laser light source 50_b receives the second switch signal DRVM _2, the second switch circuit 50 can turn on the blue laser light source 50 _band the ground terminal GND, so that the blue laser light source 50 _bemits light under the driving of the driving current.

With continued reference to fig. 2, the second switching circuit 40 may include: a plurality of first transistors M1 in one-to-one correspondence with the plurality of laser light sources 50. A gate (gate, G) of each first transistor M1 is connected to the second terminal 2 of the first switch circuit 30 as a control terminal C2 of the second switch circuit 40, a first pole of each first transistor M1 is connected to the other end of a corresponding one of the laser light sources 50 as a first terminal 1 of the second switch circuit 40, 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 40.

Alternatively, referring to fig. 2, 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).

When a first transistor M1 in the second switch circuit 40 receives the second switch signal DRVM _2, the first transistor M1 can conduct the source S and the drain D thereof under the control of the second switch signal DRVM _2, so that the laser source 50 connected to the first transistor M1 can be conducted with the ground GND. Therefore, the driving current output by the light source driving circuit 20 can flow through the one conducting laser light source 50 and flow to the ground GND, so as to realize the light emitting driving of the one conducting laser light source 50. 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 laser light source 50 to which the first transistor M1 is connected does not emit light.

Alternatively, the display control circuit 10 may sequentially output a plurality of luminance control signals DIMMING corresponding one-to-one to the plurality of laser light sources 50 to the light source driving circuit 20. In the output period of the luminance control signal DIMMING corresponding to each laser light source 50, the first transistor M1 corresponding to the laser light source 50 is in a conducting state.

The on time of the first transistor M1 corresponding to the target laser source 50 in the plurality of laser sources 50 may be a duty time of the target laser source 50. The target laser light source 50 is the laser light source 50 that the laser projection device needs to be lighted currently. After determining that the on-time of the first transistor M1 corresponding to the target laser light source 50 reaches the duty time of the target laser light source 50, the display control circuit 10 may turn off the first transistor M1 corresponding to the target laser light source 50 by controlling the on-off state of the single-pole multi-throw switch N1, so as to stop the target laser light source 50 from emitting light. In addition, the display control circuit 10 can also turn on the first transistor M1 corresponding to the other laser light source 50 (i.e., the new target laser light source 50) at the ground GND by controlling the on/off state of the single-pole multi-throw switch N1, so that the other laser light source 50 emits light under the driving of the second driving current.

Optionally, the display control circuit 10 may turn on the ground GND and the first transistor M1 corresponding to another laser light source 50 through the single-pole-multiple-throw switch N1 after the time length that the first transistor M1 corresponding to the target laser light source 50 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 laser light source 50, 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 laser light sources 50 may be the same.

The following description will discuss the driving timing of the plurality of laser light sources 50, taking as an example that the plurality of laser light sources 50 include a red laser light source 50 u r, a green laser light source 50 u g, and a blue laser light source 50 u b.

Referring to fig. 3, after the display control circuit 10 is powered on, the active level enable signal EN and the luminance control signal dim corresponding to the red laser light source 50\rmay be output to the light source driving circuit 20 first, so as to drive the light source driving circuit 20 to output the driving current I _ R and the second switch signal DRVM _2. In addition, the display control circuit 10 can also output a first output signal S1 with a first level and a second output signal S2 with a first level to the single-pole multi-throw switch N1, so that the single-pole multi-throw switch N1 can conduct the moving terminal P1 and the non-moving terminal P2_1, and further transmit the second switch signal DRVM _2 to the first transistor M1 corresponding to the red laser light source 50 xur. The first transistor M1 can further conduct the red laser source 50_r to the ground GND under the control of the second switch signal DRVM _2. The second driving current I _ R can further drive the red laser source 50\\ u R to emit light. At this time, the green laser light source 50_G and the blue laser light source 50 _Bdo not emit light. As shown in fig. 3, the active level of the enable signal EN may be high relative to the inactive level.

After the light emitting duration of the red laser source 50\uRreaches the duty time duty1 corresponding to the red laser source 50_R, the display control circuit 10 stops outputting the luminance control signal dim corresponding to the red laser source 50 _Rto the light source driving circuit 20. At this time, the red laser light source 50_rstops emitting light.

