Window module, a window and laser line projector with the window

A laser line projector, comprising:

• a housing having a window assembly with:
• a front window, a left window, and a right window positioned on the same plane, a projection of the front window, left window and right window having a shape of an isosceles trapezoid, the projection of the front window being an upper base of the isosceles trapezoid, and projections of the left window and right window being opposite legs of the isosceles trapezoid, the isosceles trapezoid having:
• the projection of the front window on the plane being line segment AB, the projection of the left window on the plane being line segment BC, and the projection of the right window on the plane being line segment AD,
• a Cartesian coordinate system having:
• a midpoint of line segment AB as the origin of the Cartesian coordinate system,
• a direction of line segment OB extending in a positive direction of the Y-axis,
• a direction that a perpendicular bisector of line segment AB extending towards C point or D point forms in a positive direction of the X-axis, such that:
• the coordinates of C point are (m, n),
• the coordinates of D point are (m, −n),
• E point is the projection of B point on the line segment CD whose coordinates are (m, e),
• the coordinates of B point are (0, e),
• the coordinates of A point are (0, −e),
• P point is the light source point whose coordinates are (p, 0), and
• wherein m, n, e, p satisfy the conditions as follows:
• m>0,n>0,e>0,p>0, and 0<p<m,
• the Cartesian coordinate system including ∠CBE is a and ∠PBE is b, which both are acute angles, wherein a and b satisfy the conditions as follows:
• a>b and a+b>90°,
• and
• n
• m
• +
• p
• <
• tan
• ⁡
• (
• a
• )
• <
• 2
• ⁢
• p
• n
• -
• n
• 2
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• pm
• ;
• and
• a hanging system having a laser module.