WO2020252888A1

WO2020252888A1 - Laser projection device

Info

Publication number: WO2020252888A1
Application number: PCT/CN2019/101759
Authority: WO
Inventors: 崔荣荣; 郭大勃
Original assignee: 青岛海信激光显示股份有限公司
Priority date: 2019-06-20
Filing date: 2019-08-21
Publication date: 2020-12-24
Also published as: CN113848677B; CN112114479A; CN113835287B; CN113835287A; CN113848677A; CN112114479B

Abstract

A laser projection device comprising: a driving chip (01), a voltage output circuit (02), and a light source switch circuit (03). The light source switch circuit (03) is used to connect a laser assembly. The driving chip (01) is used to receive a current control signal corresponding to the laser assembly, and provide a driving current corresponding to the laser assembly, to the light source switch circuit (03). The driving chip (01) is further used to receive an enable signal corresponding to the laser assembly, and control, on the basis of the enable signal, a time length for which the light source switch circuit (03) drives, by means of a switch control signal, the corresponding laser assembly to emit light. The voltage output circuit (02) is used to provide to the light source switch circuit (03) a rated voltage for the laser assembly. When the switch control signal is at a valid potential the light source switch circuit (03) is closed, and at the rated voltage, the light source switch circuit (03) provides the driving current corresponding to the laser assembly to the laser assembly connected thereto,. Thus, a monochromatic laser is independently controlled.

Description

Laser projection equipment

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office on June 20, 2019, the application number is 201910538290.8, and the invention name is "laser projection equipment", the entire content of which is incorporated into this application by reference.

Technical field

This application belongs to the field of projection display, and particularly relates to a laser projection device.

Background technique

Laser TVs such as ultra-short throw laser TVs are widely used in the display field because of their advantages of high color purity, large color gamut, and high brightness.

The light source system of the current laser TV usually includes a laser light source, a fluorescent wheel and a color filter wheel. The laser light source is usually a blue laser for emitting blue laser light. The blue laser is irradiated on three different areas of the fluorescent wheel sequentially to generate three-color light, and the three-color light is filtered through the color filter wheel in order to obtain three-color light with higher purity. It is also possible to use a full three-color light source system to generate three-color light. The laser light source of the full three-color light source system includes three-color lasers, which can directly generate three-color light.

Summary of the invention

This application provides a laser projection device, which can solve the problem of poor display effect of the laser projection device. The technical solution is as follows:

The present application provides a laser projection device, including: a display control circuit, a laser light source, and a plurality of laser driving circuits; the laser light source includes three primary color laser components, a plurality of the laser components and the plurality of laser driving circuits One-to-one correspondence, the laser assembly includes at least one laser;

The display control circuit is used to generate a plurality of enable signals corresponding to the three primary colors of each frame image in a multi-frame display image, and transmit the plurality of enable signals to the corresponding lasers respectively A driving circuit, and generating a plurality of current control signals corresponding to the three primary colors of each frame of image one-to-one, and respectively transmitting the plurality of current control signals to the corresponding laser driving circuit;

Each of the laser drive circuits is configured to provide the laser assembly to which it is connected with a drive current corresponding to the laser assembly, wherein the current control signal corresponding to each laser assembly corresponds to at least two frames of the display The size of the image is different;

The laser assembly is used to emit light under the drive of a corresponding laser drive circuit.

It should be understood that the above general description and the following detailed description are only exemplary and cannot limit the application.

Description of the drawings

In order to explain the embodiments of the present application more clearly, the following will briefly introduce the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. Ordinary technicians can obtain other drawings based on these drawings without creative work.

Fig. 1 is a partial structural diagram of an all-light source three-color system in the related art;

Figure 2 is a block diagram of a laser projection device provided by an embodiment of the present application;

3 is a schematic structural diagram of a laser driving circuit provided by an embodiment of the present application;

4 is a schematic diagram of a partial structure of a laser driving circuit provided by an embodiment of the present application;

FIG. 5 is a graph of the relationship between current and brightness provided by an embodiment of the present application;

6 is a schematic diagram of a partial structure of a laser driving circuit provided by an embodiment of the present application;

FIG. 7 is a schematic structural diagram of a repeater provided by an embodiment of the present application;

FIG. 8 is a schematic diagram of waveforms of a PWM signal before and after being processed by a repeater according to an embodiment of the present application;

FIG. 9 is a partial structural diagram of a boost circuit provided by an embodiment of the present application;

10 is a schematic diagram of a partial structure of a laser drive circuit provided by an embodiment of the present application;

FIG. 11 is a schematic structural diagram of a laser driving circuit provided by an embodiment of the present application;

12 is a graph of the relationship between the grayscale value of the input signal and the screen brightness provided by an embodiment of the present application;

FIG. 13 is a graph of the relationship between the gray scale value of the input signal and the screen brightness provided by an embodiment of the present application;

14 is a graph of the relationship between the grayscale value of the input signal and the screen brightness provided by an embodiment of the present application;

15 is a block diagram of a laser projection device provided by an embodiment of the present application;

FIG. 16 is a block diagram of a laser projection device provided by an embodiment of the present application;

Fig. 17 is a block diagram of a laser projection device provided by an embodiment of the present application.

The drawings here are incorporated into the specification and constitute a part of the specification, show embodiments that conform to the application, and are used together with the specification to explain the principle of the application.

Detailed ways

In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in the embodiments of this application will be described clearly and completely in combination with the embodiments of this application. Obviously, the described embodiments are part of the implementation of this application. Examples, not all examples. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this application.

As described in the related art, for the scheme of generating three-color light by the laser light source, since the light source system irradiates the blue laser to the fluorescent wheel to generate the three-color light, the control requirements for the fluorescent wheel are increased, and the fluorescent wheel produces The color effect of trichromatic light is poor. For the scheme that uses a full three-color light source system to generate three-color light, due to the increase in the number of lasers included in the laser light source in the full three-color light source system, each color laser needs to be controlled separately, and each color laser usually only provides a fixed brightness The laser, therefore, the final display effect of laser projection equipment is poor.