After determining that the duration of the red laser light source 50\ r stopping emitting light reaches the target duration t, the display control circuit 10 may output the luminance control signal dim corresponding to the green laser light source 50 \ G to the light source driving circuit 20 to drive the light source driving circuit 20 to output the driving current I _ G and the second switching signal DRVM _2. In addition, the display control circuit 10 can also output a first output signal S1 with a first level and a second output signal S2 with a second level to the single-pole multi-throw switch N1, so that the single-pole multi-throw switch N1 can conduct the moving terminal P1 and the non-moving terminal P2_2, and further transmit the second switch signal DRVM _2 to the first transistor M1 corresponding to the green laser light source 50 v g. The first transistor M1 can further conduct the green laser source 50\ g to the ground GND under the control of the second switching signal DRVM _2. The second driving current I _ G can further drive the green laser light source 50_g to emit light. At this time, the red laser light source 50_R and the blue laser light source 50 _Bdo not emit light.

After the light emitting duration of the green laser source 50_G reaches the duty time duty2 corresponding to the green laser source 50_G, the display control circuit 10 can stop outputting the first switch signal of the second signal value to the single-pole multi-throw switch N1, and stop outputting the luminance control signal DIMMING corresponding to the green laser source 50 _Gto the light source driving circuit 20. At this time, the green laser light source 50_g stops emitting light.

After determining that the duration of the green laser light source 50\ u G stopping emitting light reaches the target duration t, the display control circuit 10 may send a luminance control signal dim corresponding to the blue laser light source 50 _Bto drive the second light source driving circuit 30 to output the second driving current I _ B and the second switching signal DRVM _2. In addition, the display control circuit 10 can also output a first output signal S1 with a second level and a second output signal S2 with a first level to the single-pole multi-throw switch N1, so that the single-pole multi-throw switch N1 can conduct the movable terminal P1 and the fixed terminal P2_3 thereof, and further transmit the second switch signal DRVM _2 to the first transistor M1 corresponding to the blue laser light source 50_b. The first transistor M1 can further conduct the blue laser source 50_b to the ground GND under the control of the second switch signal DRVM _2. The second driving current I _ B can further drive the blue laser light source 50_b to emit light. At this time, red laser light source 50_r and green laser light source 50_g do not emit light.

After the light emitting duration of the blue laser light source 50_B reaches the duty time duty3 corresponding to the blue laser light source 50_B, the display control circuit 10 can output the enable signal EN of the inactive level to the second light source driving circuit 30, and stop outputting the luminance control signal DIMMING corresponding to the blue laser light source 50 _Bto the light source driving circuit 20. At this time, the blue laser light source 50\ u b stops emitting light.

Optionally, as shown in fig. 4, the laser projection apparatus may further include: a current regulating circuit 60. The current adjusting circuit 60 is connected to the output terminal of the light source driving circuit 20 and the plurality of laser light sources 50, respectively. The current adjusting circuit is used for adjusting the driving current output by the light source driving circuit 20.

It is understood that the driving current output by the light source driving circuit 20 may differ from the driving current flowing through the laser light source 50, i.e., the driving current received by the laser light source 50 does not coincide with the rated driving current required by the laser light source 50 when emitting light. Therefore, the current adjusting circuit 60 in the laser projection apparatus can adjust the magnitude of the driving current output by the light source driving circuit 20, so that the driving current actually flowing through the laser light source 50 is more consistent with the rated driving current required by the laser light source 50. Therefore, the plurality of laser light sources 50 can be ensured to emit light normally, and the display effect of the projected image projected by the laser projection device is ensured to be good.

Alternatively, as shown in fig. 4, the current regulating circuit 60 may include: a plurality of energy storage inductors L1 and a plurality of diodes D1 in one-to-one correspondence with the plurality of laser light sources 50.

Referring to fig. 4, one end of each energy storage inductor L1 is connected to the output terminal of the light source driving circuit 20 and the first end of one diode D1, and the other end of each energy storage inductor L1 is connected to one end of a corresponding one of the laser light sources 50. A second terminal of each diode D1 is connected to the other terminal of a corresponding one of the laser light sources 50. Alternatively, referring to fig. 4, the first terminals of the plurality of diodes D1 may be both cathodes and the second terminals may be both anodes.

