Cleaning apparatus and method for an optical machine

Abstract

This application relates to a cleaning device for an optical engine, the optical engine comprising a housing containing an LCD screen, and a first airflow path and a second airflow path forming a connection within the housing; the first airflow path flows through a first side of the LCD screen, and the second airflow path flows through a second side of the LCD screen; the housing also has a first window and a second window, the first window connecting the first airflow path to the outside, and the second window connecting the second airflow path to the outside; the cleaning device includes a vibration system and a high-pressure airflow system; the vibration system includes a vibrating plate, a vibrating element, and a base; the high-pressure airflow system is connected to the first airflow path, injecting high-pressure airflow into the first airflow path, causing the high-pressure airflow to flow along the first airflow path to the second airflow path. This invention can clean the inner cavity of the optical engine housing and the LCD screen before leaving the factory, improving the cleaning effect and reducing the rework rate and the probability of secondary contamination.

Description

Technical Field

[0001] This application relates to the field of optical engine cleaning technology, and in particular to a cleaning device and cleaning method for optical engines. Background Technology

[0002] Optical engines contain built-in optical components such as LCD screens. If dust or other foreign objects are present inside the engine's housing, the LCD screen's strong electrostatic attraction to small foreign objects can easily cause secondary contamination, affecting image quality and leading to quality issues. Utility model patent CN 212965731 U discloses an LCD projector with an electrostatic dust removal device. This device ionizes the air, causing dust to become negatively charged and thus attracting it, achieving a dust removal effect. However, this patent requires the addition of an electrostatic dust removal device, which not only increases costs but also enlarges the optical engine. Furthermore, this patent primarily addresses dust removal during use, without considering pre-shipment dust removal. Summary of the Invention

[0003] Therefore, it is necessary to provide a cleaning device and cleaning method for optical engines, the specific technical solution of which is as follows.

[0004] A cleaning device for an optical engine, the optical engine comprising a housing, the housing housing containing an LCD screen, and a first airflow path and a second airflow path forming a connection within the housing; the LCD screen comprising a first side and a second side opposite to each other, the first airflow path flowing through the first side of the LCD screen, and the second airflow path flowing through the second side of the LCD screen; the housing further comprising a first window and a second window, the first window connecting the first airflow path to the outside, and the second window connecting the second airflow path to the outside;

[0005] The cleaning equipment includes a vibration system and a high-pressure airflow system;

[0006] The vibration system includes a vibrating plate, a vibrating element, and a base; the vibrating element is installed between the vibrating plate and the base to drive the vibrating plate to vibrate, and the vibrating plate is used to fix the optical engine;

[0007] The high-pressure airflow system is connected to the first airflow path and injects high-pressure airflow into the first airflow path, causing the high-pressure airflow to flow along the first airflow path to the second airflow path.

[0008] Furthermore, the high-pressure airflow system includes a nozzle plate, a first nozzle group, a second nozzle group, a first air supply component, and a second air supply component; the first nozzle group and the second nozzle group are respectively mounted on the nozzle plate, and the first nozzle group and the second nozzle group are respectively used to inject high-pressure airflow into the first airflow path; the first air supply component is connected to the first nozzle group and is used to supply air to the first nozzle group; the second air supply component is connected to the second nozzle group and is used to supply air to the second nozzle group.

[0009] Furthermore, the first gas supply component is provided with a first switch, and the second gas supply component is provided with a second switch.

[0010] Furthermore, the vibrating plate is provided with a slide rail assembly, and the air nozzle plate is connected to the slide rail assembly. The slide rail assembly drives the air nozzle plate to move toward or away from the optical engine.

[0011] Furthermore, the vibration element includes a spring and a high-frequency vibration motor. The four corners of the vibration plate are connected to the base via springs, and the high-frequency vibration motor is connected to both the base and the vibration plate.

[0012] Furthermore, the base is equipped with multiple side plates that surround the vibrating plate, with gaps between the side plates and the vibrating plate.

[0013] Furthermore, a quick clamp is installed on the vibrating plate, the quick clamp including a support column, a suspension rod and a clamping rod; the support column is installed on the vibrating plate, the suspension rod is connected to the support column and suspended above the optical machine, and the suspension rod is provided with a sliding groove, the clamping rod passes through the sliding groove and clamps the optical machine, and two locking nuts are connected to the clamping rod, the two locking nuts are respectively placed on both sides of the suspension rod.

