CN114977115A

CN114977115A - Laser projection equipment and control method of projection screen thereof

Info

Publication number: CN114977115A
Application number: CN202210768555.5A
Authority: CN
Inventors: 张希刚
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2022-06-30
Filing date: 2022-06-30
Publication date: 2022-08-30

Abstract

The application discloses a laser projection device and a control method of a projection screen thereof, and belongs to the technical field of electronics. The curtain protection circuit in the laser projection equipment can store electric energy when the power supply voltage of the curtain driving assembly is within a first threshold range. And when the power supply voltage is out of the first threshold range, the stored electric energy is adopted to supply power for the curtain driving assembly, and a descending driving signal is output to the curtain driving assembly. Therefore, when the laser projection equipment is suddenly powered off or a power supply circuit can only provide a smaller power supply voltage for the screen driving assembly, the projection screen can be ensured to normally descend, and the reliability of controlling the projection screen is improved.

Description

Laser projection equipment and control method of projection screen thereof

Technical Field

The disclosure relates to the field of electronic technologies, and in particular, to a laser projection apparatus and a control method of a projection screen thereof.

Background

The projection screen and the host machine in the laser projection equipment can be of an integrated structure. The host computer of the laser projection equipment is provided with a holding tank, the holding tank is internally provided with a curtain driving assembly, and the curtain driving assembly is connected with the projection curtain and used for driving the projection curtain to ascend or descend.

However, in the process of ascending or descending the projection screen, if the laser projection device is suddenly powered off, the projection screen may suddenly drop to the host, so that the projection screen and the host are easily damaged and generate large noise.

Disclosure of Invention

The embodiment of the disclosure provides a laser projection device and a control method of a projection screen thereof, which can solve the problems that in the related art, if the laser projection device is powered off suddenly, the projection screen can drop to a host suddenly, so that the projection screen and the host are easy to damage and generate large noise. The technical scheme is as follows:

in one aspect, a laser projection apparatus is provided, the laser projection apparatus comprising: the screen protection device comprises a shell, a projection screen, a power circuit, a screen driving assembly, a screen protection circuit and a main control circuit;

one side of the shell is provided with an accommodating groove for accommodating the projection screen;

the power supply circuit is used for converting the received alternating current into direct current and supplying power to the curtain driving assembly, the curtain protection circuit and the main control circuit;

the main control circuit is used for responding to a lifting instruction to output a lifting driving signal or a falling driving signal to the curtain driving assembly when the power supply voltage of the curtain driving assembly is within a first threshold range, and stopping outputting the lifting driving signal and the falling driving signal to the curtain driving assembly when the power supply voltage is out of the first threshold range;

the curtain protection circuit is used for storing electric energy when the power supply voltage is within the first threshold range, and adopting the stored electric energy to supply power to the curtain driving assembly and output the descending driving signal to the curtain driving assembly when the power supply voltage is outside the first threshold range;

the screen driving assembly is used for responding to the ascending driving signal to control the projection screen to ascend from the accommodating groove and responding to the descending driving signal to control the projection screen to withdraw the accommodating groove.

In another aspect, a method for controlling a projection screen is provided, which is applied to a laser projection apparatus, the laser projection apparatus including: the screen protection device comprises a shell, a projection screen, a power circuit, a screen driving assembly, a screen protection circuit and a main control circuit; one side of the shell is provided with an accommodating groove for accommodating the projection screen; the method comprises the following steps:

the power supply circuit converts the received alternating current into direct current and supplies power to the curtain driving assembly, the curtain protection circuit and the main control circuit;

the main control circuit responds to a lifting instruction to output a lifting driving signal or a falling driving signal to the curtain driving assembly when the power supply voltage of the curtain driving assembly is within a first threshold range, and stops outputting the lifting driving signal and the falling driving signal to the curtain driving assembly when the power supply voltage is out of the first threshold range;

the curtain protection circuit stores electric energy when the power supply voltage is within the first threshold range, and adopts the stored electric energy to supply power to the curtain driving assembly and output the descending driving signal to the curtain driving assembly when the power supply voltage is outside the first threshold range;

the screen driving assembly controls the projection screen to be lifted out of the accommodating groove in response to the lifting driving signal, and controls the projection screen to be retracted into the accommodating groove in response to the falling driving signal.

The beneficial effects brought by the technical scheme provided by the embodiment of the disclosure at least comprise:

the embodiment of the disclosure provides a laser projection device and a control method of a projection screen thereof, wherein a screen protection circuit in the laser projection device can store electric energy when the power supply voltage of a screen driving component is within a first threshold range. And when the power supply voltage is out of the first threshold range, the stored electric energy is adopted to supply power for the curtain driving assembly, and a descending driving signal is output to the curtain driving assembly. Therefore, when the laser projection equipment is suddenly powered off or a power supply circuit can only provide a smaller power supply voltage for the screen driving assembly, the projection screen can be ensured to normally descend, and the reliability of controlling the projection screen is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, 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 disclosure, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

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

FIG. 2 is a schematic structural diagram of another laser projection apparatus provided in the embodiments of the present disclosure;

FIG. 3 is a schematic structural diagram of another laser projection apparatus provided in the embodiments of the present disclosure;

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

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

fig. 6 is a flowchart of a control method for a projection screen according to an embodiment of the disclosure;

fig. 7 is a flowchart of another control method for a projection screen according to an embodiment of the disclosure.

Detailed Description

To make the objects, technical solutions and advantages of the present disclosure more apparent, embodiments of the present disclosure will be described in detail 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 disclosure, and fig. 2 is a schematic structural diagram of another laser projection apparatus provided in an embodiment of the present disclosure, and as shown in fig. 1 and fig. 2, the laser projection apparatus may include a housing 10, a projection screen 20, a power circuit 30, a screen driving assembly 40, a screen protection circuit 50, and a main control circuit 60.