Please refer to FIG. 1, which shows a partial structural diagram of a full three-color light source system in the related art. As shown in FIG. 1, the full three-color light source system generally includes a laser light source 10, two dichroic mirrors 20, a reflecting mirror 30, a condenser lens 40, a diffuser 50 and a light rod 60. The laser light source 10 includes a red laser component 101 for emitting a red laser, a green laser component 102 for emitting a green laser, and a blue laser component 103 for emitting a blue laser. The red laser light emitted by the red laser assembly 101 can be transmitted to the condenser lens 40 through the dichroic mirror 201. The green laser light emitted by the green laser component 102 can be first reflected on the dichroic mirror 202 through the reflecting mirror 30, then reflected on the dichroic mirror 201 through the dichroic mirror 202, and then reflected to the dichroic mirror 201 through the dichroic mirror 201 On the condenser lens 40. The blue laser light emitted by the blue laser component 103 can be transmitted to the dichroic mirror 201 through the dichroic mirror 202, and then reflected to the condenser lens 40 through the dichroic mirror 201. The laser light irradiated on the condenser lens 40 is condensed by the condenser lens 40 and then irradiated on the diffusion wheel 50. The laser light irradiated on the diffuser wheel 50 is irradiated into the light rod 60 after being homogenized by the diffuser wheel 50, and under the uniform light effect of the light rod 60, a three-color light source is realized. Wherein, for each laser assembly, at least one laser may be included.

Since the lasers of each color in the full three-color light source system (that is, the above-mentioned laser components) need to be controlled separately, and the lasers of each color can usually only provide lasers with a fixed brightness, the final display effect of the laser projection device is poor.

The embodiment of the present application provides a laser projection device, for example, it may be a laser TV, as shown in FIG. 2, including:

Display control circuit 70, laser light source 10, multiple laser drive circuits 00, laser light source 10 includes three primary color laser components 101, multiple laser components 101 correspond to multiple laser drive circuits 00 one to one, for each laser component, It may include at least one laser.

The display control circuit 70 is used to generate multiple enable signals corresponding to the three primary colors of each frame of image one-to-one, and transmit the multiple enable signals to the laser drive circuits respectively corresponding to the laser components 101 of the three primary colors. 00, and generating multiple current control signals corresponding to the three primary colors of each frame of image one-to-one, and respectively transmitting the multiple current control signals to the laser driving circuits 00 corresponding to the laser components 101 of the three primary colors.

Each laser drive circuit 00 is configured to provide the laser assembly to which it is connected with a drive current corresponding to the laser assembly, wherein the current control signal corresponding to each laser assembly corresponds to at least two frames of the The size of the image is different when it is displayed.

The laser component 101 is used to emit light under the driving of the corresponding laser driving circuit 00.

Figure 2 assumes that the primary colors are red, green and blue, and the corresponding enable signals are red enable signal R_EN, green enable signal R_EN and blue enable signal R_EN, and current control signals are red current control signal R_PWM, green Current control signal G_PWM and blue current control signal B_PWM. For ease of description, the subsequent embodiments all take the aforementioned primary colors of red, green, and blue as examples for description. When the embodiments of the present application are actually implemented, the primary colors may also have other colors, which are not limited herein.

In summary, because the display control circuit in the laser projection device can generate multiple enable signals corresponding to the three primary colors of each frame of the multi-frame display image, and transmit the multiple enable signals to the corresponding The laser drive circuit for each frame of image, and generates multiple current control signals corresponding to the three primary colors of each frame of image, and transmits the multiple current control signals to the corresponding laser drive circuit, each of the laser drive circuits can The driving current corresponding to the laser component is provided to the laser component to which it is connected. Since the current control signal corresponding to each of the laser components is different in size when corresponding to at least two frames of the displayed image, the laser projection device can support variable-brightness laser components, effectively improving the display effect of the laser projection device.

As shown in Fig. 3, each laser driving circuit 00 includes:

The driving chip 01, the voltage output circuit 02 and the light source switch circuit 03, the light source switch circuit 03 is used to connect with a laser assembly, and the laser assembly includes at least one laser for emitting laser light of one color. When the laser assembly includes multiple lasers, the multiple lasers may be connected in series or in parallel. In an embodiment, the laser assembly includes 7-9 lasers, for example 8 lasers. In an embodiment, the laser component may be a red laser component, a green laser component or a blue laser component.

The driving chip 01 is configured to receive a current control signal corresponding to the laser component, and provide the corresponding drive current of the laser component to the light source switch circuit 03 based on the current control signal. For example, the current control signal can be Pulse Width Modulation (PWM, Pulse Width Modulation). The PWM signal is a signal composed of a series of pulse signals with equal amplitude. The PWM value is added to the duration of the switching tube during a driving cycle. average value. The longer the on-time, the larger the average value of the DC output; the PWM frequency is a ratio of the on-time to the driving period in a cycle, also known as the duty cycle.

The driving chip 01 is also used to receive an enable signal corresponding to the laser component, and based on the enable signal to control the light source switch circuit 03 to drive the corresponding laser component to light up through the switch control signal. For example, if the laser component is a red laser component, the enable signal is a red enable signal.

The voltage output circuit 02 is used to provide the rated voltage of the laser component for the light source switch circuit 03. The rated voltage of the laser component is the voltage required for the normal operation of the laser component, also called the nominal voltage.

The light source switch circuit 03 is used to turn on when the switch control signal is at an effective potential, and provide a driving current corresponding to the laser component to the laser component connected to it under the rated voltage.

For example, as shown in FIG. 4, the driving chip 01 includes a first pin ENOUT, a second pin ISN, and a third pin ISP. The first pin ENOUT is used to output a switch control signal, and the light source switch circuit 03 includes: The current detection resistor R5 and the first switching transistor Q1. The switch control signal is used to control the on and off of the light source switch circuit, so that the light source switch circuit drives the corresponding laser component to light up.

One end of the current detection resistor R5 is connected to the rated voltage output end of the voltage output circuit (not shown in Figure 4) and the second pin ISN, and the other end is connected to the positive electrode of the laser assembly and the third pin ISP, Figure 4 It is assumed that the voltage at one end of the current detection resistor R5 is the rated voltage Vo, and the voltage at the other end is the output voltage Vout, the source S1 of the first switching transistor Q1 is connected to the cathode of the laser component, and the gate G1 of the first switching transistor Q1 is connected to The first pin ENOUT is connected, the drain D1 of the first switching transistor is connected to the first signal output terminal O1, and the first signal output terminal O1 is used to output a level lower than the level of the drain D1 of the first switching transistor For the signal, FIG. 4 takes the grounding of the drain D1 of the first switching transistor as an example for illustration, that is, the first signal output terminal O1 is used as the reference ground. When the light source switch circuit 03 is turned on, a current loop h1 is formed. It should be noted that, in FIG. 4, it is assumed that the laser assembly includes n lasers connected in series, namely lasers LD1 to LDn. The lasers LD1 to LDn do not belong to the light source switch circuit 03. In an embodiment, the first switching transistor Q1 may be an N-Metal-Oxide-Semiconductor (NMOS) tube.