In this embodiment, the second switching signal DRVM _2 output by the light source driving circuit 20 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. The pulse in the on state is at a high level, and the off state corresponds to no pulse output.

When the second switching signal DRVM _2 output by the light source driving circuit 20 is output to the gate G of the first transistor M1 corresponding to the target laser light source 50 in a non-pulse manner, the source S and the drain D of the first transistor M1 can be turned on. At this time, the diode D1 corresponding to the target laser light source 50 is in an off state. This allows the light source driving circuit 20 to be electrically connected to the ground GND, thereby causing the target laser light source 50 to emit light.

It can be understood that, when the output terminal of the light source driving circuit 20 is conducted to the ground terminal GND, the energy storage inductor L1 can store a part of the driving current output by the light source driving circuit 20 in the form of electric energy. That is, when the second transistor M2 corresponding to the target laser source 50 is in a conducting state, the energy storage inductor L1 corresponding to the target laser source 50 is in a charging state.

When the second switching signal DRVM _2 output by the light source driving circuit 20 is pulsed to the gate G of the first transistor M1 corresponding to the target laser light source 50, the source S and the drain D of the first transistor M1 are turned off. At this time, the diode D1 corresponding to the target laser light source 50 is in a conducting state, and the energy storage inductor L1 corresponding to the target laser light source 50 is in a discharging state. Therefore, when the first transistor M1 corresponding to the target laser light source 50 is in the off state, the electric energy emitted from the energy storage inductor L1 corresponding to the target laser light source 50 can continue to drive the target laser light source 50 to emit light. This ensures the stability of the emission of the target laser light source 50.

It is understood that, when the light source driving circuit 20 drives the target laser light source 50 to emit light, the on-time of the first transistor M1 corresponding to the target laser light source 50 can also be changed by adjusting the duty ratio of the second switching signal DRVM _2 output by the light source driving circuit. When the duty ratio of the second switching signal DRVM _2 per unit time (e.g., 1 second) is small, the on-time of the first transistor M1 per unit time is long, and the driving current flowing through the target laser light source 50 is also large. When the duty ratio of the second switching signal DRVM _2 in a unit time is larger, the off time of the first transistor M1 in a unit time is longer (i.e., the on time is shorter), and the driving current flowing through the target laser light source 50 is also smaller. Thus, the driving current flowing through the target laser light source 50 can be adjusted so that the difference between the driving current flowing through the target laser light source 50 and the rated driving current of the target laser light source 50 is small, thereby ensuring the light emitting effect of the target laser light source 50.

Based on the above analysis, it can be seen that the plurality of first transistors M1 in the second switch circuit 40 not only can implement the driving switching of the plurality of laser light sources 50, but also can implement the adjustment of the driving current flowing through the plurality of laser light sources 50, 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 three 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. 4, the laser projection apparatus may further include: the resistor R1 is sampled. One end of the sampling resistor R1 is connected to the second end 2 of the second switch circuit 40 and the feedback end of the light source driving circuit 20, and the other end of the sampling resistor R1 is connected to the ground GND.

In the embodiment of the present application, when the output end (i.e., the end outputting the driving current) of the light source driving circuit 20 is connected to the ground end GND and drives the target laser light source 50 to emit light, the sampling resistor R1 can sample the driving current flowing through the target laser light source 50. The light source driving circuit 20 can receive the driving current sampled by the sampling resistor R1 through its feedback terminal. The rated driving current of the target laser light source 50 may be stored in the light source driving circuit 20 in advance. The light source driving circuit 20 can adjust the duty ratio of the second switching signal DRVM _2 output by the light source driving circuit based on the sampled driving current and the rated driving current stored in advance.

For example, when the light source driving circuit 20 determines that the sampled driving current is smaller than the rated driving current, the duty ratio of the first switching signal DRVM _2 output by the light source driving circuit may be reduced, so as to increase the on-time of the first transistor M1 corresponding to the target laser light source 50, and further increase the current value of the driving current flowing through the target laser light source 50. When the light source driving circuit 20 determines that the sampled driving current is greater than the rated driving current, the duty ratio of the first switching signal DRVM _2 output by the light source driving circuit may be increased, so as to reduce the on-time of the first transistor M1, and further reduce the current value of the driving current flowing through the target laser light source 50.