Referring to fig. 3, a receiving groove 001 for receiving the projection screen 20 is formed at one side of the housing 10.

The power circuit 30 is connected to the screen driving assembly 40, the screen protection circuit 50 and the main control circuit 60, respectively, and the power circuit 30 is configured to convert the received ac power into dc power and supply power to the screen driving assembly 40, the screen protection circuit 50 and the main control circuit 60.

Optionally, the power circuit 30 may also be connected to an external power source, which is used to provide ac power to the power circuit 30.

The power circuit 30 may include an Alternating Current (AC) -Direct Current (DC) converter, the AC-DC converter is respectively connected to the external power source, the screen driving assembly 40, the screen protection circuit 50 and the main control circuit 60, and the AC-DC converter is configured to convert AC power provided by the external power source into DC power and supply power to the screen driving assembly 40, the screen protection circuit 50 and the main control circuit 60.

The main control circuit 60 is further connected to the curtain driving assembly 40, and the main control circuit 60 is configured to output an up driving signal or a down driving signal to the curtain driving assembly 40 in response to the lift command when the power supply voltage of the curtain driving assembly 40 is within a first threshold range, and stop outputting the up driving signal and the down driving signal to the curtain driving assembly 40 when the power supply voltage is outside the first threshold range.

In the embodiment of the present disclosure, the power supply voltage of the curtain driving assembly 40 refers to the voltage provided by the power circuit 30 for the curtain driving assembly 40. When the power supply voltage of the screen driving assembly 40 is within the first threshold range, the screen driving assembly 40 can normally drive the projection screen 20 to ascend, descend or maintain the unfolded state under the driving of the power supply voltage. The unfolded state refers to a state in which the projection screen 20 is at the top end position.

When the power supply voltage of the screen driving assembly 40 is outside the first threshold range, the screen driving assembly 40 cannot normally drive the projection screen 20 to ascend, descend or keep the projection screen in the unfolded state under the driving of the power supply voltage.

It is understood that when the power supply voltage of the curtain driving assembly 40 is within the first threshold range, the laser projection apparatus is not in the power-off state, and the circuits in the laser projection apparatus can operate normally under the driving of the voltage provided by the power circuit 30.

When the power supply voltage of the screen driving assembly 40 is outside the first threshold range, the laser projection apparatus is in a power-off state, and the power supply circuit 30 stops supplying power to each circuit in the laser projection apparatus.

Alternatively, when the power supply voltage of the curtain driving assembly 40 is outside the first threshold range, the laser projection apparatus is not in the power-off state, but the power supply circuit 30 needs to provide a larger voltage for other circuits, and at this time, the power supply circuit 30 can only provide a smaller power supply voltage for the curtain driving assembly 40, and the smaller power supply voltage is outside the first threshold range. Wherein the other circuit may be a circuit other than the mask driving assembly 40 among a plurality of circuits included in the laser projection apparatus.

The curtain protection circuit 50 is further connected to the curtain driving assembly 40, and the curtain protection circuit 50 is configured to store electric energy when the supply voltage is within the first threshold range, and to use the stored electric energy to supply power to the curtain driving assembly 40 and output a drop driving signal to the curtain driving assembly 40 when the supply voltage is outside the first threshold range.

It is understood that when the power supply voltage is within the first threshold range, the laser projection apparatus is in a normal operation state or a sleep state, and the power supply circuit 30 can normally supply power to the curtain protection circuit 50, so that the curtain protection circuit 50 can store electric energy. When the supply voltage is outside the first threshold range, the power circuit 30 cannot normally supply power to the curtain driving assembly 40, so the curtain protection circuit 50 can use the stored power to supply power to the curtain driving assembly 40 and output a falling driving signal to the curtain driving assembly 40. Therefore, when the laser projection device is suddenly powered off or the power circuit 30 can only provide a small power supply voltage for the screen driving assembly 40, the projection screen 20 can be ensured to normally descend, and the reliability of controlling the projection screen 20 is improved. Moreover, the problem that the projection screen 20 drops to the host suddenly, so that the projection screen and the host are damaged and generate larger noise is avoided.

The screen driving assembly 40 is further connected to the projection screen 20, and the screen driving assembly 40 is used for controlling the projection screen 20 to be lifted out of the accommodating slot 001 in response to the lifting driving signal and controlling the projection screen 20 to be retracted into the accommodating slot 001 in response to the lowering driving signal.

In summary, the embodiments of the present disclosure provide a laser projection apparatus, where a screen protection circuit in the laser projection apparatus may store electric energy when a supply voltage of a screen driving component is within a first threshold range. And when the power supply voltage is out of the first threshold range, the stored electric energy is adopted to supply power for the curtain driving assembly, and a descending driving signal is output to the curtain driving assembly. Therefore, when the laser projection equipment is suddenly powered off or a power supply circuit can only provide a smaller power supply voltage for the screen driving assembly, the projection screen can be ensured to normally descend, and the reliability of controlling the projection screen is improved. The control method is simple and reliable in logic, easy to operate, low in cost and better in user experience.

Optionally, the screen protection circuit 50 may send the down driving signal to the screen driving component 40 through an integrated circuit bus (IIC) interface, a universal synchronous/asynchronous serial receiver/transmitter (USART), or a Serial Peripheral Interface (SPI).

In this disclosure, the lifting command may include a lifting command and a lowering command, where the lifting command may be a power-on command, and the lowering command may be a power-off command.

If the lifting command is a rising command, the main control circuit 60 is configured to output a rising driving signal to the curtain driving assembly 40 in response to the rising command when the power supply voltage of the curtain driving assembly 40 is within the first threshold range, and stop outputting the rising driving signal to the curtain driving assembly 40 when the power supply voltage is outside the first threshold range.