Wherein, the driving chip 01 is used to detect the current loaded on the current detection resistor R5 through the second pin ISN and the third pin ISP, and adjust the current loaded on the current detection resistor R5 to the driving current of the corresponding laser component. Please refer to FIG. 4, the current I=(Vo-Vout)/R, where R represents the resistance of the resistor R5, and I represents the current flowing through the current detection resistor R5.

It is worth noting that the driving chip 01 can determine the driving current (that is, the value of the driving current) corresponding to the laser assembly in various ways. In one embodiment, the driving chip 01 uses the first preset algorithm to calculate the value of the driving current corresponding to the laser component after receiving the current control signal; in another embodiment, the driving chip 01 prestores the current control signal and For the corresponding relationship of the current, after the drive chip 01 receives the current control signal, the corresponding drive current can be obtained by querying the corresponding relationship. For example, when the current control signal is a PWM signal, the corresponding relationship between the current control signal and the current may be characterized by the corresponding relationship between the PWM value and the current. Please refer to Table 1 and Figure 5. In order to facilitate readers’ understanding, Table 1 shows the corresponding relationship between PWM value, current and brightness (in actual applications, the driver chip 01 only needs to pre-store the corresponding relationship between PWM value and current), Figure 5 It is a graph of the relationship between current and brightness corresponding to the correspondence table. It can be seen from Figure 5 that there is a linear relationship between current and brightness. Generally, the greater the current, the greater the brightness. Therefore, the brightness of the laser assembly can be effectively adjusted by adjusting the current of the laser assembly. For example, when the PWM value of the received PWM signal is 1023, the drive current obtained by looking up the table 1 is 2.6A (A), then the current loaded on the current detection resistor R5 is adjusted to 2.6A. The brightness of the final laser assembly is 2540lumen (lumens).

Table 1

As mentioned earlier, the current control signal can be a PWM signal. The PWM signal will have a certain attenuation during transmission. The attenuation causes the amplitude of the PWM signal (also known as the high level amplitude) to be lower than the effectively set full-scale amplitude. . The embodiment of the application provides a repeater, which can adjust the received PWM signal whose amplitude is lower than the full-scale amplitude to a PWM signal whose amplitude is the full-scale amplitude without changing the duty cycle of the PWM signal. In this way, the signal attenuation caused by signal transmission is avoided, the accuracy of the current control signal input to the driving chip is ensured, and the subsequent driving accuracy is improved.

As shown in FIG. 6, when the current control signal is a PWM signal, the laser driving circuit 00 further includes:

Repeater 04. Repeater 04 is connected to driver chip 01, which is located at the front end of driver chip 01. Repeater 04 is used to receive the current control signal corresponding to the laser component and set the amplitude equal to the rated amplitude voltage VCC The current control signal is output to the driver chip 01.

For example, as shown in Figure 7, the repeater 04 includes:

The first resistor R1, the second resistor R2 and the operational amplifier (also called the operational amplifier) P, where the resistance of the first resistor R1 and the second resistor R2 are equal, and the non-inverting input terminal of the operational amplifier P (also called non-inverting The input terminal) u+ is respectively connected to one end of the first resistor R1, one end of the first resistor R1 is the input terminal of the current control signal, the inverting input terminal (also called the inverted input terminal) u- and the second resistor of the operational amplifier P One end of R2 is connected, the output end of the operational amplifier P (also called the common end) o is connected to the other end of the second resistor R2, and the output end o of the operational amplifier P is also connected to the driver chip. The rated voltage of the operational amplifier P (also Called the working voltage) is the amplitude voltage VCC. The ground terminal of the operational amplifier P is connected to the second signal output terminal O2, and the second signal output terminal O2 is used to provide a level signal lower than the amplitude voltage VCC. Normally, the second signal output terminal O2 is the reference ground .

In the actual implementation of the embodiment of the present application, since the rated voltages of the repeater and the driving chip may be different, a third resistor R3 and a fourth resistor R3 and a fourth resistor R3 are connected in series between the output terminal o of the operational amplifier P and the third signal output terminal O3. The resistor R4 and the third signal output terminal O3 are used to provide a level signal lower than that of the output terminal o, for example, the third signal output terminal O3 is grounded. The third resistor R3 and the fourth resistor R4 are voltage dividing resistors, the node e between the third resistor R3 and the fourth resistor R4 is used to output the current control signal after the voltage dividing process, and the voltage output by the node e is the driving chip Rated voltage. The resistance values of the third resistor R3 and the fourth resistor R4 are set according to the rated voltage of the repeater and the driving chip.

As shown in Figure 8, since the resistance values of the first resistor R1 and the second resistor R2 are equal, after the PWM signal passes through the operational amplifier P, the duty cycle of the PWM signal will not change, but the amplitude of the PWM signal will be lower than the amplitude. The value voltage VCC is adjusted to be equal to the amplitude voltage VCC, that is, the full range, so it can be ensured that the processed current control signal has no attenuation relative to the initially generated current control signal.

Moreover, because the repeater has the characteristics of high input impedance and low output impedance. To a certain extent, it can avoid the signal loss caused by the higher output impedance and the lower input impedance of the next stage, which plays a role of linking up and down, that is, buffering. Since the repeater has the characteristics of high input impedance and low output impedance, it presents a high-impedance state to the upper-level circuit and a low-impedance state to the next-level circuit. It is often used in the intermediate stage to isolate the front and back circuits and eliminate The mutual influence between them. In the embodiment of the present application, the repeater can isolate various noises generated by the circuit (for example, the display control circuit) driving the front end of the chip, so the accuracy of the laser driving circuit can be improved.