Optionally, as shown in fig. 5, the laser projection apparatus may further include: a power supply circuit 70. The output terminals of the power supply circuit 70 are connected to the input terminals of the light source driving circuit 20, respectively. The power supply circuit 70 is used to supply a driving voltage VCC to the light source driving circuit 20. Thus, the light source driving circuit 20 can output a driving current driven by the driving voltage VCC.

Alternatively, the power circuit 70 may include an alternating current-direct current (AC-DC) converter.

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: inductor L2, diode D2, and second transistor M2. Alternatively, as shown in fig. 6, the plurality of light sources may include: red light source 02_R, green light source 02_G, and blue light source 02_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 sampling resistor R3 connected to the plurality of current adjusting circuits 04 in one-to-one correspondence. The light source driving circuit 03 can adjust the driving current flowing through the light source by the driving current sampled by the sampling resistor R3.

When the display control circuit 01 outputs the luminance control signal dim and the enable signal EN of the active level to the light source driving circuit 03 corresponding to the red light source 02 \ u r, the light source driving circuit 02 can output a driving current to the red light source 02 \ u r through the third inductor L3 and output a driving control signal DRVM _3 to the gate G of the second transistor M2. The second transistor M2 can be switched on and off 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 projection equipment is complex in structure and high in manufacturing cost. 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 apparatus provided by the present application, only one light source driving circuit and two switch circuits are needed to drive the light emission of the plurality of laser light sources 50. 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 and one path of luminance adjusting signal dim to the light source driving circuit 20 at the same time, and output the first switch signal DRVM _1 to the first switch circuit 20. Thus, the complexity of the output signal of the display control circuit 10 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.

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 application. 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: a display control circuit 10, a light source driving circuit 20, a first switching circuit 30, a second switching circuit 40, and a plurality of laser light sources 50 different in color from each other. Referring to fig. 7, the method includes:

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

After the laser projection apparatus is powered on, the display control circuit 10 of the laser projection apparatus can output the first switching signal DRVM _1 to the first switching circuit 30 based on the light emitting information of the plurality of laser light sources 50 to control the switching state of the first switching circuit 30. The first switch circuit 30 may have a plurality of second terminals 2, and the number of the second terminals 2 is the same as the number of the plurality of laser light sources 50. Therefore, the switching state of the first switching circuit 30 may refer to the on/off state of any second terminal 2 between the first terminal 1 and the plurality of second terminals 2.

The display control circuit 10 can also output the enable signal EN and the luminance control signal DIMMING to the light source drive circuit 20 based on the emission information of the plurality of laser light sources 50. The enable signal EN is used to control the operating state of the light source driving circuit 20, that is, to control whether the light source driving circuit 20 outputs the driving current. The luminance control signal DIMMING is used to control the magnitude of the driving current output by the light source driving circuit 20.

The light emission information of the plurality of laser light sources 50 may include duty time and current information of the plurality of laser light sources 50. The duty time of the plurality of laser light sources 50 may indicate the light emitting timing and the light emitting time period of the plurality of laser light sources 50 within a unit time period. The current information of the plurality of laser light sources 50 is a rated driving current required for the plurality of laser light sources 50 to emit light. The rated driving current of the laser light source 50 is a driving current capable of driving the laser light source 50 to emit light normally.

And 102, the light source driving circuit outputs driving current to one end of the plurality of laser light sources and outputs a second switching signal to the first switching circuit under the driving of the enabling signal and the brightness control signal.

The brightness control signal DIMMING received by the light source driving circuit 20 may be a PWM signal. The magnitude of the first driving current may be in positive correlation with the duty cycle of the luminance control signal DIMMING, i.e., the larger the duty cycle of the luminance control signal DIMMING, the higher the signal value of the first driving current. Accordingly, the higher the light emission luminance of the laser light source 5 driven by the drive current.

And 103, the first switch circuit transmits the second switch signal to the second switch circuit under the control of the first switch signal.

