AR glasses laser driving circuit and AR glasses

Abstract

This utility model discloses a laser driving circuit for AR glasses and AR glasses. The driving circuit includes a power supply module, a main control module, an LCOS control module, and a driving module. The power supply module supplies power to the main control module, the LCOS control module, and the driving module. The LCOS control module outputs a switch enable signal to control the RGB laser to light up or turn off, and inputs the switch enable signal to the main control module. The main control module outputs a pulse width modulation signal with a corresponding duty cycle to the driving module according to the input switch enable signal to adjust the output current of the driving module. The driving module drives the R, G, or B laser to light up according to the pulse width modulation signal output by the main control module. Compared with the DC-DC constant voltage design, this utility model is not only lower in cost but also smaller in size, allowing for a more miniaturized AR glasses.

Description

Technical Field

[0001] This utility model relates to the field of AR glasses technology, and in particular to an AR glasses laser driving circuit and AR glasses. Background Technology

[0002] Liquid Crystal On Silicon (LCoS) microdisplay chips are a silicon-based microdisplay technology that combines CMOS chips and liquid crystal displays. Using an LCoS optical engine with a laser in AR glasses design offers advantages such as small module size, low cost, high resolution, wide color gamut, and high resolution. Because the voltage difference between the RGB lasers is relatively large in the laser power supply design, a DC-DC constant voltage design is typically used. However, while the DC-DC constant voltage design offers high precision, it also results in higher cost and a larger design size, which is detrimental to the miniaturization of AR glasses.

[0003] Therefore, existing technologies still need to be improved and developed. Utility Model Content

[0004] In view of the shortcomings of the prior art, the purpose of this utility model is to provide an AR glasses laser driving circuit and AR glasses, so as to solve the problems of high cost and large size of the existing AR glasses RGB laser driving circuit adopting the DC-DC constant voltage design scheme.

[0005] The technical solution of this utility model is as follows:

[0006] In a first aspect, this utility model provides an AR glasses laser driving circuit for driving an RGB laser. The AR glasses laser driving circuit includes: a power module, a main control module, an LCOS control module, and a driving module.

[0007] The power module is connected to the main control module, the LCOS control module and the drive module respectively, and the power module is used to supply power to the main control module, the LCOS control module and the drive module;

[0008] The LCOS control module is connected to the main control module and is used to output a switch enable signal to control the RGB laser to turn on or off, and to input the switch enable signal to the main control module.

[0009] The main control module is connected to the drive module and is used to output a pulse width modulation signal with a corresponding duty cycle to the drive module according to the input switch enable signal in order to adjust the output current of the drive module.

[0010] The driving module is used to drive the R laser, G laser or B laser to light up according to the pulse width modulation signal output by the main control module.

[0011] In a further embodiment of this invention, the drive module includes: a drive control unit, an R laser switch control unit, a G laser switch control unit, and a B laser switch control unit;

[0012] The drive control unit is connected to the power module, the main control module, and the R laser, G laser, and B laser, respectively.

[0013] The R laser switch control unit is connected to the LCOS control module and the R laser respectively;

[0014] The G laser switch control unit is connected to the LCOS control module and the G laser respectively;

[0015] The B laser switch control unit is connected to both the LCOS control module and the B laser.

[0016] In a further embodiment of this invention, the drive control unit includes: a drive chip, a first resistor, a first switching transistor, a first diode, a first inductor, a fast power-on and discharge circuit, a second resistor, a third resistor, a first capacitor, and a second capacitor;

[0017] One end of the first resistor is connected to the power module, and the other end of the first resistor is connected to the source of the first switching transistor.

[0018] The gate of the first switching transistor is connected to the output pin of the driver chip via the fast power-on and discharge circuit, and the drain of the first switching transistor is connected to the anode of the first diode and one end of the first inductor.

[0019] The cathode of the first diode is grounded;

[0020] The other end of the first inductor is connected to one end of the first capacitor and the RGB laser;

[0021] The other end of the first capacitor is grounded;

[0022] One end of the second resistor is connected to the main control module, and the other end of the second resistor is connected to the enable pin of the driver chip and one end of the third resistor;

[0023] The other end of the third resistor is grounded;

[0024] One end of the second capacitor is connected to the enable pin of the driver chip, and the other end of the second capacitor is grounded.

[0025] In a further embodiment of this invention, the driving module further includes: a first magnetic bead, a third capacitor, a fourth capacitor, and a fifth capacitor;

[0026] One end of the first magnetic bead is connected to the power module, and the other end of the first magnetic bead is connected to one end of the third capacitor.