If the lifting command is a lowering command, the main control circuit 60 is configured to output a lowering driving signal to the curtain driving assembly 40 in response to the lowering command when the power supply voltage of the curtain driving assembly 40 is within the first threshold range, and stop outputting the lowering driving signal to the curtain driving assembly 40 when the power supply voltage is outside the first threshold range.

Referring to fig. 4, the curtain protection circuit 50 may include a standby power control circuit 501, a standby power switch circuit 502, and a standby power storage circuit 503. Alternatively, the standby control circuit 501 may be a Micro Controller Unit (MCU).

Referring to fig. 4 and 5, the standby switch circuit 502 is respectively connected to the power supply circuit 30, the standby control circuit 501, the standby memory circuit 503 and the curtain driving assembly 40, and the standby memory circuit 503 is also connected to the curtain driving assembly 40 and the power supply circuit 30.

The standby power control circuit 501 is configured to control the standby power switch circuit 502 to connect the power circuit 30 and the standby power storage circuit 503 when the power supply voltage is within a first threshold range, so that the standby power storage circuit 503 stores electric energy. And when the power supply voltage is out of the first threshold range, providing a falling driving signal for the curtain driving assembly 40, and controlling the standby switch circuit 502 to conduct the standby storage circuit 503 and the curtain driving assembly 40, so that the standby storage circuit 503 supplies power to the curtain driving assembly 40.

Optionally, the standby power control circuit 501 is further configured to control the power supply circuit 30 to be disconnected from the standby power storage circuit 503 when the power supply voltage is outside the first threshold range, so that the electric energy of the standby power storage circuit 503 is prevented from flowing back to the power supply circuit 30, excessive electric energy consumption of the standby power storage circuit 503 is effectively avoided, and the standby power storage circuit 503 is ensured to normally supply power to the curtain driving assembly 40, and meanwhile, the influence on other circuits is effectively avoided.

The power backup control circuit 501 is further configured to control the power backup switch circuit 502 to disconnect the power backup storage circuit 503 from the curtain driving assembly 40 after the power backup control circuit 501 stops providing the falling driving signal to the curtain driving assembly 40, so that the power backup storage circuit 503 stops providing power to the curtain driving assembly 40.

Referring to fig. 5, the standby power control circuit 501 is configured to control the standby power switch circuit 502 to conduct the power supply circuit 30 and the standby power storage circuit 503 when the power supply voltage is within the first threshold range and the voltage of the standby power storage circuit 503 is less than or equal to the first voltage threshold, so that the power supply circuit 30 charges the standby power storage circuit 503, and accordingly, the standby power storage circuit 503 stores electric energy.

And the backup power control circuit 501 is configured to control the backup power switch circuit 502 to disconnect the power supply circuit 30 from the backup power storage circuit 503 when the power supply voltage is within the first threshold range and the voltage of the backup power storage circuit 503 is greater than or equal to the second voltage threshold, so that the power supply circuit 30 stops charging the backup power storage circuit 503, and accordingly, the backup power storage circuit 503 stops storing electric energy.

The second voltage threshold is greater than the first voltage threshold, and the standby power control circuit 501 may store the first voltage threshold and the second voltage threshold in advance. Alternatively, the power supply circuit 30 may charge the backup storage circuit 503 in the step-up mode or the step-down mode.

In the embodiment of the present disclosure, the standby power control circuit 501 may detect whether the voltage of the standby power storage circuit 503 is less than or equal to a first voltage threshold when the power supply voltage is within a first threshold range. If the voltage of the backup power storage circuit 503 is less than or equal to the first voltage threshold, it may be determined that the electric energy stored in the backup power storage circuit 503 is low, and therefore the backup power switch circuit 502 may be controlled to conduct the power supply circuit 30 with the backup power storage circuit 503, thereby causing the backup power storage circuit 503 to store the electric energy.

During the process that the power supply circuit 30 charges the standby power storage circuit 503, the standby power control circuit 501 may periodically detect whether the voltage of the standby power storage circuit 503 is greater than the second voltage threshold. If the voltage of the backup power storage circuit 503 is greater than or equal to the second voltage threshold, it may be determined that the backup power storage circuit 503 is fully charged, and at this time, the electric energy stored in the backup power storage circuit 503 is high, so the backup power switch circuit 502 may be controlled to disconnect the power supply circuit 30 from the backup power storage circuit 503, thereby causing the backup power storage circuit 503 to stop storing energy.

Optionally, after the standby power storage circuit 503 discharges, if it is detected that the voltage of the standby power storage circuit 503 is greater than the first voltage threshold and smaller than the second voltage threshold, the standby power control circuit 501 may determine that the standby power storage circuit 503 is not fully charged, and therefore, the standby power switch circuit 502 may be controlled to connect the power supply circuit 30 and the standby power storage circuit 503, so that the standby power storage circuit 503 stores more electric energy.

Referring to fig. 5, the standby switching circuit 502 may include a charging switch M1 and a discharging switch M2. Alternatively, the charging switch M1 and the discharging switch M2 may be metal-oxide-semiconductor field-effect transistors (MOSFETs).

One end of the charge switch M1 is connected to one end of the power supply circuit 30, and the other end of the charge switch M1 is connected to one end of the backup power storage circuit 503 and one end of the discharge switch M2, respectively.

The other end of the discharge switch M2 is connected to the curtain driving module 40, and the backup storage circuit 503 is also connected to the ground G.

The standby power control circuit 501 is configured to control the charging switch M1 to be closed and the discharging switch M2 to be opened when the power supply voltage is within a first threshold range, so that the standby power storage circuit 503 stores electric energy.

Alternatively, the standby power control circuit 501 may control the charging switch M1 to be closed and the discharging switch M2 to be opened when the power supply voltage is within the first threshold range and the voltage of the standby power storage circuit 503 is less than or equal to the first voltage threshold, so that the standby power storage circuit 503 stores the electric energy.

