Laser irradiation apparatus and method for controlling same

Abstract

The present invention is provided with: a light source unit that includes a laser light source that irradiates laser light (L) to a specific irradiation range (E1); a lighting control unit that performs lighting control of the laser light source; and a human body sensing detection unit that detects the presence of a person (H) within an irradiation range (E1) of the laser light L, the human body sensing detection unit including an optical sensor and an acoustic wave sensor, and the lighting control unit performs control to turn off or reduce the light of the laser light source when either the optical sensor or the acoustic wave sensor reacts.

Description

Technical Field

[0001] This invention relates to a laser irradiation device and its control method.

[0002] This application claims priority based on Japanese Patent Application No. 2023-169020, filed on September 29, 2023, the contents of which are incorporated herein by reference. Background Technology

[0003] In recent years, laser light sources such as laser diodes (LDs) that can produce high-brightness and high-output light have been used to obtain illumination light. In addition, the road surface and other objects are drawn while scanning the laser light emitted from the laser source (for example, see Patent Document 1 below).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-122365 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, in bright environments such as daytime, it is necessary to increase the laser output to improve the visual recognizability of the depiction.

[0009] On the other hand, even with increased laser output, to prevent the laser from directly entering the human eye, the laser source can be turned off when a person is detected entering the laser's irradiation range, for example, using a human body sensor. This prevents direct viewing of the laser.

[0010] However, some human body sensors are prone to false detections in bright environments due to the influence of external light, while others experience reduced sensitivity in rainy or windy conditions. On the other hand, human body sensors less affected by external environmental factors (such as TOF, cameras, LiDAR, and millimeter-wave radar) are more expensive, thus increasing costs.

[0011] The present invention provides a laser irradiation device and its control method that can appropriately extinguish or reduce the laser light source when a person enters the irradiation range of the laser.

[0012] Methods for solving problems

[0013] The present invention provides the following means.

[0014] [1] A laser irradiation device, characterized in that it comprises: The light source unit includes a laser light source that irradiates laser light onto a specific irradiation range; The illumination control unit controls the illumination of the laser light source; and A human body detection unit detects the presence of a person within the irradiation range of the laser. The human body sensing detection unit includes an optical sensor and an acoustic sensor. When either the optical sensor or the acoustic sensor reacts, the illumination control unit controls the laser light source to be turned off or its brightness to be reduced.

[0015] [2] According to the laser irradiation device described in [1] above, the human body sensing detection unit stops the detection of the optical sensor when the external illuminance within the irradiation range of the laser exceeds a threshold.

[0016] [3] The laser irradiation device according to [1] above is characterized in that the optical sensor and the acoustic sensor react within the detection range surrounding the irradiation range of the laser.

[0017] [4] The laser irradiation device according to [3] above is characterized in that the optical sensor and the acoustic sensor react within the detection range surrounding the scanning range of the laser.

[0018] [5] The laser irradiation device according to [4] above is characterized in that the acoustic sensor reacts within the detection range surrounding the detection range of the optical sensor.

[0019] [6] The laser irradiation device according to [1] above is characterized in that the optical sensor is an IR sensor and the acoustic sensor is a sonar sensor.

[0020] [7] The laser irradiation device according to [1] above is characterized in that the light source unit includes a MEMS mirror, which scans the laser emitted from the laser light source while drawing within the irradiation range.

[0021] [8] The laser irradiation device according to [1] above is characterized in that the laser irradiation device is mounted on a vehicle. The light source irradiates the road surface with laser light emitted from the laser source.

[0022] [9] A control method for a laser irradiation device, characterized in that, The laser irradiation device includes: The light source unit includes a laser light source that irradiates laser light onto a specific irradiation range; The illumination control unit controls the illumination of the laser light source; Optical and acoustic sensors detect the presence of a person within the irradiation range of the laser. External illuminance unit, which detects the surrounding environment; and The driver position detection unit detects whether the driver is inside the vehicle. The control method includes the following steps: The first step is to enable the MEMS mirror driver. The second step is to detect whether the external illuminance exceeds the threshold. In the third step, when either the optical sensor or the acoustic sensor reacts, the illumination control unit turns off or reduces the light of the laser source to stop road surface drawing. The fourth step is to check if the driver is inside the vehicle; and The fifth step is to shut down the MEMS mirror's drive after detecting that the driver is inside the vehicle.