In different application scenarios, the aforementioned voltage output circuit 02 can be a boost circuit or a step-down circuit according to different working modes. The boost circuit is a circuit that raises the input voltage Vi to the rated voltage Vo of the laser component, Vi<Vo, and the step-down circuit is a circuit that reduces the input voltage Vi to the rated voltage Vo of the laser component, Vi>Vo. Since the initial input voltage Vi of the boost circuit is lower than that of the buck circuit, if the boost circuit has a short circuit and other faults, the lower initial input voltage Vi does not exceed the rated voltage Vo of the laser component, and will not cause damage to the laser component. It will not cause the risk of electric shock to the human body. Therefore, compared with the step-down circuit, the booster circuit is less likely to damage the equipment, and the safety is higher.

For example, when the voltage output circuit 02 is a booster circuit, the booster circuit is used to boost the input voltage Vi to the rated voltage Vo of the laser component, and load the rated voltage Vo for the light source switch circuit 03.

As shown in FIG. 9, the boost circuit may include: an inductor L, a second switching transistor Q2, a diode D, a capacitor C1, a fifth resistor R6, a sixth resistor R7, and a seventh resistor R8. One end of the inductor L and the input voltage The supply terminal a is connected to the anode of the diode D and the source S2 of the second switching transistor Q2. The cathode of the diode D is the output terminal of the rated voltage Vo, and one end of the capacitor C1 is connected to the output terminal of the rated voltage Vo , The other end is connected to the fourth signal output terminal O4, and the fourth signal output terminal O4 is used to output a level signal lower than the rated voltage. FIG. 9 takes the grounding of the other end of the capacitor C1 as an example for illustration, that is, the fourth signal output terminal O4 is the reference ground. The fifth resistor R6 and the sixth resistor R7 are connected in series between the rated voltage output terminal and the fifth signal output terminal O5. The fifth signal output terminal O5 is used to output a level signal lower than the rated voltage. R6 and the sixth resistor R7 are connected in series between the output terminal of the rated voltage and the ground as an example, that is, the fifth signal output terminal O5 is the reference ground. The seventh resistor R8 is connected in series between the drain D2 of the second switching transistor Q2 and the sixth signal output terminal O6. The sixth signal output terminal O6 is used to output a signal with a level lower than the voltage of the drain D2. The seven resistor R8 is connected in series between the drain D2 of the second switching transistor Q2 and the ground as an example for description, that is, the sixth signal output terminal O6 is the reference ground.

In the aforementioned boost circuit, the rated voltage Vo can be set through the node b between the fifth resistor R6 and the sixth resistor R7, and the fifth resistor R6 and the sixth resistor R7, where the rated voltage

Vb is the reference voltage at node b. Since the rated voltage of the laser component is usually constant, the reference voltage Vb of the node b between the fifth resistor R6 and the sixth resistor R7, and the fifth resistor R6 and the sixth resistor R7 are usually constant, that is, the reference voltage Vb is not constant after the setting. change.

The boost circuit is divided into two working processes, namely the charging process and the discharging process. In these two working processes, the working principle of the boost circuit is as follows:

Charging process: the second switching transistor Q2 is turned on, the input voltage Vi continues to store energy in the inductor L, the current on the inductor L increases linearly, and at the same time, the diode D is reversely blocked to prevent the voltage of the capacitor C1 from discharging the fourth signal output terminal O4 (When the fourth signal output terminal O4 is the reference ground, that is, it discharges to the ground), so the direct current continuously charges the inductor L and stores energy, forming a current loop h2.

Discharge process: the second switching transistor Q2 is turned off, which is equivalent to the above-mentioned current loop h2 being open. Since the current of the inductor L cannot undergo abrupt changes, the current flowing through the inductor L is slowly discharged until it reaches zero. Since the circuit of the current loop h2 has been disconnected, the inductor L can only charge the capacitor C1 through the diode D, so that the electromotive force of the capacitor C1 is continuously increased, forming a current loop h3.

By controlling the gate G2 of the second switching transistor Q2, the second switching transistor Q2 is continuously turned on and off at a certain frequency, and the boost circuit is controlled to continuously charge and discharge, so that the voltage across the capacitor C1 continues to rise until it reaches the set rating Voltage Vo, thereby completing the boost of the boost circuit.

For example, the second switch transistor Q2 may be an NMOS transistor. When the level signal input from the gate G2 is high relative to the level signal of the source S2, the NMOS tube is turned on, when the level signal input from the gate G2 is low relative to the level signal of the source S2 , NMOS tube is turned off.

It is worth noting that the aforementioned control of the turning on and off of the second switching transistor Q2, and/or the setting of the reference voltage Vb of the node b between the fifth resistor R6 and the sixth resistor R7 may use a separate control chip Or the control circuit can control it, or it can be controlled by the driver chip. FIG. 9 assumes that the driving chip 01 controls the turning on and off of the second switching transistor Q2, and setting the reference voltage Vb of the node b between the fifth resistor R6 and the sixth resistor R7.

As shown in FIG. 10, the driving chip 01 also includes a fourth pin FB, a fifth pin GATE, and a sixth pin SENSE. The fourth pin FB is connected to the node b, and the fourth pin FB is used for A reference voltage Vb is provided for node b; the fifth pin GATE is connected to the gate G2 of the second switching transistor Q2, and the fifth pin GATE is used to control the turning on and off of the second switching transistor Q2; the sixth pin SENSE is connected to The node c is connected, and the node c is located between the drain D2 of the second switching transistor Q2 and the seventh resistor R8.

The fifth pin GATE and the sixth pin SENSE can form an overcurrent protection circuit. The sixth pin SENSE is used to collect the current of the boost circuit by detecting the voltage between the drain D2 and the seventh resistor R8. When the collected current is greater than the set current upper threshold, the driver chip will control the fifth pin Pin GATE turns off the current loop of the boost circuit. In this way, the overcurrent protection of the boost circuit is realized based on the collected current.

Correspondingly, referring to Figure 10, the working principle of the boost circuit is as follows:

Charging process: The driving chip 01 controls the second switching transistor Q2 to turn on through the fifth pin GATE, the input voltage Vi continues to store energy in the inductor L, and the current on the inductor L increases linearly. At the same time, the diode D is reversely cut off, and the direct current is continuously supplied The inductor L charges and stores energy to form a current loop h2.

Discharge process: The driving chip 01 controls the second switching transistor Q2 to be turned off through the fifth pin GATE, and the current flowing through the inductor L is slowly discharged until it is zero. The electromotive force of the capacitor C1 continues to rise, forming a current loop h3.