[0027] The other end of the third capacitor is grounded, one end of the fourth capacitor is connected to one end of the third capacitor, and the other end of the fourth capacitor is grounded. One end of the fifth capacitor is connected to one end of the fourth capacitor, and the other end of the fifth capacitor is grounded.

[0028] In a further embodiment of this invention, the fast power-on and power-off circuit includes: a fourth resistor, a fifth resistor, a sixth resistor, and a second diode;

[0029] One end of the fourth resistor is connected to the source of the first switching transistor, and the other end of the fourth resistor is connected to one end of the fifth resistor.

[0030] The other end of the fifth resistor is connected to the cathode of the second diode, and the anode of the second diode is connected to the output pin of the driver chip.

[0031] One end of the sixth resistor is connected to the common terminal of the fourth and fifth resistors and the gate of the first switching transistor, and the other end of the sixth resistor is connected to the output pin of the driver chip and the anode of the second diode.

[0032] In a further embodiment of this invention, the first switching transistor is a PMOS transistor.

[0033] In a further embodiment of this invention, the R laser switch control unit includes: a second switch transistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a third diode, and a sixth capacitor;

[0034] One end of the seventh resistor is connected to the LCOS control module, and the other end of the seventh resistor is connected to the gate of the second switching transistor.

[0035] The eighth resistor is connected in series with the third diode and then in parallel with the seventh resistor;

[0036] One end of the ninth resistor is connected to the gate of the second switch, and the other end of the ninth resistor is grounded.

[0037] The drain of the second switch is connected to one end of the tenth resistor and the R laser, respectively, and the source of the second switch is grounded.

[0038] The other end of the tenth resistor is connected to one end of the sixth capacitor, and the other end of the sixth capacitor is grounded.

[0039] The G laser switch control unit includes: a third switch transistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fourth diode, and a seventh capacitor;

[0040] One end of the eleventh resistor is connected to the LCOS control module, and the other end of the eleventh resistor is connected to the gate of the third switch.

[0041] The twelfth resistor is connected in series with the fourth diode and then in parallel with the eleventh resistor;

[0042] One end of the thirteenth resistor is connected to the gate of the third switch, and the other end of the thirteenth resistor is grounded.

[0043] The drain of the third switch is connected to one end of the fourteenth resistor and the R laser, respectively, and the source of the third switch is grounded.

[0044] The other end of the fourteenth resistor is connected to one end of the seventh capacitor, and the other end of the seventh capacitor is grounded.

[0045] The B laser switch control unit includes: a fourth switch transistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a fifth diode, and an eighth capacitor;

[0046] One end of the fifteenth resistor is connected to the LCOS control module, and the other end of the fifteenth resistor is connected to the gate of the fourth switch.

[0047] The sixteenth resistor is connected in series with the fifth diode, and then in parallel with the fifteenth resistor;

[0048] One end of the sixteenth resistor is connected to the gate of the fourth switch, and the other end of the sixteenth resistor is grounded.

[0049] The drain of the fourth switch is connected to one end of the eighteenth resistor and the R laser, respectively, and the source of the fourth switch is grounded.

[0050] The other end of the eighteenth resistor is connected to one end of the eighth capacitor, and the other end of the eighth capacitor is grounded.

[0051] In a further embodiment of this invention, the second switch, the third switch, and the fourth switch are NMOS transistors.

[0052] In a further embodiment of this invention, the main control module is a microcontroller.

[0053] Secondly, this utility model also provides an AR glasses, which includes an RGB laser and an AR glasses laser driving circuit as described above, wherein the AR glasses laser driving circuit is connected to the RGB laser.

[0054] This invention provides an AR glasses laser driving circuit and AR glasses. The AR glasses laser driving circuit includes a power supply module, a main control module, an LCOS control module, and a driving module. The power supply module supplies power to the main control module, the LCOS control module, and the driving module. The LCOS control module outputs a switch enable signal to control the RGB laser to turn on or off, and inputs the switch enable signal to the main control module. The main control module outputs a pulse width modulation signal with a corresponding duty cycle to the driving module according to the input switch enable signal to adjust the output current of the driving module. The driving module drives an R, G, or B laser to turn on according to the pulse width modulation signal output by the main control module. This invention controls the R, G, and B lasers to turn on or off respectively by outputting a switch enable signal from the LCOS control module, and the corresponding switch enable signal is fed back to the main control module. The main control module can then output a pulse width modulation signal with a corresponding duty cycle to the driving module according to the corresponding switch enable signal to adjust the output current of the driving module, thereby achieving the purpose of current regulation of the RGB laser. Compared with the DC-DC constant voltage design, this invention is not only cheaper but also smaller in size, allowing AR glasses to be made more compact. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0056] Figure 1 This is a circuit diagram illustrating the principle of the laser driving circuit for AR glasses in this invention.