[0023]

[10] The control method of the laser irradiation device according to [9] above is characterized in that, in the third step, when the external illuminance within the irradiation range of the laser exceeds a threshold, the human body sensing detection unit stops the detection of the optical sensor.

[0024] The effects of the invention

[0025] As described above, according to the present invention, a laser irradiation device and its control method are provided that can appropriately extinguish or reduce the laser light source when a person enters the irradiation range of the laser. Attached Figure Description

[0026] Figure 1 This is a schematic diagram illustrating an example of road surface depiction performed by a laser irradiation device according to an embodiment of the present invention.

[0027] Figure 2 This is a block diagram showing the structure of a laser irradiation device.

[0028] Figure 3 This is a schematic diagram showing the structure of the light source unit in a laser irradiation device.

[0029] Figure 4 This is a schematic diagram showing the illumination and detection range of a laser illumination device installed on the rearview mirror of a vehicle's door, viewed from the side.

[0030] Figure 5 This is a schematic diagram showing the illumination and detection range of a laser illumination device installed on the rearview mirror of a vehicle's door, viewed from above.

[0031] Figure 6 This is a flowchart illustrating the illumination control of the laser source in road surface depiction using a laser irradiation device.

[0032] Figure 7 This is a schematic diagram illustrating a scenario where the detection range of the IR sensor differs from that of the sonar sensor.

[0033] Figure 8 This is a schematic diagram showing the irradiation range and detection range of a laser irradiation device installed on a street lamp. Detailed Implementation

[0034] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0035] Furthermore, in the accompanying drawings used in the following description, the scale of the dimensions is sometimes different depending on the component to facilitate observation of each component, and the size ratios of each component are not necessarily the same as the actual dimensions.

[0036] As one embodiment of the present invention, for example... Figures 1-8 The laser irradiation device 1 shown will be described.

[0037] also, Figure 1 This is a schematic diagram illustrating an example of road surface depiction performed by laser irradiation device 1. Figure 2 This is a block diagram showing the structure of the laser irradiation device 1. Figure 3 This is a schematic diagram showing the structure of the light source unit 4 of the laser irradiation device 1. Figure 4 This is a schematic diagram showing the illumination range E1 and detection range E2 of the laser illumination device 1 installed on the rearview mirror 101 of the vehicle door 100, viewed from the side. Figure 5 This is a schematic diagram showing the illumination range E1 and detection range E2 of the laser illumination device 1 installed on the rearview mirror 101 of the vehicle door, viewed from above. Figure 6 This is a flowchart illustrating the illumination control of the laser source 2 in road surface drawing performed by the laser irradiation device 1. Figure 7 This is a schematic diagram showing the case where the detection range E3 of IR sensor 5 is different from the detection range E4 of sonar sensor 6. Figure 8 This is a schematic diagram showing the illumination range E1 and detection range E2 of the laser irradiation device 1 installed in the street lamp 200.

[0038] In addition, in the following figures, an XYZ orthogonal coordinate system is set, with the X-axis direction representing the front-to-back direction (length direction) of the vehicle 100, the Y-axis direction representing the left-to-right direction (width direction) of the vehicle 100, and the Z-axis direction representing the up-down direction (height direction) of the vehicle 100.

[0039] The laser irradiation device 1 in this embodiment is, for example, as shown in the example... Figure 1The diagram shows the structure of a vehicle drawing device that applies the present invention to a door rearview mirror 101 of a vehicle 100. Specifically, the laser irradiation device 1 uses a laser L that irradiates the road surface T to the side of the vehicle when the vehicle is stationary to project a road surface drawing pattern P, such as text or an image.

[0040] Specifically, such as Figure 1 , Figure 2 as well as Figure 3 As shown, the laser irradiation device 1 includes: a light source unit 4 comprising a laser light source 2 and a MEMS (Micro-Electro-Mechanical Systems) mirror 3; a human body detection unit 7 comprising an IR sensor 5 and a sonar sensor 6; and a lighting control unit 8 electrically connected to the light source unit 4 and the human body detection unit 7.

[0041] The laser source 2 is, for example, composed of an LD package, which includes a red LD chip that emits red light, a green LD chip that emits green light, and a blue LD chip that emits blue light. In addition, the LD package includes, for example, a first dichroic mirror that reflects blue light, a second dichroic mirror that reflects green light and allows blue light to pass through, and a third dichroic mirror that reflects both blue and green light and allows red light to pass through, emitting light of each color coaxially.