After the first switch circuit 30 receives the first switch signal DRVM _1, when the first terminal 1 of the first switch circuit is connected to one of the second terminals 2 under the control of the first switch signal DRVM _1, the first switch circuit 30 can transmit the received second switch signal DRVM _2 from the first terminal 1 to the connected second terminal 2, and further transmit the second switch signal DRVM _2 to the control terminal C2 of the second switch circuit 40 connected to the second terminal 2.

And 104, the second switching circuit controls the plurality of laser light sources to sequentially emit light under the control of the second switching signal, so that the laser projection equipment displays the projection image.

In the embodiment of the present application, the second switch circuit 40 may have a control terminal C2 corresponding to the plurality of laser light sources 50 one to one, and a plurality of first terminals 1 (not shown in fig. 1) connected to the plurality of laser light sources 50 one to one, and the plurality of control terminals C2 correspond to the plurality of first terminals 1 one to one. When the target control terminal C2 of the plurality of control terminals C2 in the second switch circuit 40 receives the second switch signal DRVM _2, it can conduct a corresponding one of the first terminal 1 and the second terminal 2. This allows the target laser light source 50 among the plurality of laser light sources 50 to be electrically connected to the ground GND. The target laser light source 50 may be a laser light source 50 that the display control circuit 10 determines based on the light emission timing of the plurality of laser light sources 50 that the laser projection apparatus currently needs to be lit. Wherein the light emitting periods of any two laser light sources 50 are not overlapped with each other

Wherein, the light emitting periods of two adjacent laser light sources 50 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

30 and 40. That is, the light source driving circuit 20 may drive only one laser light source 50 of the plurality of laser light sources 50 to emit light in the same period, that is, the light emitting periods of the plurality of laser light sources 50 are not overlapped. The time lengths of the light emitting periods of the plurality of laser light sources 50 may be the same or different.

It is understood that the first switch circuit 30 and the second switch circuit 40 require a certain period of time when switching the paths between the light source driving circuit 20 and the plurality of laser light sources 50. By spacing the conduction periods of the two adjacent laser light sources 50 and the ground GND by the target length of time, the light source driving circuit 20 can be prevented from driving the two laser light sources 50 to emit light at the same time. This can effectively ensure the emission purity of the plurality of laser light sources 50.

It can be further understood that, since the first switch circuit 30 can control the on-off states of the first end 1 and the second end 2 of the second switch circuit 40 under the control of the first switch signal DRVM _1, and further realize the control of the on-off state between any one laser light source 50 of the plurality of laser light sources 50 and the contact end GND, the laser projection apparatus can realize the light emitting driving of the plurality of laser light sources 50 with different colors only by using one light source driving circuit 20. Therefore, the structure of the laser projection equipment is effectively simplified, and the manufacturing cost of the laser projection equipment is reduced.

Referring to fig. 2, the plurality of laser light sources 50 may include a red laser light source 50_r, a green laser light source 50_g, and a blue laser light source 50_b. The first switch circuit 30 may include a single-pole multi-throw switch N1, and the second switch circuit 40 may include three first transistors M1 connected to the three laser light sources 50 in a one-to-one correspondence. The following describes a method of driving the three laser light sources. 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. In the initialization process, the display control circuit 10 may obtain light emitting information of a plurality of laser light sources in the laser projection apparatus.

And S2, the display control circuit outputs an enabling signal of an effective level and a brightness control signal corresponding to the red laser light source to the light source driving circuit, and outputs a first output signal and a second output signal of a first level to the first switch circuit.

In the embodiment of the present application, the light source driving circuit 20 is capable of outputting the first driving current to the plurality of laser light sources 50 and outputting the second switching signal DRVM _2 to the first switching circuit 30 under the driving of the enable signal of the active level and the luminance control signal dim corresponding to the red laser light source 50\r. After receiving the first output signal S1 and the second output signal S2 at the first level, the single-pole-multi-throw switch N1 in the first switch circuit 30 can turn on the moving terminal P1 and the stationary terminal P2_1, and further transmit the second switch signal DRVM _2 to the first transistor M1 corresponding to the red laser light source 50 \ u r. The first transistor M1 can further conduct the red laser source 50\ r to the ground GND under the control of the second switching signal DRVM _2. The first driving current outputted by the light source driving circuit 20 can further drive the red laser light source 50 r to emit light. At this time, green laser light source 50_g and blue laser light source 50_b do not emit light.