[0057] Figure 2 This is a timing configuration diagram of the laser driving circuit for AR glasses in one embodiment of this utility model.

[0058] Figure 3 This is a schematic diagram of the working process of the laser driving circuit for AR glasses in one embodiment of the present invention.

[0059] Figure 4This is a circuit diagram of the driving module and the RGB laser in one embodiment of the present invention.

[0060] Figure 5 This is a voltage and current simulation diagram of the R laser in one embodiment of this utility model.

[0061] The labels in the attached diagram are as follows: 100, power supply module; 200, main control module; 300, LCOS control module; 400, drive module; 410, drive control unit; 411, fast power-on and power-off circuit; 420, R laser switch control unit; 430, G laser switch control unit; 440, B laser switch control unit; 500, RGB laser. Detailed Implementation

[0062] This utility model provides a laser driving circuit for AR glasses and AR glasses. To make the purpose, technical solution, and effects of this utility model clearer and more explicit, the following describes this utility model in further detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of this utility model and are not intended to limit this utility model.

[0063] In the implementation methods and claims, unless otherwise specified in the text, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of this utility model involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0064] It should be further understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when an element is referred to as "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements present. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any of the units and all combinations thereof of one or more associatedly listed items.

[0065] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0066] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0067] The inventors discovered that due to the significant voltage difference between RGB lasers in the laser power supply design, existing laser driver designs typically employ dedicated integrated chips or multiple DC-DC converters to drive the lasers. The advantage of these solutions is the ability to control the current amplitude of each laser channel; however, they are costly and complex to debug. Because multiple DC-DC converters of the same type are needed to control the current, the layout and wiring area are large, resulting in a larger design size, which is detrimental to the miniaturization of AR glasses.

[0068] To address the aforementioned technical problems, this invention provides a laser driving circuit for AR glasses and AR glasses themselves. An LCOS control module controls the R, G, and B lasers to light up or turn off respectively via output switch enable signals. The corresponding switch enable signals are fed back to the main control module, which then outputs pulse width modulation signals with corresponding duty cycles to the driving module to regulate the output current of the driving module, thereby achieving current regulation of the RGB lasers. Compared to the DC-DC constant voltage design and dedicated integrated chip design, this invention is not only lower in cost but also smaller in size, enabling more miniaturized AR glasses.

[0069] Please also refer to Figures 1 to 5 This utility model provides a preferred embodiment of a laser driving circuit for AR glasses.

[0070] In some embodiments, such as Figure 1As shown, this utility model provides a laser driving circuit for AR glasses, used to drive an RGB laser 500. The AR glasses laser driving circuit includes: a power module 100, a main control module 200, an LCOS control module 300, and a drive module 400; the power module 100 is connected to the main control module 200, the LCOS control module 300, and the drive module 400 respectively, and the power module 100 is used to supply power to the main control module 200, the LCOS control module 300, and the drive module 400; the LCOS control module 300... The 0 is connected to the main control module 200 and is used to output a switch enable signal to control the RGB laser 500 to light up or turn off, and to input the switch enable signal to the main control module 200; the main control module 200 is connected to the drive module 400 and is used to output a pulse width modulation signal with a corresponding duty cycle to the drive module 400 according to the input switch enable signal to adjust the output current of the drive module 400; the drive module 400 is used to drive the R laser, G laser or B laser to light up according to the pulse width modulation signal output by the main control module 200.

[0071] In this embodiment, please refer to Figure 4 The RGB laser 500 internally encapsulates three lasers: an R laser, a G laser, and a B laser. The RGB laser 500 features a common anode input architecture, with RGB representing red, green, and blue lasers respectively. In this embodiment, the RGB laser 500 uses an Osram Vegalas laser, which has an overall size of only 0.7 cubic centimeters. The power module 100 can provide 12V, 3.3V, and 1.8V power supply voltages. The 12V powers the driver module 400, the 3.3V powers the main control module 200, and the 1.8V powers the LCOS control module 300. The LCOS control module 300 and the driver module 400 can output three switch enable signals to control whether the R, G, and B lasers are lit. Meanwhile, in order to control the current output of a single laser in a specific time sequence, the LCOS control module 300 is connected to the main control module 200 and can feed back the switch enable signals of each laser to the main control module 200. In this way, the main control module 200 can output pulse width modulation signals with corresponding duty cycles to the drive module 400 to regulate the current output of the drive module 400, thereby realizing the time-division multiplexing of three pulse width modulation signals with different duty cycles, achieving the purpose of current regulation of the RGB laser 500.