[0042] Therefore, in the laser source 2, the proportions of red, green, and blue light emitted by each LD chip in the LD package can be controlled while the hue (emission color) of the laser L obtained by the synthesis (color mixing) of these colored lights can be arbitrarily adjusted.

[0043] MEMS mirror 3 is a movable reflector using MEMS technology, which swings in a two-dimensional direction within the plane to control the reflection direction of the laser L emitted from the laser source 2.

[0044] In the light source unit 4, while scanning the laser L emitted from the laser source 2 using the MEMS mirror 3, the laser L is also irradiated onto the road surface T on the side of the vehicle from the rearview mirror 101 of the vehicle door. As a result, road surface mapping can be performed within the irradiation range of the laser L.

[0045] The IR sensor 5 is an optical sensor that functions as a human body sensor that detects infrared (IR) radiation based on the heat and reflected light emitted by a person. Examples of IR sensors 6 include thermoelectric IR sensors and infrared reflective sensors that combine infrared LEDs and photodiodes.

[0046] The sonar sensor 6 is a type of acoustic wave sensor that functions as a human body sensing sensor that transmits ultrasonic waves and detects ultrasonic waves reflected when they are irradiated by a person.

[0047] In the human body sensing detection unit 7, such as Figure 4 and Figure 5 As shown, within the detection range E2 of the irradiation range E1 surrounding the laser L, the IR sensor 5 and the sonar sensor 6 react, thereby enabling the detection of the presence of human H within the irradiation range E1 of the laser L.

[0048] In addition, the IR sensor 5 and the sonar sensor 6 serve as human body sensing sensors, primarily detecting people H who enter the irradiation range E1 of the laser L, but can also detect animals other than pets H. In particular, children, dogs, cats, etc., whose height is lower than the rearview mirror 101 of the car door may look directly at the laser L.

[0049] The lighting control unit 8 is composed of a microcomputer such as a CPU, which controls the switching of the laser light source 2 on and off.

[0050] Furthermore, in addition to switching the laser light source 2 on / off, the illumination control unit 8 can also control the amount of light emitted from the laser light source 2 and the grayscale of the color tone. For example, the illumination control unit 8 can also perform grayscale control (light reduction) to reduce the amount of light emitted from the laser light source 2 to achieve a brightness that is safe for the human eye.

[0051] Additionally, the illumination control unit 8 is electrically connected to the illuminance sensor 50 mounted on the vehicle 100. The illuminance sensor 50 detects the external illuminance (brightness) outside the vehicle, and if the external illuminance exceeds a threshold, it supplies the detected signal to the illumination control unit 8.

[0052] Since higher external light intensity makes it easier for IR sensor 5 to make false detections, the threshold is set to an external light intensity value that is suitable for IR sensor 5 to function as a human body sensing sensor (e.g., above 30,000 Lux in foggy conditions, above 70,000 Lux in sunny conditions, etc.).

[0053] Furthermore, the illuminance sensor 50 is not necessarily limited to a structure mounted on the vehicle 100; for example, it could also be mounted on the laser irradiation device 1.

[0054] Alternatively, in the laser irradiation device 1 of this embodiment, instead of the illuminance sensor 50 described above, the signal may be supplied to the illumination control unit 8 when it is determined that the external illuminance exceeds a threshold based on the external illuminance information supplied via the communication unit mounted on the vehicle 100.

[0055] Regarding external illuminance information, for example, it can be determined that the external illuminance exceeds a threshold based on the vehicle 100's location information and the weather information at that location. Alternatively, if it is determined that the sensitivity of the IR sensor 5 has decreased, the signal can be supplied to the illumination control unit 8.

[0056] In the laser irradiation device 1 of this embodiment, when performing road surface drawing, for example according to Figure 6 The flowchart shown illustrates the initial actions performed before starting road surface mapping.

[0057] Specifically, such as Figure 6 As shown in step S101, the system detects whether the key lock on vehicle 100 has been released or whether the driver has approached vehicle 100.

[0058] Next, as Figure 6 As shown in step S102, the power supply to the illuminance sensor 50, IR sensor 5, and sonar sensor 6, which are performing the sensing, is turned on. In this step S102, the processing of the signals detected by each sensor does not yet begin.