And S3, detecting whether the light-emitting duration of the red laser light source reaches a first duration or not by the display control circuit.

The first time period may be a duty time of 50 kr of the red laser source. If the display control circuit 10 determines that the light emission time period of the red laser light source 50 r reaches the first time period, the following step S4 may be executed. If the display control circuit 10 determines that the emission time period of the red laser light source 50_R does not reach the first time period, the light source driving circuit 20 may continue to drive the red laser light source 50_R to emit light.

And S4, stopping outputting the brightness control signal corresponding to the red laser light source to the light source driving circuit by the display control circuit, and stopping outputting the first output signal and the second output signal of the first level to the first switch circuit.

After determining that the light emitting duration of the red laser light source 50\ u r reaches the first duration, the display control circuit 10 may stop outputting the brightness control signal corresponding to the red laser light source 50_r to the light source driving circuit 20, and stop outputting the first output signal S1 and the second output signal S2 at the first level to the first switch circuit 30, so that the light source driving circuit 20 stops driving the red laser light source 50_r to emit light.

And S5, outputting a brightness control signal corresponding to the green laser light source to the light source driving circuit by the display control circuit, and outputting a first output signal of a first level and a second output signal of a second level to the first switch circuit.

The light source driving circuit 20 can output the second driving current to the plurality of laser light sources 50 and output the second switching signal DRVM _2 to the first switching circuit 30 after receiving the luminance control signal dim corresponding to the green laser light source 50\g. When receiving the first output signal S1 at the first level and the second output signal S2 at the second level, the single-pole-multi-throw switch N1 in the first switch circuit 30 can turn on the movable terminal P1 and the stationary terminal P2_2, and further transmit the second switch signal DRVM _2 to the first transistor M1 corresponding to the green laser light source 50_g. The first transistor M1 can further conduct the green laser light source 50_g to the ground GND under the control of the second switching signal DRVM _2. The second driving current outputted from the light source driving circuit 20 can further drive the green laser light source 50_ggto emit light. At this time, the red laser light source 50_R and the blue laser light source 50 _Bdo not emit light.

The display control circuit 10 may output the luminance control signal DIMMING corresponding to the green laser light source 50_Gto the light source driving circuit 20 after the time period for which the display control circuit stops outputting the luminance control signal DIMMING corresponding to the red laser light source 50_Rto the light source driving circuit 20 reaches the target time period.

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 50 ug g of the green laser source. If the display control circuit 10 determines that the emission time period of the green laser light source 50 ugg reaches 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 50 u g does not reach the second time period, the light source driving circuit 20 may continue to drive the green laser light source 50 u g to emit light.

And S7, stopping outputting the brightness control signal corresponding to the green laser light source to the light source driving circuit by the display control circuit, and stopping outputting the first output signal of the first level and the second output signal of the second level to the first switch circuit.

After determining that the light emitting duration of the green laser light source 50 \ u g reaches the second duration, the display control circuit 10 may output a luminance control signal dim corresponding to the green laser light source 50 \ u g to the light source driving circuit 20, so that the light source driving circuit 20 stops driving the green laser light source 50 \ u g to emit light.

And S8, outputting a brightness control signal corresponding to the blue laser light source to the light source driving circuit by the display control circuit, and outputting a first output signal of a second level and a second output signal of a first level to the first switch circuit.

The light source driving circuit 10 can output the third driving current to the plurality of laser light sources 50 and output the second switching signal DRVM _2 to the first switching circuit 30 after receiving the luminance control signal dim corresponding to the blue laser light source 50\b. After receiving the first output signal S1 at the second level and the second output signal S2 at the first level, the single-pole-multi-throw switch N1 can conduct the moving terminal P1 and the non-moving terminal P2_3 thereof, and further transmit the second switch signal DRVM _2 to the first transistor M1 corresponding to the blue laser light source 50\\b. The first transistor M1 can further conduct the blue laser source 50_b to the ground GND under the control of the second switch signal DRVM _2. The third driving current outputted by the light source driving circuit 20 can further drive the blue laser light source 50 u b to emit light. At this time, the red laser light source 50_r and the green laser light source 50 _gdo 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 light source 50 u b. If the display control circuit 10 determines that the emission time period of the blue laser light source 50\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 50 u b does not reach the third time period, the display control circuit may continue to drive the blue laser light source 50 u b to emit light by the second light source driving circuit 30.