Alternatively, the backup power control circuit 501 may control the charging switch M1 to be closed and the discharging switch M2 to be opened when the power supply voltage is within the first threshold range and the voltage of the backup power storage circuit 503 is greater than the first voltage threshold and less than the second voltage threshold, so that the backup power storage circuit 503 stores the electric energy.

The backup power control circuit 501 is configured to control both the charging switch M1 and the discharging switch M2 to be turned off when the power supply voltage is within a first threshold range and the voltage of the backup power storage circuit 503 is greater than a second threshold range, so that the backup power storage circuit 503 stops storing electric energy.

The standby power control circuit 501 is configured to control the charging switch M1 to be turned off and the discharging switch M2 to be turned on when the power supply voltage is outside the first threshold range, so that the standby power storage circuit 503 supplies power to the curtain driving assembly 40.

In the process of supplying power to the curtain driving assembly 40 by the standby power storage circuit 503, by controlling the charging switch M1 to be turned off, the electric energy of the standby power storage circuit 503 can be prevented from flowing back to the power supply circuit 30, so that excessive electric energy consumption of the standby power storage circuit 503 is effectively avoided, the standby power storage circuit 503 is ensured to normally supply power to the curtain driving assembly 40, and the influence on other circuits is effectively avoided.

The power backup control circuit 501 is further configured to control the discharging switch M2 to be turned off after the power backup control circuit 501 stops providing the falling driving signal to the curtain driving assembly 40, so that the power backup storage circuit 503 stops providing power to the curtain driving assembly 40.

Optionally, the charging switch M1 and the discharging switch M2 may each further include a control terminal, and referring to fig. 5, the standby power control circuit 501 is further connected to the control terminal of the charging switch M1 and the control terminal of the discharging switch M2, respectively.

The standby control circuit 501 may send a first control signal to the control terminal of the charging switch M1 to control the charging switch M1 to close (i.e., one terminal and the other terminal of the charging switch M1 are turned on). Also, the standby control circuit 501 may send a second control signal to the control terminal of the charging switch M1 to control the charging switch M1 to be turned off (i.e., one terminal and the other terminal of the charging switch M1 are turned off).

The standby control circuit 501 may also send a first control signal to the control terminal of the discharge switch M2 to control the discharge switch M2 to close (i.e., one terminal and the other terminal of the discharge switch M2 are turned on). Also, the standby control circuit 501 may also send a second control signal to the control terminal of the discharge switch M2 to control the discharge switch M2 to be turned off (i.e., one terminal and the other terminal of the discharge switch M2 are turned off).

Referring to fig. 5, the backup power storage circuit 503 may include at least one energy storage capacitor, and the at least one energy storage capacitor is connected to the backup power switch circuit 502, the curtain driving assembly 40, and the power circuit 30.

If the number of the at least one storage capacitor is multiple, the multiple storage capacitors may be connected in series or in parallel. Optionally, each energy storage capacitor may be a super capacitor, and charging and discharging of the super capacitor is a physical reaction, and the instantaneous charging and discharging current is large, so that the charging and discharging speed is high. In addition, the super capacitor is small in size and can be charged and discharged for multiple times, the charging and discharging times can reach 100 ten thousand, and therefore the super capacitor is long in service life, and the service life can reach 10 years.

Referring to fig. 5, one end of the at least one energy storage capacitor is connected to the other end of the charging switch M1 and one end of the discharging switch M2, and the other end of the at least one energy storage capacitor is connected to the other ends of the curtain driving assembly 40 and the power circuit 30, respectively.

In the embodiment of the disclosure, when the charging switch M1 is closed and the discharging switch M2 is opened, the power circuit 30 charges the at least one energy storage capacitor, so that the at least one energy storage capacitor stores electric energy. When the charging switch M1 is turned off and the discharging switch M2 is turned on, the at least one energy storage capacitor transmits the stored electric energy to the curtain driving assembly 40 to supply power to the curtain driving assembly 40.

Optionally, the backup storage circuit 503 may further include at least one resistor in one-to-one correspondence with the at least one energy storage capacitor, and each resistor of the at least one resistor is connected in parallel with a corresponding one of the energy storage capacitors. Alternatively, each resistor may be a voltage-side resistor.

Fig. 5 exemplifies that the at least one energy storage capacitor includes two energy storage capacitors, i.e., a first energy storage capacitor C1 and a second energy storage capacitor C2, and the at least one resistor includes two resistors, i.e., a first resistor R1 and a second resistor R2. The first energy storage capacitor C1 is connected in series with the second energy storage capacitor C2, the first resistor R1 is connected in parallel with the first energy storage capacitor C1, and the second resistor R2 is connected in parallel with the second energy storage capacitor C2.

Referring to fig. 5, one end of the first energy-storing capacitor C1 is connected to the other end of the charging switch M1, one end of the discharging switch M2 and one end of the first resistor R1, and the other end of the first energy-storing capacitor C1 is connected to one end of the second energy-storing capacitor C2, the other end of the first resistor R1 and one end of the second resistor R2. The other end of the second energy-storing capacitor C2 is connected to the other end of the power circuit 30, the other end of the second resistor R2, the driving module 40 and the ground G.

In the embodiment of the present disclosure, the curtain protection circuit 50 may further include a first detection circuit, which may be an analog to digital converter (ADC).

The first detection circuit is connected to the standby power storage circuit 503 and the standby power control circuit 501, respectively, and is configured to detect a voltage of the standby power storage circuit 503 and transmit the detected voltage of the standby power storage circuit 503 to the standby power control circuit 501.

Optionally, one end of the first detection circuit is connected to one end of at least one energy storage capacitor, and the other end of the first detection circuit is connected to the standby power control circuit 501. The first detection circuit is configured to transmit the voltage of the at least one energy storage capacitor to the standby power control circuit 501, so that the standby power control circuit 501 uses the voltage of the at least one energy storage capacitor as the voltage of the standby power storage circuit 503, and further detects whether the at least one energy storage capacitor needs to be charged based on the voltage of the at least one energy storage capacitor, the first voltage threshold, and the second voltage threshold.

