Scan angle mirror reflection help

[jollymolly]

Edit:

How do I determine the scan angle of a polygon mirror ?

What determines the width of line reflected, the length of each face of the polygon mirror or the scan angle.

Please explain




Can someone please explain how the scan/mirror angle affect the projection.

I have seen 8 and 20 degrees galvos but what do these numbers mean in terms of what is projected.

[Stuka]

This should help:

http://www.pangolin.com/userhelp/scanangles.htm

[jollymolly]

Update, help out with polygon mirror scan angle.

Used for liquid sky effect.
They look like this

[swamidog]

like these? http://mi-lasers.com/optics/light-sh...olygon-scanner

Update, help out with polygon mirror scan angle.

Used for liquid sky effect.
They look like this

[jollymolly]

Sweep angle is 120 degrees.

But where do they get this value from?

The internal angles of a hexagon is 120 degrees.

Care to explain if you understand the concept.

[laserist]

In the attached drawing the input beam is vertical from the top. The reflected beam is 60 degrees to the right. Since a this point in the rotation the beam is changing from max deflection left and right the sweep angle is 2x60 degrees...

Sweep angle is 120 degrees.

But where do they get this value from?

The internal angles of a hexagon is 120 degrees.

Care to explain if you understand the concept.

[-bart-]

a square will project a sheet with an angle of 180 degrees
a polygon with 5 sides will project a sheet with an angle of 144 degrees
a polygon with 6 sides will project a sheet with an angle of 120 degrees
a polygon with 7 sides will project a sheet with an angle of 103 degrees
a polygon with 8 sides will project a sheet with an angle of 90 degrees
a polygon with 9 sides will project a sheet with an angle of 80 degrees
a polygon with n sides will project a sheet with an angle of 720/n degrees

[jollymolly]

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In the attached drawing the input beam is vertical from the top. The reflected beam is 60 degrees to the right. Since a this point in the rotation the beam is changing from max deflection left and right the sweep angle is 2x60 degrees...

hi,

Can you do this with a square.

this is what I did but it's wrong.

[jollymolly]

a square will project a sheet with an angle of 180 degrees
a polygon with 5 sides will project a sheet with an angle of 144 degrees
a polygon with 6 sides will project a sheet with an angle of 120 degrees
a polygon with 7 sides will project a sheet with an angle of 103 degrees
a polygon with 8 sides will project a sheet with an angle of 90 degrees
a polygon with 9 sides will project a sheet with an angle of 80 degrees
a polygon with n sides will project a sheet with an angle of 720/n degrees

Why 720 degrees? I really Can't grasps why.

[laserist]

Angle of incidence =angle of reflection

With the square in your drawing the vertical input beam reflects off the polygon horizontally 2*45=90
So the total sweep is 180

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hi,

Can you do this with a square.

this is what I did but it's wrong.