[0014] A cleaning method for cleaning an optical engine using the cleaning equipment described in any one of the above claims includes: sequentially performing a first cleaning stage and a second cleaning stage;

[0015] In the first and second cleaning stages, high-pressure airflow is continuously injected into the first airflow path, so that the high-pressure airflow carries foreign objects along the first airflow path to the second airflow path and then discharges them to the outside.

[0016] The first cleaning stage includes: turning on the vibration system to drive the optomechanical vibration;

[0017] The second cleaning stage includes: turning off the vibration system and inserting a cleaning stick into the first and second windows respectively to wipe the foreign objects on the first and second sides of the LCD screen.

[0018] Furthermore, in the first cleaning stage, a high-pressure airflow of size A is injected into the first airflow path; in the second cleaning stage, a high-pressure airflow of size B is injected into the first airflow path, where A > B.

[0019] Furthermore, in the second cleaning stage, the optical engine is put into the power-on test interface and a projected image is generated. The location of the foreign object is determined based on the projected image, and then it is wiped with a cleaning stick.

[0020] Beneficial effects: 1. The cleaning equipment provided by the present invention can drive the optical engine to vibrate, causing foreign objects in the inner cavity of the housing and on the LCD screen to fall off and be discharged to the outside with the high-pressure airflow. In addition, the first window and the second window can also accommodate the insertion of the cleaning rod to wipe the residual foreign objects on both sides of the LCD screen, thereby improving the cleaning effect. It can be cleaned before leaving the factory, reducing the rework rate and the probability of secondary pollution.

[0021] 2. The cleaning method provided by the present invention first removes most of the foreign matter in the inner cavity of the housing and on the LCD screen by means of high-pressure airflow and vibration, and then uses a cleaning rod in conjunction with high-pressure airflow to remove the foreign matter attached to the surface of the LCD screen, thereby improving the removal effect of foreign matter. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application 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 application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the cleaning equipment after the optical engine is assembled.

[0024] Figure 2 Top sectional view of the cleaning equipment after it has been fitted with an optical engine;

[0025] Figure 3 for Figure 2 Enlarged view of region C in the middle;

[0026] Figure 4 This is a schematic diagram showing the connection between the optical engine and the air nozzle plate;

[0027] Figure 5 A schematic diagram showing the cleaning equipment with some side panels concealed.

[0028] Figure 6 This is a schematic diagram showing the matching of the air valve switch and the air valve;

[0029] Figure 7 This is a flowchart illustrating the cleaning method.

[0030] Explanation of reference numerals in the attached drawings: 1. Housing; 2. Optical components; 3. Vibration system; 4. High-pressure airflow system; 5. Quick clamp;

[0031] 11. First window; 12. Second window;

[0032] 21. Fresnel lens; 22. LCD screen; 23. Heat-insulating glass; 24. First airflow path; 25. Second airflow path;

[0033] 31. Vibrating plate; 32. High-frequency vibration motor; 33. Spring; 34. Base; 35. Side plate;

[0034] 41. Air nozzle plate; 42. First air nozzle assembly; 43. Second air nozzle assembly; 44. First air supply assembly; 45. Second air supply assembly; 46. First switch; 47. Second switch; 48. Slide rail assembly; 49. Sealed housing;

[0035] 421. Air valve A; 422. Air valve B; 423. Air valve C; 424. Air valve D;

[0036] 431. Air valve E;

[0037] 51. Support column; 52. Suspension rod; 53. Pressure rod; 54. Sliding groove; 55. Locking nut. Detailed Implementation

[0038] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0039] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0042] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0044] Example 1

[0045] This embodiment provides a cleaning device for an optical engine, referring to... Figure 1 As shown, the cleaning equipment includes a vibration system 3 and a high-pressure airflow system, as referenced. Figure 2 and Figure 3As shown, the optical engine includes a housing 1 and an optical assembly 2. The housing 1 has an internal cavity to accommodate the optical assembly 2. The optical assembly 2 includes a Fresnel lens 21, an LCD screen 22, and a heat-insulating glass 23. The LCD screen 22 includes a first side and a second side facing each other. The Fresnel lens 21 is located on the first side of the LCD screen 22, and the heat-insulating glass 23 is located on the second side of the LCD screen 22. These three components are arranged at intervals to form a first airflow path 24 and a second airflow path 25, that is, the first airflow path 24 is formed between the Fresnel lens 21 and the LCD screen 22, and the second airflow path 25 is formed between the LCD screen 22 and the heat-insulating glass 23. (Refer to...) Figure 4 As shown, the housing 1 is also provided with a first window 11 and a second window 12. The first window 11 is located at the top of the housing 1 and connects the first airflow path 24 to the outside. The second window 12 is located on the side of the housing 1 and connects the second airflow path 25 to the outside.