The driver chip 01 provides the reference voltage Vb for the node b through the fourth pin FB, thereby setting the rated voltage Vo, and then controls the gate G2 of the second switching transistor Q2, so that the second switching transistor Q2 is continuously turned on and off at a certain frequency , Control the boost circuit to continuously charge and discharge, so that the voltage across the capacitor C1 continues to rise until it reaches the set rated voltage Vo, thereby completing the boost of the boost circuit.

For example, the driving chip 01 can perform turn-on and turn-off control of the second switching transistor Q2 at a frequency above 100 kHz (kilohertz), that is, the switching frequency is greater than or equal to 100 kHz. This switching frequency can minimize the size of discrete components, such as inductors, diodes, etc., and maintain a high driving efficiency, so that the temperature rise of the discrete components is smaller, the heat is easier to control, and the drive circuit is prevented from overheating. .

Please refer to FIG. 11. FIG. 11 is a schematic structural diagram of a laser driving circuit provided by an embodiment of the application. The driving chip includes: a first pin ENOUT, a second pin ISN, a third pin ISP, and a fourth pin FB, fifth pin GATE, sixth pin SENSE, seventh pin CTRL, eighth pin EN, among them, the first pin ENOUT, the second pin ISN, and the third pin ISP, the fourth pin The connection relationship and working principle of the pin FB, the fifth pin GATE, and the sixth pin SENSE refer to the contents of Fig. 3, Fig. 4 and Fig. 9 in the foregoing embodiment. Normally, the current control signal and the enable signal are controlled by the display Circuit generation, the seventh pin CTRL is used to receive the current control signal, which can be directly connected to the display control circuit, or can be connected through a repeater 04, which is used for relaying. In FIG. 10, the seventh pin CTRL is connected to the repeater 04 for receiving the current control signal processed by the repeater. The eighth pin EN is used to receive an enable signal, and it can be directly connected to the display control circuit.

For ease of understanding, the laser driving circuit is described below by taking Figure 11 as an example: after the driving chip 01 receives the current control signal transmitted by the repeater 04 through the seventh pin CTRL, it provides the laser to the light source switch circuit 03 based on the current control signal The drive current corresponding to the component. The driving chip 01 receives the enable signal corresponding to the laser component through the eighth pin EN, and based on the enable signal, controls the light source switch circuit 03 to drive the corresponding laser component to light up through the switch control signal; the voltage output circuit 02 is used for Provide the light source switch circuit 03 with the rated voltage Vo of the laser component; the light source switch circuit 03 is used to turn on when the switch control signal is at an effective potential, and provide the laser component connected to it with the corresponding drive current of the laser component under the rated voltage Vo . For the specific working process of each element in FIG. 11, reference may be made to the foregoing embodiment, which will not be repeated here.

In the embodiment of the present application, the driving chip 01 can use multiple methods to adjust the current (that is, the adjustment of the current value). With reference to the foregoing embodiment, the embodiment of the present application uses the following two optional methods as examples for description:

In the first embodiment, the current adjustment is achieved by adjusting the value of the current control signal sent by the driving chip (for example, the current control signal sent by the aforementioned main controller). For example, when the current control signal is a PWM signal, the current value can be adjusted by adjusting the PWM value of the PWM signal. The driving chip is used to adjust the value of the current control signal to adjust the current loaded on the current detection resistor to the driving current of the corresponding laser component.

Please refer to Figure 4, the driving current of the laser component I=(VCTRL-100mV)/(R*10), where R is the resistance of resistor R5, and VCTRL is the average voltage amplitude of the PWM signal, that is, the seventh pin mentioned above The average voltage amplitude of the signal received by CTRL. When the resistance of the resistor R5 remains unchanged, the adjustment of the current I is adjusted by the average voltage amplitude of the PWM signal VCTRL. The driving current I of the laser component is related to the seventh pin. The average voltage amplitude of the signal received by CTRL VCTRL (when the laser drive circuit 00 includes the repeater 04, VCTRL is the average voltage amplitude output by the PWM signal through the repeater 04; when the laser drive circuit 00 does not include the repeater 04 When VCTRL is the average voltage amplitude of the PWM signal, the driving current changes with the current corresponding to the brightness value of each pixel in each frame of image, and quickly responds to the change of the grayscale value of the pixel of each frame of image.

In the second embodiment, the current detection resistor R5 is an adjustable resistor, and the driving chip is used to adjust the resistance value of the resistance detection resistor R5 to adjust the current loaded on the current detection resistor R5 to the corresponding driving current of the laser component. It is worth noting that the current detecting resistor R5 may include one or more resistors. When it includes multiple resistors, the multiple resistors may be connected in series or in parallel. The current detecting resistor R5 may also be implemented by other components or circuits. The equivalent resistance is not limited in the embodiment of this application.

The aforementioned drive chip 01 can also use other methods to adjust the current. For example, combining the above two implementation methods, the current detection resistor R5 is an adjustable resistor, and the drive chip adjusts the value of the current control signal synchronously, and adjusts the resistance detection. The resistance of the resistor R5 is used to adjust the current of the current detection resistor R5 to the driving current of the corresponding laser component.

In laser projection equipment, the display control circuit generates multiple current control signals corresponding to the three primary colors one-to-one. For example, if the three primary colors are red, green, and blue, the display control circuit generates a red current control signal and a green current. The control signal and the blue current control signal, correspondingly, the red laser component, the green laser component, and the blue laser component light up sequentially in one driving cycle. Take the laser driving circuit of the red laser component in Figure 10 as an example. Assuming that the driving period of each frame of image in one frame is T, and the high level is the effective potential, the turn-on time of the red laser component in a driving period T (ie point Light duration) is t, then the high level duration of the enable signal of the red laser component in a driving period T is t, and the enable signal is input to the enable pin of the driver chip 01 (ie the aforementioned eighth pin) EN, through the first pin ENOUT to control the on and off of the light source switch circuit, so as to realize the lighting and extinction of the red laser component. When the first pin ENOUT is at a high level, the first switch transistor Q1 is turned on, and the light source switch circuit is turned on and works normally. The lighting time of the red laser component is t. When the first pin ENOUT is at a low level, the first The switching transistor Q1 is turned off, the light source switching circuit is not turned on, and the red laser component does not work, the time for which the red laser component is extinguished is Tt. Further, by controlling the on and off of the first switch transistor Q1, self-protection of the switch control circuit, such as over-current protection, can also be realized.