[0059] As another sensing method, the power supply to a driver position detection unit (not shown) capable of detecting the driver's presence within the vehicle 100 can also be turned on. The driver position detection unit can also perform detection using any one or more combinations of a door contact sensor that detects the opening and closing of the door on the driver's side, an engine start sensor that detects engine start, and sensors (thermal sensing, pressure sensing, etc.) that detect a person sitting in the driver's seat.

[0060] Next, as Figure 6 As shown in step S103, in the light source unit 4, the driving of the MEMS mirror 3 is started (ON), and in the state of the laser light source 2 being turned off (OFF), it becomes a state in which scanning by the MEMS mirror 3 can begin.

[0061] The MEMS mirror 3 is activated in advance because illumination preparation takes time, but if it were an instantaneous start-up, it could be done as described later. Figure 6 After step S201.

[0062] In the lighting control unit 8, such as Figure 6 As shown in step S201, a determination is made as to whether the external illuminance is below the threshold.

[0063] Then, if it is determined that the external illuminance exceeds the threshold (no), proceed to... Figure 6 In step S205, in the human body sensing detection unit 7, the detection of the IR sensor 5 is stopped (OFF), and the detection of the sonar sensor 6 is continued (ON).

[0064] Specifically, starting the reception of the detection signal of sonar sensor 6 is turned on (ON). Stopping the detection of IR sensor 5 means that while the power supply to IR sensor 5 is on, only the reception of the detection signal is turned off.

[0065] Alternatively, the power supply to IR sensor 5 can be disconnected. If the external illuminance in the loop falls below the threshold again, the power supply to IR sensor 5 can be turned on again.

[0066] Then, after sonar sensor 6 reacted, it entered... Figure 6 In step S203, if it is determined that person H exists within the detection range E2 of the human body sensing detection unit 7, road surface drawing will not start while the laser light source 2 is turned off (OFF) (the drive of MEMS mirror 3 remains on).

[0067] On the other hand, Figure 6 In step S205, if it is determined that there is no response from either the sonar sensor 6 (No), proceed to... Figure 6 In step S206, if it is determined that there is no human H within the detection range E2 of the human body sensing detection unit 7, the laser source 2 is turned on, and the laser L of the laser source 2 is scanned by the MEMS mirror 3, thereby starting the road surface drawing.

[0068] On the other hand, if it is determined that the external illuminance is below the threshold (yes), then proceed... Figure 6 In step S202, the detection of IR sensor 5 and sonar sensor 6 is started in human body sensing detection unit 7 (both are connected). Specifically, the reception of detection signals from both sonar sensor 6 and IR sensor 5 is enabled.

[0069] Next, as Figure 6 As shown in step S202, a determination is made as to whether either the IR sensor 5 or the sonar sensor 6 has a response.

[0070] Then, if it is determined that either the IR sensor 5 or the sonar sensor 6 has reacted ("yes"), proceed to... Figure 6 In step S203, the illumination control unit 8 controls the laser light source 2 to turn off (OFF) and stop road surface drawing (the drive of the MEMS mirror 3 remains on).

[0071] That is, if either the IR sensor 5 or the sonar sensor 6 reacts, it is determined that a person H is present in the detection range E2 of the human body sensing detection unit 7, and the laser light source 2 is turned off, and road surface mapping is stopped (the drive of the MEMS mirror 3 remains on).

[0072] On the other hand, Figure 6 In step S202, if it is determined that there is no response from either the sonar sensor 6 (No), proceed to... Figure 6 In step S204, if it is determined that there is no human H within the detection range E2 of the human body sensing detection unit 7, the laser source 2 is turned on, and the laser L of the laser source 2 is scanned by the MEMS mirror 3, thereby starting the road surface drawing.

[0073] Then, return to step S201 above and repeat steps S201 to S206 until the driver approaches the vehicle 100 and enters the detection range E2 of the human body sensing detection unit 7.

[0074] Next, as Figure 6 As shown in step S207, when the driver reacts to the human body detection unit, approaches the vehicle, and the system detects that the driver is inside the vehicle, road surface mapping is not required. Therefore, as... Figure 6 As shown in step S208, the drive of MEMS mirror 3 is also turned off. Since illumination preparation takes time, MEMS mirror 3 is preferably not turned off until road surface mapping is no longer needed.