[0046] Reference Figure 5 As shown, the vibration system 3 includes a vibrating plate 31, a vibrating element, and a base 34. The vibrating element is installed between the vibrating plate 31 and the base 34, and drives the vibrating plate 31 to vibrate relative to the base 34. The vibrating plate 31 is used to fix the optical engine, thereby driving the optical engine to vibrate.

[0047] The cleaning equipment provided in this embodiment can drive the optical engine to vibrate, causing foreign objects in the inner cavity of the housing 1 and the LCD screen 22 to fall off and be discharged to the outside with the high-pressure airflow. The first window 11 and the second window 12 can also accommodate the insertion of a cleaning rod to wipe the residual foreign objects on both sides of the LCD screen 22, thereby improving the cleaning effect. It can be cleaned before leaving the factory, reducing the rework rate and the probability of secondary pollution.

[0048] Specifically, refer to Figure 1 As shown, the high-pressure airflow system includes a nozzle plate 41, a first nozzle group 42, a second nozzle group 43, a first air supply assembly 44, and a second air supply assembly 45. The first nozzle group 42 and the second nozzle group 43 are respectively mounted on the nozzle plate 41. The first air supply assembly 44 is connected to the first nozzle group 42, injecting high-pressure airflow into the first airflow path 24 through the first nozzle group 42. The second air supply assembly 45 is connected to the second nozzle group 43, injecting high-pressure airflow into the first airflow path 24 through the second nozzle group 43. (Refer to...) Figure 4 As shown, the first nozzle group 42 includes nozzles A421, B422, C423, and D424, and the second nozzle group 43 includes nozzle E431. Nozzles A421, B422, C423, and D424 are respectively arranged at the four corners of the nozzle plate 41, and nozzle E431 is arranged at the center of the nozzle plate 41. (Refer to...) Figure 6As shown, nozzles A421, B422, C423, and D424 are respectively connected to a first switch 46, which is connected to a first air supply assembly 44. Nozzle E431 is connected to a second switch 47, which is connected to a second air supply assembly 45. The first switch 46 and the second switch 47 can respectively switch the on / off state of the first nozzle group 42 and the second nozzle group 43. When airflow is injected into the first nozzle group 42 and the second nozzle group 43 simultaneously, the nozzles located at the four corners and in the center ensure a sufficiently large and evenly distributed flow rate within the airflow path. When airflow is injected into the second nozzle group 43 alone, nozzle E431, located in the center, supplies air separately, reducing the flow rate within the airflow path while still ensuring even distribution.

[0049] Specifically, continue to refer to Figure 1 As shown, the vibrating plate 31 is provided with a slide rail assembly 48, and the air nozzle plate 41 is connected to the slide rail assembly 48. The slide rail assembly 48 drives the air nozzle plate 41 to move toward or away from the optical engine. A sealing shell 49 is also provided around the air nozzle plate 41. When the air nozzle plate 41 moves toward the optical engine, the sealing shell 49 makes the air nozzle plate 41 and the housing 1 of the optical engine airtight.

[0050] Specifically, the housing 1 of the optical engine is provided with a heat sink mounting port for installing a heat sink. During the cleaning process, the heat sink is not yet installed, so the sealed shell 49 contacts the lip of the heat sink mounting port to form an airtight seal. The heat sink mounting port is connected to the first airflow path 24, and the high-pressure air injected by the air nozzle flows into the first airflow path 24 after passing through the heat sink mounting port.

[0051] Specifically, continue to refer to Figure 1 As shown, a quick clamp 5 is installed on the vibrating plate 31. The quick clamp 5 includes a support column 51, a suspension rod 52, and a clamping rod 53. The support column 51 is installed on the vibrating plate 31. The suspension rod 52 is connected to the support column 51 and suspended above the optical machine. The suspension rod 52 is provided with a sliding groove 54. The clamping rod 53 passes through the sliding groove 54 and can move along the extension direction of the sliding groove 54 and the vertical direction. Two locking nuts 55 are connected to the clamping rod 53. After the clamping rod 53 passes through the sliding groove 54, it clamps the optical machine. The two locking nuts 55 are respectively placed on both sides of the suspension rod 52. The clamping rod 53 and the suspension rod 52 are locked by the two locking nuts 55, thereby clamping the optical machine.