In the light source switch circuit 03, when the first switch transistor Q1 is a MOS tube, such as an NMOS tube, the on-off time of the light source switch circuit reaches ns (nanosecond) level, and the on-off time of the laser drive circuit reaches μs (microsecond) Level, so that the current response speed of the laser component is fast, the accuracy is high, the high current and the low ripple are reduced, and the serious image quality problem of the color mixing caused by the slow response speed of the laser driving circuit is reduced.

In summary, in the laser drive circuit provided by the embodiments of the present application, since the display control circuit in the laser projection device can generate multiple enable signals corresponding to the three primary colors of each frame of the multi-frame display image, Transmit multiple enable signals to the corresponding laser drive circuits, and generate multiple current control signals corresponding to the three primary colors of each frame of image, and transmit multiple current control signals to the corresponding laser drive. Circuit, each of the laser drive circuits can provide the laser assembly to which it is connected with a drive current corresponding to the laser assembly. Since the current control signal corresponding to each of the laser components is different in size when corresponding to at least two frames of the displayed image, the laser projection device can support variable-brightness laser components, effectively improving the display effect of the laser projection device.

With the development of society, people have higher and higher requirements for the display effect of laser projection equipment, and therefore have higher requirements for a series of parameters that affect the display effect (for example, contrast). Among them, the contrast of laser projection equipment is usually divided into static contrast and dynamic contrast. Static contrast usually refers to the contrast calculated by the contrast algorithm formulated by the American National Standards Institute (ANSI), which refers to the brightness of the white area and the black area in a picture (that is, the same frame of image) ratio.

Dynamic contrast refers to the light-dark ratio of the same frame of image during the display process, which is related to the brightness of the laser light source during the display process, that is, the brightest white area and the darkest black area of the image during the display process. Brightness ratio. For example, as shown in formula (1), the dynamic contrast C satisfies:

Luminance Lw for an image display during the brightest white region, L _B luminance for an image display during the black region darkest.

It can be known from the above dynamic contrast formula that when Lw reaches the maximum value, the dynamic contrast can be improved by reducing the value of L _B. Among them, the actual display brightness of the image of the laser projection device is usually determined by two factors. One factor is the brightness of the laser light source, and the other factor is the grayscale value of the image (that is, the brightness of the image itself). The superposition can finally determine the actual display brightness of a frame of image. Therefore, the display effect can be optimized by adjusting the ratio of the two factors.

Normally, the brightness of the image itself in the video displayed by the laser projection device is constantly changing based on its content. For each frame of image, the laser light source can be adjusted according to the brightness of the image itself to adjust the actual display brightness of the image. For example, when a frame of image is a black screen, the brightness of the laser light source can be reduced to make the actual display brightness of the frame of image lower than its own brightness. In this way, by reducing the brightness of the laser light source, the lower limit of the actual display brightness of the laser projection device when displaying images, that is, the lowest actual display brightness (LB), can be reduced, and the dynamic contrast of the laser projection device when displaying images can be improved. At the same time, since the brightness of the laser light source is reduced, the power consumption of the laser projection device is also reduced.

The laser projection device provided by the embodiment of the present application can improve the dynamic contrast of the laser projection device without changing the actual display brightness of the image. The principle of image display is: separately processing the brightness of the laser light source and the grayscale value of the image to be displayed to enhance the detail expression of the image, and then reduce the brightness of the light source and increase the laser light on the premise that the brightness of the displayed image remains unchanged. The dynamic contrast of the projection device. In order to facilitate readers’ understanding, the embodiments of the present application take FIGS. 12 to 14 as examples to illustrate the image display principles involved in the embodiments of the present application:

As described in FIGS. 12 to 14, FIGS. 12 to 14 show the relationship between the input signal grayscale value (also called display grayscale value or image brightness) and screen brightness (that is, actual display brightness). In Figure 12 to Figure 14, the abscissa is the grayscale value of the input signal, and the ordinate is the screen brightness. Assuming that the maximum grayscale value of the image that can be processed by the laser projection device is 256, the power of the laser light source (because the power of the laser light source is proportional to the brightness of the laser light source, in the embodiment of this application, it is assumed that the power of the laser light source is equivalent to the laser light source). The brightness of the light source) is a standard quantity (that is, a reference quantity). For example, the unit is one. Then, as shown in FIG. 12, the curve of the gray scale value of the input signal of the laser projection device and the screen brightness (that is, the Horse curve) is the solid line in Figure 12. Assuming that the input signal grayscale value of a frame of image A currently displayed is 160, the corresponding screen brightness is 96. As shown in Figure 13, the input signal grayscale value of this frame of image A is increased by D times. Image A is transformed into image A', and the screen brightness corresponding to this image A'is 192. As shown in Figure 14, the screen brightness can be reduced to 96 by reducing the power of the laser light source, thereby converting image A'into image A. In this way, because the larger the display grayscale value range of the image, the richer the detail expression of the image, and the laser projection device provided by the embodiment of the present application can expand the display grayscale value range of the image, that is, increase the display grayscale. The upper limit of the value, therefore, enhances the detailed expression of the image, and at the same time, under the premise of ensuring that the actual display brightness of the image A remains unchanged, the brightness of the laser light source is reduced, the contrast is increased, and the power consumption is reduced.

In an embodiment, as shown in FIG. 15, the laser projection device further includes a light modulation device 80, and the light modulation device 80 may be a digital micromirror device (Digital Micromirror Device, DMD) or a liquid crystal on silicon (Liquid Crystal on Silicon). , LCOS).

Further, the display control circuit 70 includes an algorithm processor 701 and a control processing module 702. The algorithm processor 701 is connected to the control processing module 702, and the control processing module 702 is also connected to the laser driving circuit 00 and the light modulation device 80, respectively. The algorithm processor can be implemented using Field-Programmable Gate Array (FPGA).

The algorithm processor 701 is configured to determine the gain value α of each frame image, α≥1 according to the grayscale value of each frame image in the multi-frame display image. Among them, the image display data of each frame of image can reflect the basic distribution and basic tone of each frame of image color. When the image display data is 4K data, the 4K data can be V-by-One (an image-oriented transmission The developed digital interface standard) signal is input to the algorithm processor 701.