Referring to fig. 5, one end of the first detection circuit is connected to one end of the first energy storage capacitor C1, and the first detection circuit is used to detect the voltage across the first energy storage capacitor C1 and the second energy storage capacitor C2.

In the embodiment of the present disclosure, the power circuit 30 is further configured to output a first detection signal to the curtain protection circuit 50 if a zero-crossing signal in the alternating current is detected, and not output the first detection signal to the curtain protection circuit 50 if the zero-crossing signal is not detected.

Wherein the zero-crossing signal refers to a signal in which the amplitude of the alternating current is zero. The first detection signal may be Pulse Width Modulation (PWM).

Optionally, the power circuit 30 may further include a zero-crossing detection circuit, the zero-crossing detection circuit is respectively connected to the external power supply and the curtain protection circuit 50, and the zero-crossing detection circuit is configured to output a first detection signal to the curtain protection circuit 50 if a zero-crossing signal in the ac power supplied by the external power supply is detected, and not output the first detection signal to the curtain protection circuit 50 if the zero-crossing signal is not detected.

The zero-crossing detection circuit can also be used for isolating other interference signals, so that the reliability of zero-crossing signal detection is ensured.

The laser projection device may further include a second detection circuit, which may be an ADC. The second detection circuit is respectively connected to the curtain driving assembly 40 and the curtain protection circuit 50, and is configured to detect the driving voltage of the curtain driving assembly 40 and transmit the detected driving voltage of the curtain driving assembly 40 to the curtain protection circuit 50.

The curtain protection circuit 50 is configured to determine that the laser projection apparatus is not in the power-off state if the first detection signal is received and the driving voltage is within the second threshold range, and determine that the power supply voltage is within the first threshold range because each circuit can normally operate under the driving of the voltage provided by the power supply circuit 30.

The curtain protection circuit 50 is configured to determine that the laser projection apparatus is in the power-off state if the first detection signal is not received, and at this time, the power circuit 30 cannot supply power to each circuit, so that it can be determined that the power supply voltage is outside the first threshold range, and the power supply voltage is 0.

The curtain protection circuit 50 is configured to determine that the laser projection apparatus is not in the power-off state if the first detection signal is received and the driving voltage is outside the second threshold range, but the power circuit 30 can only provide a smaller power supply voltage for the curtain driving component 40, so that it can be determined that the power supply voltage is outside the first threshold range and is greater than 0.

Optionally, if the curtain protection circuit 50 does not receive the first detection signal within the target time period, it may be determined that the power supply voltage is outside the first threshold range, and the power supply voltage is 0. The curtain protection circuit 50 may be pre-stored with the target time period, which may be greater than the period of the alternating current provided by the power circuit 30.

In the embodiment of the present disclosure, the screen driving assembly 40 may include a motor driving circuit, a motor, and a lifting assembly, wherein the motor driving circuit is respectively connected to the power circuit 30, the main control circuit 60, the screen protection circuit 50, and the motor, and the lifting assembly is respectively connected to the motor and the projection screen 20.

The power circuit 30 is also used to power the motor drive circuit. The motor driving circuit is used for responding to an ascending driving signal (or a descending driving signal) and sending a driving current to the motor, and the motor is used for driving the lifting assembly to drive the projection screen to ascend (or descend) under the driving of the driving current.

Alternatively, the second detection circuit may be connected to the motor and the screen protection circuit 50, respectively, and the driving voltage of the screen driving assembly 40 may refer to a driving voltage for driving the motor.

When the power supply voltage of the screen driving assembly 40 is within the first threshold range, the driving voltage of the screen driving assembly 40 is also within the second threshold range, and at this time, the motor can normally drive the lifting assembly to drive the projection screen 20 to ascend, descend or keep the unfolding state. When the power supply voltage of the screen driving assembly 40 is outside the first threshold range, the driving voltage of the screen driving assembly 40 is outside the second threshold range, and at this time, the motor cannot normally drive the lifting assembly to drive the projection screen 20 to ascend, descend or keep the unfolded state.

In the embodiment of the present disclosure, the motor driving circuit may include a capacitor, and if the laser projection apparatus is suddenly powered off, the driving voltage of the motor is greater than 0 because a small amount of electric energy is stored in the capacitor in the motor driving circuit. That is, when the curtain protection circuit 50 does not receive the first detection signal and the power supply voltage is 0, the curtain protection circuit 50 does not need to detect the magnitude of the driving voltage in this case because the driving voltage of the curtain driving component 40 is greater than 0. That is, the curtain protection circuit 50 may directly determine that the power supply voltage is outside the first threshold range and the power supply voltage is 0 after receiving no first detection signal.

When the laser projection apparatus is not in the power-off state and the power circuit 30 can only provide a small supply voltage for the curtain driving assembly 40, the curtain protection circuit 50 can receive the first detection signal, but because the supply voltage is small, the supply voltage is greater than 0 at this time, the supply voltage is outside the first threshold range, and the driving voltage is also outside the second threshold range.

In the embodiment of the present disclosure, the curtain protection circuit 50 is further configured to determine that the power circuit 30 can normally supply power to the main control circuit 60 when the power supply voltage is outside the first threshold range and is greater than 0, and thus, may send a prompt signal to the main control circuit 60.

The main control circuit 60 is further configured to send a prompt message in response to the prompt signal, where the prompt message is used to prompt that the power supply voltage of the curtain driving assembly 40 is abnormal.

Optionally, the laser projection apparatus may further include an audio player and an indicator light, and the main control circuit 60 may control the audio player to play the prompt message and/or control the indicator light to flash.