[0052] Before dust removal, the clamping rod 53 clamps the optical machine and drives the air nozzle plate 41 to move towards the optical machine until the sealed shell 49 contacts the lip of the radiator mounting port to form an airtight seal, putting the cleaning equipment into the cleaning preparation state. After cleaning, the clamping rod 53 is released and the air nozzle plate 41 is moved in the opposite direction, allowing the optical machine to be picked up directly.

[0053] Specifically, refer to Figure 5 As shown, the vibration element includes a spring 33 and a high-frequency vibration motor 32. The four corners of the vibration plate 31 are connected to the base 34 via the springs 33, and the high-frequency vibration motor 32 is connected to both the base 34 and the vibration plate 31. The high-frequency vibration motor 32 drives the vibration plate 31 to vibrate, and the springs 33 provide cushioning. Four side plates 35 are also installed on the base 34, surrounding the vibration plate 31 from all four sides, with gaps between the vibration plate 31 and the side plates 35. When the vibration plate 31 undergoes horizontal displacement, the collision between the vibration plate 31 and the side plates 35 restricts its horizontal displacement and generates vibrations of different frequencies and directions, increasing the type of vibration and thus maximizing the removal of foreign objects from the optical engine and the LCD screen 22.

[0054] Example 2

[0055] Reference Figure 7 As shown, this embodiment provides a cleaning method for cleaning an optical engine using the cleaning equipment described in Embodiment 1. The method mainly consists of two steps: a first cleaning stage and a second cleaning stage are performed sequentially.

[0056] In the first cleaning stage and the second cleaning stage, high-pressure airflow is continuously injected into the first airflow path 24, so that the high-pressure airflow carries foreign objects along the first airflow path 24 to the second airflow path 25 and then discharges them to the outside.

[0057] In the first cleaning stage, the vibration system 3 is activated to drive the optical engine to vibrate. Foreign objects inside the optical engine housing 1 and on the LCD screen 22 are dislodged due to the vibration and discharged to the outside under the action of high-pressure airflow, mainly removing foreign objects from the housing 1 and most of the foreign objects on the LCD screen 22.

[0058] In the second cleaning stage, the vibration system 3 is turned off, and cleaning rods are inserted into the first window 11 and the second window 12 respectively to wipe the foreign objects on the first and second sides of the LCD screen 22. Since the foreign objects detached from the inner cavity of the housing 1 during the first cleaning stage may adhere to the LCD screen 22 with the airflow, and the LCD screen 22 itself may also contain foreign objects that are difficult to be removed by vibration, the cleaning rods are used to wipe out or remove the foreign objects, and the removed foreign objects continue to be discharged with the high-pressure airflow, thus thoroughly removing the foreign objects on the LCD screen 22, thereby removing the foreign objects more comprehensively.

[0059] After cleaning is completed, the first window 11 and the second window 12 are sealed with auxiliary materials to form a closed environment inside the shell 1, which prevents foreign objects from entering the inner cavity of the shell 1 during subsequent transportation and use, reduces the probability of contamination, thereby reducing the return rate and improving economic efficiency.

[0060] The cleaning method provided in this embodiment first uses vibration and high-pressure airflow to remove foreign objects from the inner cavity of the housing 1 and most of the foreign objects from the LCD screen 22, and then wipes the foreign objects with a cleaning rod. On the one hand, it reduces the amount of work required for wiping, and on the other hand, it removes foreign objects more thoroughly. Vibrating before wiping also avoids secondary pollution during the cleaning process.

[0061] Specifically, in the first cleaning stage, the first switch 46 and the second switch 47 are turned on, and the first air nozzle group 42 and the second air nozzle group 43 simultaneously inject high-pressure airflow into the first airflow path 24, ensuring that the airflow in the airflow path is sufficiently large and evenly distributed. Since the total amount of foreign matter is relatively large at the beginning of cleaning, and all of them are in a detached state, the sufficient airflow ensures that the detached foreign matter is smoothly discharged. In the second cleaning stage, the first switch 46 is turned off and the second switch 47 is turned on, and the second air nozzle group 43 injects high-pressure airflow into the first airflow path 24 alone, reducing the airflow in the airflow path. On the one hand, this avoids excessive airflow causing the cleaning rod to shake, ensuring the stability of the cleaning rod during operation. On the other hand, in the second cleaning stage, the total amount of foreign matter is relatively small, and some foreign matter is carried out by the cleaning rod. Therefore, the injection of high-pressure airflow by the second air nozzle group 43 alone can also ensure that the detached foreign matter is smoothly discharged with the airflow.