[0075] On the other hand, in the case of instantaneous startup, the drive of the MEMS mirror 3 can be turned off immediately after road mapping stops. The driver position detection unit detects whether a driver is inside the vehicle 100. Furthermore, as... Figure 6 As shown in step S209, the sensor power supply is also disconnected, ending the process of this embodiment.

[0076] As described above, in the laser irradiation device 1 of this embodiment, during the road surface drawing process, when either the IR sensor 5 or the sonar sensor 6 reacts, the illumination control unit 8 controls the laser light source 2 to turn off (OFF) and stop the road surface drawing.

[0077] In the laser irradiation device 1 of this embodiment, a relatively inexpensive IR sensor 5 and a sonar sensor 6 are used in the human body sensing sensor. In addition, by utilizing the difference in characteristics between the IR sensor 5, which is an optical sensor, and the sonar sensor 6, which is an acoustic sensor, the detection accuracy can be improved without being affected by the external environment.

[0078] That is, in the human body sensing sensor, the IR sensor 5 is prone to false detection due to the influence of external light in the aforementioned bright environment. On the other hand, the sonar sensor 6 is not affected by external light.

[0079] Therefore, in the laser irradiation device 1 of this embodiment, when the external illuminance in the detection range E2 of the human body sensing detection unit 7 exceeds the threshold, the detection by the IR sensor 5 is stopped, and the detection is performed by the sonar sensor 6.

[0080] Therefore, even in bright environments such as daytime, it will not be affected by external light. When a person H enters the detection range E2 of the human body sensing detection unit 7, the laser light source 2 can be turned off or reduced appropriately.

[0081] On the other hand, the sensitivity of sonar sensor 6 may decrease due to the attenuation of ultrasonic waves in environments such as rain or strong winds. In contrast, the sensitivity of IR sensor 5 will not decrease in such environments.

[0082] Therefore, in the laser irradiation device 1 of this embodiment, even if the sonar sensor 6 is falsely detected due to the decrease in the sensitivity of the sonar sensor 6, the IR sensor 5 will still react when a person H enters the detection range E2 of the human body sensing detection unit 7, so detection can be performed even in rainy or windy conditions.

[0083] Therefore, even in rainy or windy conditions, when a person H enters the detection range E2 of the human body sensing detection unit 7, the laser light source 2 can be appropriately extinguished or its brightness reduced.

[0084] As described above, in the laser irradiation device 1 of this embodiment, the relatively inexpensive IR sensor 5 and sonar sensor 6 are used, which can maintain the detection accuracy when a person H enters the irradiation range E1 of the laser L without being affected by the external environment, and appropriately turn off or reduce the light of the laser source 2.

[0085] Furthermore, the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0086] Specifically, in the above embodiment, a structure in which a laser irradiation device 1 is provided in the rearview mirror 101 of the vehicle door of the vehicle 100 is illustrated. However, in addition to this, a structure in which the laser irradiation device 1 is provided around the door, side, top or bottom of the vehicle 100 is also possible.

[0087] In addition, in the above embodiment, the detection range E2 of the IR sensor 5 and the sonar sensor 6 constituting the human body sensing detection unit 7 is approximately the same, but the detection range E2 does not necessarily need to be the same, and there may be a deviation of a few centimeters to tens of centimeters in the detection range E2.

[0088] Furthermore, in the aforementioned laser irradiation device 1, for example, Figure 7 As shown, it can also be configured such that the IR sensor 5 reacts within a detection range E3 surrounding the irradiation range E1 of the laser L, and the sonar sensor 6 reacts within a detection range E4 surrounding the detection range E3 of the IR sensor 5. That is, Figure 7 This refers to the case where the detection range E4 of the sonar sensor 6 is expanded compared to the detection range E3 of the IR sensor 5.

[0089] The three-dimensional detection range E3 of the IR sensor 5 is set to the three-dimensional illumination range E1 surrounding the laser L, but it is sufficient to set it to at least the three-dimensional scanning range surrounding the laser L. Therefore, even if a person H happens to look directly at the light source 4, the IR sensor 5 will react, preventing the person H from looking directly at the laser L.

[0090] Furthermore, IR sensor 5, which has a detection range E3 equal to that of sonar sensor 6, is relatively expensive. Therefore, by using IR sensor 5, which has a detection range E3 that is narrower than that of sonar sensor 6, cost reduction can be achieved.