[0072] In some embodiments, the main control module 200 adopts a microcontroller, such as a GD32 microcontroller. The microcontroller has three switch enable signal receiving ports and one PWM signal output port. The three signal receiving ports are PA2, PA3, and PA4, respectively. The three switch enable signals can receive three switch enable signals respectively. Among them, the PA4 port receives the switch enable signal of the R laser, the PA2 port receives the switch enable signal of the G laser, and the PA3 port receives the switch enable signal of the B laser. The port that receives the switch enable signal will notify the microcontroller's PWM signal output port PB15 to output a pulse width modulation signal with a configured current duty cycle to the drive module 400, and the drive module 400 drives the R laser, G laser, or B laser to light up.

[0073] In some embodiments, the LCOS control module 300 may employ an RDC200A main control chip, which has image conversion and duty cycle modulation functions. Image conversion refers to the RDC200A main control chip's ability to convert MIPI signals into LVDS signals, and simultaneously flip and translate the input image horizontally or vertically to meet different resolution requirements within a certain range. Duty cycle modulation refers to the RDC200A main control chip's integrated 8051 MCU chip, which has a duty cycle PWM output interface. The RGB duty cycle can be configured by configuring the MCU register values.

[0074] like Figure 2 As shown, Figure 2 The first graph shows the timing configuration of the laser driver circuit for AR glasses. The first graph is the timing diagram for the single-channel PWM control of the main controller. The horizontal axis represents the difference in PWM duty cycle at different times, and the vertical axis represents the equivalent RGB current at the corresponding duty cycle. The graph shows that the current amplitude is 186mA when the R channel is on, and 200mA and 170mA for the G and B channels, respectively. The second graph shows the control timing of the selected LCOS main control chip RDC200A. The LCOS main control chip RDC200A can switch between RGB lasers, and the microcontroller can output the corresponding PWM signal for the RGB lasers, thus achieving RGB three-color sequential lighting output. Figure 2In the process, when the enable signal of the switch connected to the RGB laser 500 is high (1.8V), the red laser lights up for 2.0ms, with an interval of 0.9ms waiting for the G laser to light up. After G lights up for 2.3ms, there is a 0.6ms wait before the B laser lights up for 1.3ms. The entire cycle is about 15.2ms, which is about 66Hz per second. In this way, the laser timing output frequency can ensure a driving cycle of about 60Hz per second, so that the imaging quality can meet the requirements. The entire laser timing sequence is R→G→B→B→G→R.

[0075] like Figure 2 As shown, due to the timing of the corresponding channel being lit, there is a blackout period (the actual on time of the three RGB channels does not completely occupy the entire cycle time; the blackout period interval is due to the switching response time of the circuit itself and the time delay of the LCD panel flipping). During this time, there is no switch enable signal, and the output can be maintained in the previous state through software configuration. It should be noted that outside the interval, although the PWM signal continues to output the previous segment, the laser will not be lit because the switch enable signal has been turned off.

[0076] In specific implementation, please combine Figure 3 First, the main control module 200 and the LCOS control module 300 undergo main control initialization. This initialization process includes configuring the RGB duty cycle output, configuring the input signal LCDS or MIPI of the RDC200A main control chip, and setting the screen power timing. After initialization, the RDC200A main control chip outputs the RGB switching timing. Since the switch enable signal is synchronously connected to the corresponding configuration interface of the microcontroller, when the switch enable signal receiving port receives the switch enable signal, the three different switch enable signal receiving ports will identify the synchronization signal, i.e., identify whether a switch enable signal is connected. The port that receives the switch enable signal will notify the corresponding PWM signal output port of the microcontroller to output the PWM signal with the initialized current duty cycle, thereby modulating the current of the drive module 400. Because a single PWM output port is used, the corresponding laser will be lit within the interval time, thus achieving RGBBGR timing laser control. Outside the interval time, although the PWM signal continues to output the previous segment, the laser will not be lit because the enable signal is turned off.