Step S10, the display control circuit stops outputting the luminance control signal corresponding to the blue laser light source to the light source driving circuit, and stops outputting the first output signal of the second level and the second output signal of the first level to the first switch circuit.

After determining that the light emitting time duration of the blue laser light source 50_B reaches the third time duration, the display control circuit 10 may stop outputting the luminance control signal dim corresponding to the blue laser light source 50 _Bto the light source driving circuit 20, so that the light source driving circuit 20 stops driving the blue laser light source 50 _Bto emit light.

And S11, detecting whether a shutdown signal is received by the display control circuit.

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 signal to the first switch circuit and output an enable signal and a brightness control signal to the light source driving circuit so as to drive the light source driving circuit to output a driving current. The first switch circuit can transmit the second switch signal to the second switch circuit under the control of the first switch signal, so that the second switch circuit sequentially conducts the grounding end and the plurality of laser light sources, and the plurality of laser light sources sequentially emit light under the drive of the drive current. Therefore, the driving current output by the light source driving circuit can drive the plurality of laser light sources to emit light sequentially. Because the laser projection equipment can realize the light-emitting drive of a plurality of laser light sources with different colors only by one light source drive circuit, the structure of the projection equipment is effectively simplified.

In addition, because the light-emitting periods of the plurality of laser light sources do not overlap, the light-emitting purity of the plurality of laser light sources can be ensured, and the display effect of the projected image is effectively improved.

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 in the memory, wherein the processor implements the driving method of the light source (for example, the method shown in fig. 7 or fig. 8) provided by the above method embodiment 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 or fig. 8) 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 (e.g. the method shown in fig. 7 or fig. 8) as provided in the above method embodiments.

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 a program instructing relevant hardware, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.

It is to be understood that the term "plurality" means two or more in the present application. 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 or limitation on the number 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: a display control circuit, a light source drive circuit, a first switch circuit, a second switch circuit, and a plurality of laser light sources different in color from each other;

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 connected with the display control circuit, the movable end of the single-pole multi-throw switch is used as the first end of the first switch circuit and connected with the output end of the light source driving circuit, and the plurality of fixed ends of the single-pole multi-throw switch are used as the second end of the first switch circuit and connected with the 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 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 laser light sources comprises a first laser light source, a second laser light source, and a third laser light source, the single-pole-multiple-throw switch is a single-pole-three-throw switch, and the first switch signal comprises a first output signal and a second output signal;

the single-pole-three-throw switch is used for:

if the first output signal and the second output signal are both at a first level, transmitting the second switching signal to a control end of the second switching circuit corresponding to the first laser light source;

if the first output signal is at the first level and the second output signal is at the second level, transmitting the second switching signal to a control end of the second switching circuit corresponding to the second laser light source;

and if the first output signal is the second level and the second output signal is the first level, transmitting the second switching signal to a control end, corresponding to the third laser light source, in the second switching circuit.

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 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 laser 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 laser light sources one to the light source driving circuit;

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

6. The laser projection device of any of claims 1 to 5, further comprising: a current regulating circuit;

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

7. The laser projection device of claim 6, wherein the current regulation circuit comprises: a plurality of energy storage inductors and a plurality of diodes in one-to-one correspondence with the plurality of laser light sources;

one end of each energy storage inductor is connected with the output end of the light source driving circuit and the first end of one diode respectively, and the other end of each energy storage inductor is connected with one end of a corresponding laser light source;

and the second end of each diode is connected with the other end of the corresponding laser light source.

8. The laser projection device of any of claims 1 to 5, further comprising: sampling a resistor;

one end of the sampling resistor is connected with the second end of the second switch circuit and the feedback end of the light source driving circuit respectively, and the other end of the sampling resistor is connected with the grounding end.

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

10. The method of claim 9, wherein the emission periods of two adjacent laser light sources are spaced apart by a target length of time.