The algorithm processor 701 is further configured to send image display data and a current control signal corresponding to the laser component to the control processing module 702, wherein each of the aforementioned current control signals is used to indicate the adjusted brightness of the corresponding laser component. The brightness of is 1/α of the brightness before adjustment, the image display data is used to indicate the gray scale value of each frame of image after adjustment, and the adjusted gray scale value is α times the gray scale value before adjustment.

The control processing module 702 is configured to send image display data and a current control signal corresponding to the laser assembly to the light modulation device 80.

The light modulation device 80 is used for modulating the beam of the laser light source based on the image display data to generate an image beam, and project the image beam onto the display screen to realize the display of each frame of image. It should be noted that the laser projection device may also include a plurality of optical lenses located between the light modulation device 80 and the display screen, and the plurality of optical lenses are used to transmit, reflect and/or refract the image beam. Then, it is projected onto the display.

In the embodiment of the present application, the display control circuit 70 can adjust the brightness of the laser light source in real time based on the gain value α of each frame of image, that is, the change of each frame of image, so as to achieve dynamic contrast. And because in the light source switch circuit of the laser drive circuit, when the first switch transistor is a MOS tube, such as an NMOS tube, the on-off time of the light source switch circuit reaches the ns (nanosecond) level, and the on-off time of the laser drive circuit reaches μs ( Microsecond) level, so that the current response speed of the laser assembly is fast and the accuracy is high, that is, the laser drive circuit can quickly and accurately respond to the changes in the brightness of each pixel of the image, and the brightness of the laser assembly can be changed from 0 to rated The arbitrary adjustment of the brightness corresponding to the current value reduces the serious image quality problem of color mixing caused by the slow response of the laser drive circuit due to the slow response of the laser drive circuit. This drive circuit is the basis for achieving high dynamic contrast, that is, it is supported in hardware Dynamic brightness adjustment of laser projection equipment. And because the laser projection device expands the grayscale value range of each frame of image according to the gain value, and at the same time reduces the brightness of the laser light source, the detail expression of the image is enhanced, and the contrast of the image is improved, that is, increase The contrast of the laser projection device when displaying the image.

As the resolution of laser projection equipment increases, the image display data of laser projection equipment becomes larger and larger. For example, the image display data is 4K data, that is, data with a pixel resolution of 4096×2160, and the display control circuit 70 uses only one processing The processor is likely to cause low processing efficiency of the processor. Therefore, an embodiment of the present application proposes a manner in which the master and slave processors co-process image display data to improve processing efficiency. As shown in Figure 16, the control processing module 702: a master control processor 7021 and a slave control processor 7022. The algorithm processor 701 is connected to the master control processor 7021 and the slave control processor 7022 respectively. The master control processor 7021 is also connected to The laser driving circuit 00 and the light modulation device 80 are connected, and the slave control processor 7022 is also connected with the light modulation device 80.

The algorithm processor 701 is configured to determine the gain value α of each frame of image, α≥1 according to the grayscale value of each frame of image.

The algorithm processor 701 is further configured to send a current control signal and first sub-data to the main control processor 7021, and send second sub-data to the slave control processor. The first sub-data and the second sub-data constitute image display data.

For example, when the image display data is 4K data, the first sub-data and the second sub-data are both 60bit (bit) data, and both the first sub-data and the second sub-data may be low-voltage differential signals (Low-Voltage Differential Signaling, LVDS), where the first sub-data is two-channel west (west) LVDS, and the second sub-data can be two-channel east (east) LVDS.

In one embodiment, the algorithm processor 701 can generate the current control signal in a variety of ways. In an optional way, the algorithm processor 701 determines the gain value α of each frame of image, and then calculates each laser component The current control signal is generated based on the brightness through the second preset algorithm; in another optional manner, the algorithm processor 701 may pre-store the corresponding relationship between the current control signal and the brightness, and after determining each frame of image After the gain value α of, the algorithm processor 701 calculates the brightness of each laser component, and then queries the corresponding relationship according to the calculated brightness to obtain the current control signal corresponding to the laser component. For example, when the current control signal is a PWM signal, the corresponding relationship between the current control signal and the current can be characterized by the corresponding relationship between the PWM value and the brightness. The corresponding relationship can refer to the corresponding relationship between PWM value and brightness in Table 1.

The main control processor 7021 is configured to send a current control signal and an enable signal to the laser driving circuit 00, and send the first sub-data to the optical modulation device.

The slave control processor 7022 is configured to send the second sub-data to the light modulation device 80.

The light modulation device 80 is used for modulating the beam of the laser light source based on the first sub-data and the second sub-data to generate an image beam, and project the image beam onto the display screen to realize the display of each frame of image.

In one embodiment, as shown in FIG. 17, the laser projection device further includes: a memory 90, a galvanometer drive circuit 100, a galvanometer 110, and a power module 120. The memory 90 is connected to the algorithm processor 701 for storing For image display data, please refer to Figures 15 and 16, which store the adjusted grayscale value of each frame of image. For example, the memory is a Double Data Rate (DDR) memory; the galvanometer drive circuit 100 and the algorithm respectively The processor 701 and the galvanometer 110 are connected to drive the galvanometer 110 to vibrate under the control of the algorithm processor 701. For example, the galvanometer 110 may be a 4-dimensional galvanometer, that is, it can vibrate in 4 directions. By providing the galvanometer drive circuit 100 and the galvanometer 110, images can be superimposed and displayed, which increases the expressive power of details, which is equivalent to an increase in resolution; the power module 120 is used to provide electrical energy for electrical components, which is compatible with each of the laser projection equipment. The electrical components are connected separately. FIG. 11 is only connected with the algorithm processor 701, the master processor 7021, and the slave processor 7022 for schematic illustration.

It is worth noting that the laser projection equipment may also include: two dichroic mirrors 20, a reflecting mirror 30, a condenser lens 40, a diffuser wheel 50 and an optical rod 60, etc. The function of each element can be referred to FIG. 1, and the implementation of this application I won't repeat this example.

After considering the specification and practicing the invention disclosed herein, those skilled in the art will easily think of other embodiments of the present application. This application is intended to cover any variations, uses, or adaptive changes of this application. These variations, uses, or adaptive changes follow the general principles of this application and include common knowledge or customary technical means in the technical field not disclosed in this application. . The description and embodiments are only regarded as exemplary, and the true scope and spirit of the application are pointed out by the claims.

It should be understood that the present application is not limited to the precise structure described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the application is only limited by the appended claims.