[0091] On the other hand, the three-dimensional detection range E4 of the sonar sensor 6 is set wider in a way that surrounds the three-dimensional detection range E3 of the IR sensor 5, thereby enabling an earlier reaction to people H who suddenly fly in, such as cyclists or motorcycles, and thus enabling the construction of a safer eye protection system.

[0092] Furthermore, the three-dimensional detection range E3 of the IR sensor 5 does not need to completely surround the three-dimensional irradiation range E1 of the laser L. For example, even if it does not surround a part of the vehicle 100 side of the irradiation range E1, the person H will not approach from the vehicle 100 side, so it will not have an adverse effect on the human body sensing detection unit 7.

[0093] Furthermore, in the above embodiment, a laser irradiation device 1 mounted on the vehicle 100 is exemplified, but other than this, for example, Figure 8 As shown, the laser irradiation device 1 described above can also be applied to a road surface drawing device that is installed on a street lamp 200 and performs road surface drawing while irradiating the road surface T with laser L.

[0094] Furthermore, the laser irradiation device using the present invention is not limited to the case of depicting the road surface T described above; for example, it can be applied to a depiction device for depicting walls, screens, etc.

[0095] Furthermore, the laser irradiation device using the present invention is not limited to the above-described drawing device, but can also be applied to lighting devices such as vehicle lamps that use laser light sources to irradiate the road surface T.

[0096] Explanation of reference numerals in the attached figures

[0097] 1…Laser irradiation device; 2…Laser light source; 3…MEMS mirror; 4…Light source unit; 5…IR sensor (optical sensor); 6…Sonar sensor (acoustic wave sensor); 7…Human body detection unit; 8…Lighting control unit; 50…Illumination sensor; 100…Vehicle; 101…Vehicle door rearview mirror; 200…Street lamp; E1…Illumination range; E2…Detection range; L…Laser; H…Person; T…Road surface.

Claims

1. A laser irradiation device, characterized in that, The laser irradiation device includes: The light source unit includes a laser light source that irradiates laser light onto a specific irradiation range; The illumination control unit controls the illumination of the laser light source; and A human body detection unit detects the presence of a person within the irradiation range of the laser. The human body sensing detection unit includes an optical sensor and an acoustic sensor. When either the optical sensor or the acoustic sensor reacts, the illumination control unit controls the laser light source to be turned off or its brightness to be reduced.

2. The laser irradiation device according to claim 1, characterized in that, When the external illuminance within the laser's irradiation range exceeds a threshold, the human body sensing detection unit stops the detection by the optical sensor.

3. The laser irradiation device according to claim 1, characterized in that, The optical sensor and the acoustic sensor react within the detection range surrounding the irradiation range of the laser.

4. The laser irradiation device according to claim 3, characterized in that, The optical sensor and the acoustic sensor react within the detection range surrounding the scanning range of the laser.

5. The laser irradiation device according to claim 4, characterized in that, The acoustic sensor reacts within the detection range surrounding the detection range of the optical sensor.

6. The laser irradiation device according to claim 1, characterized in that, The optical sensor is an IR sensor, and the acoustic sensor is a sonar sensor.

7. The laser irradiation device according to claim 1, characterized in that, The light source includes a MEMS mirror that scans the laser emitted from the laser source while mapping the illumination range.

8. The laser irradiation device according to claim 1, characterized in that, The laser irradiation device is mounted on the vehicle. The light source irradiates the road surface with laser light emitted from the laser source.

9. A control method for a laser irradiation device, characterized in that, The laser irradiation device includes: The light source unit includes a laser light source that irradiates laser light onto a specific irradiation range; The illumination control unit controls the illumination of the laser light source; Optical and acoustic sensors detect the presence of a person within the irradiation range of the laser. External illuminance unit, which detects the surrounding environment; and The driver position detection unit detects whether the driver is inside the vehicle. The control method comprises the following steps: The first step is to enable the MEMS mirror driver. The second step is to detect whether the external illuminance exceeds the threshold. In the third step, when either the optical sensor or the acoustic sensor reacts, the illumination control unit turns off or reduces the light of the laser source to stop road surface drawing. The fourth step is to check if the driver is inside the vehicle; as well as The fifth step is to shut down the MEMS mirror's drive after detecting that the driver is inside the vehicle.

10. The control method for the laser irradiation device according to claim 9, characterized in that, In the third step, when the external illuminance within the irradiation range of the laser exceeds a threshold, the detection by the optical sensor is stopped.

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