[0062] Specifically, in the second cleaning stage, the optical engine is put into a power-on test interface and projects a picture. The location of the foreign object is determined based on the projected image, and then the cleaning stick is used to wipe it. This allows for precise wiping and improves cleaning efficiency. It should be noted that the optical engine can also be turned on and put into a power-on test interface to project a picture before the first cleaning stage.

[0063] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0064] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A cleaning method for cleaning an optical engine using cleaning equipment, characterized in that, The optical engine includes a housing, which houses an LCD screen, and a first airflow path and a second airflow path are formed within the housing; the LCD screen includes a first side and a second side opposite to each other, the first airflow path flows through the first side of the LCD screen, and the second airflow path flows through the second side of the LCD screen; the housing is also provided with a first window and a second window, the first window connecting the first airflow path to the outside, and the second window connecting the second airflow path to the outside. The cleaning equipment includes a vibration system and a high-pressure airflow system; The vibration system includes a vibrating plate, a vibrating element, and a base; the vibrating element is installed between the vibrating plate and the base to drive the vibrating plate to vibrate, and the vibrating plate is used to fix the optical engine; The high-pressure airflow system is connected to the first airflow path and injects high-pressure airflow into the first airflow path, causing the high-pressure airflow to flow along the first airflow path to the second airflow path. The high-pressure airflow system includes a nozzle plate, a first nozzle group, a second nozzle group, a first air supply component, and a second air supply component. The first nozzle group and the second nozzle group are respectively installed on the nozzle plate and are used to inject high-pressure airflow into the first airflow path. The first air supply component is connected to the first nozzle group and is used to supply air to the first nozzle group. The second air supply component is connected to the second nozzle group and is used to supply air to the second nozzle group. The first air supply component is provided with a first switch, and the second air supply component is provided with a second switch. The air nozzle plate is also surrounded by a sealed shell. The housing of the optical engine is provided with a heat sink mounting port for installing a heat sink. During the cleaning process, the heat sink is not installed yet, so that the sealed shell contacts the lip of the heat sink mounting port to form an air seal. The heat sink mounting port is connected to the first airflow path. The cleaning method includes: performing a first cleaning stage and a second cleaning stage sequentially; In the first and second cleaning stages, high-pressure airflow is continuously injected into the first airflow path, so that the high-pressure airflow carries foreign objects along the first airflow path to the second airflow path and then discharges them to the outside. The first cleaning stage includes: turning on the vibration system to drive the optomechanical vibration, and simultaneously turning on the first switch and the second switch, and injecting high-pressure airflow into the first airflow path by the first air nozzle group and the second air nozzle group at the same time; The second cleaning stage includes: turning off the vibration system, turning off the first switch and turning on the second switch, injecting high-pressure airflow into the first airflow path separately by the second air nozzle group, and inserting cleaning rods into the first window and the second window respectively to wipe foreign objects on the first and second sides of the LCD screen.

2. The cleaning method according to claim 1, characterized in that, The vibrating plate is equipped with a slide rail assembly, and the air nozzle plate is connected to the slide rail assembly. The slide rail assembly drives the air nozzle plate to move toward or away from the optical machine.

3. The cleaning method according to claim 1, characterized in that, The vibration element includes a spring and a high-frequency vibration motor. The four corners of the vibration plate are connected to the base via springs, and the high-frequency vibration motor is connected to both the base and the vibration plate.

4. The cleaning method according to claim 3, characterized in that, The base is equipped with multiple side plates that surround the vibrating plate, with gaps between the side plates and the vibrating plate.

5. The cleaning method according to claim 1, characterized in that, The vibrating plate is equipped with a quick clamp, which includes a support column, a suspension rod, and a clamping rod. The support column is installed on the vibrating plate, the suspension rod is connected to the support column and suspended above the optical machine, and the suspension rod is provided with a sliding groove. The clamping rod passes through the sliding groove and clamps the optical machine. Two locking nuts are connected to the clamping rod, and the two locking nuts are respectively placed on both sides of the suspension rod.

6. The cleaning method according to claim 1, characterized in that, In the first cleaning stage, a high-pressure airflow of size A is injected into the first airflow path; in the second cleaning stage, a high-pressure airflow of size B is injected into the first airflow path, where A > B.

7. The cleaning method according to claim 1, characterized in that, In the second cleaning stage, the optical engine is put into the power-on test interface and a projected image is generated. The location of the foreign object is determined based on the projected image, and then it is wiped with a cleaning stick.

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