Miniature dust resistant projection device

1. A miniature projection device comprising:

a housing;

a display module mounted inside the housing; and

a lens module mounted inside the housing or a left lens module and a right lens module that are mounted inside the housing, wherein the lens module is located rearwards of the display module in a front-to-rear direction, wherein the lens module comprises:

a lens barrel and a lens mounted inside the lens barrel;

a front dustproof cushion sandwiched between an edge of a front opening of the lens barrel and a display region frame of the display module; and

a rear dustproof cushion sandwiched between an edge of a rear opening of the lens barrel and a window of the housing, such that the lens is packaged in a sealed space enclosed by the lens barrel, the window and the display module,

wherein a display region of the display module is located in the sealed space,

wherein said dustproof cushions create a dustproof seal between the components between which they are sandwiched,

wherein said sealed space enclosed by the lens barrel, the window and the display module is effectively completely sealed from dust intrusion, and

wherein the lens module comprises at least two lens assemblies connected in serial from a front side to a rear side; the lens assembly comprises an assembly lens barrel and a lens mounted inside the assembly lens barrel; all the assembly lens barrels are sequentially fitted over one another to form the lens barrel; and a dustproof ring is provided between adjacent assembly lens barrels.

2. The miniature projection device of claim 1 wherein the front dustproof cushion and/or the rear dustproof cushion is/are made of dustproof foam, non-woven fabric or silica gel.

3. The miniature projection device of claim 1 , characterized in that, the front dustproof cushion and/or the rear dustproof cushion is/are of a single layer structure, respectively, or of a laminated structure including at least two layers laminated together, respectively.

4. The miniature projection device of claim 1 wherein a surface of the front dustproof cushion contacting the display region frame is a plane or a curved surface, and a surface of the front dustproof cushion contacting the edge of the front opening is a plane or a curved surface; and/or

a surface of the rear dustproof cushion contacting the window is a plane or a curved surface, and a surface of the rear dustproof cushion contacting the edge of the rear opening is a plane or a curved surface.

5. The miniature projection device of claim 1 comprising the left lens module and the right lens module, wherein the display module comprises a left display region and a right display region corresponding to the left lens module and the right lens module, respectively; and

wherein the lens barrels of the left lens module and the right lens module are independent with respect to each other, such that a lens of the left lens module is packaged in a left sealed space enclosed by a lens barrel of the left lens module, a window at a corresponding side and the display module, the left display region being located in the left sealed space, and a lens of the right lens module is packaged in a right sealed space enclosed by a lens barrel of the right lens module, a window at a corresponding side and the display module, the right display region being located in the right sealed space.

6. The miniature projection device of claim 1 comprising the left lens module and the right lens module, wherein the display module comprises a left display region and a right display region corresponding to the left lens module and the right lens module respectively; and

wherein a light barrier is provided between the left and right display regions of the display module;

wherein lens barrels of the left lens module and the right lens module are provided with recesses to match with the light barrier;

wherein recessed frames of the lens barrels are overlapped with each other in the front-to-rear direction such that the lens barrels run through at their respective recess frames; and

wherein an intermediate dustproof cushion is provided between the recess frames of the lens barrels.

7. The miniature projection device of claim 1 further comprising a diopter adjusting mechanism configured to drive the display module to slide in the front-to-rear direction, wherein among all the assembly lens barrels that are connected in serial to form the lens barrel, at least one assembly lens barrel from the assembly lens barrel at the front-most position forms a movable lens barrel of the lens barrel, and the remaining assembly lens barrels form a fixed lens barrel of the lens barrel, the movable lens barrel being fixedly mounted to the display module along the front-to-rear direction and the fixed lens barrel being fixedly mounted to the housing along the front-to-rear direction and further comprising an overlapped width configured to allow the fixed and movable lens barrels to sleeve within one another, wherein the assembly meets the following condition: when the movable lens barrel moves to the front-most position together with the display module, the dustproof ring between the fixed and movable lens barrels remains in a state of being sandwiched between the fixed and movable lens barrels.

8. The miniature projection device of claim 1 further comprising a diopter adjusting mechanism configured to drive the display module to slide in the front-to-rear direction;

wherein the lens module is fixedly mounted to the housing along the front-to-rear direction; and

wherein a thickness of the front dustproof cushion in the front-to-rear direction meets the following condition: when the display module moves to the front-most position, the front dustproof cushion remains in a state of being sandwiched between the edge of the front opening of the lens barrel and the display region frame of the display module.

9. The miniature projection device of claim 1 comprising the left lens module and the right lens module, wherein the display module comprises a left display region and a right display region corresponding to the left lens module and the right lens module respectively; and

wherein the miniature projection device further comprises an interpupillary distance adjusting mechanism configured to drive the left lens module and the right lens module to move in a left and right direction.