[0077] In the above technical solution, this invention uses the LCOS control module 300 to output switch enable signals to control the R, G, and B lasers to light up or turn off respectively. The corresponding switch enable signals are fed back to the main control module 200, which then outputs pulse width modulation signals with corresponding duty cycles to the drive module 400 to regulate the output current of the drive module 400, thereby achieving the purpose of current regulation of the RGB laser 500. Compared with the DC-DC constant voltage design or dedicated integrated chip design, this invention is not only lower in cost but also smaller in size, allowing for more miniaturized AR glasses.

[0078] In some embodiments, please refer to Figure 1 and Figure 4 The drive module 400 includes: a drive control unit 410, an R laser switch control unit 420, a G laser switch control unit 430, and a B laser switch control unit 440; the drive control unit 410 is connected to the power module 100, the main control module 200, and the R, G, and B lasers respectively; the R laser switch control unit 420 is connected to the LCOS control module 300 and the R laser respectively; the G laser switch control unit 430 is connected to the LCOS control module 300 and the G laser respectively; and the B laser switch control unit 440 is connected to the LCOS control module 300 and the B laser respectively.

[0079] In this embodiment, the drive control unit 410 is connected to the RGB laser 500 and drives the RGB laser 500 to light up according to the PWM signal output by the main control module 200. The R laser switch control unit 420 is connected between the LCOS control module 300 and the R laser, the G laser switch control unit 430 is connected between the LCOS control module 300 and the G laser, and the B laser switch control unit 440 is connected between the LCOS control module 300 and the B laser. The LCOS control module 300 outputs switch enable signals to the R laser switch control unit 420, the G laser switch control unit 430, and the B laser switch control unit 440 to switch the R laser, G laser, and B laser, and the switch enable signals can be synchronously input to the main control module 200.

[0080] In some embodiments, please refer to Figure 4The drive control unit 410 includes: a drive chip U1, a first resistor R1, a first switch Q1, a first diode D1, a first inductor L1, a fast power-on and discharge circuit 411, a second resistor R2, a third resistor R3, a first capacitor C1, and a second capacitor C2; one end of the first resistor R1 is connected to the power module 100, and the other end of the first resistor R1 is connected to the source of the first switch Q1; the gate of the first switch Q1 is connected to the output pin of the drive chip U1 via the fast power-on and discharge circuit 411, and the drain of the first switch Q1 is connected to the first diode D1. The anode of the first diode D1 is connected to one end of the first inductor L1; the cathode of the first diode D1 is grounded; the other end of the first inductor L1 is connected to one end of the first capacitor C1 and the RGB laser 500; the other end of the first capacitor C1 is grounded; one end of the second resistor R2 is connected to the main control module 200, and the other end of the second resistor R2 is connected to the enable pin of the driver chip U1 and one end of the third resistor R3; the other end of the third resistor R3 is grounded; one end of the second capacitor C2 is connected to the enable pin of the driver chip U1, and the other end of the second capacitor C2 is grounded.

[0081] In this embodiment, a driver chip U1 is used to control the current of the RGB laser 500. The first resistor R1 is an output current-limiting resistor, which determines the magnitude of the output current. The first switch Q1 is a PMOS transistor, and the first diode D1 is a freewheeling diode. The first switch Q1, the first inductor L1, and the first diode D1 form an external step-down circuit, enabling the 12V input to the driver chip U1 to output the required laser current voltage at a certain frequency. The first capacitor C1 is an output capacitor. Because the driver chip U1 has an internal constant current output structure, the filter capacitor is extremely small; the first capacitor C1 only needs to be 0.1uF. In one implementation, the driver chip U1 can be an LM3409 driver chip.

[0082] The second resistor R2 and the third resistor R3 are voltage divider resistors. The common terminal of the second resistor R2 and the third resistor R3 is connected to the enable terminal EN of the driver chip U1. The PWM signal output by the main control module 200 is input to the enable terminal EN of the driver chip via the second resistor R2. The second resistor R2 has a pulse suppression function. The second capacitor C2 is a filter capacitor. When the voltage at the enable terminal EN of the driver chip U1 is greater than 1.74V, the output terminal PGATE of the driver chip U1 has an output. The fast power-on and power-off circuit 411 is connected between the first switch Q1 and the output terminal PGATE of the driver chip U1, enabling the first switch Q1 to be quickly powered on when turned on and quickly powered off when turned off.