Claims

A laser projection device, characterized by comprising: a display control circuit, a laser light source, and a plurality of laser driving circuits; the laser light source includes three primary color laser components, a plurality of the laser components and the plurality of laser driving circuits The circuits have a one-to-one correspondence, and the laser assembly includes at least one laser;

The display control circuit is used to generate a plurality of enable signals corresponding to the three primary colors of each frame image in a multi-frame display image, and transmit the plurality of enable signals to the corresponding lasers respectively A driving circuit, and generating a plurality of current control signals corresponding to the three primary colors of each frame of image one-to-one, and respectively transmitting the plurality of current control signals to the corresponding laser driving circuit;

Each of the laser drive circuits is configured to provide the laser assembly to which it is connected with a drive current corresponding to the laser assembly, wherein the current control signal corresponding to each laser assembly corresponds to at least two frames of the display The size of the image is different;

The laser assembly is used to emit light under the drive of a corresponding laser drive circuit.
The laser projection device according to claim 1, wherein each of the laser drive circuits comprises: a drive chip, a voltage output circuit, and a light source switch circuit, and the light source switch circuit is used to connect to a laser assembly;

The driving chip is configured to receive a current control signal corresponding to the laser component, and provide the corresponding drive current of the laser component to the light source switch circuit based on the current control signal;

The driving chip is further configured to receive an enable signal corresponding to the laser component, and based on the enable signal, control the light source switch circuit to drive the corresponding laser component to light up through the switch control signal;

The voltage output circuit is used to provide the rated voltage of the laser component for the light source switch circuit;

The light source switch circuit is configured to be turned on when the switch control signal is at an effective potential, and provide the driving current corresponding to the laser component to the laser component connected to the laser component under the rated voltage.
The laser projection device according to claim 2, wherein:

The driving chip includes a first pin, a second pin, and a third pin, and the first pin is used to output the switch control signal;

The light source switch circuit includes: a current detection resistor and a first switch transistor;

One end of the current detection resistor is connected to the output terminal of the rated voltage of the voltage output circuit and the second pin, and the other end is connected to the anode of the laser assembly and the third pin. The source of the first switching transistor is connected to the negative electrode of the laser component, the gate of the first switching transistor is connected to the first pin, and the drain of the first switching transistor is connected to a low potential;

Wherein, the driving chip is used to detect the current loaded on the current detection resistor through the second pin and the third pin, and adjust the current loaded on the current detection resistor to the laser component The corresponding drive current.
The laser projection device according to claim 3, wherein the driving chip is used to adjust the value of the current control signal to adjust the current loaded on the current detection resistor to the corresponding laser component Drive current.
The laser projection device according to claim 3 or 4, wherein the current detection resistor is an adjustable resistor, and the drive chip is used to adjust the resistance value of the resistance detection resistor to reduce the current detection resistor The current loaded on the upper side is adjusted to the driving current of the corresponding laser assembly.
3. The laser projection device according to claim 2, wherein the current control signal is a pulse width modulated PWM signal, and the laser driving circuit further comprises:

A repeater, the repeater is connected to the drive chip, and the repeater is used to receive a current control signal corresponding to the laser component, and output a current control signal with an amplitude equal to the rated amplitude voltage to The driving chip.
The laser projection device according to claim 6, wherein the repeater comprises:

The first resistor, the second resistor and the operational amplifier;

Wherein, the resistance values of the first resistor and the second resistor are equal, the non-inverting input end of the operational amplifier is respectively connected to one end of the first resistor, and one end of the first resistor is the current control signal The inverting input terminal of the operational amplifier is connected to one end of the second resistor and the second signal output terminal, and the output terminal of the operational amplifier is respectively connected to the other end of the second resistor and the driver Chip connection, the rated voltage of the operational amplifier is the amplitude voltage.
The laser projection device according to claim 2, wherein:

The voltage output circuit is a booster circuit, and the booster circuit is used to boost the input voltage to the rated voltage of the laser assembly, and load the rated voltage for the light source switch circuit.
8. The laser projection device according to claim 8, wherein the booster circuit comprises:

An inductor, a second switching transistor, a diode, a capacitor, and a fifth resistor, a sixth resistor, and a seventh resistor;

One end of the inductor is connected to the input voltage supply end, the other end is respectively connected to the anode of the diode and the source of the second switching transistor, and the cathode of the diode is the output end of the rated voltage;

One end of the capacitor is connected to the output terminal of the rated voltage, and the other end is connected to the fourth signal output terminal, and the fourth signal output terminal is used to output a level signal lower than the rated voltage;

The fifth resistor and the sixth resistor are connected in series between the output terminal of the rated voltage and the fifth signal output terminal, and the fifth signal output terminal is used to output a level signal lower than the rated voltage;

The seventh resistor is connected in series between the drain of the second switching transistor and the sixth signal output terminal, and the sixth signal output terminal is used to output a signal with a level lower than the drain voltage.
The laser projection device according to any one of claims 1 to 9, wherein the laser projection device further comprises a light modulation device, the display control circuit comprises: an algorithm processor and a control processing module, the algorithm processor Connected to the control processing module, and the control processing module is also connected to the laser drive circuit and the light modulation device respectively.
The laser projection device according to claim 10, wherein the control processing module comprises: a master control processor and a slave control processor, and the algorithm processor is respectively connected to the master control processor and the slave control processor. The processor is connected, the master control processor is also connected to the laser drive circuit and the light modulation device, and the slave control processor is also connected to the light modulation device,

The algorithm processor is configured to determine the gain value α of each frame of image, α≥1 according to the grayscale value of each frame of image;

The algorithm processor is further configured to send the current control signal and first sub-data to the master control processor, and send second sub-data to the slave control processor, the first sub-data and the first sub-data The second sub-data constitutes image display data, each of the current control signals is used to indicate the adjusted brightness of the corresponding laser assembly, the adjusted brightness is 1/α times the brightness before adjustment, and the image display data Used to indicate the grayscale value of each frame of image after adjustment, and the adjusted grayscale value is α times the grayscale value before adjustment;

The main control processor is configured to send the current control signal and the enable signal to the laser drive circuit, and send the first sub-data to the optical modulation device;

The slave control processor is configured to send the second sub-data to the light modulation device;

The light modulation device is configured to modulate the beam of the laser light source based on the first sub-data and the second sub-data to generate an image beam.