It can be understood that, when the laser projection apparatus is not in the power-off state, if the main control circuit 60 does not receive the prompt signal sent by the curtain protection circuit 50, it may be determined that the power supply voltage is within the first threshold range. The main control circuit 60 may determine that the power supply voltage is out of the first threshold range if receiving the prompt signal sent by the curtain protection circuit 50, and thus may stop sending the up driving signal and the down driving signal to the curtain driving assembly 40.

When the laser projection apparatus is in the power-off state, the power supply circuit 30 stops supplying power to each circuit, and at this time, the main control circuit 60 is in the power-off state, and stops sending the rising driving signal and the falling driving signal to the curtain driving assembly 40.

Moreover, the curtain protection circuit 50 is further configured to control the power supply circuit 30 to stop supplying power to the curtain driving component 40 when the power supply voltage is outside the first threshold range and is greater than 0, so as to prevent the power supply circuit 30 from affecting the power supply of the standby power storage circuit 503 to the curtain control component.

Optionally, the laser projection apparatus may further include a power switch, one end of the power switch is connected to the power circuit 30, and the other end of the power switch is connected to the screen driving assembly 40.

The curtain protection circuit 50 is further configured to control the power switch to be turned off (i.e., one end of the power switch is turned off from the other end of the power switch) when the power supply voltage is outside the first threshold range and is greater than 0, so that the power circuit 30 stops supplying power to the curtain driving assembly 40.

The power switches may each include a control terminal, and the curtain protection circuit 50 is further connected to the control terminal of the power switch. The curtain protection circuit 50 may send a second control signal to the control terminal of the power switch to control the power switch to be turned off (i.e., one terminal and the other terminal of the power switch are turned off).

Optionally, the standby power control circuit 501 is connected to the main control circuit 60 and the control end of the power supply switch, and the standby power control circuit 501 is further configured to control the power supply switch to be turned off and send a prompt signal to the main control circuit 60 when the power supply voltage is outside the first threshold range and is greater than 0.

Optionally, the laser projection apparatus may further include a limit switch, the limit switch is located in the accommodating groove 001, and the limit switch is connected to the curtain protection circuit 50, and the limit switch is configured to send a second detection signal to the curtain protection circuit 50 when detecting that the projection curtain 20 descends to the initial position. The curtain protection circuit 50 is further configured to stop outputting the falling driving signal to the curtain driving assembly 40 if receiving the second detection signal.

The initial position refers to a mechanical zero position of the projection screen 20, and the projection screen 20 will not be lowered when lowered to the initial position.

Optionally, the limit switch may be connected to the standby power control circuit 501, and the standby power control circuit 501 is configured to receive the second detection signal and stop outputting the falling driving signal to the screen driving assembly 40 after receiving the second detection signal.

Referring to fig. 4, the main control circuit 60 may include a main control sub-circuit 601 and a screen control sub-circuit 602, the screen control sub-circuit 602 is respectively connected to the main control sub-circuit 601, the screen driving component 40 and the power circuit 30, and the main control sub-circuit 601 is further connected to the standby control circuit 501 and the power circuit 30. The main control sub-circuit 601 may be a system on a chip (SOC).

The main control sub-circuit 601 is configured to send a lift command to the curtain control sub-circuit 602 when the supply voltage of the curtain driving assembly 40 is within a first threshold range. The curtain control sub-circuit 602 is configured to send an up driving signal or a down driving signal to the curtain driving assembly 40 in response to the lift command. And when the power supply voltage of the curtain driving assembly 40 is outside the first threshold range and the power supply voltage is greater than 0, sending a power supply abnormal instruction to the curtain control sub-circuit 602, where the curtain control sub-circuit 602 is configured to stop sending the up driving signal and the down driving signal to the curtain driving assembly 40 in response to the power supply abnormal instruction.

When the power supply voltage of the curtain driving assembly 40 is outside the first threshold range and the power supply voltage is 0, the curtain control sub-circuit 602 stops sending the up driving signal and the down driving signal to the curtain driving assembly 40 because the power supply circuit 30 cannot supply power to each circuit.

The standby power control circuit 501 is configured to send a prompt signal to the main control sub-circuit 601 when the power supply voltage is outside the first threshold range and is greater than 0. The master subcircuit 601 may issue a prompt message in response to the prompt signal.

The laser projection apparatus may further include: a memory, which is connected to the screen control sub-circuit 602 and the standby control circuit 501 respectively, and stores the current height of the projection screen 20. The memory may be a charged erasable programmable read only memory (EEPROM).

The curtain control sub-circuit 602 may include a plurality of pulse signals in the up driving signal (or the down driving signal) transmitted to the curtain driving assembly 40, and the curtain control sub-circuit 602 may determine the current height of the projection curtain 20 according to the number of pulse signals transmitted to the curtain driving assembly 40 and store the current height in the memory.

The standby control circuit 501 may retrieve the current height of the projection screen 20 from the memory when the supply voltage is outside the first threshold range, and send a falling driving signal to the screen driving assembly 40 based on the current height.

The standby power control circuit 501 controls the number of pulse signals required to be sent by the projection screen 20 to drop from the current height to the initial position to be positively correlated with the current height.

It is understood that, since the current height of the projection screen 20 stored in the memory may not be accurate, the standby control circuit 501 may stop sending the falling driving signal to the screen driving assembly 40 after receiving the second detection signal sent by the limit switch.

In summary, the embodiments of the present disclosure provide a laser projection apparatus, where a screen protection circuit in the laser projection apparatus may store electric energy when a supply voltage of a screen driving component is within a first threshold range. And when the power supply voltage is out of the first threshold range, the stored electric energy is adopted to supply power for the curtain driving assembly, and a descending driving signal is output to the curtain driving assembly. Therefore, when the laser projection equipment is suddenly powered off or a power supply circuit can only provide a smaller power supply voltage for the screen driving assembly, the projection screen can be ensured to normally descend, and the reliability of controlling the projection screen is improved.