[0083] In some embodiments, please refer to Figure 4 The driving module 400 further includes: a first magnetic bead FB1, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5; one end of the first magnetic bead FB1 is connected to the power module 100, and the other end of the first magnetic bead FB1 is connected to one end of the third capacitor C3; the other end of the third capacitor C3 is grounded; one end of the fourth capacitor C4 is connected to one end of the third capacitor C3, and the other end of the fourth capacitor C4 is grounded; one end of the fifth capacitor C5 is connected to one end of the fourth capacitor C4, and the other end of the fifth capacitor C5 is grounded.

[0084] In this embodiment, the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 are filter capacitors for a 12V input voltage. The first ferrite bead FB1, connected to a 12V input voltage, can suppress high-frequency noise and spike interference on the power line and can also absorb electrostatic pulses.

[0085] In some embodiments, please refer to Figure 4 A second ferrite bead FB2 is also connected between the RGB laser 500 and the output of the drive control unit 410, which can suppress high-frequency noise and spike interference on the output power line of the drive control unit 410.

[0086] In some embodiments, please refer to Figure 4The fast power-on and power-off circuit 411 includes: a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a second diode D2; one end of the fourth resistor R4 is connected to the source of the first switching transistor Q1, and the other end of the fourth resistor R4 is connected to one end of the fifth resistor R5; the other end of the fifth resistor R5 is connected to the cathode of the second diode D2, and the anode of the second diode D2 is connected to the output pin of the driver chip U1; one end of the sixth resistor R6 is connected to the common terminal of the fourth resistor R4 and the fifth resistor R5 and the gate of the first switching transistor Q1, and the other end of the sixth resistor R6 is connected to the output pin of the driver chip U1 and the anode of the second diode D2.

[0087] In this embodiment, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6 and the second diode D2 constitute the fast power-on and discharge circuit 411 of the first switch Q1. When the first switch Q1 is turned on, the first switch Q1 can be powered on quickly, and when the first switch Q1 is turned off, the first switch Q1 can be powered off quickly.

[0088] In some embodiments, please refer to Figure 4 The R laser switch control unit 420 includes: a second switch Q2, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a third diode D3, and a sixth capacitor C6; one end of the seventh resistor R7 is connected to the LCOS control module 300, and the other end of the seventh resistor R7 is connected to the gate of the second switch Q2; the eighth resistor R8 is connected in series with the third diode D3 and then in parallel with the seventh resistor R7; one end of the ninth resistor R9 is connected to the gate of the second switch Q2, and the other end of the ninth resistor R9 is grounded; the drain of the second switch Q2 is connected to one end of the tenth resistor R10 and the R laser, and the source of the second switch Q2 is grounded; the other end of the tenth resistor R10 is connected to one end of the sixth capacitor C6, and the other end of the sixth capacitor C6 is grounded.

[0089] The G laser switch control unit 430 includes: a third switch Q3, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fourth diode D4, and a seventh capacitor C7; one end of the eleventh resistor R11 is connected to the LCOS control module 300, and the other end of the eleventh resistor R11 is connected to the gate of the third switch Q3; the twelfth resistor R12 is connected in series with the fourth diode D4 and then in parallel with the eleventh resistor R11; one end of the thirteenth resistor R13 is connected to the gate of the third switch Q3, and the other end of the thirteenth resistor R13 is grounded; the drain of the third switch Q3 is connected to one end of the fourteenth resistor R14 and the R laser, and the source of the third switch Q3 is grounded; the other end of the fourteenth resistor R14 is connected to one end of the seventh capacitor C7, and the other end of the seventh capacitor C7 is grounded.

[0090] The B laser switch control unit 440 includes: a fourth switch Q4, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a fifth diode D5, and an eighth capacitor C8; one end of the fifteenth resistor R15 is connected to the LCOS control module 300, and the other end of the fifteenth resistor R15 is connected to the gate of the fourth switch Q4; the sixteenth resistor R16 is connected in series with the fifth diode D5 and then in parallel with the fifteenth resistor R15; one end of the sixteenth resistor R16 is connected to the gate of the fourth switch Q4, and the other end of the sixteenth resistor R16 is grounded; the drain of the fourth switch Q4 is connected to one end of the eighteenth resistor R18 and the R laser, and the source of the fourth switch Q4 is grounded; the other end of the eighteenth resistor R18 is connected to one end of the eighth capacitor C8, and the other end of the eighth capacitor C8 is grounded.

[0091] In this embodiment, the second switch Q2, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, the third diode D3, and the sixth capacitor C6 constitute the switching circuit of the R laser. The second switch Q2 is an NMOS transistor. When the seventh resistor R7 is connected to the switch enable signal output by the LCOS control module 300, the second switch Q2 is turned on, and the source and drain of the second switch Q2 are connected. At the same time, the switch enable signal is fed back to the main control module 200. The main control module 200 outputs a corresponding PWM signal to the drive control unit 410. The drive control unit 410 outputs a voltage VOUT to the R laser. Because the source of the second switch Q2 is grounded and the drain of the second switch Q2 is connected to the R laser, the voltage VOUT output by the drive control unit 410 to the R laser is connected to ground, thus illuminating the R laser. The third diode D3 is a Zener diode. The seventh resistor R7, the eighth resistor R8 and the third diode D3 form a voltage regulator circuit, which can provide a stable driving voltage for the second switch Q2. The tenth resistor R10 and the sixth capacitor C6 are used to discharge when the second switch Q2 is turned off.

[0092] The working principle of the G laser switch control unit 430 and the B laser switch control unit 440 is the same as that of the R laser switch control unit 420, and will not be described again here.

[0093] This invention utilizes the LM3409 to design the laser current, employing only a single driver chip with an external transistor circuit to control the current of the RGB laser 500. Simultaneously, combined with the three timing feedback signals from the LCOS control module 300, the main control module 200 can output three different duty cycle signals in a time-division multiplexing manner, achieving the purpose of RGB current regulation. This invention simplifies circuit design, makes debugging more convenient, allows for a more compact layout, and significantly reduces costs compared to integrated chips and DC-DC designs. This is highly beneficial for laser driver design used in miniaturized AR glasses.

[0094] like Figure 5 As shown, Figure 5 This is a voltage and current simulation diagram of the R laser in one embodiment of the present invention. After the RC parameters are configured, the output simulation diagram obtained from the simulation schematic is as follows. Figure 5 As shown, the simulation diagram represents the voltage and current waveforms of the red laser. The input voltage VIN is 12V, the output voltage VOUT is approximately 3.1V, and the output current I is approximately 190mA, which meets the specifications of the selected laser and also satisfies the optical flux requirements. After verification, this invention can achieve good laser driving effect.

[0095] In some embodiments, the present invention also provides AR glasses, which include an RGB laser and an AR glasses laser driving circuit as described above, wherein the AR glasses laser driving circuit is connected to the RGB laser. Specific details are provided in the embodiment of an AR glasses laser driving circuit, and will not be repeated here.

[0096] In summary, the AR glasses laser driving circuit and AR glasses provided by this utility model have the following beneficial effects:

[0097] The LCOS control module controls the R, G, and B lasers to turn on or off individually via output switch enable signals. These enable signals are fed back to the main control module, which then outputs pulse width modulation (PWM) signals with corresponding duty cycles to the driver module to regulate its output current, thus achieving current control of the RGB lasers. Compared to using a DC-DC constant voltage design and dedicated integrated chip design, this approach is not only more cost-effective but also smaller in size, allowing for more miniaturized AR glasses.

[0098] It should be understood that the application of this utility model is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A laser driving circuit for AR glasses, used to drive an RGB laser, characterized in that, The laser driving circuit for AR glasses includes: a power module, a main control module, an LCOS control module, and a driving module; The power module is connected to the main control module, the LCOS control module and the drive module respectively, and the power module is used to supply power to the main control module, the LCOS control module and the drive module; The LCOS control module is connected to the main control module and is used to output a switch enable signal to control the RGB laser to turn on or off, and to input the switch enable signal to the main control module. The main control module is connected to the drive module and is used to output a pulse width modulation signal with a corresponding duty cycle to the drive module according to the input switch enable signal in order to adjust the output current of the drive module. The driving module is used to drive the R laser, G laser or B laser to light up according to the pulse width modulation signal output by the main control module.

2. The AR glasses laser driving circuit according to claim 1, characterized in that, The drive module includes: a drive control unit, an R laser switch control unit, a G laser switch control unit, and a B laser switch control unit; The drive control unit is connected to the power module, the main control module, and the R laser, G laser, and B laser, respectively. The R laser switch control unit is connected to the LCOS control module and the R laser respectively; The G laser switch control unit is connected to the LCOS control module and the G laser respectively; The B laser switch control unit is connected to both the LCOS control module and the B laser.