Fig. 6 is a flowchart of a method for controlling a projection screen according to an embodiment of the disclosure, where the method may be applied to the laser projection apparatus shown in any one of fig. 1 to 5. As shown in fig. 6, the method may include:

step 601, the power circuit converts the received alternating current into direct current and supplies power to the curtain driving assembly, the curtain protection circuit and the main control circuit.

Step 602, the main control circuit responds to the lifting command to output a lifting driving signal or a lowering driving signal to the curtain driving assembly when the power supply voltage of the curtain driving assembly is within the first threshold range, and stops outputting the lifting driving signal and the lowering driving signal to the curtain driving assembly when the power supply voltage is outside the first threshold range.

Step 603, the curtain protection circuit stores the electric energy when the power supply voltage is within the first threshold range, and when the power supply voltage is outside the first threshold range, the stored electric energy is used for supplying power to the curtain driving assembly and outputting a descending driving signal to the curtain driving assembly.

Step 604, the screen driving assembly controls the projection screen to be lifted out of the receiving slot in response to the lifting driving signal, and controls the projection screen to be retracted into the receiving slot in response to the lowering driving signal.

For specific implementation processes of step 601 to step 604, reference may be made to the above device embodiment, and details of the embodiment of the present disclosure are not repeated here.

In summary, the embodiments of the present disclosure provide a control method for a projection screen, in which a screen protection circuit can store electric energy when a supply voltage of a screen driving component is within a first threshold range. And when the power supply voltage is out of the first threshold range, the stored electric energy is adopted to supply power for the curtain driving assembly, and a descending driving signal is output to the curtain driving assembly. Therefore, when the laser projection equipment is suddenly powered off or a power supply circuit can only provide a smaller power supply voltage for the screen driving assembly, the projection screen can be ensured to normally descend, and the reliability of controlling the projection screen is improved.

Fig. 7 is a flowchart of another control method for a projection screen according to an embodiment of the disclosure, where the method may be applied to the laser projection apparatus shown in any one of fig. 1 to 5. As shown in fig. 7, the method may include:

step 701, the power circuit converts the received alternating current into direct current and supplies power to the curtain driving assembly, the curtain protection circuit and the main control circuit.

The power supply circuit converts the received alternating current into direct current and supplies power to the curtain driving assembly, the curtain protection circuit and the main control circuit.

The power supply circuit is also used for outputting a first detection signal to the curtain protection circuit if a zero-crossing signal in the alternating current is detected, and not outputting the first detection signal to the curtain protection circuit if the zero-crossing signal is not detected.

Step 702, if the standby power control circuit receives the first detection signal and the driving voltage is within the second threshold range, determining that the power supply voltage is within the first threshold range, and controlling the standby power switch circuit to connect the power circuit and the standby power storage circuit, so that the standby power storage circuit stores electric energy.

The second detection circuit is used for transmitting the detected driving voltage of the curtain driving assembly to the curtain protection circuit.

Optionally, the standby power control circuit is configured to control the charging switch to be turned on and control the discharging switch to be turned off when the power supply voltage is within the first threshold range.

And 703, when the power supply voltage of the curtain driving component is within a first threshold range, the main control circuit responds to the lifting instruction to output a lifting driving signal or a descending driving signal to the curtain driving component.

Step 704, if the standby power control circuit does not receive the first detection signal, it is determined that the power supply voltage is outside the first threshold range and the power supply voltage is 0.

And when the power supply voltage is out of the first threshold range, the standby power control circuit controls the charging switch to be switched off and controls the discharging switch to be switched on.

Step 705, if the standby power control circuit receives the first detection signal and the driving voltage is outside the second threshold range, determining that the power supply voltage is outside the first threshold range and is greater than 0, and prompting a signal to the main control circuit.

And step 706, the main control circuit responds to the prompt signal and sends out prompt information.

The prompt message is used for prompting the abnormity of the power supply voltage of the curtain driving component.

And 707, when the supply voltage is outside the first threshold range, the standby power control circuit provides a falling driving signal for the curtain driving component, and controls the standby power switch circuit to connect the standby power storage circuit and the curtain driving component, so that the standby power storage circuit supplies power to the curtain driving component.

A power backup control circuit for:

and when the power supply voltage is within the first threshold range and the voltage of the standby power storage circuit is less than or equal to the first voltage threshold, controlling the standby power switch circuit to conduct the power supply circuit and the standby power storage circuit.

And when the power supply voltage is within the first threshold range and the voltage of the standby power storage circuit is greater than or equal to the second voltage threshold, controlling the standby power switch circuit to disconnect the power supply circuit from the standby power storage circuit.

Wherein the second voltage threshold is greater than the first voltage threshold.

The curtain protection circuit still includes: the first detection circuit is respectively connected with the standby power storage circuit and the standby power control circuit and is used for transmitting the detected voltage of the standby power storage circuit to the standby power control circuit.

Step 708, the main control circuit stops outputting the rising driving signal and the falling driving signal to the curtain driving assembly when the power supply voltage is outside the first threshold range.

And step 709, if the standby power control circuit receives a second detection signal sent by the limit switch, stopping outputting a descending driving signal to the screen driving component.

Optionally, when the limit switch detects that the projection screen falls to the initial position, the limit switch sends a second detection signal to the standby power control circuit.

Step 710, the screen driving assembly controls the projection screen to be lifted out of the accommodating slot in response to the lifting driving signal, and controls the projection screen to be retracted into the accommodating slot in response to the lowering driving signal.

The specific implementation process of step 701 to step 709 may refer to the above device embodiment, and details of the embodiment of the present disclosure are not repeated here.