3. The AR glasses laser driving circuit according to claim 2, characterized in that, The drive control unit includes: a drive chip, a first resistor, a first switching transistor, a first diode, a first inductor, a fast power-on and discharge circuit, a second resistor, a third resistor, a first capacitor, and a second capacitor; One end of the first resistor is connected to the power module, and the other end of the first resistor is connected to the source of the first switching transistor. The gate of the first switching transistor is connected to the output pin of the driver chip via the fast power-on and discharge circuit, and the drain of the first switching transistor is connected to the anode of the first diode and one end of the first inductor. The cathode of the first diode is grounded; The other end of the first inductor is connected to one end of the first capacitor and the RGB laser; The other end of the first capacitor is grounded; One end of the second resistor is connected to the main control module, and the other end of the second resistor is connected to the enable pin of the driver chip and one end of the third resistor; The other end of the third resistor is grounded; One end of the second capacitor is connected to the enable pin of the driver chip, and the other end of the second capacitor is grounded.

4. The AR glasses laser driving circuit according to claim 2, characterized in that, The driving module also includes: a first magnetic bead, a third capacitor, a fourth capacitor, and a fifth capacitor; One end of the first magnetic bead is connected to the power module, and the other end of the first magnetic bead is connected to one end of the third capacitor. The other end of the third capacitor is grounded, one end of the fourth capacitor is connected to one end of the third capacitor, and the other end of the fourth capacitor is grounded. One end of the fifth capacitor is connected to one end of the fourth capacitor, and the other end of the fifth capacitor is grounded.

5. The AR glasses laser driving circuit according to claim 3, characterized in that, The rapid power-on and power-off circuit includes: a fourth resistor, a fifth resistor, a sixth resistor, and a second diode; One end of the fourth resistor is connected to the source of the first switching transistor, and the other end of the fourth resistor is connected to one end of the fifth resistor. The other end of the fifth resistor is connected to the cathode of the second diode, and the anode of the second diode is connected to the output pin of the driver chip. One end of the sixth resistor is connected to the common terminal of the fourth and fifth resistors and the gate of the first switching transistor, and the other end of the sixth resistor is connected to the enable pin of the driver chip and the anode of the second diode.

6. The AR glasses laser driving circuit according to claim 3, characterized in that, The first switching transistor is a PMOS transistor.

7. The AR glasses laser driving circuit according to claim 2, characterized in that, The R laser switch control unit includes: a second switch transistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a third diode, and a sixth capacitor; One end of the seventh resistor is connected to the LCOS control module, and the other end of the seventh resistor is connected to the gate of the second switching transistor. The eighth resistor is connected in series with the third diode and then in parallel with the seventh resistor; One end of the ninth resistor is connected to the gate of the second switch, and the other end of the ninth resistor is grounded. The drain of the second switch is connected to one end of the tenth resistor and the R laser, respectively, and the source of the second switch is grounded. The other end of the tenth resistor is connected to one end of the sixth capacitor, and the other end of the sixth capacitor is grounded. The G laser switch control unit includes: a third switch transistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fourth diode, and a seventh capacitor; One end of the eleventh resistor is connected to the LCOS control module, and the other end of the eleventh resistor is connected to the gate of the third switch. The twelfth resistor is connected in series with the fourth diode and then in parallel with the eleventh resistor; One end of the thirteenth resistor is connected to the gate of the third switch, and the other end of the thirteenth resistor is grounded. The drain of the third switch is connected to one end of the fourteenth resistor and the R laser, respectively, and the source of the third switch is grounded. The other end of the fourteenth resistor is connected to one end of the seventh capacitor, and the other end of the seventh capacitor is grounded. The B laser switch control unit includes: a fourth switch transistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a fifth diode, and an eighth capacitor; One end of the fifteenth resistor is connected to the LCOS control module, and the other end of the fifteenth resistor is connected to the gate of the fourth switch. The sixteenth resistor is connected in series with the fifth diode, and then in parallel with the fifteenth resistor; One end of the sixteenth resistor is connected to the gate of the fourth switch, and the other end of the sixteenth resistor is grounded. The drain of the fourth switch is connected to one end of the eighteenth resistor and the R laser, respectively, and the source of the fourth switch is grounded. The other end of the eighteenth resistor is connected to one end of the eighth capacitor, and the other end of the eighth capacitor is grounded.

8. The AR glasses laser driving circuit according to claim 7, characterized in that, The second, third, and fourth switching transistors are NMOS transistors.

9. The AR glasses laser driving circuit according to claim 1, characterized in that, The main control module is a microcontroller.

10. An AR glasses, characterized in that, It includes an RGB laser and an AR glasses laser driving circuit as described in any one of claims 1-9, wherein the AR glasses laser driving circuit is connected to the RGB laser.

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