It should be noted that, the order of the steps of the control method for a projection screen provided in the embodiment of the present disclosure may be appropriately adjusted, and the steps may also be deleted according to the situation. For example, step 704 may be deleted as appropriate, or steps 705 and 706 may be deleted as appropriate. Any method that can be easily conceived by those skilled in the art within the technical scope of the present disclosure is covered by the protection scope of the present disclosure, and thus, the detailed description thereof is omitted.

The disclosed embodiment provides a laser projection apparatus, including: the processor executes the computer program to realize the steps executed by the main control circuit, the standby power control circuit and the motor driving circuit in the embodiment.

The disclosed embodiments provide a computer-readable storage medium, in which instructions are stored, and the instructions are loaded and executed by a processor to implement the steps executed by a main control circuit, a standby power control circuit and a motor driving circuit in the above embodiments.

The disclosed embodiments provide a computer program product containing instructions that, when run on a computer, cause the computer to perform the steps performed by the main control circuit, the standby control circuit, and the motor drive circuit as in the above embodiments.

In the disclosed embodiments, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "plurality" in the embodiments of the present disclosure means two or more. The term "and/or" in the embodiments of the present disclosure is only one kind of association relationship describing an associated object, and means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone.

The above description is intended to be exemplary only and not to limit the present disclosure, and any modification, equivalent replacement, or improvement made without departing from the spirit and scope of the present disclosure is to be considered as the same as the present disclosure.

Claims

1. A laser projection device, characterized in that the laser projection device comprises: the screen protection device comprises a shell, a projection screen, a power circuit, a screen driving assembly, a screen protection circuit and a main control circuit;

2. The laser projection device of claim 1, wherein the curtain protection circuit comprises: the power supply control circuit, the power supply switch circuit and the power supply storage circuit are connected in series;

the standby power switch circuit is respectively connected with the power circuit, the standby power control circuit and the standby power storage circuit, and the standby power storage circuit is also connected with the screen driving assembly and the power circuit;

the standby power control circuit is used for:

when the power supply voltage is within the first threshold range, controlling the standby power switch circuit to conduct the power supply circuit and the standby power storage circuit so as to enable the standby power storage circuit to store electric energy; and when the power supply voltage is out of the first threshold range, providing the drop driving signal for the curtain driving assembly, and controlling the standby power switch circuit to conduct the standby power storage circuit and the curtain driving assembly so as to enable the standby power storage circuit to supply power for the curtain driving assembly.

3. The laser projection device of claim 2, wherein the power backup control circuit is configured to:

when the power supply voltage is within the first threshold range and the voltage of the standby power storage circuit is smaller than or equal to a first voltage threshold, controlling the standby power switch circuit to conduct the power supply circuit and the standby power storage circuit;

when the power supply voltage is within the first threshold range and the voltage of the standby power storage circuit is greater than or equal to a second voltage threshold, controlling the standby power switch circuit to disconnect the power supply circuit from the standby power storage circuit;

4. The laser projection device of claim 3, wherein the curtain protection circuit further comprises: a first detection circuit;

the first detection circuit is respectively connected with the standby power storage circuit and the standby power control circuit, and the first detection circuit is used for transmitting the detected voltage of the standby power storage circuit to the standby power control circuit.

5. The laser projection device of claim 2, wherein the back-up switch circuit comprises: a charge switch and a discharge switch;

one end of the charging switch is connected with one end of the power supply circuit, and the other end of the charging switch is respectively connected with the standby power storage circuit and one end of the discharging switch;

the other end of the discharge switch is connected with the curtain driving assembly;

the standby power control circuit is used for: when the power supply voltage is within the first threshold range, controlling the charging switch to be closed and controlling the discharging switch to be opened; and when the power supply voltage is out of the first threshold range, controlling the charging switch to be switched off and controlling the discharging switch to be switched on.

6. The laser projection device of claim 2, wherein the power backup storage circuit comprises: and the at least one energy storage capacitor is respectively connected with the standby switch circuit, the curtain sheet driving assembly and the power circuit.

7. The laser projection device as claimed in any one of claims 1 to 6, wherein the screen protection circuit is further configured to control the power circuit to stop supplying power to the screen driving component and send a prompt signal to the main control circuit when the power supply voltage is outside the first threshold range and the power supply voltage is greater than 0;

the main control circuit is further used for responding to the prompt signal and sending prompt information, and the prompt information is used for prompting that the power supply voltage of the curtain driving assembly is abnormal.

8. The laser projection device of any of claims 1 to 6, further comprising: a second detection circuit;

the power supply circuit is further used for outputting a first detection signal to the curtain protection circuit if a zero-crossing signal in the alternating current is detected, and not outputting the first detection signal to the curtain protection circuit if the zero-crossing signal is not detected;

the second detection circuit is respectively connected with the curtain driving assembly and the curtain protection circuit and is used for transmitting the detected driving voltage of the curtain driving assembly to the curtain protection circuit;

the curtain protection circuit is used for:

if the first detection signal is received and the driving voltage is within a second threshold range, determining that the power supply voltage is within the first threshold range;

if the first detection signal is not received, determining that the power supply voltage is out of the first threshold range and is 0;

if the first detection signal is received and the driving voltage is located outside the second threshold range, it is determined that the power supply voltage is located outside the first threshold range and is greater than 0.

9. The laser projection device of any of claims 1 to 6, further comprising: a limit switch;

the limit switch is used for sending a second detection signal to the screen protection circuit when detecting that the projection screen falls to the initial position;

the curtain protection circuit is further configured to stop outputting the falling driving signal to the curtain driving assembly if the second detection signal is received.

10. A control method of a projection screen is characterized by being applied to a laser projection device, and the laser projection device comprises the following steps: the screen protection device comprises a shell, a projection screen, a power circuit, a screen driving assembly, a screen protection circuit and a main control circuit; one side of the shell is provided with an accommodating groove for accommodating the projection screen; the method comprises the following steps: